Expression of basement membrane components through morphological changes in the hair growth cycle

DEFF Research Database (Denmark)

Couchman, J R; Gibson, W T

1985-01-01

The amount and distribution of fibronectin associated with hair follicles was found to vary during the hair growth cycle in the rat. Immunocytochemical staining of follicles in mid-late anagen (the growth stage) revealed the presence of fibronectin in the dermal papilla matrix, in the basement...... membrane separating this from the epithelial cells of the hair bulb, and in the basement membrane and connective tissue sheath which underly the cells of the outer root sheath. Early in catagen, the transitional stage, staining of the dermal papilla matrix disappeared. Fibronectin persisted in the basement...

Characterizing nanoscale topography of the aortic heart valve basement membrane for tissue engineering heart valve scaffold design.

Science.gov (United States)

Brody, Sarah; Anilkumar, Thapasimuthu; Liliensiek, Sara; Last, Julie A; Murphy, Christopher J; Pandit, Abhay

2006-02-01

A fully effective prosthetic heart valve has not yet been developed. A successful tissue-engineered valve prosthetic must contain a scaffold that fully supports valve endothelial cell function. Recently, topographic features of scaffolds have been shown to influence the behavior of a variety of cell types and should be considered in rational scaffold design and fabrication. The basement membrane of the aortic valve endothelium provides important parameters for tissue engineering scaffold design. This study presents a quantitative characterization of the topographic features of the native aortic valve endothelial basement membrane; topographical features were measured, and quantitative data were generated using scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), and light microscopy. Optimal conditions for basement membrane isolation were established. Histological, immunohistochemical, and TEM analyses following decellularization confirmed basement membrane integrity. SEM and AFM photomicrographs of isolated basement membrane were captured and quantitatively analyzed. The basement membrane of the aortic valve has a rich, felt-like, 3-D nanoscale topography, consisting of pores, fibers, and elevations. All features measured were in the sub-100 nm range. No statistical difference was found between the fibrosal and ventricular surfaces of the cusp. These data provide a rational starting point for the design of extracellular scaffolds with nanoscale topographic features that mimic those found in the native aortic heart valve basement membrane.

Vascular basement membranes as pathways for the passage of fluid into and out of the brain.

Science.gov (United States)

Morris, Alan W J; Sharp, Matthew MacGregor; Albargothy, Nazira J; Fernandes, Rute; Hawkes, Cheryl A; Verma, Ajay; Weller, Roy O; Carare, Roxana O

2016-05-01

In the absence of conventional lymphatics, drainage of interstitial fluid and solutes from the brain parenchyma to cervical lymph nodes is along basement membranes in the walls of cerebral capillaries and tunica media of arteries. Perivascular pathways are also involved in the entry of CSF into the brain by the convective influx/glymphatic system. The objective of this study is to differentiate the cerebral vascular basement membrane pathways by which fluid passes out of the brain from the pathway by which CSF enters the brain. Experiment 1: 0.5 µl of soluble biotinylated or fluorescent Aβ, or 1 µl 15 nm gold nanoparticles was injected into the mouse hippocampus and their distributions determined at 5 min by transmission electron microscopy. Aβ was distributed within the extracellular spaces of the hippocampus and within basement membranes of capillaries and tunica media of arteries. Nanoparticles did not enter capillary basement membranes from the extracellular spaces. Experiment 2: 2 µl of 15 nm nanoparticles were injected into mouse CSF. Within 5 min, groups of nanoparticles were present in the pial-glial basement membrane on the outer aspect of cortical arteries between the investing layer of pia mater and the glia limitans. The results of this study and previous research suggest that cerebral vascular basement membranes form the pathways by which fluid passes into and out of the brain but that different basement membrane layers are involved. The significance of these findings for neuroimmunology, Alzheimer's disease, drug delivery to the brain and the concept of the Virchow-Robin space are discussed.

ULTRASTRUCTURAL-CHANGES OF THE BASEMENT-MEMBRANE ZONE IN BENIGN LESIONS OF THE VOCAL FOLDS

NARCIS (Netherlands)

DIKKERS, FG; HULSTAERT, CE; OOSTERBAAN, JA; CERVERAPAZ, FJ

The basement membrane zone (BMZ) of the epithelium of the vocal folds was investigated electron microscopically in 10 patients suffering from various benign lesions and in 3 controls. Various defects were observed: a thickening by deposition of electron dense material, a loss of normal architecture,

A Case of Alport Syndrome with Posttransplant Antiglomerular Basement Membrane Disease despite Negative Antiglomerular Basement Membrane Antibodies by EIA Treated with Plasmapheresis and Intravenous Immunoglobulin

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Sumiko I. Armstead

2013-01-01

Full Text Available Posttransplant antiglomerular basement membrane (anti-GBM disease occurs in approximately 5% of Alport patients and usually ends in irreversible graft failure. Recent research has focused on characterizing the structure of the anti-GBM alloepitope. Here we present a case of a 22-year-old male with end-stage renal disease secondary to Alport syndrome, with a previously failed renal allograft, who received a second deceased-donor kidney transplant. Six days after transplantation, he developed acute kidney injury. The serum anti-GBM IgG was negative by enzyme immunoassay (EIA. On biopsy, he had crescentic glomerulonephritis with linear GBM fixation of IgG. With further analysis by western blotting, we were able to detect antibodies to an unidentified protein from the basement membrane. This patient was treated with plasmapheresis twice per week and monthly intravenous immunoglobulin (IVIG for a total of five months. At the end of treatment, these unknown antibodies were no longer detected. His renal function improved, and he has not required dialysis. We conclude that anti-GBM disease in patients with Alport Syndrome may be caused by circulating antibodies to other components of the basement membrane that are undetectable by routine anti-GBM EIA and may respond to treatment with plasmapheresis and IVIG.

A Case of Alport Syndrome with Posttransplant Antiglomerular Basement Membrane Disease despite Negative Antiglomerular Basement Membrane Antibodies by EIA Treated with Plasmapheresis and Intravenous Immunoglobulin.

Science.gov (United States)

Armstead, Sumiko I; Hellmark, Thomas; Wieslander, Jorgen; Zhou, Xin J; Saxena, Ramesh; Rajora, Nilum

2013-01-01

Posttransplant antiglomerular basement membrane (anti-GBM) disease occurs in approximately 5% of Alport patients and usually ends in irreversible graft failure. Recent research has focused on characterizing the structure of the anti-GBM alloepitope. Here we present a case of a 22-year-old male with end-stage renal disease secondary to Alport syndrome, with a previously failed renal allograft, who received a second deceased-donor kidney transplant. Six days after transplantation, he developed acute kidney injury. The serum anti-GBM IgG was negative by enzyme immunoassay (EIA). On biopsy, he had crescentic glomerulonephritis with linear GBM fixation of IgG. With further analysis by western blotting, we were able to detect antibodies to an unidentified protein from the basement membrane. This patient was treated with plasmapheresis twice per week and monthly intravenous immunoglobulin (IVIG) for a total of five months. At the end of treatment, these unknown antibodies were no longer detected. His renal function improved, and he has not required dialysis. We conclude that anti-GBM disease in patients with Alport Syndrome may be caused by circulating antibodies to other components of the basement membrane that are undetectable by routine anti-GBM EIA and may respond to treatment with plasmapheresis and IVIG.

Basement membrane proteoglycans in glomerular morphogenesis: chondroitin sulfate proteoglycan is temporally and spatially restricted during development

DEFF Research Database (Denmark)

McCarthy, K J; Bynum, K; St John, P L

1993-01-01

We previously reported the presence of a basement membrane-specific chondroitin sulfate proteoglycan (BM-CSPG) in basement membranes of almost all adult tissues. However, an exception to this ubiquitous distribution was found in the kidney, where BM-CSPG was absent from the glomerular capillary......, the present study used light and electron microscopic immunohistochemistry to examine the distribution of BM-CSPG and basement membrane heparan sulfate proteoglycan (BM-HSPG) during prenatal and postnatal renal development in the rat. Our results show that the temporal and spatial pattern of expression of BM...

Basement Membrane Type IV Collagen and Laminin: An Overview of Their Biology and Value as Fibrosis Biomarkers of Liver Disease.

Science.gov (United States)

Mak, Ki M; Mei, Rena

2017-08-01

Basement membranes provide structural support to epithelium, endothelium, muscles, fat cells, Schwann cells, and axons. Basement membranes are multifunctional: they modulate cellular behavior, regulate organogenesis, promote tissue repair, form a barrier to filtration and tumor metastasis, bind growth factors, and mediate angiogenesis. All basement membranes contain type IV collagen (Col IV), laminin, nidogen, and perlecan. Col IV and laminin self-assemble into two independent supramolecular networks that are linked to nidogen and perlecan to form a morphological discernable basement membrane/basal lamina. The triple helical region, 7S domain and NCI domain of Col IV, laminin and laminin fragment P1 have been evaluated as noninvasive fibrosis biomarkers of alcoholic liver disease, viral hepatitis, and nonalcoholic fatty liver disease. Elevated serum Col IV and laminin are related to degrees of fibrosis and severity of hepatitis, and may reflect hepatic basement membrane metabolism. But the serum assays have not been linked to disclosing the anatomical sites and lobular distribution of perisinusoidal basement membrane formation in the liver. Hepatic sinusoids normally lack a basement membrane, although Col IV is a normal matrix component of the space of Disse. In liver disease, laminin deposits in the space of Disse and codistributes with Col IV, forming a perisinusoidal basement membrane. Concomitantly, the sinusoidal endothelium loses its fenestrae and is transformed into vascular type endothelium. These changes lead to capillarization of hepatic sinusoids, a significant pathology that impairs hepatic function. Accordingly, codistribution of Col IV and laminin serves as histochemical marker of perisinusoidal basement membrane formation in liver disease. Anat Rec, 300:1371-1390, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Regulation of the basement membrane by epithelia generated forces

Science.gov (United States)

Tanner, Kandice

2012-12-01

Tumor metastasis involves a progressive loss of tissue architecture and dissolution of structural boundaries between the epithelium and connective tissue. The basement membrane (BM), a specialized network of extracellular matrix proteins forms a barrier that physically restricts pre-invasive lesions such that they remain as local insults. The BM is not a static structure, but one that is constantly regenerated and remodeled in the adult organism. Matrix organization also regulates cell function. Thus alterations in the balance of synthesis, remodeling and proteolytic degradation of the extracellular matrix proteins may contribute to a loss of structural integrity. However, the de novo assembly and maintenance of the complex structural properties of in vivo basement membranes remain elusive. Here, this paper highlights the current understanding on the structural properties and the establishment of the BM, and discusses the potential role of self-generated forces in adult tissue remodeling and the maintenance of the BM as a malignancy suppressor.

Regulation of the basement membrane by epithelia generated forces

International Nuclear Information System (INIS)

Tanner, Kandice

2012-01-01

Tumor metastasis involves a progressive loss of tissue architecture and dissolution of structural boundaries between the epithelium and connective tissue. The basement membrane (BM), a specialized network of extracellular matrix proteins forms a barrier that physically restricts pre-invasive lesions such that they remain as local insults. The BM is not a static structure, but one that is constantly regenerated and remodeled in the adult organism. Matrix organization also regulates cell function. Thus alterations in the balance of synthesis, remodeling and proteolytic degradation of the extracellular matrix proteins may contribute to a loss of structural integrity. However, the de novo assembly and maintenance of the complex structural properties of in vivo basement membranes remain elusive. Here, this paper highlights the current understanding on the structural properties and the establishment of the BM, and discusses the potential role of self-generated forces in adult tissue remodeling and the maintenance of the BM as a malignancy suppressor. (paper)

Regeneration of the epidermis and basement membrane of the planarian Dugesia japonica after total-body x irradiation

Energy Technology Data Exchange (ETDEWEB)

Hori, I.

1979-03-01

Fresh-water planarians were studied to examine effects of x rays on regeneration of the epidermis and basement membrane. During early stages of regeneration, free rhabdite-forming cells were associated with the wound epidermis and recruited it. In later stages, however, a gradual degeneration occurred in the epidermis and cells undergoing epithelization decreased in number. Eventually epidermal cells on the wound surface appeared necrotic as evidenced by pyknotic nuclei and vacuolized dense cytoplasm. The entire basement membrane could not be reconstituted in any stage after wounding though its precursor-like material was secreted in the interspace between epidermis and parenchyma. Morphological changes in extracellular products and in the cells surrounding the products suggest that epidermal cells which have covered the wound surface synthesize precursors of the basement membrane. Possible factors of a characteristic perturbation in epithelization and basement membrane formation after total-body irradiation are discussed.

Regeneration of the epidermis and basement membrane of the planarian Dugesia japonica after total-body x irradiation

International Nuclear Information System (INIS)

Hori, I.

1979-01-01

Fresh-water planarians were studied to examine effects of x rays on regeneration of the epidermis and basement membrane. During early stages of regeneration, free rhabdite-forming cells were associated with the wound epidermis and recruited it. In later stages, however, a gradual degeneration occurred in the epidermis and cells undergoing epithelization decreased in number. Eventually epidermal cells on the wound surface appeared necrotic as evidenced by pyknotic nuclei and vacuolized dense cytoplasm. The entire basement membrane could not be reconstituted in any stage after wounding though its precursor-like material was secreted in the interspace between epidermis and parenchyma. Morphological changes in extracellular products and in the cells surrounding the products suggest that epidermal cells which have covered the wound surface synthesize precursors of the basement membrane. Possible factors of a characteristic perturbation in epithelization and basement membrane formation after total-body irradiation are discussed

Role of 17 beta-estradiol on type IV collagen fibers volumetric density in the basement membrane of bladder wall.

Science.gov (United States)

de Fraga, Rogerio; Dambros, Miriam; Miyaoka, Ricardo; Riccetto, Cássio Luís Zanettini; Palma, Paulo César Rodrigues

2007-10-01

The authors quantified the type IV collagen fibers volumetric density in the basement membrane of bladder wall of ovariectomized rats with and without estradiol replacement. This study was conducted on 40 Wistar rats (3 months old) randomly divided in 4 groups: group 1, remained intact (control); group 2, submitted to bilateral oophorectomy and daily replacement 4 weeks later of 17 beta-estradiol for 12 weeks; group 3, sham operated and daily replacement 4 weeks later of sesame oil for 12 weeks; and group 4, submitted to bilateral oophorectomy and killed after 12 weeks. It was used in immunohistochemistry evaluation using type IV collagen polyclonal antibody to stain the fibers on paraffin rat bladder sections. The M-42 stereological grid system was used to analyze the fibers. Ovariectomy had an increase effect on the volumetric density of the type IV collagen fibers in the basement membrane of rat bladder wall. Estradiol replacement in castrated animals demonstrated a significative difference in the stereological parameters when compared to the castrated group without hormonal replacement. Surgical castration performed on rats induced an increasing volumetric density of type IV collagen fibers in the basement membrane of rats bladder wall and the estradiol treatment had a significant effect in keeping a low volumetric density of type IV collagen fibers in the basement membrane of rats bladder wall.

Effect of diabetes on in vivo metabolism of [35S]-labeled glomerular basement membrane

International Nuclear Information System (INIS)

Cohen, M.P.; Surma, M.L.

1984-01-01

Glomerular basement membrane (GBM) was labeled in vivo by the injection of tracer amounts of [ 35 S]-sulfate into normal and streptozotocin-diabetic rats. The biosynthesis and turnover of sulfated glycosaminoglycans in the GBM was determined from the specific activity of [ 35 S] after pronase digestion of basement membranes purified from glomeruli isolated 1-7 days after injection. Peak radiolabeling of both normal and diabetic GBM occurred 24 h after injection and, when corrected for differences in serum sulfate specific activities, was less in diabetic than in normal samples. The specific activity of GBM sulfate, expressed as cpm/microgram uronic acid, progressively diminished over the ensuing period of study in both normal and diabetic samples. The rate of decrease in specific activity of [ 35 S]-labeled GBM was not significantly different in diabetic preparations compared with that in normal controls. The findings are compatible with diminished sulfation and/or production but normal turnover of glycosaminoglycans in the renal GBM in experimental diabetes

Human skin basement membrane-associated heparan sulphate proteoglycan: distinctive differences in ultrastructural localization as a function of developmental age

DEFF Research Database (Denmark)

Horiguchi, Y; Fine, J D; Couchman, J R

1991-01-01

was identical to that observed in neonatal and adult human skin. These findings demonstrate that active remodelling of the dermo-epidermal junction occurs during at least the first two trimesters, and affects not only basement membrane-associated structures but also specific antigens.......Recent studies have demonstrated that skin basement membrane components are expressed within the dermo-epidermal junction in an orderly sequence during human foetal development. We have investigated the ultrastructural localization of basement membrane-related antigens in human foetal skin...... at different developmental ages using two monoclonal antibodies to a well-characterized basement membrane-associated heparan sulphate proteoglycan. A series of foetal skin specimens (range, 54-142 gestational days) were examined using an immunoperoxidase immunoelectron microscopic technique. In specimens...

VEGF-A/Notch-Induced Podosomes Proteolyse Basement Membrane Collagen-IV during Retinal Sprouting Angiogenesis

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Pirjo Spuul

2016-10-01

Full Text Available During angiogenic sprouting, endothelial tip cells emerge from existing vessels in a process that requires vascular basement membrane degradation. Here, we show that F-actin/cortactin/P-Src-based matrix-degrading microdomains called podosomes contribute to this step. In vitro, VEGF-A/Notch signaling regulates the formation of functional podosomes in endothelial cells. Using a retinal neovascularization model, we demonstrate that tip cells assemble podosomes during physiological angiogenesis in vivo. In the retina, podosomes are also part of an interconnected network that surrounds large microvessels and impinges on the underlying basement membrane. Consistently, collagen-IV is scarce in podosome areas. Moreover, Notch inhibition exacerbates podosome formation and collagen-IV loss. We propose that the localized proteolytic action of podosomes on basement membrane collagen-IV facilitates endothelial cell sprouting and anastomosis within the developing vasculature. The identification of podosomes as key components of the sprouting machinery provides another opportunity to target angiogenesis therapeutically.

Basement membrane proteoglycans are of epithelial origin in rodent skin

DEFF Research Database (Denmark)

Yamane, Y; Yaoita, H; Couchman, J R

1996-01-01

. For in vivo experiments, pieces of newborn rat epidermis obtained by dispase treatment were grafted onto athymic nude mice. Three and six weeks after grafting, immunofluorescence analysis of the grafted skin was carried out, using monoclonal antibodies specific for rat basement membrane chondroitin sulfate...

Evidence for the existence of multiple heparan sulfate proteoglycans in the human glomerular basement membrane and mesangial matrix

NARCIS (Netherlands)

Groffen, Alexander J A; Hop, Frank W H; Tryggvason, Karl; Dijkman, Henri; Assmann, Karel J M; Veerkamp, Jacques H.; Monnens, Leo A H; Van Den Heuvel, Lambert P W J

1997-01-01

Heparan sulfate proteoglycans (HSPGs) are essential components of the glomerular basement membrane (GBM) carrying a strong anionic charge. A well- characterized extracellular HSPG is perlecan, ubiquitously expressed in basement membranes. A cDNA construct encoding domains I and II of human perlecan

Rac1 is essential for basement membrane-dependent epiblast survival

DEFF Research Database (Denmark)

He, Xiaowen; Liu, Jie; Qi, Yanmei

2010-01-01

During murine peri-implantation development, the egg cylinder forms from a solid cell mass by the apoptotic removal of inner cells that do not contact the basement membrane (BM) and the selective survival of the epiblast epithelium, which does. The signaling pathways that mediate this fundamental...

Accelerating repaired basement membrane after bevacizumab treatment on alkali-burned mouse cornea

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Koon-Ja Lee

2013-04-01

Full Text Available To understand the corneal regeneration induced by bevacizumab,we investigated the structure changes of stroma andbasement membrane regeneration. A Stick soaked in 0.5 NNaOH onto the mouse cornea and 2.5 mg/ml of bevacizumabwas delivered into an alkali-burned cornea (2 μl by subconjunctivalinjections at 1 hour and 4 days after injury. At 7 daysafter injury, basement membrane regeneration was observedby transmission electron microscope. Uneven and thin epithelialbasement membrane, light density of hemidesmosomes,and edematous collagen fibril bundles are shown in thealkali-burned cornea. Injured epithelial basement membraneand hemidesmosomes and edematous collagen fibril bundlesresulting from alkali-burned mouse cornea was repaired bybevacizumab treatment. This study demonstrates that bevacizumabcan play an important role in wound healing in thecornea by accelerating the reestablishment of basementmembrane integrity that leads to barriers for scar formation.[BMB Reports 2013; 46(4: 195-200

Basement Membrane Defects in Genetic Kidney Diseases

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Christine Chew

2018-01-01

Full Text Available The glomerular basement membrane (GBM is a specialized structure with a significant role in maintaining the glomerular filtration barrier. This GBM is formed from the fusion of two basement membranes during development and its function in the filtration barrier is achieved by key extracellular matrix components including type IV collagen, laminins, nidogens, and heparan sulfate proteoglycans. The characteristics of specific matrix isoforms such as laminin-521 (α5β2γ1 and the α3α4α5 chain of type IV collagen are essential for the formation of a mature GBM and the restricted tissue distribution of these isoforms makes the GBM a unique structure. Detailed investigation of the GBM has been driven by the identification of inherited abnormalities in matrix proteins and the need to understand pathogenic mechanisms causing severe glomerular disease. A well-described hereditary GBM disease is Alport syndrome, associated with a progressive glomerular disease, hearing loss, and lens defects due to mutations in the genes COL4A3, COL4A4, or COL4A5. Other proteins associated with inherited diseases of the GBM include laminin β2 in Pierson syndrome and LMX1B in nail patella syndrome. The knowledge of these genetic mutations associated with GBM defects has enhanced our understanding of cell–matrix signaling pathways affected in glomerular disease. This review will address current knowledge of GBM-associated abnormalities and related signaling pathways, as well as discussing the advances toward disease-targeted therapies for patients with glomerular disease.

Immunohistochemical localization of basement membrane components during hair follicle morphogenesis

DEFF Research Database (Denmark)

Westgate, G E; Shaw, D A; Harrap, G J

1984-01-01

Specific antisera were used to investigate the distributions of several basement membrane zone (BMZ) components, namely, bullous pemphigoid antigen (BPA), heparan sulfate proteoglycan (HSPG), laminin, and type IV collagen, during the development of hair follicles in late embryo rats. BPA was not ......Specific antisera were used to investigate the distributions of several basement membrane zone (BMZ) components, namely, bullous pemphigoid antigen (BPA), heparan sulfate proteoglycan (HSPG), laminin, and type IV collagen, during the development of hair follicles in late embryo rats. BPA...... of the elongating follicle. HSPG was associated with the basal cell layer prior to the appearance of hair follicle primordia and became BMZ-associated before birth but after follicle buds were first observed. HSPG was also found to be associated with the basal cell surfaces in the epidermis, but not in the hair...... follicle. Laminin and type IV collagen were continually present in epidermal and follicular BMZ both before and during development of hair follicles and were later present in the dermal papilla matrix. From these observations we conclude that (1) laminin and type IV collagen are functionally important...

Rituximab for the treatment of refractory simultaneous anti-glomerular basement membrane (anti-GBM) and membranous nephropathy.

Science.gov (United States)

Bandak, Ghassan; Jones, Bruce A; Li, Jian; Yee, Jerry; Umanath, Kausik

2014-02-01

Antibody-mediated anti-glomerular basement membrane (anti-GBM) disease occurs rarely in the presence of another B-cell disorder, membranous nephropathy. The coexistence of these two autoimmune disorders would be anticipated to require differing, specific therapies targeted to each disease process. We describe a case of concomitant membranous nephropathy and anti-GBM disease in which conventional therapy, including steroids, plasmapheresis and cyclophosphamide, failed to attenuate the anti-GBM disease, yet responded to an alternative treatment of rituximab. This B-cell directed, monoclonal, chimeric antibody treatment substantially reduced anti-GBM antibody titers and led to discontinuation of plasmapheresis, while maintaining the remission of membranous nephropathy and anti-GBM disease.

Nephritogenic antigen determinants in epidermal and renal basement membranes of kindreds with Alport-type familial nephritis.

OpenAIRE

Kashtan, C; Fish, A J; Kleppel, M; Yoshioka, K; Michael, A F

1986-01-01

We probed epidermal basement membranes (EBM) of acid-urea denatured skin from members of kindreds with Alport-type familial nephritis (FN) for the presence of antigens reactive with Goodpasture sera (GPS) and serum (FNS) from an Alport patient who developed anti-glomerular basement membrane (GBM) nephritis in a renal allograft. By immunoblotting, GPS reacted primarily with the 28,000 molecular weight (mol wt) monomer but also the 24,000 mol wt and 26,000 mol wt monomers of the noncollagenous ...

Basement membrane changes in breast cancer detected by immunohistochemical staining for laminin

DEFF Research Database (Denmark)

Albrechtsen, R; Nielsen, M; Wewer, U

1981-01-01

The distribution of the basement membrane glycoprotein laminin was studied by the immunoperoxidase technique in benign and malignant human breast tissue and in axillary lymph nodes from patients with breast cancer. An antiserum prepared against rat laminin was used. The specificity...

The basement membrane constituents in the mouse embryo's tooth. An autoradiographic study

International Nuclear Information System (INIS)

Osman, M.

1987-01-01

Enamel organs isolated from the lower first teeth of 18-days old white mouse embryo by trypsin treatment were used in this study. The organs were cultured during periods of increasing time on a semi-solid medium containing cock serum. In another chase experiments, the organs were cultured on a liquid medium containing proline- 3 H, leucine- 3 H, and glucosamine- 3 H, were studied by autoradiography using both light and electron microscopes. It has been shown that the nature of the culture medium does not apparently interfere with the ability of the enamel to reconstitute the basement membrane. On the other hand, it have been found obvious differences concerning the kinetic of the used isotopes. The results indicate that the turn-over of the basement membrane constituents represents a continuous and homogenous process which continues to take place during, before and after reconstitution. 42 refs. (author)

Immunochemical and autoantigenic properties of the globular domain of basement membrane collagen (type IV).

Science.gov (United States)

von der Mark, H; Oberbäumer, I; Timpl, R; Kemler, R; Wick, G

1985-02-01

Polyclonal rabbit antibodies raised against the globular domain NC1 of collagen IV from human placenta and a mouse tumor react with conformational antigenic determinants present on the NC1 hexamers and also with the three major subunits obtained after dissociation. The antibodies recognized unique structures within basement membranes and showed a broad tissue reactivity but only limited species cross-reactivity. Using these antibodies, it was possible to detect small amounts of collagen IV antigens from cell cultures and in serum. Monoclonal rat antibodies against mouse NC1 revealed a similar reaction potential. Autoantibodies could be produced in mice against mouse NC1 which react with kidney and lung basement membranes in a pathological manner, mimicking Goodpasture syndrome.

Concerted regulation of retinal pigment epithelium basement membrane and barrier function by angiocrine factors.

Science.gov (United States)

Benedicto, Ignacio; Lehmann, Guillermo L; Ginsberg, Michael; Nolan, Daniel J; Bareja, Rohan; Elemento, Olivier; Salfati, Zelda; Alam, Nazia M; Prusky, Glen T; Llanos, Pierre; Rabbany, Sina Y; Maminishkis, Arvydas; Miller, Sheldon S; Rafii, Shahin; Rodriguez-Boulan, Enrique

2017-05-19

The outer blood-retina barrier is established through the coordinated terminal maturation of the retinal pigment epithelium (RPE), fenestrated choroid endothelial cells (ECs) and Bruch's membrane, a highly organized basement membrane that lies between both cell types. Here we study the contribution of choroid ECs to this process by comparing their gene expression profile before (P5) and after (P30) the critical postnatal period when mice acquire mature visual function. Transcriptome analyses show that expression of extracellular matrix-related genes changes dramatically over this period. Co-culture experiments support the existence of a novel regulatory pathway: ECs secrete factors that remodel RPE basement membrane, and integrin receptors sense these changes triggering Rho GTPase signals that modulate RPE tight junctions and enhance RPE barrier function. We anticipate our results will spawn a search for additional roles of choroid ECs in RPE physiology and disease.

ER stress and basement membrane defects combine to cause glomerular and tubular renal disease resulting from Col4a1 mutations in mice

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Frances E. Jones

2016-02-01

Full Text Available Collagen IV is a major component of basement membranes, and mutations in COL4A1, which encodes collagen IV alpha chain 1, cause a multisystemic disease encompassing cerebrovascular, eye and kidney defects. However, COL4A1 renal disease remains poorly characterized and its pathomolecular mechanisms are unknown. We show that Col4a1 mutations in mice cause hypotension and renal disease, including proteinuria and defects in Bowman's capsule and the glomerular basement membrane, indicating a role for Col4a1 in glomerular filtration. Impaired sodium reabsorption in the loop of Henle and distal nephron despite elevated aldosterone levels indicates that tubular defects contribute to the hypotension, highlighting a novel role for the basement membrane in vascular homeostasis by modulation of the tubular response to aldosterone. Col4a1 mutations also cause diabetes insipidus, whereby the tubular defects lead to polyuria associated with medullary atrophy and a subsequent reduction in the ability to upregulate aquaporin 2 and concentrate urine. Moreover, haematuria, haemorrhage and vascular basement membrane defects confirm an important vascular component. Interestingly, although structural and compositional basement membrane defects occurred in the glomerulus and Bowman's capsule, no tubular basement membrane defects were detected. By contrast, medullary atrophy was associated with chronic ER stress, providing evidence for cell-type-dependent molecular mechanisms of Col4a1 mutations. These data show that both basement membrane defects and ER stress contribute to Col4a1 renal disease, which has important implications for the development of treatment strategies for collagenopathies.

Removal of the basement membrane enhances corneal wound healing.

Science.gov (United States)

Pal-Ghosh, Sonali; Pajoohesh-Ganji, Ahdeah; Tadvalkar, Gauri; Stepp, Mary Ann

2011-12-01

Recurrent corneal erosions are painful and put patients' vision at risk. Treatment typically begins with debridement of the area around the erosion site followed by more aggressive treatments. An in vivo mouse model has been developed that reproducibly induces recurrent epithelial erosions in wild-type mice spontaneously within two weeks after a single 1.5 mm corneal debridement wound created using a dulled-blade. This study was conducted to determine whether 1) inhibiting MMP9 function during healing after dulled-blade wounding impacts erosion development and 2) wounds made with a rotating-burr heal without erosions. Oral or topical inhibition of MMPs after dulled-blade wounding does not improve healing. Wounds made by rotating-burr heal with significantly fewer erosions than dulled-blade wounds. The localization of MMP9, β4 integrin and basement membrane proteins (LN332 and type VII collagen), immune cell influx, and reinnervation of the corneal nerves were compared after both wound types. Rotating-burr wounds remove the anterior basement membrane centrally but not at the periphery near the wound margin, induce more apoptosis of corneal stromal cells, and damage more stromal nerve fibers. Despite the fact that rotating-burr wounds do more damage to the cornea, fewer immune cells are recruited and significantly more wounds resolve completely. Copyright © 2011 Elsevier Ltd. All rights reserved.

Coexistence of anti-glomerular basement membrane antibodies and myeloperoxidase-ANCAs in crescentic glomerulonephritis

NARCIS (Netherlands)

Rutgers, Abraham; Slot, Marjan; van Paassen, Pieter; van Breda Vriesman, Peter; Heeringa, Peter; Tervaert, Jan Willem Cohen

BACKGROUND: In a substantial proportion of patients with crescentic glomerulonephritis (CGN), both anti-glomerular basement membrane (GBM) antibodies and antineutrophil cytoplasmic antibodies (ANCAs) with specificity for myeloperoxidase (MPO-ANCA) are detected. In the present study, we questioned

Pentoxifylline Ameliorates Glomerular Basement Membrane Ultrastructural Changes Caused by Gentamicin Administration in Rats

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Nenad Stojiljković

2009-08-01

Full Text Available Gentamicin is commonly used for the treatment of severe gram negative bacterial infections but inevi-tably cause renal failure during prolonged use. The aim of our study was to emphasize protective effects of pentoxifylline on glomerular basement membrane (GBM alterations induced by gentamicin in rats. Experiments were done on 40 male Wistar rats divided in three experimental groups. GM-group was treated daily with gentamicin in dose of 100 mg/kg during 8 days. PTX-group was treated daily with pentoxifylline in dose of 45 mg/kg and the same dose of gentamicin as in GM-group during 8 days. The control group received 1 ml/day saline intraperitoneally. Morphometric parameter measured during the analysis was glomerular basement membrane thickness. In GM-group of animals glomeruli were en-larged and GMB was diffusely and unequally thickened with neutrophil cells infiltration. In proximal tu-bules epithelial cells, vacuolization of cytoplasm with coagulation-type necrosis were observed. In PTX-group of animals glomeruli were somewhat enlarged and GBM was thickened only in some segments. Coagulation-type necrosis was not found. Blood urea and serum creatinine concentration in GM-group were significantly elevated in comparison with PTX-group while potassium level was decreased. Our results suggest that PTX has protective effects on GBM and proximal tubules in GM-treated rats.

Embryoid body attachment to reconstituted basement membrane induces a genetic program of epithelial differentiation via jun N-terminal kinase signaling.

Science.gov (United States)

Ho, Hoang-Yen; Moffat, Ryan C; Patel, Rupal V; Awah, Franklin N; Baloue, Kaitrin; Crowe, David L

2010-09-01

Embryonic stem (ES) cells are derived from early stage mammalian embryos and have broad developmental potential. These cells can be manipulated experimentally to generate cells of multiple tissue types which could be important in treating human diseases. The ability to produce relevant amounts of these differentiated cell populations creates the basis for clinical interventions in tissue regeneration and repair. Understanding how embryonic stem cells differentiate also can reveal important insights into cell biology. A previously reported mouse embryonic stem cell model demonstrated that differentiated epithelial cells migrated out of embryoid bodies attached to reconstituted basement membrane. We used genomic technology to profile ES cell populations in order to understand the molecular mechanisms leading to epithelial differentiation. Cells with characteristics of cultured epithelium migrated from embryoid bodies attached to reconstituted basement membrane. However, cells that comprised embryoid bodies also rapidly lost ES cell-specific gene expression and expressed proteins characteristic of stratified epithelia within hours of attachment to basement membrane. Gene expression profiling of sorted cell populations revealed upregulation of the BMP/TGFbeta signaling pathway, which was not sufficient for epithelial differentiation in the absence of basement membrane attachment. Activation of c-jun N-terminal kinase 1 (JNK1) and increased expression of Jun family transcription factors was observed during epithelial differentiation of ES cells. Inhibition of JNK signaling completely blocked epithelial differentiation in this model, revealing a key mechanism by which ES cells adopt epithelial characteristics via basement membrane attachment. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Agrin is a major heparan sulfate proteoglycan in the human glomerular basement membrane

NARCIS (Netherlands)

Groffen, Alexander J.; Ruegg, Markus A.; Dijkman, Henri; Van De Velden, Thea J.; Buskens, Carin A.; Van Den Born, Jacob; Assmann, Karel J.; Monnens, Leo A.; Veerkamp, Jacques H.; Van Den Heuvel, Lambert P.

Agrin is a heparan sulfate proteoglycan (HSPG) that is highly concentrated in the synaptic basal lamina at the neuromuscular junction (NMJ). Agrin-like immunoreactivity is also detected outside the NMJ. Here we show that agrin is a major HSPG component of the human glomerular basement membrane

Basement membrane abnormalities in human eyes with diabetic retinopathy

DEFF Research Database (Denmark)

Ljubimov, A V; Burgeson, R E; Butkowski, R J

1996-01-01

Vascular and parenchymal basement membranes (BMs) are thickened in diabetes, but alterations in individual BM components in diabetic eyes, especially in diabetic retinopathy (DR), are obscure. To identify abnormalities in the distribution of specific constituents, we analyzed cryostat sections...... of human eyes obtained at autopsy (seven normal, five diabetic without DR, and 13 diabetic with DR) by immunofluorescence with antibodies to 30 BM and extracellular matrix components. In non-DR eyes, no qualitative changes of ocular BM components were seen. In some DR corneas, epithelial BM was stained...... discontinuously for laminin-1, entactin/nidogen, and alpha3-alpha4 Type IV collagen, in contrast to non-DR corneas. Major BM alterations were found in DR retinas compared to normals and non-DR diabetics. The inner limiting membrane (retinal BM) of DR eyes had accumulations of fibronectin (including cellular...

Basement membrane-specific chondroitin sulfate proteoglycan is abnormally associated with the glomerular capillary basement membrane of diabetic rats

DEFF Research Database (Denmark)

McCarthy, K J; Abrahamson, D R; Bynum, K R

1994-01-01

exception being the normal glomerular capillary basement membrane (GBM), where it is absent. In the present study of mature kidneys we examined the distribution of BM-CSPG in streptozocin-induced diabetes mellitus in rats. We found BM-CSPG atypically associated with the GBM of diabetic animals as early as 1...... month after induction of diabetes mellitus. Immunoelectron microscopy (IEM) of affected capillary loops showed BM-CSPG present in the subendothelial matrix in areas of GBM thickening and absent in areas where the GBM appears to be of normal thickness. Moreover, the association of BM-CSPG with regions...... of the pericapillary GBM affects the morphology of the capillary endothelial cells within these areas, directly displacing the cell body from the GBM proper and causing loss of fenestrae. These new data on BM-CSPG distribution reflect abnormal glomerular extracellular matrix protein biosynthesis/turnover in diabetes...

Antibody response against the glomerular basement membrane protein agrin in patients with transplant glomerulopathy.

NARCIS (Netherlands)

Joosten, S.A.; Sijpkens, Y.W.; Ham, V. van; Trouw, L.A.; Vlag, J. van der; Heuvel, L.P.W.J. van den; Kooten, C. van; Paul, L.C.

2005-01-01

Chronic allograft nephropathy (CAN) of renal allografts is still the most important cause of graft loss. A subset of these patients have transplant glomerulopathy (TGP), characterized by glomerular basement membrane (GBM) duplications, but of unknown etiology. Recently, a role for the immune system

De novo deposition of laminin-positive basement membrane in vitro by normal hepatocytes and during hepatocarcinogenesis

DEFF Research Database (Denmark)

Albrechtsen, R; Wewer, U M; Thorgeirsson, S S

1988-01-01

De novo formation of laminin-positive basement membranes was found to be a distinct morphologic feature of diethylnitrosamine/phenobarbital-induced hepatocellular carcinomas of the rat. The first appearance of extracellularly located laminin occurred in the preneoplastic liver lesions...... (corresponding to neoplastic nodules), and this feature became successively more prominent during the course of hepatocellular carcinoma development. Most groups of tumor cells were surrounded by laminin-positive basement membrane material. The laminin-positive material was also deposited along the sinusoids......, a location where no laminin was seen in normal rat liver. The amount of extractable laminin from hepatocellular carcinomas was significantly higher (approximately 100 ng per mg tissue) than that of normal liver tissue (less than 20 ng per mg). In vitro experiments demonstrated that normal and preneoplastic...

Fluid Mechanics of the Vascular Basement Membrane in the Brain

Science.gov (United States)

Coloma, Mikhail; Hui, Jonathan; Chiarot, Paul; Huang, Peter; Carare, Roxana; McLeod, Kenneth; Schaffer, David

2013-11-01

Beta-amyloid is a normal product of brain metabolic function and is found within the interstitial fluid of the brain. Failure of the clearance of beta-amyloid from the aging brain leads to its accumulation within the walls of arteries and to Alzheimer's disease. The vascular basement membrane (VBM) within the walls of cerebral arteries surrounds the spirally arranged smooth muscle cells and represents an essential pathway for removal of beta-amyloid from the brain. This process fails with the stiffening of arterial walls associated with aging. In this study we hypothesize that the deformation of the VBM associated with arterial pulsations drives the interstitial fluid to drain in the direction opposite of the arterial blood flow. This hypothesis is theoretically investigated by modeling the VBM as a thin, coaxial, fluid-filled porous medium surrounding a periodically deforming cylindrical tube. Flow and boundary conditions required to achieve such a backward clearance are derived through a control volume analysis of mass, momentum, and energy.

Electron microscopic study of the myelinated nerve fibres and the perineurial cell basement membrane in the diabetic human peripheral nerves

International Nuclear Information System (INIS)

ElBarrany, Wagih G.; Hamdy, Raid M.; AlHayani, Abdulmonem A.; Jalalah, Sawsan M.

2009-01-01

To study the quantitative and ultrastructural changes in myelinated nerve fibers and the basement membranes of the perineurial cells in diabetic nerves. The study was performed at the Department of Anatomy, Faculty of Medicine, King Abdul-Aziz University, Jeddah, Saudi Arabia from 2003 to 2005. Human sural nerves were obtained from 15 lower limbs and 5 diabetic nerve biopsies. The total mean and density of myelinated nerve fibers per fascicle were calculated, with density of microtubules and mitochondria in the axoplasm. The number of the perineurial cell basement membrane layers was counted, and thickness of the basement membrane was measured. Among the 15 diabetic and 5 normal human sural nerves, the average diameters, number and surface area of myelinated nerve fibers and axonal microtubules density were found to be less in diabetic nerves. Mitochondrial density was higher in diabetic axons. Thickness of the perineurial cell basement membrane had a greater mean, but the number of perineurial cell layers was less than that of the diabetic group. The inner cellular layer of the perineurium of the diabetic nerves contained large vacuoles containing electron-dense degenerated myelin. A few specimens showed degenerated myelinated nerve fibers, while others showed recovering ones. Retracted axoplasms were encountered with albumin extravasation. Diabetes caused an increase in perineurial permeability. The diabetic sural nerve showed marked decrease in the myelinated nerve fibres, increase degenerated mitochondria, and decreased microtubules. (author)

Experimental autoimmune glomerulonephritis induced by anti-glomerular basement membrane antibody. II. Effects of injecting heterologous, homologous, or autologous glomerular basement membranes and complete Freund's adjuvant into sheep.

OpenAIRE

Steblay, R. W.; Rudofsky, U. H.

1983-01-01

The effects of injecting human, rabbit, rat, or single-kidney homologous glomerular basement membrane (GBM) or autologous GBM, each in complete Freund's adjuvant (CFA), into 15- to 18-month-old sheep are compared. All sheep receiving heterologous GBM and 3 of 6 sheep receiving homologous GBM had anti-GBM nephritis, but such sheep did not bind autoantibodies or have Goodpasturelike lesions in their lungs. Sheep given injections of human GBM had autoantibodies to antigenic determinants shared b...

Immunochemical and ultrastructural assessment of the nature of the pericellular basement membrane of human decidual cells

DEFF Research Database (Denmark)

Wewer, U M; Faber, M; Liotta, L A

1985-01-01

Human decidual cells of early and late pregnancy were studied immunochemically and ultrastructurally with respect to the presence and nature of pericellular basement membrane material. The most prominent cell type in decidual tissue of both early and late pregnancy were large, mature epithelioid......-linked immunosorbent assay. Biosynthesis of laminin was shown by [35S]methionine labeling of short term organ cultures of decidual tissue followed by immunoprecipation, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and fluorography. The laminin chains migrated with the apparent molecular weights of 300...... and 200 kilodaltons under reducing conditions. Two other separate populations of cells were apparent in the decidual tissue of early pregnancy. A smaller group of rounded intermediate sized (15 to 25 micron) decidual cells had focal deposits basement membrane immunoreactive material scattered at the cell...

Aluminum-containing dense deposits of the glomerular basement membrane: identification by energy dispersive X-ray analysis

International Nuclear Information System (INIS)

Smith, D.M. Jr.; Pitcock, J.A.; Murphy, W.M.

1982-01-01

Heavy metals, including gold, mercury, lead, bismuth, and cadmium, have the potential to cause renal disease. With the development of X-ray microanalysis, these heavy metals can now be identified in tissue deposits. This report describes a case of renal failure, probably related to dysproteinemia, in which granular, electron-opaque dense deposits were present in the glomerular basement membranes. Energy dispersive X-ray analysis demonstrated that these dense deposits contained aluminum. An analysis of this patient's history in relation to the current knowledge of aluminum metabolism suggests that the aluminum deposition occurred secondary to previous glomerular injury. This case emphasizes the need to utilize heavy metal identification technology whenever granular, electron-opaque dense deposits are identified and represents, to our knowledge, the first study to document aluminum deposits within the glomerular basement membrane of humans

Convective influx/glymphatic system: tracers injected into the CSF enter and leave the brain along separate periarterial basement membrane pathways.

Science.gov (United States)

Albargothy, Nazira J; Johnston, David A; MacGregor-Sharp, Matthew; Weller, Roy O; Verma, Ajay; Hawkes, Cheryl A; Carare, Roxana O

2018-05-12

Tracers injected into CSF pass into the brain alongside arteries and out again. This has been recently termed the "glymphatic system" that proposes tracers enter the brain along periarterial "spaces" and leave the brain along the walls of veins. The object of the present study is to test the hypothesis that: (1) tracers from the CSF enter the cerebral cortex along pial-glial basement membranes as there are no perivascular "spaces" around cortical arteries, (2) tracers leave the brain along smooth muscle cell basement membranes that form the Intramural Peri-Arterial Drainage (IPAD) pathways for the elimination of interstitial fluid and solutes from the brain. 2 μL of 100 μM soluble, fluorescent fixable amyloid β (Aβ) were injected into the CSF of the cisterna magna of 6-10 and 24-30 month-old male mice and their brains were examined 5 and 30 min later. At 5 min, immunocytochemistry and confocal microscopy revealed Aβ on the outer aspects of cortical arteries colocalized with α-2 laminin in the pial-glial basement membranes. At 30 min, Aβ was colocalised with collagen IV in smooth muscle cell basement membranes in the walls of cortical arteries corresponding to the IPAD pathways. No evidence for drainage along the walls of veins was found. Measurements of the depth of penetration of tracer were taken from 11 regions of the brain. Maximum depths of penetration of tracer into the brain were achieved in the pons and caudoputamen. Conclusions drawn from the present study are that tracers injected into the CSF enter and leave the brain along separate periarterial basement membrane pathways. The exit route is along IPAD pathways in which Aβ accumulates in cerebral amyloid angiopathy (CAA) in Alzheimer's disease. Results from this study suggest that CSF may be a suitable route for delivery of therapies for neurological diseases, including CAA.

Perlecan (basement membrane heparan sulfate proteoglycan and its role in oral malignancies: An overview

Directory of Open Access Journals (Sweden)

Mithilesh Mishra

2011-01-01

Full Text Available Perlecan means pearl-like structures. Perlecan is a large proteoglycan (400-500 kDa present in virtually all vascularized tissues with a distribution that is primarily confined to basement membranes including those of oral mucosa. It is a basement membrane-type heparan sulfate proteoglycan. Perlecan is synthesized by basal cells and fibroblasts adjacent to the basal lamina . Perlecan is also synthesized by vascular endothelial and smooth muscle cells present in the extracellular matrix. It has been demonstrated in recent years that perlecan is distributed in the stromal space of various pathophysiological conditions. The complex pleiotropy of perlecan suggests that this gene product is involved in several developmental processes, at both early and late stages of embryogenesis, as well as in cancer and diabetes. In the oral cavity, perlecan expression is reported to basal cells in normal mucosa and its expression increases in precancer and cancerous conditions. It is also expressed in various odontogenic tumors such as ameloblastoma, keratocyst odontogenic tumor, and also salivary gland tumors such as adenoid cystic carcinoma, mucoepidermoid carcinoma, etc.

cDNA cloning of the basement membrane chondroitin sulfate proteoglycan core protein, bamacan: a five domain structure including coiled-coil motifs

DEFF Research Database (Denmark)

Wu, R R; Couchman, J R

1997-01-01

Basement membranes contain several proteoglycans, and those bearing heparan sulfate glycosaminoglycans such as perlecan and agrin usually predominate. Most mammalian basement membranes also contain chondroitin sulfate, and a core protein, bamacan, has been partially characterized. We have now....... The protein sequence has low overall homology, apart from very small NH2- and COOH-terminal motifs. At the junctions between the distal globular domains and the coiled-coil regions lie glycosylation sites, with up to three N-linked oligosaccharides and probably three chondroitin chains. Three other Ser...

Synthesis and deposition of basement membrane proteins by primary brain capillary endothelial cells in a murine model of the blood-brain barrier.

Science.gov (United States)

Thomsen, Maj Schneider; Birkelund, Svend; Burkhart, Annette; Stensballe, Allan; Moos, Torben

2017-03-01

The brain vascular basement membrane is important for both blood-brain barrier (BBB) development, stability, and barrier integrity and the contribution hereto from brain capillary endothelial cells (BCECs), pericytes, and astrocytes of the BBB is probably significant. The aim of this study was to analyse four different in vitro models of the murine BBB for expression and possible secretion of major basement membrane proteins from murine BCECs (mBCECs). mBCECs, pericytes and glial cells (mainly astrocytes and microglia) were prepared from brains of C57BL/6 mice. The mBCECs were grown as monoculture, in co-culture with pericytes or mixed glial cells, or as a triple-culture with both pericytes and mixed glial cells. The integrity of the BBB models was validated by measures of transendothelial electrical resistance (TEER) and passive permeability to mannitol. The expression of basement membrane proteins was analysed using RT-qPCR, mass spectrometry and immunocytochemistry. Co-culturing mBCECs with pericytes, mixed glial cells, or both significantly increased the TEER compared to the monoculture, and a low passive permeability was correlated with high TEER. The mBCECs expressed all major basement membrane proteins such as laminin-411, laminin-511, collagen [α1(IV)] 2 α2(IV), agrin, perlecan, and nidogen 1 and 2 in vitro. Increased expression of the laminin α5 subunit correlated with the addition of BBB-inducing factors (hydrocortisone, Ro 20-1724, and pCPT-cAMP), whereas increased expression of collagen IV α1 primarily correlated with increased levels of cAMP. In conclusion, BCECs cultured in vitro coherently form a BBB and express basement membrane proteins as a feature of maturation. Cover Image for this issue: doi: 10.1111/jnc.13789. © 2016 International Society for Neurochemistry.

Deposition of nucleosomal antigens (histones and DNA) in the epidermal basement membrane in human lupus nephritis.

NARCIS (Netherlands)

Grootscholten, C.; Bruggen, M.C.J. van; Pijl, J.W. van der; Jong, E.M.G.J. de; Ligtenberg, G.; Derksen, R.H.W.M.; Berden, J.H.M.

2003-01-01

OBJECTIVE: Antinuclear autoantibodies complexed to nucleosomes can bind to heparan sulfate (HS) in the glomerular basement membrane. This binding is due to the binding of the positively charged histones to the strongly anionic HS. Nucleosomes and histones have been identified in glomerular deposits

Study of the relationship between mononuclear inflammatory infiltrate and Ki-67 and basement membrane and extracellular matrix protein expression in radicular cysts.

Science.gov (United States)

Mourão, R V C; Júnior, E C Pinheiro; Barros Silva, P G; Turatti, E; Mota, M R L; Alves, A P N N

2016-05-01

To evaluate the relationship between mononuclear inflammatory infiltrate and the expression of a proliferative immunomarker (Ki-67) as well as to evaluate basement membrane and extracellular matrix proteins (laminin and collagen type IV) in radicular cysts and dentigerous cysts (DC). Immunohistochemical analyses were performed in heavily inflamed radicular cysts (HIRC), slightly inflamed radicular cysts (SIRC) and DC (n = 20) using Ki-67 (Dako(®) , 1 : 50), anticollagen type IV (DBS(®) , 1 : 40) and antilaminin (DBS(®) , 1 : 20). The data were analysed using anova/Tukey's test (Ki-67) and Kruskal-Wallis/Dunn's test (collagen type IV and laminin) (P collagen type IV in the basement membrane of the SIRC group was significantly more continuous (P = 0.0475) than in the HIRC group. DC had significantly less collagen type IV in extracellular matrix immunoexpression than HIRC and SIRC (P = 0.0246). Laminin was absent in the basement membrane in the SIRC and DC groups, and the extracellular matrix of the HIRC was weak and punctate. The presence of inflammatory factors in the radicular cyst wall modified the expression of proliferation factors in the epithelial lining and the expression of collagen type IV and laminin in the basement membrane, but did not modify extracellular matrix behaviour in radicular cysts. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

The chest X-ray in antiglomerular basement membrane antibody disease (Goodpasture's syndrome)

International Nuclear Information System (INIS)

Bowley, N.B.; Steiner, R.E.; Chin, W.S.

1979-01-01

The chest radiographs of 25 patients with proven antiglomerular basement membrane antibody disease (Goodpasture's syndrome) were analysed. All except two of the patients had pulmonary haemorrhage at some stage of their disease. Altogether there were 39 episodes of pulmonary haemorrhage, 25 being relapses. During seven episodes the chest radiograph was normal. Relapses of pulmonary haemorrhage never occurred in isolation but were usually associated with infection (not necessarily a chest infection) or occasionally fluid overload. Conversely fluid overload or infection were always associated with pulmonary haemorrhage provided there were high or rising titres of circulating antibodies at the time. Therefore in a patient with antiglomerular basement membrane antibody disease, the presence of shadowing in the lung fields on the chest radiograph almost invariably means the patient has pulmonary haemorrhage whether or not pulmonary oedema or a chest infection are present. Limitation of shadowing by a fissure, loss of major portions of the diaphragmatic or cardiac silhouette, involvement of the lung apex or costophrenic angles suggest an underlying chest infection. Septal lines suggest fluid overload. Pleural effusions are seen with chest infections and fluid overload. The carbon monoxide uptake (KCO) was invariably high in the presence of pulmonary haemorrhage even if the chest radiograph was normal. A combined use of KCO and chest radiographs is the best method of monitoring lung disease in these patients. (author)

Anti-glomerular basement membrane: A rare cause of renal failure in children

Directory of Open Access Journals (Sweden)

Indira Agarwal

2017-01-01

Full Text Available Anti-glomerular basement membrane (GBM disease is a rare cause of acute renal failure and known to have bad prognosis regarding renal functions recovery and patient survival specially when diagnosed late and presents with severe renal failure that requires dialysis. We report a case of 11-year-old child with acute renal failure secondary to anti-GBM disease and associated with antineutrophil cytoplasmic antibody-positive vasculitis. He was treated with plasmapheresis, steroids, and cyclophosphamide with recovery of his kidney functions.

Basement membrane and interstitial proteoglycans produced by MDCK cells correspond to those expressed in the kidney cortex

DEFF Research Database (Denmark)

Erickson, A C; Couchman, J R

2001-01-01

Multiple proteoglycans (PGs) are present in all basement membranes (BM) and may contribute to their structure and function, but their effects on cell behavior are not well understood. Their postulated functions include: a structural role in maintaining tissue histoarchitecture, or aid in selective...... filtration processes; sequestration of growth factors; and regulation of cellular differentiation. Furthermore, expression PGs has been found to vary in several disease states. In order to elucidate the role of PGs in the BM, a well-characterized model of polarized epithelium, Madin-Darby canine kidney (MDCK...... core proteins or CS stubs generated by cABC treatment, revealed that both basement membrane and interstitial PGs are secreted by MDCK cells. HSPGs expressed by MDCK cells are perlecan, agrin, and collagen XVIII. Various CSPG core proteins are made by MDCK cells and have been identified as biglycan...

Distribution of two basement membrane proteoglycans through hair follicle development and the hair growth cycle in the rat

DEFF Research Database (Denmark)

Couchman, J R; King, J L; McCarthy, K J

1990-01-01

The distribution of two distinct populations of basement membrane proteoglycans has been monitored through hair growth development in the rat embryo and subsequent hair growth cycle. An antiserum against a small heparan sulfate proteoglycan uniformly stained the dermal-epidermal junction...... of embryonic rats throughout the period of hair follicle formation. On the other hand, monoclonal antibodies recognizing a basement membrane-specific chondroitin sulfate proteoglycan only weakly stained 16-d embryo dermal-epidermal junction, but strong staining was associated with hair follicle buds...... as they developed. Through the hair growth cycle, it was found that the heparan sulfate proteoglycan persisted around the follicles, while the chondroitin sulfate proteoglycan decreased in amount through catagen until it was undetectable at the base and dermal papilla of the telogen follicle. As anagen commenced...

MT1-MMP-mediated basement membrane remodeling modulates renal development

International Nuclear Information System (INIS)

Riggins, Karen S.; Mernaugh, Glenda; Su, Yan; Quaranta, Vito; Koshikawa, Naohiko; Seiki, Motoharu; Pozzi, Ambra; Zent, Roy

2010-01-01

Extracellular matrix (ECM) remodeling regulates multiple cellular functions required for normal development and tissue repair. Matrix metalloproteinases (MMPs) are key mediators of this process and membrane targeted MMPs (MT-MMPs) in particular have been shown to be important in normal development of specific organs. In this study we investigated the role of MT1-MMP in kidney development. We demonstrate that loss of MT1-MMP leads to a renal phenotype characterized by a moderate decrease in ureteric bud branching morphogenesis and a severe proliferation defect. The kidneys of MT1-MMP-null mice have increased deposition of collagen IV, laminins, perlecan, and nidogen and the phenotype is independent of the MT-1MMP target, MMP-2. Utilizing in vitro systems we demonstrated that MTI-MMP proteolytic activity is required for renal tubule cells to proliferate in three dimensional matrices and to migrate on collagen IV and laminins. Together these data suggest an important role for MT1-MMP in kidney development, which is mediated by its ability to regulate cell proliferation and migration by proteolytically cleaving kidney basement membrane components.

Immunological characterization of a basement membrane-specific chondroitin sulfate proteoglycan

DEFF Research Database (Denmark)

McCarthy, K J; Accavitti, M A; Couchman, J R

1989-01-01

with the proteoglycan preparation and four mAbs recognizing the core protein of a high-density, buoyant chondroitin sulfate proteoglycan were raised. Confirmation of antibody specificity was carried out by the preparation of affinity columns made from each of the mAbs. Chondroitin sulfate proteoglycans (CSPGs) were...... (Mr = 5-6 x 10(5)), with a core protein of Mr = approximately 1.5-1.6 x 10(5) and composed exclusively of chondroitin sulfate chains with an average Mr = 1.6-1.8 x 10(4). In addition, a CSPG was purified from adult rat kidney, whose core protein was also Mr = 1.6 x 10(5). The proteoglycan and its core...... sulfate proteoglycans, it therefore appears that at least one CSPG is a widespread basement membrane component....

Ultrastructural localization of the core protein of a basement membrane-specific chondroitin sulfate proteoglycan in adult rat skin

DEFF Research Database (Denmark)

McCarthy, K J; Horiguchi, Y; Couchman, J R

1990-01-01

Basement membranes are complex extracellular matrices present at epithelial/mesenchymal interfaces of tissues. The dermal-epidermal junction has been shown to contain numerous components, some of the most well known being laminin, types IV and VII collagens, heparan sulfate proteoglycan, fibronec...

Expression of periglandular tenascin-C and basement membrane laminin in normal prostate, benign prostatic hyperplasia and prostate carcinoma

NARCIS (Netherlands)

Xue, Y.; Li, J.; Latijnhouwers, M. A.; Smedts, F.; Umbas, R.; Aalders, T. W.; Debruyne, F. M.; de la Rosette, J. J.; Schalken, J. A.

1998-01-01

To evaluate the structural relationship of the distribution between tenascin (tenascin-C, an extra-cellular matrix glycoprotein involved in stromal-epithelial interactions in both normal and pathological conditions) and laminin, an important component of the basement membrane, in normal and

Spumiform basement membrane aberrations in the microvasculature of the midbrain periaqueductal gray region in hamster : Rostro-caudal pathogenesis?

NARCIS (Netherlands)

Gerrits, P.O.; Kortekaas, R.; de Weerd, Heleen; Luiten, P.G.M.; van der Want, J.J.L.; Veening, Jan

2013-01-01

Spumiform basement membrane degeneration (sbmd) is a specific kind of aberration present in the capillaries of the midbrain periaqueductal gray (PAG) region of the senescent hamster. These capillaries, separated by the ependymal cell layer, are bordering the Sylvian cerebral aqueduct. The aqueduct,

Spumiform basement membrane aberrations in the microvasculature of the midbrain periaqueductal gray region in hamster: rostro-caudal pathogenesis?

NARCIS (Netherlands)

Gerrits, P.O.; Kortekaas, R.; Weerd, H. de; Luiten, P.G.M.; Want, J.J. van der; Veening, J.G.

2013-01-01

Spumiform basement membrane degeneration (sbmd) is a specific kind of aberration present in the capillaries of the midbrain periaqueductal gray (PAG) region of the senescent hamster. These capillaries, separated by the ependymal cell layer, are bordering the Sylvian cerebral aqueduct. The aqueduct,

Expression and deposition of basement membrane proteins by brain capillary endothelial cells in a primary murine model of the blood-brain barrier

DEFF Research Database (Denmark)

Thomsen, Maj Schneider; Birkelund, Svend; Larsen, Annette Burkhart

2016-01-01

The blood-brain barrier (BBB) represents the interface between the blood and the brain parenchyma and consists of endothelial cells which are tightly sealed together by tight junction proteins. The endothelial cells are in addition supported by pericytes, which are embedded in the vascular basement...... of the present study was to create four different in vitro constructs of the murine BBB to characterise if the expression and secretion of basement membrane proteins by the murine brain capillary endothelial cells (mBCECs) was affected by co-culturing with pericytes, mixed glial cells, or both. Primary m......BCECs and pericytes were isolated from brains of adult mice. Mixed glial cells were prepared from cerebral cortices of newborn mice. The mBCECs were grown as mono-culture, or co-cultured with pericytes, mixed glial cells, or both. To study the expression of basement membrane proteins RT-qPCR, mass spectrometry...

Basement membrane heparan sulfate proteoglycan from the L2 rat yolk sac carcinoma

DEFF Research Database (Denmark)

Fenger, M; Wewer, U; Albrechtsen, R

1984-01-01

Heparan sulfate proteoglycan from the L2 rat yolk sac carcinoma has been purified and partially characterized. The proteoglycan has an apparent Mr of 750 000, 35% of which represents the core protein. The core protein seems to be homogeneous, whereas the heparan sulfate chains are heterogeneous...... with an Mr of about 50 000-70 000, with 30% of the glucosamine being N-sulfated. Antibodies raised against the core protein of the heparan sulfate proteoglycan reacted with basement membranes of various rat and human tissue....

Agrin is a major heparan sulfate proteoglycan in the human glomerular basement membrane.

Science.gov (United States)

Groffen, A J; Ruegg, M A; Dijkman, H; van de Velden, T J; Buskens, C A; van den Born, J; Assmann, K J; Monnens, L A; Veerkamp, J H; van den Heuvel, L P

1998-01-01

Agrin is a heparan sulfate proteoglycan (HSPG) that is highly concentrated in the synaptic basal lamina at the neuromuscular junction (NMJ). Agrin-like immunoreactivity is also detected outside the NMJ. Here we show that agrin is a major HSPG component of the human glomerular basement membrane (GBM). This is in addition to perlecan, a previously characterized HSPG of basement membranes. Antibodies against agrin and against an unidentified GBM HSPG produced a strong staining of the GBM and the NMJ, different from that observed with anti-perlecan antibodies. In addition, anti-agrin antisera recognized purified GBM HSPG and competed with an anti-GBM HSPG monoclonal antibody in ELISA. Furthermore, both antibodies recognized a molecule that migrated in SDS-PAGE as a smear and had a molecular mass of approximately 200-210 kD after deglycosylation. In immunoelectron microscopy, agrin showed a linear distribution along the GBM and was present throughout the width of the GBM. This was again different from perlecan, which was exclusively present on the endothelial side of the GBM and was distributed in a nonlinear manner. Quantitative ELISA showed that, compared with perlecan, the agrin-like GBM HSPG showed a sixfold higher molarity in crude glomerular extract. These results show that agrin is a major component of the GBM, indicating that it may play a role in renal ultrafiltration and cell matrix interaction. (J Histochem Cytochem 46:19-27, 1998)

Smad4-dependent pathways control basement membrane deposition and endodermal cell migration at early stages of mouse development

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Taylor Jennifer M

2009-10-01

Full Text Available Abstract Background Smad4 mutant embryos arrest shortly after implantation and display a characteristic shortened proximodistal axis, a significantly reduced epiblast, as well as a thickened visceral endoderm layer. Conditional rescue experiments demonstrate that bypassing the primary requirement for Smad4 in the extra-embryonic endoderm allows the epiblast to gastrulate. Smad4-independent TGF-β signals are thus sufficient to promote mesoderm formation and patterning. To further analyse essential Smad4 activities contributed by the extra-embryonic tissues, and characterise Smad4 dependent pathways in the early embryo, here we performed transcriptional profiling of Smad4 null embryonic stem (ES cells and day 4 embryoid bodies (EBs. Results Transcripts from wild-type versus Smad4 null ES cells and day 4 EBs were analysed using Illumina arrays. In addition to several known TGF-β/BMP target genes, we identified numerous Smad4-dependent transcripts that are mis-expressed in the mutants. As expected, mesodermal cell markers were dramatically down-regulated. We also observed an increase in non-canonical potency markers (Pramel7, Tbx3, Zscan4, germ cell markers (Aire, Tuba3a, Dnmt3l as well as early endoderm markers (Dpp4, H19, Dcn. Additionally, expression of the extracellular matrix (ECM remodelling enzymes Mmp14 and Mmp9 was decreased in Smad4 mutant ES and EB populations. These changes, in combination with increased levels of laminin alpha1, cause excessive basement membrane deposition. Similarly, in the context of the Smad4 null E6.5 embryos we observed an expanded basement membrane (BM associated with the thickened endoderm layer. Conclusion Smad4 functional loss results in a dramatic shift in gene expression patterns and in the endodermal cell lineage causes an excess deposition of, or an inability to breakdown and remodel, the underlying BM layer. These structural abnormalities probably disrupt reciprocal signalling between the epiblast and

Intercellular deposits of basement membrane material in active human pituitary adenomas detected by immunostaining for laminin and electron microscopy

DEFF Research Database (Denmark)

Holck, S; Wewer, U M; Albrechtsen, R

1986-01-01

and one patient with Cushing's syndrome). Concurrently, at the ultrastructural level, bunches of basement membrane-like material intermingled between the adenoma cells were demonstrated in seven of these ten active adenomas. Furthermore, secretory granules were entrapped occasionally in this intercellular...

Nanoscale protein architecture of the kidney glomerular basement membrane

Science.gov (United States)

Suleiman, Hani; Zhang, Lei; Roth, Robyn; Heuser, John E; Miner, Jeffrey H; Shaw, Andrey S; Dani, Adish

2013-01-01

In multicellular organisms, proteins of the extracellular matrix (ECM) play structural and functional roles in essentially all organs, so understanding ECM protein organization in health and disease remains an important goal. Here, we used sub-diffraction resolution stochastic optical reconstruction microscopy (STORM) to resolve the in situ molecular organization of proteins within the kidney glomerular basement membrane (GBM), an essential mediator of glomerular ultrafiltration. Using multichannel STORM and STORM-electron microscopy correlation, we constructed a molecular reference frame that revealed a laminar organization of ECM proteins within the GBM. Separate analyses of domains near the N- and C-termini of agrin, laminin, and collagen IV in mouse and human GBM revealed a highly oriented macromolecular organization. Our analysis also revealed disruptions in this GBM architecture in a mouse model of Alport syndrome. These results provide the first nanoscopic glimpse into the organization of a complex ECM. DOI: http://dx.doi.org/10.7554/eLife.01149.001 PMID:24137544

Overexpression of β1-chain-containing laminins in capillary basement membranes of human breast cancer and its metastases

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Fujita, Manabu; Khazenzon, Natalya M; Bose, Shikha; Sekiguchi, Kiyotoshi; Sasaki, Takako; Carter, William G; Ljubimov, Alexander V; Black, Keith L; Ljubimova, Julia Y

2005-01-01

Introduction Laminins are the major components of vascular and parenchymal basement membranes. We previously documented a switch in the expression of vascular laminins containing the α4 chain from predominantly laminin-9 (α4β2γ1) to predominantly laminin-8 (α4β1γ1) during progression of human brain gliomas to high-grade glioblastoma multiforme. Here, differential expression of laminins was studied in blood vessels and ductal epithelium of the breast. Method In the present study the expressions of laminin isoforms α1–α5, β1–β3, γ1, and γ2 were examined during progression of breast cancer. Forty-five clinical samples of breast tissues including normal breast, ductal carcinomas in situ, invasive ductal carcinomas, and their metastases to the brain were compared using Western blot analysis and immunohistochemistry for various chains of laminin, in particular laminin-8 and laminin-9. Results Laminin α4 chain was observed in vascular basement membranes of most studied tissues, with the highest expression in metastases. At the same time, the expression of laminin β2 chain (a constituent of laminin-9) was mostly seen in normal breast and carcinomas in situ but not in invasive carcinomas or metastases. In contrast, laminin β1 chain (a constituent of laminin-8) was typically found in vessel walls of carcinomas and their metastases but not in those of normal breast. The expression of laminin-8 increased in a progression-dependent manner. A similar change was observed from laminin-11 (α5β2γ1) to laminin-10 (α5β1γ1) during breast tumor progression. Additionally, laminin-2 (α2β1γ1) appeared in vascular basement membranes of invasive carcinomas and metastases. Chains of laminin-5 (α3β3γ2) were expressed in the ductal epithelium basement membranes of the breast and diminished with tumor progression. Conclusion These results suggest that laminin-2, laminin-8, and laminin-10 are important components of tumor microvessels and may associate with breast

Overexpression of β1-chain-containing laminins in capillary basement membranes of human breast cancer and its metastases

International Nuclear Information System (INIS)

Fujita, Manabu; Khazenzon, Natalya M; Bose, Shikha; Sekiguchi, Kiyotoshi; Sasaki, Takako; Carter, William G; Ljubimov, Alexander V; Black, Keith L; Ljubimova, Julia Y

2005-01-01

Laminins are the major components of vascular and parenchymal basement membranes. We previously documented a switch in the expression of vascular laminins containing the α4 chain from predominantly laminin-9 (α4β2γ1) to predominantly laminin-8 (α4β1γ1) during progression of human brain gliomas to high-grade glioblastoma multiforme. Here, differential expression of laminins was studied in blood vessels and ductal epithelium of the breast. In the present study the expressions of laminin isoforms α1–α5, β1–β3, γ1, and γ2 were examined during progression of breast cancer. Forty-five clinical samples of breast tissues including normal breast, ductal carcinomas in situ, invasive ductal carcinomas, and their metastases to the brain were compared using Western blot analysis and immunohistochemistry for various chains of laminin, in particular laminin-8 and laminin-9. Laminin α4 chain was observed in vascular basement membranes of most studied tissues, with the highest expression in metastases. At the same time, the expression of laminin β2 chain (a constituent of laminin-9) was mostly seen in normal breast and carcinomas in situ but not in invasive carcinomas or metastases. In contrast, laminin β1 chain (a constituent of laminin-8) was typically found in vessel walls of carcinomas and their metastases but not in those of normal breast. The expression of laminin-8 increased in a progression-dependent manner. A similar change was observed from laminin-11 (α5β2γ1) to laminin-10 (α5β1γ1) during breast tumor progression. Additionally, laminin-2 (α2β1γ1) appeared in vascular basement membranes of invasive carcinomas and metastases. Chains of laminin-5 (α3β3γ2) were expressed in the ductal epithelium basement membranes of the breast and diminished with tumor progression. These results suggest that laminin-2, laminin-8, and laminin-10 are important components of tumor microvessels and may associate with breast tumor progression. Angiogenic switch

Rat mesangial cells in vitro synthesize a spectrum of proteoglycan species including those of the basement membrane and interstitium

DEFF Research Database (Denmark)

Thomas, G J; Shewring, L; McCarthy, K J

1995-01-01

is localized in the mesangium but is not found in the pericapillary glomerular basement membrane (GBM). Further characterization of the proteoglycans synthesized by RMC in vitro revealed: (i) a second large CSPG, identified as versican; (ii) two small dermatan sulphate proteoglycans identified as biglycan...

The Peri-islet Basement Membrane, a Barrier to Infiltrating Leukocytes in Type 1 Diabetes in Mouse and Human

DEFF Research Database (Denmark)

Korpos, Eva; Kadri, Nadir; Kappelhoff, Reinhild

2013-01-01

We provide the first comprehensive analysis of the extracellular matrix (ECM) composition of peri-islet capsules, composed of the peri-islet basement membrane (BM) and subjacent interstitial matrix (IM), in development of type 1 diabetes in NOD mice and in human type 1 diabetes. Our data demonstr...... IM are reconstituted once inflammation subsides, indicating that the peri-islet BM-producing cells are not lost due to the inflammation, which has important ramifications to islet transplantation studies.......We provide the first comprehensive analysis of the extracellular matrix (ECM) composition of peri-islet capsules, composed of the peri-islet basement membrane (BM) and subjacent interstitial matrix (IM), in development of type 1 diabetes in NOD mice and in human type 1 diabetes. Our data...... demonstrate global loss of peri-islet BM and IM components only at sites of leukocyte infiltration into the islet. Stereological analyses reveal a correlation between incidence of insulitis and the number of islets showing loss of peri-islet BM versus islets with intact BMs, suggesting that leukocyte...

Assessment of proteolytic degradation of the basement membrane: a fragment of type IV collagen as a biochemical marker for liver fibrosis

DEFF Research Database (Denmark)

Veidal, Sanne S.; Karsdal, Morten A.; Nawrocki, Arkadiusz

2011-01-01

Collagen deposition and an altered matrix metalloproteinase (MMP) expression profile are hallmarks of fibrosis. Type IV collagen is the most abundant structural basement membrane component of tissue, which increases 14-fold during fibrogenesis in the liver. Proteolytic degradation of collagens...

In vivo turnover of the basement membrane and other heparan sulfate proteoglycans of rat glomerulus

DEFF Research Database (Denmark)

Beavan, L A; Davies, M; Couchman, J R

1989-01-01

The metabolic turnover of rat glomerular proteoglycans in vivo was investigated. Newly synthesized proteoglycans were labeled during a 7-h period after injecting sodium [35S]sulfate intraperitoneally. At the end of the labeling period a chase dose of sodium sulfate was given. Subsequently......-propanesulfonate-4 M guanidine hydrochloride, a procedure which solubilized greater than 95% of the 35S-labeled macromolecules. Of these 11-13% was immunoprecipitated by an antiserum against heparan sulfate proteoglycan which, in immunolocalization experiments, showed specificity for staining the basement membrane...

Heparan sulfate proteoglycans made by different basement-membrane-producing tumors have immunological and structural similarities

DEFF Research Database (Denmark)

Wewer, U M; Albrechtsen, R; Hassell, J R

1985-01-01

in the native basement membrane of surrounding normal murine tissues. Blocking and ELISA assays demonstrated that the antibodies recognized both antigens. Using techniques involving the chemical and enzymatic degradation of 35S-sulfate-labeled glycosaminoglycans, the mouse EHS tumor cells were found to produce...... proteoglycans obtained from these two sources immunoprecipitated the same precursor protein with a molecular mass of 400,000 daltons from 35S-methionine pulse-labeled cells of both tumors. Immunohistochemistry showed the heparan sulfate proteoglycan to be distributed in the extracellular matrix and also...

Deletion of the basement membrane heparan sulfate proteoglycan type XVIII collagen causes hypertriglyceridemia in mice and humans.

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Joseph R Bishop

2010-11-01

Full Text Available Lipoprotein lipase (Lpl acts on triglyceride-rich lipoproteins in the peripheral circulation, liberating free fatty acids for energy metabolism or storage. This essential enzyme is synthesized in parenchymal cells of adipose tissue, heart, and skeletal muscle and migrates to the luminal side of the vascular endothelium where it acts upon circulating lipoproteins. Prior studies suggested that Lpl is immobilized by way of heparan sulfate proteoglycans on the endothelium, but genetically altering endothelial cell heparan sulfate had no effect on Lpl localization or lipolysis. The objective of this study was to determine if extracellular matrix proteoglycans affect Lpl distribution and triglyceride metabolism.We examined mutant mice defective in collagen XVIII (Col18, a heparan sulfate proteoglycan present in vascular basement membranes. Loss of Col18 reduces plasma levels of Lpl enzyme and activity, which results in mild fasting hypertriglyceridemia and diet-induced hyperchylomicronemia. Humans with Knobloch Syndrome caused by a null mutation in the vascular form of Col18 also present lower than normal plasma Lpl mass and activity and exhibit fasting hypertriglyceridemia.This is the first report demonstrating that Lpl presentation on the lumenal side of the endothelium depends on a basement membrane proteoglycan and demonstrates a previously unrecognized phenotype in patients lacking Col18.

Frequently relapsing anti-glomerular basement membrane antibody disease with changing clinical phenotype and antibody characteristics over time

OpenAIRE

Gu, Bobby; Magil, Alex B.; Barbour, Sean J.

2016-01-01

Anti-glomerular basement membrane (GBM) antibody disease is a typically monophasic autoimmune disease with severe pulmonary and renal involvement. We report an atypical case of frequently relapsing anti-GBM antibody disease with both anti-GBM antibody?positive flares with pulmonary and renal involvement, and anti-GBM antibody?negative flares that were pulmonary limited with no histologic renal disease. This is the first report of alternating disease phenotype and anti-GBM antibody status over...

Laminin, a noncollagenous component of epithelial basement membranes synthesized by a rat yolk sac tumor

DEFF Research Database (Denmark)

Wewer, U; Albrechtsen, R; Ruoslahti, E

1981-01-01

Laminin, a glycoprotein antigenically similar or identical to a component of epithelial basement membranes, was identified as a major component of the abundant extracellular matrix synthesized by an experimentally induced rat yolk sac tumor. Immunocytochemical staining revealed laminin in cultured...... polypeptides with molecular weights of approximately 200,000 and 400,000. These comigrated with the polypeptides of mouse laminin isolated previously. The yolk sac tumor tissue grown in vivo contained laminin in the tumor cells and in the extracellular material as evidenced by immunofluorescence...... membranes in rat tissues in a manner indistinguishable from antilaminin. The presence of laminin in rat yolk sac cells, the presumed origin of our yolk sac tumor, was studied in some detail. Laminin was found to be present in normal cells of the visceral as well as the parietal yolk sac layer...

In vivo turnover of the basement membrane and other heparan sulfate proteoglycans of rat glomerulus

International Nuclear Information System (INIS)

Beavan, L.A.; Davies, M.; Couchman, J.R.; Williams, M.A.; Mason, R.M.

1989-01-01

The metabolic turnover of rat glomerular proteoglycans in vivo was investigated. Newly synthesized proteoglycans were labeled during a 7-h period after injecting sodium [35S]sulfate intraperitoneally. At the end of the labeling period a chase dose of sodium sulfate was given. Subsequently at defined times (0-163 h) the kidneys were perfused in situ with 0.01% cetylpyridinium chloride in phosphate-buffered saline to maximize the recovery of 35S-proteoglycans. Glomeruli were isolated from the renal cortex and analyzed for 35S-proteoglycans by autoradiographic, biochemical, and immunochemical methods. Grain counting of autoradiographs revealed a complex turnover pattern of 35S-labeled macromolecules, commencing with a rapid phase followed by a slower phase. Biochemical analysis confirmed the biphasic pattern and showed that the total population of [35S]heparan sulfate proteoglycans had a metabolic half-life (t1/2) of 20 and 60 h in the early and late phases, respectively. Heparan sulfate proteoglycans accounted for 80% of total 35S-proteoglycans, the remainder being chondroitin/dermatan sulfate proteoglycans. Whole glomeruli were extracted with 4% 3-[(cholamidopropyl)dimethy-lammonio]-1-propanesulfonate-4 M guanidine hydrochloride, a procedure which solubilized greater than 95% of the 35S-labeled macromolecules. Of these 11-13% was immunoprecipitated by an antiserum against heparan sulfate proteoglycan which, in immunolocalization experiments, showed specificity for staining the basement membrane of rat glomeruli. Autoradiographic analysis showed that 18% of total radioactivity present at the end of the labeling period was associated with the glomerular basement membrane

Multiple recurrences of anti-glomerular basement membrane disease with variable antibody detection: can the laboratory be trusted?

OpenAIRE

Liu, Patricia; Waheed, Sana; Boujelbane, Lamya; Maursetter, Laura J.

2016-01-01

Anti-glomerular basement membrane (GBM) disease is commonly a monophasic illness. We present the case of multiple recurrences of anti-GBM disease with varying serum anti-GBM antibody findings. A 33-year-old female tobacco user presenting with hematuria was diagnosed with anti-GBM disease by renal biopsy. Five years later, she presented with alveolar hemorrhage and positive anti-GBM antibody. She presented a third time with alveolar hemorrhage but undetectable anti-GBM antibody. With each occu...

Collagen metabolism and basement membrane formation in cultures of mouse mammary epithelial cells: Induction of assembly on fibrillar type I collagen substrata

International Nuclear Information System (INIS)

David, G.; van der Schueren, B.; van den Berghe, H.; Nusgens, B.; Van Cauwenberge, D.; Lapiere, C.

1987-01-01

Collagen metabolism was compared in cultures of mouse mammary epithelial cells maintained on plastic or fibrillar type I collagen gel substrata. The accumulation of dialysable and non-dialysable [ 3 H]hydroxyproline and the identification of the collagens produced suggest no difference between substrata in the allover rates of collagen synthesis and degradation. The proportion of the [ 3 H]collagen which accumulates in the monolayers of cultures on collagen, however, markedly exceeds that of cultures on plastic. Cultures on collagen deposit a sheet-like layer of extracellular matrix materials on the surface of the collagen fibers. Transformed cells on collagen produce and accumulate more [ 3 H]collage, yet are less effective in basement membrane formation than normal cells, indicting that the accumulation of collagen alone and the effect of interstitial collagen thereupon do not suffice. Thus, exogenous fibrillar collagen appears to enhance, but is not sufficient for proper assembly of collagenous basement membrane components near the basal epithelial cell surface

The central role of vascular extracellular matrix and basement membrane remodeling in metabolic syndrome and type 2 diabetes: the matrix preloaded

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Tyagi Suresh C

2005-06-01

Full Text Available Abstract The vascular endothelial basement membrane and extra cellular matrix is a compilation of different macromolecules organized by physical entanglements, opposing ionic charges, chemical covalent bonding, and cross-linking into a biomechanically active polymer. These matrices provide a gel-like form and scaffolding structure with regional tensile strength provided by collagens, elasticity by elastins, adhesiveness by structural glycoproteins, compressibility by proteoglycans – hyaluronans, and communicability by a family of integrins, which exchanges information between cells and between cells and the extracellular matrix of vascular tissues. Each component of the extracellular matrix and specifically the capillary basement membrane possesses unique structural properties and interactions with one another, which determine the separate and combined roles in the multiple diabetic complications or diabetic opathies. Metabolic syndrome, prediabetes, type 2 diabetes mellitus, and their parallel companion (atheroscleropathy are associated with multiple metabolic toxicities and chronic injurious stimuli. The adaptable quality of a matrix or form genetically preloaded with the necessary information to communicate and respond to an ever-changing environment, which supports the interstitium, capillary and arterial vessel wall is individually examined.

Immunohistochemical localization of chondroitin sulfate, chondroitin sulfate proteoglycan, heparan sulfate proteoglycan, entactin, and laminin in basement membranes of postnatal developing and adult rat lungs

DEFF Research Database (Denmark)

Sannes, P L; Burch, K K; Khosla, J

1993-01-01

Histologic preparations of lungs from 1-, 5-, 10-, 18-, and 25-day-old postnatal and adult rats were examined immunohistochemically with antibodies specific against chondroitin sulfate (CS), basement membrane chondroitin sulfate proteoglycan (BM-CSPG), heparan sulfate proteoglycan (HSPG), entactin...

Proteolytic processing of lysyl oxidase-like-2 in the extracellular matrix is required for crosslinking of basement membrane collagen IV.

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López-Jiménez, Alberto J; Basak, Trayambak; Vanacore, Roberto M

2017-10-13

Lysyl oxidase-like-2 (LOXL2) is an enzyme secreted into the extracellular matrix that crosslinks collagens by mediating oxidative deamination of lysine residues. Our previous work demonstrated that this enzyme crosslinks the 7S domain, a structural domain that stabilizes collagen IV scaffolds in the basement membrane. Despite its relevant role in extracellular matrix biosynthesis, little is known about the structural requirements of LOXL2 that enable collagen IV crosslinking. In this study, we demonstrate that LOXL2 is processed extracellularly by serine proteases, generating a 65-kDa form lacking the first two scavenger receptor cysteine-rich domains. Site-specific mutagenesis to prevent proteolytic processing generated a full-length enzyme that is active in vitro toward a soluble substrate, but fails to crosslink insoluble collagen IV within the extracellular matrix. In contrast, the processed form of LOXL2 binds to collagen IV and crosslinks the 7S domain. Together, our data demonstrate that proteolytic processing is an important event that allows LOXL2-mediated crosslinking of basement membrane collagen IV. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Targeted Expression of Stromelysin-1 in Mammary Gland Provides Evidence for a Role of Proteinases in Branching Morphogenesis and the Requirement for an Intact Basement Membrane for Tissue-specific Gene Expression

Energy Technology Data Exchange (ETDEWEB)

Sympson, Carolyn J; Talhouk, Rabih S; Alexander, Caroline M; Chin, Jennie R; Cliff, Shirley M; Bissell, Mina J; Werb, Zena

1994-05-01

The extracellular matrix (ECM) is an important regulator of the differentiated phenotype of mammary epithelial cells in culture. Despite the fact that ECM-degrading enzymes have been implicated in morphogenesis and tissue remodeling, there is little evidence for a direct role for such regulation in vivo. We generated transgenic mice that express autoactivated isoforms of the matrix metalloproteinase stromelysin-1, under the control of the whey acidic protein gene promoter, to examine the effect of inappropriate expression of this enzyme. Stromelysin-1 is implicated as the primary player in the loss of basement membrane and loss of function in the mammary gland during involution. The transgene was expressed at low levels in mammary glands of virgin female mice, leading to an unexpected phenotype: The primary ducts had supernumerary branches and showed precocious development of alveoli that expressed beta-casein at levels similar to that of an early- to mid-pregnant gland. Lactating glands showed high levels of transgene expression, with accumulation at the basement membrane, and a decrease in laminin and collagen IV, resulting in a loss of basement membrane integrity; this was accompanied by a dramatic alteration of alveolar morphology, with decreased size and shrunken lumina containing little beta-casein. During pregnancy, expression of endogenous whey acidic protein and beta-casein was reduced in transgenic glands, confirming the observed dependence of milk protein transcription of ECM in mammary epithelial cells in culture. These data provide direct evidence that stromelysin-1 activity can be morphogenic for mammary epithelial cells, inducing hyperproliferation and differentiation in virgin animals, and that its lytic activity can, indeed, disrupt membrane integrity and reduce mammary-specific function. We conclude that the balance of ECM-degrading enzymes with their inhibitors, and the associated regulation of ECM structure, is crucial for tissue-specific gene

Podocytes regulate the glomerular basement membrane protein nephronectin by means of miR-378a-3p in glomerular diseases.

Science.gov (United States)

Müller-Deile, Janina; Dannenberg, Jan; Schroder, Patricia; Lin, Meei-Hua; Miner, Jeffrey H; Chen, Rongjun; Bräsen, Jan-Hinrich; Thum, Thomas; Nyström, Jenny; Staggs, Lynne Beverly; Haller, Hermann; Fiedler, Jan; Lorenzen, Johan M; Schiffer, Mario

2017-10-01

The pathophysiology of many proteinuric kidney diseases is poorly understood, and microRNAs (miRs) regulation of these diseases has been largely unexplored. Here, we tested whether miR-378a-3p is a novel regulator of glomerular diseases. MiR-378a-3p has two predicted targets relevant to glomerular function, the glomerular basement membrane matrix component, nephronectin (NPNT), and vascular endothelial growth factor VEGF-A. In zebrafish (Danio rerio), miR-378a-3p mimic injection or npnt knockdown by a morpholino oligomer caused an identical phenotype consisting of edema, proteinuria, podocyte effacement, and widening of the glomerular basement membrane in the lamina rara interna. Zebrafish vegf-A protein could not rescue this phenotype. However, mouse Npnt constructs containing a mutated 3'UTR region prevented the phenotype caused by miR-378a-3p mimic injection. Overexpression of miR-378a-3p in mice confirmed glomerular dysfunction in a mammalian model. Biopsies from patients with focal segmental glomerulosclerosis and membranous nephropathy had increased miR-378a-3p expression and reduced glomerular levels of NPNT. Thus, miR-378a-3p-mediated suppression of the glomerular matrix protein NPNT is a novel mechanism for proteinuria development in active glomerular diseases. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Normal and tumor-derived myoepithelial cells differ in their ability to interact with luminal breast epithelial cells for polarity and basement membrane deposition

Energy Technology Data Exchange (ETDEWEB)

Gudjonsson, Thorarinn; Ronnov-Jessen, Lone; Villadsen, Rene; Rank, Fritz; Bissell, Mina J.; Petersen, Ole William

2001-10-04

The signals that determine the correct polarity of breast epithelial structures in vivo are not understood. We have shown previously that luminal epithelial cells can be polarized when cultured within a reconstituted basement membrane gel. We reasoned that such cues in vivo may be given by myoepithelial cells. Accordingly, we used an assay where luminal epithelial cells are incorrectly polarized to test this hypothesis. We show that culturing human primary luminal epithelial cells within collagen-I gels leads to formation of structures with no lumina and with reverse polarity as judged by dual stainings for sialomucin, epithelial specific antigen or occludin. No basement membrane is deposited, and {beta}4-integrin staining is negative. Addition of purified human myoepithelial cells isolated from normal glands corrects the inverse polarity, and leads to formation of double-layered acini with central lumina. Among the laminins present in the human breast basement membrane (laminin-1, -5 and -10/11), laminin-1 was unique in its ability to substitute for myoepithelial cells in polarity reversal. Myoepithelial cells were purified also from four different breast cancer sources including a biphasic cell line. Three out of four samples either totally lacked the ability to interact with luminal epithelial cells, or conveyed only correction of polarity in a fraction of acini. This behavior was directly related to the ability of the tumor myoepithelial cells to produce {alpha}-1 chain of laminin. In vivo, breast carcinomas were either negative for laminin-1 (7/12 biopsies) or showed a focal, fragmented deposition of a less intensely stained basement membrane (5/12 biopsies). Dual staining with myoepithelial markers revealed that tumorassociated myoepithelial cells were either negative or weakly positive for expression of laminin-1, establishing a strong correlation between loss of laminin-1 and breast cancer. We conclude that the double-layered breast acinus may be

Comparing The Efficacy of Hematoxylin and Eosin, Periodic Acid Schiff and Fluorescent Periodic Acid Schiff-Acriflavine Techniques for Demonstration of Basement Membrane in Oral Lichen Planus: A Histochemical Study.

Science.gov (United States)

Pujar, Ashwini; Pereira, Treville; Tamgadge, Avinash; Bhalerao, Sudhir; Tamgadge, Sandhya

2015-01-01

Basement membrane (BM) is a thick sheet of extracellular matrix molecules, upon which epithelial cells attach. Various immunohistochemical studies in the past have been carried out but these advanced staining techniques are expensive and not feasible in routine laboratories. Although hematoxylin and eosin (H-E) is very popular among pathologists for looking at biopsies, the method has some limitations. This is where special stains come handy. The aim of the present study was to demonstrate and compare the efficacy of H-E, periodic acid Schiff (PAS) and fluorescent periodic acid-acriflavine staining techniques for the basement membrane and to establish a histochemical stain which could be cost effective, less time consuming, and unambiguous for observation of the basement membrane zone. A total number of 40 paraffin-embedded tissue sections of known basement membrane containing tissues including 10 - Normal oral mucosa (NOM) and 30 - oral lichen planus (OLP) were considered in the study. Four-micron-thick sections of each block were cut and stained with H-E stain, PAS and fluorescent periodic acid-acriflavine stain. Sections were evaluated by three oral pathologists independently for continuity, contrast and pattern. Though all the three stains showed favorable features at different levels, acriflavine stain was better than the other stains in demonstrating BM continuity, contrast and also the pattern followed by PAS stain. Acriflavine stain was the better in demonstrating a fibrillar pattern of a BM. Acriflavine stains a BM distinctly and is less time consuming and easy to carry out using readily available dyes as compared to other stains. The continuity and contrast along with the homogenous pattern and the afibrillar pattern of the BM was better demonstrated by acriflavine followed by the PAS stain.

Comparing the efficacy of hematoxylin and eosin, periodic acid schiff and fluorescent periodic acid schiff-acriflavine techniques for demonstration of basement membrane in oral lichen planus: A histochemical study

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Ashwini Pujar

2015-01-01

Full Text Available Background: Basement membrane (BM is a thick sheet of extracellular matrix molecules, upon which epithelial cells attach. Various immunohistochemical studies in the past have been carried out but these advanced staining techniques are expensive and not feasible in routine laboratories. Although hematoxylin and eosin (H-E is very popular among pathologists for looking at biopsies, the method has some limitations. This is where special stains come handy. Aims and Objectives: The aim of the present study was to demonstrate and compare the efficacy of H-E, periodic acid Schiff (PAS and fluorescent periodic acid-acriflavine staining techniques for the basement membrane and to establish a histochemical stain which could be cost effective, less time consuming, and unambiguous for observation of the basement membrane zone. Materials and Methods: A total number of 40 paraffin-embedded tissue sections of known basement membrane containing tissues including 10 - Normal oral mucosa (NOM and 30 - oral lichen planus (OLP were considered in the study. Four-micron-thick sections of each block were cut and stained with H-E stain, PAS and fluorescent periodic acid-acriflavine stain. Sections were evaluated by three oral pathologists independently for continuity, contrast and pattern. Results: Though all the three stains showed favorable features at different levels, acriflavine stain was better than the other stains in demonstrating BM continuity, contrast and also the pattern followed by PAS stain. Acriflavine stain was the better in demonstrating a fibrillar pattern of a BM. Acriflavine stains a BM distinctly and is less time consuming and easy to carry out using readily available dyes as compared to other stains. Conclusion: The continuity and contrast along with the homogenous pattern and the afibrillar pattern of the BM was better demonstrated by acriflavine followed by the PAS stain.

Deletion of PPAR-γ in immune cells enhances susceptibility to antiglomerular basement membrane disease

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Cristen Chafin

2010-10-01

Full Text Available Cristen Chafin2, Sarah Muse2, Raquel Hontecillas5, Josep Bassaganya-Riera5, David L Caudell2, Samuel K Shimp III4, M Nichole Rylander4, John Zhang6, Liwu Li3, Christopher M Reilly1,21Virginia College of Osteopathic Medicine, 2Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA; 3Department of Biological Sciences, 4Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA; 5Nutritional Immunology and Molecular Medicine Laboratory, Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA; 6Medical University of SC, Charleston, SC, USAAbstract: Activation of the nuclear hormone receptor peroxisome proliferator-activated receptor gamma (PPAR-γ has been shown to be immunoregulatory in autoimmune diseases by inhibiting production of a number of inflammatory mediators. We investigated whether PPAR-γ gene deletion in hematopoietic cells would alter disease pathogenesis in the antiglomerular basement membrane (anti-GBM mouse model. PPAR-γ+/+ and PPAR-γ-/- mice were immunized with rabbit antimouse GBM antibodies and lipopolysaccharide and evaluated for two weeks. Although both the PPAR-γ+/+ and PPAR-γ-/- mice had IgG deposition in the glomerulus and showed proteinuria two weeks after injection, glomerular and tubulointerstitial disease in PPAR-γ-/- mice were significantly more severe compared with the PPAR-γ+/+ animals. We observed that the PPAR-γ-/- mice had decreased CD4+CD25+ regulatory T cells and an increased CD8+:CD4+ ratio as compared with the PPAR-γ+/+ mice, suggesting that PPAR-γ has a role in the regulation of T cells. Furthermore, plasma interleukin-6 levels were significantly increased in the PPAR-γ-/- mice at two weeks as compared with the PPAR-γ+/+ animals. Taken together, these studies show that

Functional differentiation and alveolar morphogenesis of primary mammary cultures on reconstituted basement membrane

Energy Technology Data Exchange (ETDEWEB)

BARCELLOS-HOFF, M. H; AGGELER, J.; RAM, T. G; BISSELL, M. J

1989-02-01

An essential feature of mammary gland differentiation during pregnancy is the formation of alveoli composed of polarized epithelial cells, which, under the influence of lactogenic hormones, secrete vectorially and sequester milk proteins. Previous culture studies have described either organization of cells polarized towards lumina containing little or no demonstrable tissue-specific protein, or establishment of functional secretory cells exhibiting little or no glandular architecture. In this paper, we report that tissue-specific vectorial secretion coincides with the formation of functional alveoli-like structures by primary mammary epithelial cells cultured on a reconstituted basement membrane matrix (derived from Engelbreth-Holm-Swarm murine tumour). Morphogenesis of these unique three-dimensional structures was initiated by cell-directed remodelling of the exogenous matrix leading to reorganization of cells into matrixensheathed aggregates by 24 h after plating. The aggregates subsequently cavitated, so that by day 6 the cells were organized into hollow spheres in which apical cell surfaces faced lumina sealed by tight junctions and basal surfaces were surrounded by a distinct basal lamina. The profiles of proteins secreted into the apical (luminal) and basal (medium) compartments indicated that these alveoli-like structures were capable of an appreciable amount of vectorial secretion. Immunoprecipitation with a broad spectrum milk antiserum showed that more than 80% of caseins were secreted into the lumina, whereas iron-binding proteins (both lactoferrin and transferrin) were present in comparable amounts in each compartment. Thus, these mammary cells established protein targeting pathways directing milk-specific proteins to the luminal compartment. A time course monitoring secretory activity demonstrated that establishment of tissue-specific vectorial secretion and increased total and milk protein secretion coincided with functional alveolar

The vascular basement membrane as "soil" in brain metastasis.

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W Shawn Carbonell

2009-06-01

Full Text Available Brain-specific homing and direct interactions with the neural substance are prominent hypotheses for brain metastasis formation and a modern manifestation of Paget's "seed and soil" concept. However, there is little direct evidence for this "neurotropic" growth in vivo. In contrast, many experimental studies have anecdotally noted the propensity of metastatic cells to grow along the exterior of pre-existing vessels of the CNS, a process termed vascular cooption. These observations suggest the "soil" for malignant cells in the CNS may well be vascular, rather than neuronal. We used in vivo experimental models of brain metastasis and analysis of human clinical specimens to test this hypothesis. Indeed, over 95% of early micrometastases examined demonstrated vascular cooption with little evidence for isolated neurotropic growth. This vessel interaction was adhesive in nature implicating the vascular basement membrane (VBM as the active substrate for tumor cell growth in the brain. Accordingly, VBM promoted adhesion and invasion of malignant cells and was sufficient for tumor growth prior to any evidence of angiogenesis. Blockade or loss of the beta1 integrin subunit in tumor cells prevented adhesion to VBM and attenuated metastasis establishment and growth in vivo. Our data establishes a new understanding of CNS metastasis formation and identifies the neurovasculature as the critical partner for such growth. Further, we have elucidated the mechanism of vascular cooption for the first time. These findings may help inform the design of effective molecular therapies for patients with fatal CNS malignancies.

Immunohistochemical expression of basement membrane proteins of verrucous carcinoma of the oral mucosa.

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Arduino, Paolo G; Carrozzo, Marco; Pagano, Marco; Broccoletti, Roberto; Scully, Crispian; Gandolfo, Sergio

2010-06-01

Squamous cell carcinoma (SCC) of the oral cavity is an extremely invasive tumour of stratified squamous epithelium that spreads throughout degradation of the basement membrane (BM) and extra-cellular matrix. Oral verrucous carcinoma (VC) is a rare low-grade variant of oral SCC that penetrates into the subepithelial connective tissue. It also has a different clinical behaviour from classical oral SCC. We investigated the immunohistochemical expression of laminin, laminin-5, collagen IV and fibronectin in VC, severe epithelial dysplasia (SED) and SCC in order to analyse if the pattern of these molecules expression contributes to the differences in the biological behaviour of these diseases. The staining pattern of laminin was less intensive in SCC compared with SED and VC, and collagen IV expression was increased in VC compared with SED. Discontinuities of laminin, collagen IV and fibronectin were more evident in SED than in VC. This study indicates that VC has a biological behaviour different from SED or SCC, observable by immunohistochemistry in the BM zone.

WY14,643, a PPARα ligand, attenuates expression of anti-glomerular basement membrane disease

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Archer, D C; Frkanec, J T; Cromwell, J; Clopton, P; Cunard, R

2007-01-01

Peroxisome proliferator-activated receptor alpha (PPARα) ligands are medications used to treat hyperlipidaemia and atherosclerosis. Increasing evidence suggests that these agents are immunosuppressive. In the following studies we demonstrate that WY14,643, a PPARα ligand, attenuates expression of anti-glomerular basement membrane disease (AGBMD). C57BL/6 mice were fed 0·05% WY14,643 or control food and immunized with the non-collagenous domain of the α3 chain of Type IV collagen [α3(IV) NC1] in complete Freund's adjuvant (CFA). WY14,643 reduced proteinuria and greatly improved glomerular and tubulo-interstitial lesions. However, the PPARα ligand did not alter the extent of IgG-binding to the GBM. Immunohistochemical studies revealed that the prominent tubulo-interstitial infiltrates in the control-fed mice consisted predominately of F4/80+ macrophages and WY14,643-feeding decreased significantly the number of renal macrophages. The synthetic PPARα ligand also reduced significantly expression of the chemokine, monocyte chemoattractant protein (MCP)-1/CCL2. Sera from mice immunized with AGBMD were also evaluated for antigen-specific IgGs. There was a significant increase in the IgG1 : IgG2c ratio and a decline in the intrarenal and splenocyte interferon (IFN)-γ mRNA expression in the WY14,643-fed mice, suggesting that the PPARα ligand could skew the immune response to a less inflammatory T helper 2-type of response. These studies suggest that PPARα ligands may be a novel treatment for inflammatory renal disease. PMID:17888025

WY14,643, a PPARalpha ligand, attenuates expression of anti-glomerular basement membrane disease.

Science.gov (United States)

Archer, D C; Frkanec, J T; Cromwell, J; Clopton, P; Cunard, R

2007-11-01

Peroxisome proliferator-activated receptor alpha (PPARalpha) ligands are medications used to treat hyperlipidaemia and atherosclerosis. Increasing evidence suggests that these agents are immunosuppressive. In the following studies we demonstrate that WY14,643, a PPARalpha ligand, attenuates expression of anti-glomerular basement membrane disease (AGBMD). C57BL/6 mice were fed 0.05% WY14,643 or control food and immunized with the non-collagenous domain of the alpha3 chain of Type IV collagen [alpha3(IV) NC1] in complete Freund's adjuvant (CFA). WY14,643 reduced proteinuria and greatly improved glomerular and tubulo-interstitial lesions. However, the PPARalpha ligand did not alter the extent of IgG-binding to the GBM. Immunohistochemical studies revealed that the prominent tubulo-interstitial infiltrates in the control-fed mice consisted predominately of F4/80(+) macrophages and WY14,643-feeding decreased significantly the number of renal macrophages. The synthetic PPARalpha ligand also reduced significantly expression of the chemokine, monocyte chemoattractant protein (MCP)-1/CCL2. Sera from mice immunized with AGBMD were also evaluated for antigen-specific IgGs. There was a significant increase in the IgG1 : IgG2c ratio and a decline in the intrarenal and splenocyte interferon (IFN)-gamma mRNA expression in the WY14,643-fed mice, suggesting that the PPARalpha ligand could skew the immune response to a less inflammatory T helper 2-type of response. These studies suggest that PPARalpha ligands may be a novel treatment for inflammatory renal disease.

19-DEJ-1, a hemidesmosome-anchoring filament complex-associated monoclonal antibody. Definition of a new skin basement membrane antigenic defect in junctional and dystrophic epidermolysis bullosa

DEFF Research Database (Denmark)

Fine, J D; Horiguchi, Y; Couchman, J R

1989-01-01

A murine monoclonal antibody (19-DEJ-1) was recently produced that recognizes a unique antigenic epitope of human skin basement membrane localized to the midlamina lucida exclusively in those areas bordered by overlying hemidesmosomes. To determine whether the antigen defined by 19-DEJ-1 is norma...

Regeneration of defective epithelial basement membrane and restoration of corneal transparency

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Marino, Gustavo K.; Santhiago, Marcony R.; Santhanam, Abirami; Torricelli, Andre A. M.; Wilson, Steven E.

2018-01-01

PURPOSE To study regeneration of the normal ultrastructure of the epithelial basement membrane (EBM) in rabbit corneas that had -9D photorefractive keratectomy (PRK) and developed late haze (fibrosis) with restoration of transparency over one to four months after surgery and in corneas that had incisional wounds. METHODS Twenty-four rabbits had one of their eyes included into one of the two procedure groups (-9D PRK or nearly full-thickness incisional wounds), while the opposite eye serving as unwounded controls. All corneas were evaluated with slit lamp photos, transmission electron microscopy and immunohistochemistry for the myofibroblast marker alpha-smooth muscle actin and collagen type III. RESULTS In the ‘-9D PRK group’, corneas at one month after surgery had dense corneal haze and no evidence of regenerated EBM ultrastructure. By two months after surgery, however, small areas of stromal clearing began to appear within the confluent opacity (lacunae), and these corresponded to small islands of normally-regenerated EBM detected within larger area of the excimer laser-ablated zone with no evidence of normal EBM. By four months after surgery, the EBM was fully-regenerated and the corneal transparency was completely restored to the ablated zone. In the ‘Incisional wound group’, the two dense, linear corneal opacities were observed at one month after surgery and progressively faded by two and three months after surgery. The EBM ultrastructure was fully regenerated at the site of the incisions, including around epithelial plugs that extended into the stroma, by one month after surgery in all eyes. CONCLUSIONS In the rabbit model, spontaneous resolution of corneal fibrosis (haze) after high correction PRK is triggered by regeneration of EBM with normal ultrastructure in the excimer laser- ablated zone. Conversely, incisional wounds heal in rabbit corneas without the development of myofibroblasts because the EBM regenerates normally by one month after surgery

Glucuronylated core 1 glycans are required for precise localization of neuromuscular junctions and normal formation of basement membranes on Drosophila muscles.

Science.gov (United States)

Itoh, Kazuyoshi; Akimoto, Yoshihiro; Kondo, Shu; Ichimiya, Tomomi; Aoki, Kazuhiro; Tiemeyer, Michael; Nishihara, Shoko

2018-04-15

T antigen (Galβ1-3GalNAcα1-Ser/Thr) is an evolutionary-conserved mucin-type core 1 glycan structure in animals synthesized by core 1 β1,3-galactosyltransferase 1 (C1GalT1). Previous studies showed that T antigen produced by Drosophila C1GalT1 (dC1GalT1) was expressed in various tissues and dC1GalT1 loss in larvae led to various defects, including decreased number of circulating hemocytes, hyper-differentiation of hematopoietic stem cells in lymph glands, malformation of the central nervous system, mislocalization of neuromuscular junction (NMJ) boutons, and ultrastructural abnormalities in NMJs and muscle cells. Although glucuronylated T antigen (GlcAβ1-3Galβ1-3GalNAcα1-Ser/Thr) has been identified in Drosophila, the physiological function of this structure has not yet been clarified. In this study, for the first time, we unraveled biological roles of glucuronylated T antigen. Our data show that in Drosophila, glucuronylation of T antigen is predominantly carried out by Drosophila β1,3-glucuronyltransferase-P (dGlcAT-P). We created dGlcAT-P null mutants and found that mutant larvae showed lower expression of glucuronylated T antigen on the muscles and at NMJs. Furthermore, mislocalization of NMJ boutons and a partial loss of the basement membrane components collagen IV (Col IV) and nidogen (Ndg) at the muscle 6/7 boundary were observed. Those two phenotypes were correlated and identical to previously described phenotypes in dC1GalT1 mutant larvae. In addition, dGlcAT-P null mutants exhibited fewer NMJ branches on muscles 6/7. Moreover, ultrastructural analysis revealed that basement membranes that lacked Col IV and Ndg were significantly deformed. We also found that the loss of dGlcAT-P expression caused ultrastructural defects in NMJ boutons. Finally, we showed a genetic interaction between dGlcAT-P and dC1GalT1. Therefore, these results demonstrate that glucuronylated core 1 glycans synthesized by dGlcAT-P are key modulators of NMJ bouton localization

Degradation of endothelial basement membrane by human breast cancer cell lines

International Nuclear Information System (INIS)

Yee, C.; Shiu, R.P.

1986-01-01

During metastasis, it is believed that tumor cells destroy the basement membrane (BM) of blood vessels in order to disseminate through the circulatory system. By radioactively labeling the extracellular matrix produced by primary endothelial cells in vitro, the ability of human breast cancer cells to degrade BM components was studied. We found that T-47D, a human breast cancer line, was able to degrade significant amounts of [35S]methionine-labeled and [3H]proline-labeled BM, but not 35SO4-labeled BM. Six other tumor cell lines of human breast origin were assayed in the same manner and were found to degrade BM to varying degrees. Several non-tumor cell lines tested showed relatively little degrading activity. The use of serum-free medium greatly enhanced degradation of the BM by tumor cells, suggesting a role for naturally occurring enzyme inhibitors in the serum. Direct cell contact with the BM was required for BM degradation, suggesting that the active enzymes are cell associated. The addition of hormones implicated in the etiology of breast cancer did not significantly alter the ability of T-47D cells to degrade the BM. The use of this assay affords future studies on the mechanism of invasion and metastasis of human breast cancer

Ultrastructural study of electron dense deposits in renal tubular basement membrane: prevalence and relationship to epithelial atrophy.

Science.gov (United States)

Yong, Jim L C; Killingsworth, Murray C

2014-08-01

This study reports the prevalence of immune deposits associated with the proximal and distal tubules in a series of routine renal biopsies received in our department during a single calendar year. From 87 cases, 65 (74%) were found to have glomerular immune deposits by immunofluorescence. Tubular immune deposits were found in 12 cases (18%), 3 of which had no glomerular deposits. By transmission electron microscopy (EM), 58 cases (66%) were found to have deposits of granular or vesicular material associated with the tubular basement membranes (TBM). Finely granular electron dense deposits appeared to correspond to the immune deposits seen by immunofluorescence microscopy (IF) and may be a sensitive marker of immune deposition.

Defective muscle basement membrane and lack of M-laminin in the dystrophic dy/dy mouse

DEFF Research Database (Denmark)

Xu, H; Christmas, P; Wu, X R

1994-01-01

-linked Duchenne and Becker muscular dystrophies. We have examined M-laminin expression in mice with autosomal recessive muscular dystrophy caused by the mutation dy. The heavy chain of M-laminin was undetectable in skeletal muscle, heart muscle, and peripheral nerve by immunofluorescence and immunoblotting......M-laminin is a major member of the laminin family of basement membrane proteins. It is prominently expressed in striated muscle and peripheral nerve. M-laminin is deficient in patients with the autosomal recessive Fukuyama congenital muscular dystrophy but is normal in patients with the sex...... tissue from dy/dy mice, suggesting that M-laminin heavy-chain mRNA may be produced at very low levels or is unstable. Information about the chromosomal localization of the M heavy-chain in human and mouse suggests that a mutation in the M-chain gene causes the muscular dystrophy in dy/dy mice. The dy...

Fluorescent and radiolabelling of pepsin-digested human glomerular basement membrane with a newly developed hydroxy-coumarin derivative (CASE)

International Nuclear Information System (INIS)

Rand-Weaver, M.; Abuknesha, R.A.; Price, R.G.

1985-01-01

The labelling of pepsin-digested human glomerular basement membrane (pHGBM) with a newly developed fluorescent iodine acceptor 7-hydroxy-coumarin-3-acetic acid N-hydroxysucciniimydyl ester (CASE) is described. The binding of a monoclonal antibody to pHGBM was assessed by radiobinding assays, and when directly iodinated pHGBM was used there was no apparent binding. When CASE was conjugated to pHGBM prior to iodination 11% binding was achieved. CASE acting as an iodine acceptor may be useful for proteins containing few or inaccessible tyrosine residues or which are destroyed by introduction of 125 I. Since CASE is fluorescent, small amounts of material can be detected during isolation prior to iodination. (orig.)

Anti-glomerular basement membrane autoantibodies in the Brown Norway rat: detection by a solid-phase radioimmunoassay

International Nuclear Information System (INIS)

Bowman, C.; Peters, D.K.; Lockwood, C.M.

1983-01-01

A solid-phase radioimmunoassay (RIA) is described for the detection of IgG autoantibodies to glomerular basement membrane (GBM) induced in the Brown Norway rat by mercuric chloride. The assay involves the adsorption of a collagenase digest of GBM to plastic microtitre plates and detection of bound antibody with affinity purified radiolabelled rabbit anti-rat IgG. Comparison with existing immunofluorescence methods for detection of anti-GBM antibody showed that the solid-phase RIA is highly sensitive, allowing detection of antibody in solutions with as low as 0.5 ng protein/ml. The assay is suitable for detection of anti-GBM antibody both in serum and in eluates from nephritic kidneys. The assay proved to be specific in competitive studies of inhibition brought about by GBM, keyhole limpet antigen and ovalbumin. This solid-phase RIA is reproducible, robust and easy to perform. (Auth.)

Quantitative Proteome Analysis Reveals Increased Content of Basement Membrane Proteins in Arteries from Patients with Type 2 Diabetes and Lower Levels among Metformin Users

DEFF Research Database (Denmark)

Rørdam Preil, Simone; Kristensen, Lars P; Beck, Hans C

2015-01-01

hypothesized that metformin intake influences the protein composition. METHODS AND RESULTS: -We analyzed non-atherosclerotic repair arteries gathered at coronary by-pass operations from 30 patients with type 2 diabetes, as well as from 30 age- and gender-matched non-diabetic individuals. Quantitative proteome......BACKGROUND: -The increased risk of cardiovascular diseases (CVD) in type 2 diabetes has been extensively documented, but the origins of the association remain largely unknown. We sought to determine changes in protein expressions in arterial tissue from patients with type 2 diabetes and moreover...... analysis was done by iTRAQ-labelling and LC-MS/MS analysis on individual arterial samples. The amounts of the basement membrane (BM) components, alpha-1- and alpha-2- type IV collagen, gamma-1- and beta-2-laminin were significantly increased in patients with diabetes. Moreover, the expressions of basement...

A direct contact between astrocyte and vitreous body is possible in the rabbit eye due to discontinuities in the basement membrane of the retinal inner limiting membrane

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A. Haddad

2003-02-01

Full Text Available Different from most mammalian species, the optic nerve of the rabbit eye is initially formed inside the retina where myelination of the axons of the ganglion cells starts and vascularization occurs. Astrocytes are confined to these regions. The aforementioned nerve fibers known as medullated nerve fibers form two bundles that may be identified with the naked eye. The blood vessels run on the inner surface of these nerve fiber bundles (epivascularization and, accordingly, the accompanying astrocytes lie mostly facing the vitreous body from which they are separated only by the inner limiting membrane of the retina. The arrangement of the astrocytes around blood vessels leads to the formation of structures known as glial tufts. Fragments (N = 3 or whole pieces (N = 3 of the medullated nerve fiber region of three-month-old male rabbits (Orictolagus cuniculus were fixed in glutaraldehyde followed by osmium tetroxide, and their thin sections were examined with a transmission electron microscope. Randomly located discontinuities (up to a few micrometers long of the basement membrane of the inner limiting membrane of the retina were observed in the glial tufts. As a consequence, a direct contact between the astrocyte plasma membrane and vitreous elements was demonstrated, making possible functional interactions such as macromolecular exchanges between this glial cell type and the components of the vitreous body.

Anti-glomerular basement membrane glomerulonephritis in an HIV positive patient: case report

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Eduardo José Bellotto Monteiro

Full Text Available We report on a case of a patient with HIV infection, diagnosed 18 months prior to the development of an anti-glomerular basement membrane (anti-GBM rapidly progressive glomerulonephritis; this is probably the first report of such an association. A 30-year-old white man presented with elevation of serum creatinine (1.3 - 13.5 mg/dL within one month. At admission, the urinalysis showed proteinuria of 7.2 g/L and 8,000,000 erythrocytes/mL. Renal biopsy corresponded to a crescentic diffuse proliferative glomerulonephritis mediated by anti-GBM, and serum testing for anti-GBM antibodies was positive; antinuclear antibodies (ANA and anti-neutrophilic cytoplasmic antibodies (ANCA were also positive. The patient underwent hemodyalisis and was treated with plasmapheresis, cyclophosphamide and prednisone. The association described here is not casual, as crescentic glomerulonephritis is not common in HIV-positive patients, anti-GBM glomerulonephritis is rare and anti-GBM antibodies are frequently observed in HIV-positive subjects when compared to the overall population. Based on the current case and on the elevated frequency of the positivity for such antibodies in this group of patients, it is advisable to be aware of the eventual association between these two conditions and to promote an active search for anti-GBM antibodies and early diagnosis of eventual urinary abnormalities in HIV-positive subjects, considering the severity of anti-GBM glomerulonephritis.

An in vitro model of the glomerular capillary wall using electrospun collagen nanofibres in a bioartificial composite basement membrane.

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Sadie C Slater

Full Text Available The filtering unit of the kidney, the glomerulus, contains capillaries whose walls function as a biological sieve, the glomerular filtration barrier. This comprises layers of two specialised cells, glomerular endothelial cells (GEnC and podocytes, separated by a basement membrane. Glomerular filtration barrier function, and dysfunction in disease, remains incompletely understood, partly due to difficulties in studying the relevant cell types in vitro. We have addressed this by generation of unique conditionally immortalised human GEnC and podocytes. However, because the glomerular filtration barrier functions as a whole, it is necessary to develop three dimensional co-culture models to maximise the benefit of the availability of these cells. Here we have developed the first two tri-layer models of the glomerular capillary wall. The first is based on tissue culture inserts and provides evidence of cell-cell interaction via soluble mediators. In the second model the synthetic support of the tissue culture insert is replaced with a novel composite bioartificial membrane. This consists of a nanofibre membrane containing collagen I, electrospun directly onto a micro-photoelectroformed fine nickel supporting mesh. GEnC and podocytes grew in monolayers on either side of the insert support or the novel membrane to form a tri-layer model recapitulating the human glomerular capillary in vitro. These models will advance the study of both the physiology of normal glomerular filtration and of its disruption in glomerular disease.

Airway basement membrane perimeter in human airways is not a constant; potential implications for airway remodeling in asthma.

Science.gov (United States)

McParland, Brent E; Paré, Peter D; Johnson, Peter R A; Armour, Carol L; Black, Judith L

2004-08-01

Many studies that demonstrate an increase in airway smooth muscle in asthmatic patients rely on the assumption that bronchial internal perimeter (P(i)) or basement membrane perimeter (P(bm)) is a constant, i.e., not affected by fixation pressure or the degree of smooth muscle shortening. Because it is the basement membrane that has been purported to be the indistensible structure, this study examines the assumption that P(bm) is not affected by fixation pressure. P(bm) was determined for the same human airway segment (n = 12) fixed at distending pressures of 0 cmH(2)O and 21 cmH(2)O in the absence of smooth muscle tone. P(bm) for the segment fixed at 0 cmH(2)O was determined morphometrically, and the P(bm) for the same segment, had the segment been fixed at 21 cmH(2)O, was predicted from knowing the luminal volume and length of the airway when distended to 21 cmH(2)O (organ bath-derived P(i)). To ensure an accurate transformation of the organ bath-derived P(i) value to a morphometry-derived P(bm) value, had the segment been fixed at 21 cmH(2)O, the relationship between organ bath-derived P(i) and morphometry-derived P(bm) was determined for five different bronchial segments distended to 21 cmH(2)O and fixed at 21 cmH(2)O (r(2) = 0.99, P < 0.0001). Mean P(bm) for bronchial segments fixed at 0 cmH(2)O was 9.4 +/- 0.4 mm, whereas mean predicted P(bm), had the segments been fixed at 21 cmH(2)O, was 14.1 +/- 0.5 mm (P < 0.0001). This indicates that P(bm) is not a constant when isolated airway segments without smooth muscle tone are fixed distended to 21 cmH(2)O. The implication of these results is that the increase in smooth muscle mass in asthma may have been overestimated in some previous studies. Therefore, further studies are required to examine the potential artifact using whole lungs with and without abolition of airway smooth muscle tone and/or inflation.

Expression and organization of basement membranes and focal adhesion proteins in pregnant myometrium is regulated by uterine stretch.

Science.gov (United States)

Shynlova, Oksana; Chow, Michelle; Lye, Stephen J

2009-10-01

The mechanisms underlying the preparation of the uterus for labor are not fully understood. We have previously found a significant increase in the expression of messenger RNA (mRNAs) encoding extracellular basement membrane (BM) proteins of the smooth muscle cells (SMCs) in late pregnant rat myometrium. At term, the myometrium is stretched by growing fetuses and these mechanical signals are transmitted from extracellular matrix into SMCs through focal adhesions (FA). The aim of this study was to investigate the effect of gravidity on the expression and spatiotemporal distribution of major BM proteins, laminin-gamma2 and collagen IV, as well as typical FA constituents, vinculin and paxillin, in the myometrium during gestation and parturition, using a unilaterally pregnant rat model. We found that the expression of laminin-gamma2 and collagen IV proteins increased significantly with gestational age (P proteins were not affected. Near term, BM proteins from gravid horn myometrium demonstrated increased extracellular immunostaining and major rearrangement from sporadic protein distribution to organized, continuous, and regular structures surrounding the plasma membrane of each myocyte. Examination of FA proteins revealed that paxillin was translocated from the cytoplasm to the cell periphery, while vinculin was sequestered specifically to FAs. At labor, BM and FA proteins, organized in similar bead-like structures, were localized on opposing sides of SMC plasma membrane into 2 different compartments. We suggest that these stretch-induced changes facilitate formation of stable cell-matrix adhesions and provide the molecular basis for optimal force transduction during labor contractions.

Age-related collagen turnover of the interstitial matrix and basement membrane: Implications of age- and sex-dependent remodeling of the extracellular matrix.

Science.gov (United States)

Kehlet, Stephanie N; Willumsen, Nicholas; Armbrecht, Gabriele; Dietzel, Roswitha; Brix, Susanne; Henriksen, Kim; Karsdal, Morten A

2018-01-01

The extracellular matrix (ECM) plays a vital role in maintaining normal tissue function. Collagens are major components of the ECM and there is a tight equilibrium between degradation and formation of these proteins ensuring tissue health and homeostasis. As a consequence of tissue turnover, small collagen fragments are released into the circulation, which act as important biomarkers in the study of certain tissue-related remodeling factors in health and disease. The aim of this study was to establish an age-related collagen turnover profile of the main collagens of the interstitial matrix (type I and III collagen) and basement membrane (type IV collagen) in healthy men and women. By using well-characterized competitive ELISA-assays, we assessed specific fragments of degraded (C1M, C3M, C4M) and formed (PINP, Pro-C3, P4NP7S) type I, III and IV collagen in serum from 617 healthy men and women ranging in ages from 22 to 86. Subjects were divided into 5-year age groups according to their sex and age. Groups were compared using Kruskal-Wallis adjusted for Dunn's multiple comparisons test and Mann-Whitney t-test. Age-specific changes in collagen turnover was most profound for type I collagen. PINP levels decreased in men with advancing age, whereas in women, the level decreased in early adulthood followed by an increase around the age of menopause (age 40-60). Sex-specific changes in type I, III and IV collagen turnover was present at the age around menopause (age 40-60) with women having an increased turnover. In summary, collagen turnover is affected by age and sex with the interstitial matrix and the basement membrane being differently regulated. The observed changes needs to be accounted for when measuring ECM related biomarkers in clinical studies.

Basement control in the development of the early cretaceous West and Central African rift system

Science.gov (United States)

Maurin, Jean-Christophe; Guiraud, René

1993-12-01

The structural framework of the Precambrian basement of the West and Central African Rift System (WCARS) is described in order to examine the role of ancient structures in the development of this Early Cretaceous rift system. Basement structures are represented in the region by large Pan-African mobile belts (built at ca. 600 Ma) surrounding the > 2 Ga West African, Congo and Sao Francisco cratons. Except for the small Gao trough (eastern Mali) located near the contact nappe of the Pan-African Iforas suture zone along the edge of the West African craton, the entire WCARS is located within the internal domains of the Pan-African mobile belts. Within these domains, two main structural features occur as the main basement control of the WCARS: (1) an extensive network of near vertical shear zones which trend north-south through the Congo, Brazil, Nigeria, Niger and Algeria, and roughly east-west through northeastern Brazil and Central Africa. The shear zones correspond to intra-continental strike-slip faults which accompanied the oblique collision between the West African, Congo, and Sao Francisco cratons during the Late Proterozoic; (2) a steep metamorphic NW-SE-trending belt which corresponds to a pre-Pan-African (ca. 730 Ma) ophiolitic suture zone along the eastern edge of the Trans-Saharian mobile belt. The post-Pan-African magmatic and tectonic evolution of the basement is also described in order to examine the state of the lithosphere prior to the break-up which occurred in the earliest Cretaceous. After the Pan-African thermo-tectonic event, the basement of the WCARS experienced a long period of intra-plate magmatic activity. This widespread magmatism in part relates to the activity of intra-plate hotspots which have controlled relative uplift, subsidence and occasionally block faulting. During the Paleozoic and the early Mesozoic, this tectonic activity was restricted to west of the Hoggar, west of Aïr and northern Cameroon. During the Late Jurassic

A bioartificial environment for kidney epithelial cells based on a supramolecular polymer basement membrane mimic and an organotypical culture system.

Science.gov (United States)

Mollet, Björne B; Bogaerts, Iven L J; van Almen, Geert C; Dankers, Patricia Y W

2017-06-01

Renal applications in healthcare, such as renal replacement therapies and nephrotoxicity tests, could potentially benefit from bioartificial kidney membranes with fully differentiated and functional human tubular epithelial cells. A replacement of the natural environment of these cells is required to maintain and study cell functionality cell differentiation in vitro. Our approach was based on synthetic supramolecular biomaterials to mimic the natural basement membrane (BM) on which these cells grow and a bioreactor to provide the desired organotypical culture parameters. The BM mimics were constructed from ureidopyrimidinone (UPy)-functionalized polymer and bioactive peptides by electrospinning. The resultant membranes were shown to have a hierarchical fibrous BM-like structure consisting of self-assembled nanofibres within the electrospun microfibres. Human kidney-2 (HK-2) epithelial cells were cultured on the BM mimics under organotypical conditions in a custom-built bioreactor. The bioreactor facilitated in situ monitoring and functionality testing of the cultures. Cell viability and the integrity of the epithelial cell barrier were demonstrated inside the bioreactor by microscopy and transmembrane leakage of fluorescently labelled inulin, respectively. Furthermore, HK-2 cells maintained a polarized cell layer and showed modulation of both gene expression of membrane transporter proteins and metabolic activity of brush border enzymes when subjected to a continuous flow of culture medium inside the new bioreactor for 21 days. These results demonstrated that both the culture and study of renal epithelial cells was facilitated by the bioartificial in vitro environment that is formed by synthetic supramolecular BM mimics in our custom-built bioreactor. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

A role for PDGF-C/PDGFRα signaling in the formation of the meningeal basement membranes surrounding the cerebral cortex

Science.gov (United States)

Andrae, Johanna; Gouveia, Leonor; Gallini, Radiosa; He, Liqun; Fredriksson, Linda; Nilsson, Ingrid; Johansson, Bengt R.; Eriksson, Ulf; Betsholtz, Christer

2016-01-01

ABSTRACT Platelet-derived growth factor-C (PDGF-C) is one of three known ligands for the tyrosine kinase receptor PDGFRα. Analysis of Pdgfc null mice has demonstrated roles for PDGF-C in palate closure and the formation of cerebral ventricles, but redundancy with other PDGFRα ligands might obscure additional functions. In search of further developmental roles for PDGF-C, we generated mice that were double mutants for Pdgfc−/− and PdgfraGFP/+. These mice display a range of severe phenotypes including spina bifida, lung emphysema, abnormal meninges and neuronal over-migration in the cerebral cortex. We focused our analysis on the central nervous system (CNS), where PDGF-C was identified as a critical factor for the formation of meninges and assembly of the glia limitans basement membrane. We also present expression data on Pdgfa, Pdgfc and Pdgfra in the cerebral cortex and microarray data on cerebral meninges. PMID:26988758

Retinoid inhibition of in vitro invasion of human amnion basement membrane by human tumor cells

International Nuclear Information System (INIS)

Fazely, F.

1988-01-01

The effects measured were the inhibition of tumor cell migration through the basement membrane (BM) and tumor cell degradative enzyme activity on 3 H-proline labeled collagenous and non collagenous components of the BM. The human lung carcinoma A549 or the human Ewing's sarcoma TC-106 cell lines treated with retinoids for two days were incubated on the BM in the absence of retinoids. A dose-dependent inhibition of cell invasion was produced by retinoids. Among the retinoids tested the most powerful was retinol acetate which inhibited invasion by 50% of A549 cells at a concentration of 0.09 μg/ml, and TC-106 cells at 0.08 μg/ml. Retinol acetate inhibited A549 and TC-106 cell growth by approximately 50% at levels almost 100-fold higher than those needed for antiinvasive activity. Retinol acetate was about 20 times more potent than retinoic acid and 30 times more than retinol palmitate. Furthermore, A549 cells treated with retinol acetate, under conditions whereby an anti-invasive state was induced,showed an increase in the number of cellular retinoic acid binding proteins (CRABP), a decrease in the activity of type IV collagenase and ectosialyltransferase, and no change in the activity of transglutaminase

Retinoid inhibition of in vitro invasion of human amnion basement membrane by human tumor cells

International Nuclear Information System (INIS)

Fazely, F.; Ledinko, N.; Smith, D.J.

1986-01-01

The biological activity of retinoids was assayed in an in vitro quantitative assay of human tumor cell invasion using human amnion basement membrane (BM). The effects measured were the inhibition of tumor cell migration through the BM and tumor cell degradative enzyme activity on 14 C-proline labeled collagenous and noncollagenous components of the BM. The human lung carcinoma A549 or the human Ewing's sarcoma TC-106 cell lines treated with retinoids for two days were incubated on the BM in the absence of retinoids. A dose-dependent inhibition of cell invasion was produced by retinoids. Among the retinoids tested, the most powerful was retinol acetate which inhibited invasion by 50% of A549 cells at a concentration of 0.009 μg/mL, and of TC-106 cells at 0.07 μg/mL. Retinol acetate inhibited A549 and TC-106 cell growth by approximately 50% at levels over 100-fold higher than those needed for antiinvasive activity. Retinol acetate was about 20 times more potent than retinoic acid and 30 times more potent than retinol palmitate. The model system will be useful for investigating antiinvasive activity of other retinoids as well as other compounds

Use of natural basement ventilation to control radon in single family dwellings

International Nuclear Information System (INIS)

Cavallo, A.; Gadsby, K.; Reddy, T.A.

1992-01-01

Natural basement ventilation has always been recommended as a means of reducing radon levels in houses. However, its efficacy has never been documented. In these experiments, natural ventilation has for the first time been studied systematically in two research houses during both the summer cooling season and the winter heating season. Ventilation rates, environmental and house operating parameters, as well as radon levels, have been monitored. It can be definitely concluded from radon entry rate calculations that natural ventilation can reduce radon levels in two ways. The first is by simple dilution. The second is by reducing basement depressurization and thus the amount of radon-contaminated soil gas drawn into the structure. Therefore, basement ventilation can be an effective mitigation strategy under some circumstances. It might be especially useful in houses with low radon concentrations (of the order of 370 Bq m -1 ) or those with low levels and which cannot be mitigated cost-effectively with conventional technology. (Author)

Distribution of Basement Membrane Molecules, Laminin and Collagen Type IV, in Normal and Degenerated Cartilage Tissues.

Science.gov (United States)

Foldager, Casper Bindzus; Toh, Wei Seong; Gomoll, Andreas H; Olsen, Bjørn Reino; Spector, Myron

2014-04-01

The objective of the present study was to investigate the presence and distribution of 2 basement membrane (BM) molecules, laminin and collagen type IV, in healthy and degenerative cartilage tissues. Normal and degenerated tissues were obtained from goats and humans, including articular knee cartilage, the intervertebral disc, and meniscus. Normal tissue was also obtained from patella-tibial enthesis in goats. Immunohistochemical analysis was performed using anti-laminin and anti-collagen type IV antibodies. Human and goat skin were used as positive controls. The percentage of cells displaying the pericellular presence of the protein was graded semiquantitatively. When present, laminin and collagen type IV were exclusively found in the pericellular matrix, and in a discrete layer on the articulating surface of normal articular cartilage. In normal articular (hyaline) cartilage in the human and goat, the proteins were found co-localized pericellularly. In contrast, in human osteoarthritic articular cartilage, collagen type IV but not laminin was found in the pericellular region. Nonpathological fibrocartilaginous tissues from the goat, including the menisci and the enthesis, were also positive for both laminin and collagen type IV pericellularly. In degenerated fibrocartilage, including intervertebral disc, as in degenerated hyaline cartilage only collagen type IV was found pericellularly around chondrocytes but with less intense staining than in non-degenerated tissue. In calcified cartilage, some cells were positive for laminin but not type IV collagen. We report differences in expression of the BM molecules, laminin and collagen type IV, in normal and degenerative cartilaginous tissues from adult humans and goats. In degenerative tissues laminin is depleted from the pericellular matrix before collagen type IV. The findings may inform future studies of the processes underlying cartilage degeneration and the functional roles of these 2 extracellular matrix proteins

Distribution of Basement Membrane Molecules, Laminin and Collagen Type IV, in Normal and Degenerated Cartilage Tissues

Science.gov (United States)

Toh, Wei Seong; Gomoll, Andreas H.; Olsen, Bjørn Reino; Spector, Myron

2014-01-01

Objective: The objective of the present study was to investigate the presence and distribution of 2 basement membrane (BM) molecules, laminin and collagen type IV, in healthy and degenerative cartilage tissues. Design: Normal and degenerated tissues were obtained from goats and humans, including articular knee cartilage, the intervertebral disc, and meniscus. Normal tissue was also obtained from patella-tibial enthesis in goats. Immunohistochemical analysis was performed using anti-laminin and anti–collagen type IV antibodies. Human and goat skin were used as positive controls. The percentage of cells displaying the pericellular presence of the protein was graded semiquantitatively. Results: When present, laminin and collagen type IV were exclusively found in the pericellular matrix, and in a discrete layer on the articulating surface of normal articular cartilage. In normal articular (hyaline) cartilage in the human and goat, the proteins were found co-localized pericellularly. In contrast, in human osteoarthritic articular cartilage, collagen type IV but not laminin was found in the pericellular region. Nonpathological fibrocartilaginous tissues from the goat, including the menisci and the enthesis, were also positive for both laminin and collagen type IV pericellularly. In degenerated fibrocartilage, including intervertebral disc, as in degenerated hyaline cartilage only collagen type IV was found pericellularly around chondrocytes but with less intense staining than in non-degenerated tissue. In calcified cartilage, some cells were positive for laminin but not type IV collagen. Conclusions: We report differences in expression of the BM molecules, laminin and collagen type IV, in normal and degenerative cartilaginous tissues from adult humans and goats. In degenerative tissues laminin is depleted from the pericellular matrix before collagen type IV. The findings may inform future studies of the processes underlying cartilage degeneration and the functional

Basement membrane reconstruction in human skin equivalents is regulated by fibroblasts and/or exogenously activated keratinocytes.

Science.gov (United States)

El Ghalbzouri, Abdoelwaheb; Jonkman, Marcel F; Dijkman, Remco; Ponec, Maria

2005-01-01

This study was undertaken to examine the role fibroblasts play in the formation of the basement membrane (BM) in human skin equivalents. For this purpose, keratinocytes were seeded on top of fibroblast-free or fibroblast-populated collagen matrix or de-epidermized dermis and cultured in the absence of serum and exogenous growth factors. The expression of various BM components was analyzed on the protein and mRNA level. Irrespective of the presence or absence of fibroblasts, keratin 14, hemidesmosomal proteins plectin, BP230 and BP180, and integrins alpha1beta1, alpha2beta1, alpha3beta1, and alpha6beta4 were expressed but laminin 1 was absent. Only in the presence of fibroblasts or of various growth factors, laminin 5 and laminin 10/11, nidogen, uncein, type IV and type VII collagen were decorating the dermal/epidermal junction. These findings indicate that the attachment of basal keratinocytes to the dermal matrix is most likely mediated by integrins alpha1beta1 and alpha2beta1, and not by laminins that bind to integrin alpha6beta4 and that the epithelial-mesenchymal cross-talk plays an important role in synthesis and deposition of various BM components.

Age-related collagen turnover of the interstitial matrix and basement membrane: Implications of age- and sex-dependent remodeling of the extracellular matrix

DEFF Research Database (Denmark)

Kehlet, Stephanie N.; Willumsen, Nicholas; Armbrecht, Gabriele

2018-01-01

The extracellular matrix (ECM) plays a vital role in maintaining normal tissue function. Collagens are major components of the ECM and there is a tight equilibrium between degradation and formation of these proteins ensuring tissue health and homeostasis. As a consequence of tissue turnover, small...... collagen fragments are released into the circulation, which act as important biomarkers in the study of certain tissue-related remodeling factors in health and disease. The aim of this study was to establish an age-related collagen turnover profile of the main collagens of the interstitial matrix (type I...... an increased turnover. In summary, collagen turnover is affected by age and sex with the interstitial matrix and the basement membrane being differently regulated. The observed changes needs to be accounted for when measuring ECM related biomarkers in clinical studies....

Long-term outcome of anti-glomerular basement membrane antibody disease treated with immunoadsorption.

Science.gov (United States)

Biesenbach, Peter; Kain, Renate; Derfler, Kurt; Perkmann, Thomas; Soleiman, Afschin; Benharkou, Alexandra; Druml, Wilfred; Rees, Andrew; Säemann, Marcus D

2014-01-01

Anti-glomerular basement membrane (GBM) antibody disease may lead to acute crescentic glomerulonephritis with poor renal prognosis. Current therapy favours plasma exchange (PE) for removal of pathogenic antibodies. Immunoadsorption (IAS) is superior to PE regarding efficiency of antibody-removal and safety. Apart from anecdotal data, there is no systemic analysis of the long-term effects of IAS on anti-GBM-disease and antibody kinetics. To examine the long-term effect of high-frequency IAS combined with standard immunosuppression on patient and renal survival in patients with anti-GBM-disease and to quantify antibody removal and kinetics through IAS. Retrospective review of patients treated with IAS for anti-GBM-antibody disease confirmed by biopsy and/or anti-GBM-antibodies. University Hospital of Vienna, Austria. 10 patients with anti-GBM-disease treated with IAS. Patient and renal survival, renal histology, anti-GBM-antibodies. Anti-GBM-antibodies were reduced by the first 9 IAS treatments (mean number of 23) to negative levels in all patients. Renal survival was 40% at diagnosis, 70% after the end of IAS, 63% after one year and 50% at the end of observation (mean 84 months, range 9 to 186). Dialysis dependency was successfully reversed in three of six patients. Patient survival was 90% at the end of observation. IAS efficiently eliminates anti-GBM-antibodies suggesting non-inferiority to PE with regard to renal and patient survival. Hence IAS should be considered as a valuable treatment option for anti-GBM-disease, especially in patients presenting with a high percentage of crescents and dialysis dependency due to an unusual high proportion of responders.

Long-term outcome of anti-glomerular basement membrane antibody disease treated with immunoadsorption.

Directory of Open Access Journals (Sweden)

Peter Biesenbach

Full Text Available Anti-glomerular basement membrane (GBM antibody disease may lead to acute crescentic glomerulonephritis with poor renal prognosis. Current therapy favours plasma exchange (PE for removal of pathogenic antibodies. Immunoadsorption (IAS is superior to PE regarding efficiency of antibody-removal and safety. Apart from anecdotal data, there is no systemic analysis of the long-term effects of IAS on anti-GBM-disease and antibody kinetics.To examine the long-term effect of high-frequency IAS combined with standard immunosuppression on patient and renal survival in patients with anti-GBM-disease and to quantify antibody removal and kinetics through IAS.Retrospective review of patients treated with IAS for anti-GBM-antibody disease confirmed by biopsy and/or anti-GBM-antibodies.University Hospital of Vienna, Austria.10 patients with anti-GBM-disease treated with IAS.Patient and renal survival, renal histology, anti-GBM-antibodies.Anti-GBM-antibodies were reduced by the first 9 IAS treatments (mean number of 23 to negative levels in all patients. Renal survival was 40% at diagnosis, 70% after the end of IAS, 63% after one year and 50% at the end of observation (mean 84 months, range 9 to 186. Dialysis dependency was successfully reversed in three of six patients. Patient survival was 90% at the end of observation.IAS efficiently eliminates anti-GBM-antibodies suggesting non-inferiority to PE with regard to renal and patient survival. Hence IAS should be considered as a valuable treatment option for anti-GBM-disease, especially in patients presenting with a high percentage of crescents and dialysis dependency due to an unusual high proportion of responders.

Viruses in the Oceanic Basement.

Science.gov (United States)

Nigro, Olivia D; Jungbluth, Sean P; Lin, Huei-Ting; Hsieh, Chih-Chiang; Miranda, Jaclyn A; Schvarcz, Christopher R; Rappé, Michael S; Steward, Grieg F

2017-03-07

Microbial life has been detected well into the igneous crust of the seafloor (i.e., the oceanic basement), but there have been no reports confirming the presence of viruses in this habitat. To detect and characterize an ocean basement virome, geothermally heated fluid samples (ca. 60 to 65°C) were collected from 117 to 292 m deep into the ocean basement using seafloor observatories installed in two boreholes (Integrated Ocean Drilling Program [IODP] U1362A and U1362B) drilled in the eastern sediment-covered flank of the Juan de Fuca Ridge. Concentrations of virus-like particles in the fluid samples were on the order of 0.2 × 10 5 to 2 × 10 5  ml -1 ( n = 8), higher than prokaryote-like cells in the same samples by a factor of 9 on average (range, 1.5 to 27). Electron microscopy revealed diverse viral morphotypes similar to those of viruses known to infect bacteria and thermophilic archaea. An analysis of virus-like sequences in basement microbial metagenomes suggests that those from archaeon-infecting viruses were the most common (63 to 80%). Complete genomes of a putative archaeon-infecting virus and a prophage within an archaeal scaffold were identified among the assembled sequences, and sequence analysis suggests that they represent lineages divergent from known thermophilic viruses. Of the clustered regularly interspaced short palindromic repeat (CRISPR)-containing scaffolds in the metagenomes for which a taxonomy could be inferred (163 out of 737), 51 to 55% appeared to be archaeal and 45 to 49% appeared to be bacterial. These results imply that the warmed, highly altered fluids in deeply buried ocean basement harbor a distinct assemblage of novel viruses, including many that infect archaea, and that these viruses are active participants in the ecology of the basement microbiome. IMPORTANCE The hydrothermally active ocean basement is voluminous and likely provided conditions critical to the origins of life, but the microbiology of this vast habitat is not

Magnetotelluric inversion for depth-to-basement estimation

DEFF Research Database (Denmark)

Cai, Hongzhu; Zhdanov, Michael

2015-01-01

The magnetotelluric (MT) method can be effectively applied for depth-to-basement estimation, because there exists a strong contrast in resistivity between a conductive sedimentary basin and a resistive crystalline basement. Conventional inversions of MT data are usually aimed at determining...... the volumetric distribution of the conductivity within the inversion domain. By the nature of the MT method, the recovered distribution of the subsurface conductivity is typically diffusive, which makes it difficult to select the sediment-basement interface. This paper develops a novel approach to 3D MT...... inversion for the depth-to-basement estimate. The key to this approach is selection of the model parameterization with the depth to basement being the major unknown parameter. In order to estimate the depth to the basement, the inversion algorithm recovers both the thickness and the conductivities...

Permeation of macromolecules into the renal glomerular basement membrane and capture by the tubules

Science.gov (United States)

Lawrence, Marlon G.; Altenburg, Michael K.; Sanford, Ryan; Willett, Julian D.; Bleasdale, Benjamin; Ballou, Byron; Wilder, Jennifer; Li, Feng; Miner, Jeffrey H.; Berg, Ulla B.; Smithies, Oliver

2017-01-01

How the kidney prevents urinary excretion of plasma proteins continues to be debated. Here, using unfixed whole-mount mouse kidneys, we show that fluorescent-tagged proteins and neutral dextrans permeate into the glomerular basement membrane (GBM), in general agreement with Ogston's 1958 equation describing how permeation into gels is related to molecular size. Electron-microscopic analyses of kidneys fixed seconds to hours after injecting gold-tagged albumin, negatively charged gold nanoparticles, and stable oligoclusters of gold nanoparticles show that permeation into the lamina densa of the GBM is size-sensitive. Nanoparticles comparable in size with IgG dimers do not permeate into it. IgG monomer-sized particles permeate to some extent. Albumin-sized particles permeate extensively into the lamina densa. Particles traversing the lamina densa tend to accumulate upstream of the podocyte glycocalyx that spans the slit, but none are observed upstream of the slit diaphragm. At low concentrations, ovalbumin-sized nanoparticles reach the primary filtrate, are captured by proximal tubule cells, and are endocytosed. At higher concentrations, tubular capture is saturated, and they reach the urine. In mouse models of Pierson’s or Alport’s proteinuric syndromes resulting from defects in GBM structural proteins (laminin β2 or collagen α3 IV), the GBM is irregularly swollen, the lamina densa is absent, and permeation is increased. Our observations indicate that size-dependent permeation into the lamina densa of the GBM and the podocyte glycocalyx, together with saturable tubular capture, determines which macromolecules reach the urine without the need to invoke direct size selection by the slit diaphragm. PMID:28246329

Crosslinked basement membrane-based coatings enhance glucose sensor function and continuous glucose monitoring in vivo.

Science.gov (United States)

Klueh, Ulrike; Ludzinska, Izabela; Czajkowski, Caroline; Qiao, Yi; Kreutzer, Donald L

2018-01-01

Overcoming sensor-induced tissue reactions is an essential element of achieving successful continuous glucose monitoring (CGM) in the management of diabetes, particularly when used in closed loop technology. Recently, we demonstrated that basement membrane (BM)-based glucose sensor coatings significantly reduced tissue reactions at sites of device implantation. However, the biocompatible BM-based biohydrogel sensor coating rapidly degraded over a less than a 3-week period, which effectively eliminated the protective sensor coating. In an effort to increase the stability and effectiveness of the BM coating, we evaluated the impact of crosslinking BM utilizing glutaraldehyde as a crosslinking agent, designated as X-Cultrex. Sensor performance (nonrecalibrated) was evaluated for the impact of these X-Cultrex coatings in vitro and in vivo. Sensor performance was assessed over a 28-day time period in a murine CGM model and expressed as mean absolute relative difference (MARD) values. Tissue reactivity of Cultrex-coated, X-Cultrex-coated, and uncoated glucose sensors was evaluated over a 28-day time period in vivo using standard histological techniques. These studies demonstrated that X-Cultrex-based sensor coatings had no effect on glucose sensor function in vitro. In vivo, glucose sensor performance was significantly enhanced following X-Cultrex coating throughout the 28-day study. Histological evaluations of X-Cultrex-treated sensors demonstrated significantly less tissue reactivity when compared to uncoated sensors. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 7-16, 2018. © 2017 Wiley Periodicals, Inc.

A large-sized bubbling appearance of the glomerular basement membrane in a patient with pulmonary limited AL amyloidosis and a past history of lupus nephritis.

Science.gov (United States)

Suga, Norihiro; Miura, Naoto; Uemura, Yuko; Nakamura, Toshinobu; Morita, Hiroyuki; Banno, Shogo; Imai, Hirokazu

2011-12-01

We report an unusual pathological finding, a large-sized bubbling appearance of the glomerular basement membrane (GBM), in a patient with pulmonary limited AL amyloidosis and a past history of lupus nephritis. The first renal biopsy specimen from 10 years ago, when systemic lupus erythematosus was diagnosed, demonstrated mild mesangial proliferation and subepithelial deposits (WHO classification: III + V). Light microscopy of the current biopsy using periodic acid methenamine silver (PAMS) stain demonstrated a large-sized bubbling appearance of the GBM; however, very weak immunoglobulin and complement deposition was observed in immunofluorescence studies. Routine electron microscopy demonstrated partial subendothelial expansion with electron-lucent materials, but no electron-dense deposits or amyloid fibrils. Electron microscopy with PAMS stain revealed electron-lucent endothelial scalloping, including some cellular components and microspheres in the GBM; however, it is not clear if these materials are derived from endothelial cells. One possibility is that these unique findings represent a recovery phase of lupus membranous nephritis; another is that these findings correspond to a new disease entity.

Modulation of interferon-induced genes by lipoxin analogue in anti-glomerular basement membrane nephritis.

Science.gov (United States)

Ohse, Takamoto; Ota, Tatsuru; Kieran, Niamh; Godson, Catherine; Yamada, Koei; Tanaka, Tetsuhiro; Fujita, Toshiro; Nangaku, Masaomi

2004-04-01

Immune complex deposition is associated with the accumulation of neutrophils, which play an important role in the various immune-mediated diseases. A novel anti-inflammatory agent, the lipoxin A (LXA) analogue (15-epi-16-(FPhO)-LXA-Me)), a stable synthetic analogue of aspirin-triggered 15-epi-lipoxin A4 (ATLa), was used in experimental anti-glomerular basement membrane (GBM) antibody nephritis in mice. ATLa was administered before the induction of the disease, and 2 h later, the animals were killed. ATLa reduced the infiltrating neutrophils and nitrotyrosine staining in glomeruli. Subsequent changes of gene expression in the early phase were evaluated, and 5674 genes were present under the basal conditions in kidneys from normal mice; 54 upregulated genes and 25 downregulated genes were detected in anti-GBM nephritis. Eighteen of these upregulated genes were those induced by IFN-gamma. Real-time quantitative PCR analysis confirmed the results of the microarrays. To investigate a role of IFN-gamma in neutrophil infiltration, anti-GBM nephritis was induced in IFN-gamma knockout mice. The number of infiltrating neutrophils in these mice did not differ from those in wild-type mice. Also examined were CD11b expression on neutrophils from mice treated with ATLa by flow cytometry, but suppression of this adhesion molecule was not observed. Neutrophil infiltration was successfully inhibited by ATLa in the early phase of murine anti-GBM nephritis. Microarray analysis detected the change of mRNA expression in anti-GBM nephritis and demonstrated amelioration of various genes by ATLa, which may provide a clue to the development of novel therapeutic approaches in immune renal injury.

Viruses in the Oceanic Basement

Directory of Open Access Journals (Sweden)

Olivia D. Nigro

2017-03-01

Full Text Available Microbial life has been detected well into the igneous crust of the seafloor (i.e., the oceanic basement, but there have been no reports confirming the presence of viruses in this habitat. To detect and characterize an ocean basement virome, geothermally heated fluid samples (ca. 60 to 65°C were collected from 117 to 292 m deep into the ocean basement using seafloor observatories installed in two boreholes (Integrated Ocean Drilling Program [IODP] U1362A and U1362B drilled in the eastern sediment-covered flank of the Juan de Fuca Ridge. Concentrations of virus-like particles in the fluid samples were on the order of 0.2 × 105 to 2 × 105 ml−1 (n = 8, higher than prokaryote-like cells in the same samples by a factor of 9 on average (range, 1.5 to 27. Electron microscopy revealed diverse viral morphotypes similar to those of viruses known to infect bacteria and thermophilic archaea. An analysis of virus-like sequences in basement microbial metagenomes suggests that those from archaeon-infecting viruses were the most common (63 to 80%. Complete genomes of a putative archaeon-infecting virus and a prophage within an archaeal scaffold were identified among the assembled sequences, and sequence analysis suggests that they represent lineages divergent from known thermophilic viruses. Of the clustered regularly interspaced short palindromic repeat (CRISPR-containing scaffolds in the metagenomes for which a taxonomy could be inferred (163 out of 737, 51 to 55% appeared to be archaeal and 45 to 49% appeared to be bacterial. These results imply that the warmed, highly altered fluids in deeply buried ocean basement harbor a distinct assemblage of novel viruses, including many that infect archaea, and that these viruses are active participants in the ecology of the basement microbiome.

H-ras oncogene-transformed human bronchial epithelial cells (TBE-1) secrete a single metalloprotease capable of degrading basement membrane collagen

International Nuclear Information System (INIS)

Collier, I.E.; Wilhelm, S.M.; Eisen, A.Z.

1988-01-01

H-ras transformed human bronchial epithelial cells (TBE-1) secrete a single major extracellular matrix metalloprotease which is not found in the normal parental cells. The enzyme is secreted in a latent form which can be activated to catalyze the cleavage of the basement membrane macromolecule type IV collagen. The substrates in their order of preference are: gelatin, type IV collagen, type V collagen, fibronectin, and type VII collagen; but the enzyme does not cleave the interstitial collagens or laminin. This protease is identical to gelatinase isolated from normal human skin explants, normal human skin fibroblasts, and SV40-transformed human lung fibroblasts. Based on this ability to initiate the degradation of type IV collagen in a pepsin-resistant portion of the molecule, it will be referred to as type IV collagenase. This enzyme is most likely the human analog of type IV collagenase detected in several rodent tumors. Type IV collagenase consists of three domains. Type IV collagenase represents the third member of a newly recognized gene family coding for secreted extracellular matrix metalloproteases, which includes interstitial fibroblast collagenase and stromelysin

A Case of Fibrillary Glomerulonephritis Associated with Thrombotic Microangiopathy and Anti-Glomerular Basement Membrane Antibody

Directory of Open Access Journals (Sweden)

Akishi Momose

2015-02-01

Full Text Available We present the first report of a case of fibrillary glomerulonephritis (FGN associated with thrombotic microangiopathy (TMA and anti-glomerular basement membrane antibody (anti-GBM antibody. A 54-year-old man was admitted to our hospital for high fever and anuria. On the first hospital day, we initiated hemodialysis for renal dysfunction. Laboratory data revealed normocytic-normochromic anemia with schistocytes in the peripheral smear, thrombocytopenia, increased serum lactate dehydrogenase, decreased serum haptoglobin, and negative results for both direct and indirect Coombs tests. Based on these results, we diagnosed TMA. Assays conducted several days later indicated a disintegrin-like and metalloprotease with a thrombospondin motif 13 (ADAMTS13 activity of 31.6%, and ADAMTS13 inhibitors were negative. We started plasma exchange using fresh frozen plasma and steroid pulse therapy. Anti-GBM antibody was found to be positive. Renal biopsy showed FGN. Blood pressure rose on the 46th hospital day, and mild convulsions developed. Based on magnetic resonance imaging of the head, the patient was diagnosed with reversible posterior leukoencephalopathy syndrome. Hypertension persisted despite administration of multiple antihypertensive agents, and the patient experienced a sudden generalized seizure. Computed tomography of the head showed multiple cerebral hemorrhages. However, his blood pressure subsequently decreased and the platelet count increased. TMA remitted following 36 plasma exchange sessions, but renal function was not restored, and maintenance hemodialysis was continued. The patient was discharged on the 119th day of hospitalization. In conclusion, it was shown that TMA, FGN and anti-GBM antibody were closely related.

Expression of matrix metalloproteinase genes during basement membrane degradation in the metamorphosis of Bombyx mori.

Science.gov (United States)

Kawasaki, Hideki; Manickam, Asaithambi; Shahin, Rima; Ote, Manabu; Iwanaga, Masashi

2018-01-05

The present study was conducted to clarify the involvement of the basement membrane (BM) in insect metamorphosis through analysis of the expression profile of two types of metalloproteinase (MMP and ADAMTS) genes in several organs, their ecdysone involvement, and the histological change of BM. BM was observed around wing sac and in the wing cavity and around fat bodies at the W0 stage but disappeared after the W3 stage, and wing discs evaginated and fat body cells scattered after the W3 stage. The disappearance of the BM of midgut and silk glands was not observed after the W3 stage, but degenerated epithelium cells in the midgut and shrunken cells in the silk gland were observed after the W3 stage. BmMMP1 showed a peak at P0 in the wing discs, fat bodies, midgut, and silk gland. BmMMP2 showed a broad peak around pupation in the wing discs, fat bodies, midgut, and silk gland. BmADAMTS-1 showed enhanced expression at W2 in the wing discs, fat bodies, midgut, and hemocyte, while BmADAMTS-L showed enhanced expression at W3 in the fat bodies, midgut, silk gland, and hemocyte. After pupation, they showed a different expression in different organs. All of four genes were induced by 20-hydroxyecdysone in wing discs in vitro. The present results suggested the involvement of MMPs and ADAMTS in the BM digestion and the morphogenesis of organs during Bombyx metamorphosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Determination of the factors that control migration and entry of radon into basements

International Nuclear Information System (INIS)

Borak, T.B.; Gadd, M.S.; Ward, D.C.; Barry, M.S.

1992-01-01

'Full Text:' Elevated concentrations of radon gas indoors are the result or a complicated combination of factors. This report describes results from a facility designed to test and verify theories of radon migration into underground structures. The buildings resemble miniature basements using conventional construction methods, hut eliminate other confounding factors introduced by the activities of occupants. Sensors accumulate data on soil properties such as temperature, moisture, pressure differentials, and permeability, as well as outdoor meteorological conditions and indoor environment. Results indicate that indoor radon concentrations do not correlate with changes in the adjacent soil gas concentration or the rate that radon enters the structure. When no attempt is made to control the indoor environment, periods of highest indoor concentration occur when the rate of entry is low. Methods to identify the driving mechanisms and implication for mitigation and control will he described. (author)

Hydrogeologic controls on induced seismicity in crystalline basement rocks due to fluid injection into basal reservoirs.

Science.gov (United States)

Zhang, Yipeng; Person, Mark; Rupp, John; Ellett, Kevin; Celia, Michael A; Gable, Carl W; Bowen, Brenda; Evans, James; Bandilla, Karl; Mozley, Peter; Dewers, Thomas; Elliot, Thomas

2013-01-01

A series of Mb 3.8-5.5 induced seismic events in the midcontinent region, United States, resulted from injection of fluid either into a basal sedimentary reservoir with no underlying confining unit or directly into the underlying crystalline basement complex. The earthquakes probably occurred along faults that were likely critically stressed within the crystalline basement. These faults were located at a considerable distance (up to 10 km) from the injection wells and head increases at the hypocenters were likely relatively small (∼70-150 m). We present a suite of simulations that use a simple hydrogeologic-geomechanical model to assess what hydrogeologic conditions promote or deter induced seismic events within the crystalline basement across the midcontinent. The presence of a confining unit beneath the injection reservoir horizon had the single largest effect in preventing induced seismicity within the underlying crystalline basement. For a crystalline basement having a permeability of 2 × 10(-17)  m(2) and specific storage coefficient of 10(-7) /m, injection at a rate of 5455 m(3) /d into the basal aquifer with no underlying basal seal over 10 years resulted in probable brittle failure to depths of about 0.6 km below the injection reservoir. Including a permeable (kz  = 10(-13)  m(2) ) Precambrian normal fault, located 20 m from the injection well, increased the depth of the failure region below the reservoir to 3 km. For a large permeability contrast between a Precambrian thrust fault (10(-12)  m(2) ) and the surrounding crystalline basement (10(-18)  m(2) ), the failure region can extend laterally 10 km away from the injection well. © 2013, National Ground Water Association.

A “Mini-Epidemic” of anti-glomerular basement membrane disease: Clinical and epidemiological study

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Umesh Lingaraj

2017-01-01

Full Text Available Acute glomerulonephritis due to anti-glomerular basement membrane (anti-GBM antibody disease is rare, estimated to occur in fewer than one case per million population and accounts for less than 20% of rapidly progressive glomerulonephritis. The prevalence among patients evaluated for potential glomerular disease is lower. It accounts for fewer than 3% of all kidney biopsies done with crescentic glomerulonephritis. Cases of anti-GBM disease occurring in a cluster have rarely been reported. All biopsy proven anti-GBM disease cases were collected from January 2015 to March 2015 at our Institute. All cases were analyzed for demographic and clinical profile, pathological findings, treatment received and for any common environmental antigenic source. A total of 11 new biopsy proven anti-GBM cases were seen within a span of three months. Age group varied from 17–80 years. Seven were males and four were females. All were dialysis dependent at presentation. Seven had active cellular crescents, and four had fibrocellular. Only one patient was a smoker and none had a history of exposure to any forms of hydrocarbons. The peak seen from January 2015 to March 2015 does not correlate with any of seasonal occurrence of infections in southern India. Although there was clustering of cases to southern territories of Karnataka state, no common etiological agents could be identified. No patient had any previous urological surgeries. All patients received methylprednisolone with plasmapheresis 5–7 sessions and cyclophosphamide. All 11 patients were dialysis dependent at the end of three months. We conclude anti-GBM disease cannot be regarded as a rare cause of renal failure and lung hemorrhage. The occurrence of such epidemic within a short period suggests a possible unidentified environmental factor like infection or occupational agents as inciting agents. Identification of such inciting agents could help us in instituting appropriate preventing measures.

Potential Development of Hydrocarbon in Basement Reservoirs In Indonesia

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D. Sunarjanto

2014-07-01

Full Text Available DOI: 10.17014/ijog.v8i3.165Basement rocks, in particular igneous and metamorphic rocks are known to have porosity and permeability which should not be ignored. Primary porosity of basement rocks occurs as the result of rock formation. The porosity increases by the presence of cracks occurring as the result of tectonic processes (secondary porosity. Various efforts have been carried out to explore hydrocarbon in basement rocks. Some oil and gas fields proved that the basement rocks are as reservoirs which so far have provided oil and gas in significant amount. A review using previous research data, new data, and observation of igneous rocks in some fields has been done to see the development of exploration and basement reservoirs in Indonesia. A review on terminology of basement rock up till the identification of oil and gas exploration in basement rocks need to be based on the latest technology. An environmental approach is suggested to be applied as an alternative in analyzing the policy on oil and gas exploration development, especially in basement reservoirs.

Ultrastructural immunocytochemical localization of chondroitin sulfate proteoglycan in Bruch's membrane of the rat

DEFF Research Database (Denmark)

Lin, W L; Essner, E; McCarthy, K J

1992-01-01

Two monoclonal antibodies (Mab 4D5 and 2D6) raised against the core protein of a basement membrane chondroitin sulfate proteoglycan from Reichert's membrane of the rat, were used for ultrastructural immunoperoxidase localization of this protein in Bruch's membrane of the rat. Immunoreactivity...

Structural control of the basement in the central portion of the Santos Basin-Brazil; Controle estrutural do embasamento na porcao central da Bacia de Santos

Energy Technology Data Exchange (ETDEWEB)

Izeli, Maira G.B.; Morales, Norberto; Souza, Iata A. de [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil). Inst. de Geociencias e Ciencias Exatas

2008-07-01

New discoveries of oil in deep water and ultra-deep water in Santos Basin suggest that it needs to be studied to better understanding of basement structures and their role in the basin control and configuration. This study characterizes the main tectonic structures of a portion at the central area of this basin, looking for their relation to the geological basement framework. The study is based on the integration of the geological and geophysical data from subsurface (offshore) and surface of the adjacent continent. These analyses include the continental structures that continue in direction of this basin (Guapiara Lineament and Ponta Grossa Arc), checking their possible influence on the basin evolution and deformation. To achieve the proposed goals, the Precambrian basement lineaments were extracted from the offshore area using remote sensing, as result was obtained strong NW-SE structural trend. According to the interpretation of seismic sections, it is possible to observe that this portion of the basin presents main NE-SW structural trend, and most of the structures are typical of passive margin and halokintics process. It is possible to see that some recognized faults in the rift deposits may be coinciding with the main continental guidelines which are projected into the basin. (author)

Characteristics of the crystalline basement beneath the Ordos Basin: Constraint from aeromagnetic data

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Zhentao Wang

2015-05-01

Full Text Available Aeromagnetic anomaly zonation of the Ordos Basin and adjacent areas was obtained by processing high-precision and large-scale aeromagnetic anomalies with an approach of reduction to the pole upward continuation. Comparative study on aeromagnetic and seismic tomography suggests that aeromagnetic anomalies in this area are influenced by both the magnetic property of the rock and the burial depth of the Precambrian crystalline basement. Basement depth might be the fundamental control factor for aeromagnetic anomalies because the positive and negative anomalies on the reduction to the pole-upward-continuation anomaly maps roughly coincide with the uplifts and depressions of the crystalline basement in the basin. The results, together with the latest understanding of basement faults, SHRIMP U-Pb zircon dating of metamorphic rock and granite, drilling data, detrital zircon ages, and gravity data interpretation, suggest that the Ordos block is not an entirety of Archean.

Skin Basement Membrane: The Foundation of Epidermal Integrity—BM Functions and Diverse Roles of Bridging Molecules Nidogen and Perlecan

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Dirk Breitkreutz

2013-01-01

Full Text Available The epidermis functions in skin as first defense line or barrier against environmental impacts, resting on extracellular matrix (ECM of the dermis underneath. Both compartments are connected by the basement membrane (BM, composed of a set of distinct glycoproteins and proteoglycans. Herein we are reviewing molecular aspects of BM structure, composition, and function regarding not only (i the dermoepidermal interface but also (ii the resident microvasculature, primarily focusing on the per se nonscaffold forming components perlecan and nidogen-1 and nidogen-2. Depletion or functional deficiencies of any BM component are lethal at some stage of development or around birth, though BM defects vary between organs and tissues. Lethality problems were overcome by developmental stage- and skin-specific gene targeting or by cell grafting and organotypic (3D cocultures of normal or defective cells, which allows recapitulating BM formation de novo. Thus, evidence is accumulating that BM assembly and turnover rely on mechanical properties and composition of the adjacent ECM and the dynamics of molecular assembly, including further “minor” local components, nidogens largely functioning as catalysts or molecular adaptors and perlecan as bridging stabilizer. Collectively, orchestration of BM assembly, remodeling, and the role of individual players herein are determined by the developmental, tissue-specific, or functional context.

Ten cases of severe oral lichen planus showing granular C3 deposition in oral mucosal basement membrane zone.

Science.gov (United States)

Hashimoto, Takashi; Fukuda, Aoi; Himejima, Akio; Morita, Shosuke; Tsuruta, Daisuke; Koga, Hiroshi; Krol, Rafal P; Ishii, Norito

2015-01-01

Oral lichen planus (OLP) may show depositions of immunoglobulins and complement components in oral mucosal basement membrane zone (BMZ) in direct immunofluorescence, although these finding are not frequently seen. We collected and examined ten cases of severe OLP showing granular C3 deposition in BMZ. In addition to clinical, histopathological and direct immunofluorescence assessments, we performed various immune-serological tests, including indirect immunofluorescence of normal human skin and 1M NaCl-split skin, immunoblotting of normal human epidermal and dermal extracts, recombinant proteins of BP180 NC16a and C-terminal domains, concentrated culture supernatant of HaCaT cells and purified human laminin-332, and enzyme-linked immunosorbent assays for BP230 and BP180. Direct immunofluorescence showed C3 deposition in BMZ exclusively of granular pattern in 7 cases and of both granular and linear patterns in 3 cases. The 10 cases showed no positive reactivity for either IgG or IgA antibodies in any immuno-serological tests. Detailed analyses of clinical, histopathological and immunological findings revealed striking female prevalence, although other parameters were in general characteristic of OLP. Granular C3 deposition in oral BMZ may be one of the characteristic features of severe OLP, although mechanisms for C3 deposition and its pathogenic role in OLP are currently unknown.

Contribution To The Geology Of Basement Rocks In The South Western Desert Of Egypt

International Nuclear Information System (INIS)

Sadek, M.F.; Khyamy, A.A.

2003-01-01

Three major Precambrian basement inliers are exposed in the South Western Desert of Egypt between Long. 29 degree E and the River Nile within the Uweinat-Bir Safsaf-Aswan E-W uplift system. These are Bir Safsaf, Gabal EI-Asr and Gabal Umm Shaghir areas. Smaller outcrops include Gabal EI-Gara El-Hamra and Gabal El-Gara EI-Soda, Gabal Siri, GabaI EI-Fantas and Aswan-Kalabsha area as well as the scattered outcrops around Darb El-Arbain road. Band ratios 5/7, 5/1, 4 of Landsat TM images were applied to delineate the borders, the lithologic units and structural features of low relief basement outcrops within the surrounding flat lying sedimentary rocks and sand plains. These basement rocks comprise ortho gneisses (assumed by many authors as related to old continent pre Pan-African rocks), G 1 tonalite-granodiorite, and G2 monzogranite-alkali feldspar granite intruded by variable dykes. The boundaries between the basement exposures and the sedimentary rocks are marked by nonconformity surfaces or sets of faults. Both basement and sedimentary rocks are intruded by Mesozoic syenite-G3 granites, rhyolite, trachytic plugs and Upper Cretaceous to Tertiary basalts. The basement exposures are structurally controlled by major E- W fault systems. Their vertical uplifting is overprinted by folding the overlying sedimentary rocks. This study revealed that, the different basement exposures in the SE of the Western Desert of Egypt are similar in appearance and field relations to the Pan-African basement rocks extending towards the east of the River Nile and exposed everywhere in the Eastern Desert of Egypt

Membranous nephropathy (bubbling appearance and spike formation) without immunoglobulin deposition in a patient with systemic lupus erythematosus.

Science.gov (United States)

Miura, Naoto; Mori, Yuki; Yoshino, Masabumi; Suga, Norihiro; Kitagawa, Wataru; Yamada, Harutaka; Nishikawa, Kazuhiro; Imai, Hirokazu

2008-12-01

A 53-year-old Japanese man with systemic lupus erythematosus developed proteinuria and hematuria after a urinary stone episode. A light microscopic study of a kidney biopsy specimen demonstrated a bubbling appearance and spike formation of the basement membrane. Immunofluorescent studies revealed that there were no significant depositions of immunoglobulins, such as IgG (-), IgA (-), IgM (+/-), kappa light chain (+/-), lambda light chain (+/-), or C3 (-) in the glomerular capillary wall, though C1q was present as one-plus positive staining in mesangial areas. Electron microscopic studies showed that the thickness of the basement membrane varied from thin to thick without electron dense deposits, and that the cellular components of the podocyte were irregularly present in the basement membrane. Urinary protein decreased after the usage of prednisolone and mizoribine; however, proteinuria aggravated after an episode of urinary stone during the same treatment.

Air exchange rates and migration of VOCs in basements and residences.

Science.gov (United States)

Du, L; Batterman, S; Godwin, C; Rowe, Z; Chin, J-Y

2015-12-01

Basements can influence indoor air quality by affecting air exchange rates (AERs) and by the presence of emission sources of volatile organic compounds (VOCs) and other pollutants. We characterized VOC levels, AERs, and interzonal flows between basements and occupied spaces in 74 residences in Detroit, Michigan. Flows were measured using a steady-state multitracer system, and 7-day VOC measurements were collected using passive samplers in both living areas and basements. A walk-through survey/inspection was conducted in each residence. AERs in residences and basements averaged 0.51 and 1.52/h, respectively, and had strong and opposite seasonal trends, for example, AERs were highest in residences during the summer, and highest in basements during the winter. Airflows from basements to occupied spaces also varied seasonally. VOC concentration distributions were right-skewed, for example, 90th percentile benzene, toluene, naphthalene, and limonene concentrations were 4.0, 19.1, 20.3, and 51.0 μg/m(3), respectively; maximum concentrations were 54, 888, 1117, and 134 μg/m(3). Identified VOC sources in basements included solvents, household cleaners, air fresheners, smoking, and gasoline-powered equipment. The number and type of potential VOC sources found in basements are significant and problematic, and may warrant advisories regarding the storage and use of potentially strong VOCs sources in basements. Few IAQ studies have examined basements. A sizable volume of air can flow between the basement and living area, and AERs in these two zones can differ considerably. In many residences, the basement contains significant emission sources and contributes a large fraction of VOC concentrations found in the living area. Exposures can be lowered by removing VOC sources from the basement; other exposure management options, such as local ventilation or isolation, are unlikely to be practical. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A two-dimensional model of the colonic crypt accounting for the role of the basement membrane and pericryptal fibroblast sheath.

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Sara-Jane Dunn

Full Text Available The role of the basement membrane is vital in maintaining the integrity and structure of an epithelial layer, acting as both a mechanical support and forming the physical interface between epithelial cells and the surrounding connective tissue. The function of this membrane is explored here in the context of the epithelial monolayer that lines the colonic crypt, test-tube shaped invaginations that punctuate the lining of the intestine and coordinate a regular turnover of cells to replenish the epithelial layer every few days. To investigate the consequence of genetic mutations that perturb the system dynamics and can lead to colorectal cancer, it must be possible to track the emerging tissue level changes that arise in the crypt. To that end, a theoretical crypt model with a realistic, deformable geometry is required. A new discrete crypt model is presented, which focuses on the interaction between cell- and tissue-level behaviour, while incorporating key subcellular components. The model contains a novel description of the role of the surrounding tissue and musculature, based upon experimental observations of the tissue structure of the crypt, which are also reported. A two-dimensional (2D cross-sectional geometry is considered, and the shape of the crypt is allowed to evolve and deform. Simulation results reveal how the shape of the crypt may contribute mechanically to the asymmetric division events typically associated with the stem cells at the base. The model predicts that epithelial cell migration may arise due to feedback between cell loss at the crypt collar and density-dependent cell division, an hypothesis which can be investigated in a wet lab. This work forms the basis for investigation of the deformation of the crypt structure that can occur due to proliferation of cells exhibiting mutant phenotypes, experiments that would not be possible in vivo or in vitro.

[Morphology of basement membrane and associated matrix proteins in normal and pathological tissues].

Science.gov (United States)

Nerlich, A

1995-01-01

Basement membranes (BM) are specialized structures of the extracellular matrix. Their composition is of particular importance for the maintenance of normal morphological and functional properties of a multitude of organs and tissue systems and it is thus required for regular homeostasis of body function. Generally, they possess three main functions, i.e. participation in the maintenance of tissue structure, control of fluid and substrate exchange, and regulation of cell growth and differentiation. BMs are made up by various components which are in part specifically localized within the BM zone, or which represent ubiquitous matrix constituents with specific quantitative and/or qualitative differences in their localization. On the basis of a thorough immunohistochemical analysis of normal and diseased tissues, we provide here a concept of "functional morphology/pathomorphology" of the different BM components analyzed: 1.) The ubiquitous BM-constituent collagen IV primarily stabilizes the BM-zone and thus represents the "backbone" of the BM providing mechanical strength. Its loss leads to cystic tissue transformation as it is evidenced from the analysis of polycystic nephropathies. Thus, in other cystic tissue transformations a similar formal pathogenesis may be present. 2.) The specific localization of collagen VII as the main structural component of anchoring fibrils underlines the mechanical anchoring function of this collagenous protein. Defects in this protein lead to hereditary epidermolysis. The rapid re-occurrence of epidermal collagen VII during normal human wound healing indicates a quick reconstitution of the mechanical tensile strength of healing wounds. 3.) The BM-specific heparan sulfate proteoglycan (HSPG, Perlecan) with its highly negative anionic charge can be assumed to exert filter control. This assumption is corroborated by the localizatory findings of a preferential deposition of HSPG in endothelial and particularly in glomerular BM. Similarly

Basement structure of the United Arab Emirates derived from an analysis of regional gravity and aeromagnetic database

Science.gov (United States)

Ali, M. Y.; Fairhead, J. D.; Green, C. M.; Noufal, A.

2017-08-01

Gravity and aeromagnetic data covering the whole territory of the United Arab Emirates (UAE) have been used to evaluate both shallow and deep geological structures, in particular the depth to basement since it is not imaged by seismic data anywhere within the UAE. Thus, the aim has been to map the basement so that its structure can help to assess its control on the distribution of hydrocarbons within the UAE. Power spectrum analysis reveals gravity and magnetic signatures to have some similarities, in having two main density/susceptibility interfaces widely separated in depth such that regional-residual anomaly separation could effectively be undertaken. The upper density/susceptibility interface occurs at a depth of about 1.0 km while the deeper interface varies in depth throughout the UAE. For gravity, this deeper interface is assumed to be due to the combined effect of lateral changes in density structures within the sediments and in depth of basement while for magnetics it is assumed the sediments have negligible susceptibility and the anomalies unrelated to the volcanic/magmatic bodies result from only changes in depth to basement. The power spectrum analysis over the suspect volcanic/magmatic bodies indicates they occur at 5 km depth. The finite tilt-depth and finite local wavenumber methods were used to estimate depth to source and only depths that agree to within 10% of each other were used to generate the depth to basement map. This depth to basement map, to the west of the UAE-Oman Mountains, varies in depth from 5 km to in excess of 15 km depth and is able to structurally account for the location of the shear structures, seen in the residual magnetic data, and the location of the volcanic/magmatic centres relative to a set of elongate N-S to NE-SW trending basement highs. The majority of oilfields in the UAE are located within these basement highs. Therefore, the hydrocarbon distribution in the UAE basin appears to be controlled by the location of the

Frictional Behavior of Altered Basement Approaching the Nankai Trough

Science.gov (United States)

Saffer, D. M.; Ikari, M.; Rooney, T. O.; Marone, C.

2017-12-01

The frictional behavior of basement rocks plays an important role in subduction zone faulting and seismicity. This includes earthquakes seaward of the trench, large megathrust earthquakes where seamounts are subducting, or where the plate interface steps down to basement. In exhumed subduction zone rocks such as the Shimanto complex in Japan, slivers of basalt are entrained in mélange which is evidence of basement involvement in the fault system. Scientific drilling during the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) recovered basement rock from two reference sites (C0011 and C0012) located seaward of the trench offshore the Kii Peninsula during Integrated Ocean Discovery Program (IODP) Expeditions 322 and 333. The basement rocks are pillow basalts that appear to be heterogeneously altered, resulting in contrasting dense blue material and more vesicular gray material. Major element geochemistry shows differences in silica, calcium oxides and loss-on-ignition between the two types of samples. Minor element geochemistry reveals significant differences in vanadium, chromium, and barium. X-ray diffraction on a bulk sample powder representing an average composition shows a phyllosilicate content of 20%, most of which is expandable clays. We performed laboratory friction experiments in a biaxial testing apparatus as either intact sample blocks, or as gouge powders. We combine these experiments with measurements of Pennsylvania slate for comparison, including a mixed-lithology intact block experiment. Intact Nankai basement blocks exhibit a coefficient of sliding friction of 0.73; for Nankai basement powder, slate powder, slate blocks and slate-on-basement blocks the coefficient of sliding friction ranges from 0.44 to 0.57. At slip rates ranging from 3x10-8 to 3x10-4 m/s we observe predominantly velocity-strengthening frictional behavior, indicating a tendency for stable slip. At rates of < 1x10-6 m/s some velocity-weakening was observed, specifically in

Magnetic Basement Depth Inversion in the Space Domain

Science.gov (United States)

Nunes, Tiago Mane; Barbosa, Valéria Cristina F.; Silva, João Batista C.

2008-10-01

We present a total-field anomaly inversion method to determine both the basement relief and the magnetization direction (inclination and declination) of a 2D sedimentary basin presuming negligible sediment magnetization. Our method assumes that the magnetic intensity contrast is constant and known. We use a nonspectral approach based on approximating the vertical cross section of the sedimentary basin by a polygon, whose uppermost vertices are forced to coincide with the basin outcrop, which are presumably known. For fixed values of the x coordinates our method estimates the z coordinates of the unknown polygon vertices. To obtain the magnetization direction we assume that besides the total-field anomaly, information about the basement’s outcrops at the basin borders and the basement depths at a few points is available. To obtain stable depth-to-basement estimates we impose overall smoothness and positivity constraints on the parameter estimates. Tests on synthetic data showed that the simultaneous estimation of the irregular basement relief and the magnetization direction yields good estimates for the relief despite the mild instability in the magnetization direction. The inversion of aeromagnetic data from the onshore Almada Basin, Brazil, revealed a shallow, eastward-dipping basement basin.

Geoelectrical characterisation of basement aquifers: the case of Iberekodo, southwestern Nigeria

Science.gov (United States)

Aizebeokhai, Ahzegbobor P.; Oyeyemi, Kehinde D.

2018-03-01

Basement aquifers, which occur within the weathered and fractured zones of crystalline bedrocks, are important groundwater resources in tropical and subtropical regions. The development of basement aquifers is complex owing to their high spatial variability. Geophysical techniques are used to obtain information about the hydrologic characteristics of the weathered and fractured zones of the crystalline basement rocks, which relates to the occurrence of groundwater in the zones. The spatial distributions of these hydrologic characteristics are then used to map the spatial variability of the basement aquifers. Thus, knowledge of the spatial variability of basement aquifers is useful in siting wells and boreholes for optimal and perennial yield. Geoelectrical resistivity is one of the most widely used geophysical methods for assessing the spatial variability of the weathered and fractured zones in groundwater exploration efforts in basement complex terrains. The presented study focuses on combining vertical electrical sounding with two-dimensional (2D) geoelectrical resistivity imaging to characterise the weathered and fractured zones in a crystalline basement complex terrain in southwestern Nigeria. The basement aquifer was delineated, and the nature, extent and spatial variability of the delineated basement aquifer were assessed based on the spatial variability of the weathered and fractured zones. The study shows that a multiple-gradient array for 2D resistivity imaging is sensitive to vertical and near-surface stratigraphic features, which have hydrological implications. The integration of resistivity sounding with 2D geoelectrical resistivity imaging is efficient and enhances near-surface characterisation in basement complex terrain.

Geochemistry of the Puna Austral and Cordillera Oriental basement

International Nuclear Information System (INIS)

Becchio, Raul; Lucassen, Friedrich; Franz, Gerhard; Kasemann, Simone

1998-01-01

Major and trace elements, rare earths, and 143 Nd/ 147 Nd and, 147 Sm/ 144 Nd isotope ratios have been determined in the Puna Austral and Cordillera Oriental basement. The basement is formed by high temperature amphibolite facies rocks ranulites (750-550 degrees C) and green schists. They are represented by schists, paragneiss, orthogneiss, migmatites, few metabasites, marbles and chalcosilicatic banks. Hypotheses on the formation and evolution of the basement are presented

NATURAL BASEMENT VENTILATION AS A RADON MITIGATION TECHNIQUE

Science.gov (United States)

The report documents a study of natural basement ventilation in two research houses during both the summer cooling season and the winter heating season. NOTE: Natural basement ventilation has always been recommended as a way to reduce radon levels in houses. However, its efficacy...

Basement domain map of the conterminous United States and Alaska

Science.gov (United States)

Lund, Karen; Box, Stephen E.; Holm-Denoma, Christopher S.; San Juan, Carma A.; Blakely, Richard J.; Saltus, Richard W.; Anderson, Eric D.; DeWitt, Ed

2015-01-01

The basement-domain map is a compilation of basement domains in the conterminous United States and Alaska designed to be used at 1:5,000,000-scale, particularly as a base layer for national-scale mineral resource assessments. Seventy-seven basement domains are represented as eighty-three polygons on the map. The domains are based on interpretations of basement composition, origin, and architecture and developed from a variety of sources. Analysis of previously published basement, lithotectonic, and terrane maps as well as models of planetary development were used to formulate the concept of basement and the methodology of defining domains that spanned the ages of Archean to present but formed through different processes. The preliminary compilations for the study areas utilized these maps, national-scale gravity and aeromagnetic data, published and limited new age and isotopic data, limited new field investigations, and conventional geologic maps. Citation of the relevant source data for compilations and the source and types of original interpretation, as derived from different types of data, are provided in supporting descriptive text and tables.

PF-1355, a mechanism-based myeloperoxidase inhibitor, prevents immune complex vasculitis and anti-glomerular basement membrane glomerulonephritis.

Science.gov (United States)

Zheng, Wei; Warner, Roscoe; Ruggeri, Roger; Su, Chunyan; Cortes, Christian; Skoura, Athanasia; Ward, Jessica; Ahn, Kay; Kalgutkar, Amit; Sun, Dexue; Maurer, Tristan S; Bonin, Paul D; Okerberg, Carlin; Bobrowski, Walter; Kawabe, Thomas; Zhang, Yanwei; Coskran, Timothy; Bell, Sammy; Kapoor, Bhupesh; Johnson, Kent; Buckbinder, Leonard

2015-05-01

Small vessel vasculitis is a life-threatening condition and patients typically present with renal and pulmonary injury. Disease pathogenesis is associated with neutrophil accumulation, activation, and oxidative damage, the latter being driven in large part by myeloperoxidase (MPO), which generates hypochlorous acid among other oxidants. MPO has been associated with vasculitis, disseminated vascular inflammation typically involving pulmonary and renal microvasculature and often resulting in critical consequences. MPO contributes to vascular injury by 1) catabolizing nitric oxide, impairing vasomotor function; 2) causing oxidative damage to lipoproteins and endothelial cells, leading to atherosclerosis; and 3) stimulating formation of neutrophil extracellular traps, resulting in vessel occlusion and thrombosis. Here we report a selective 2-thiouracil mechanism-based MPO inhibitor (PF-1355 [2-(6-(2,5-dimethoxyphenyl)-4-oxo-2-thioxo-3,4-dihydropyrimidin-1(2H)-yl)acetamide) and demonstrate that MPO is a critical mediator of vasculitis in mouse disease models. A pharmacokinetic/pharmacodynamic response model of PF-1355 exposure in relation with MPO activity was derived from mouse peritonitis. The contribution of MPO activity to vasculitis was then examined in an immune complex model of pulmonary disease. Oral administration of PF-1355 reduced plasma MPO activity, vascular edema, neutrophil recruitment, and elevated circulating cytokines. In a model of anti-glomerular basement membrane disease, formerly known as Goodpasture disease, albuminuria and chronic renal dysfunction were completely suppressed by PF-1355 treatment. This study shows that MPO activity is critical in driving immune complex vasculitis and provides confidence in testing the hypothesis that MPO inhibition will provide benefit in treating human vasculitic diseases. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

Fibrillar, fibril-associated and basement membrane collagens of the arterial wall: architecture, elasticity and remodeling under stress.

Science.gov (United States)

Osidak, M S; Osidak, E O; Akhmanova, M A; Domogatsky, S P; Domogatskaya, A S

2015-01-01

The ability of a human artery to pass through 150 million liters of blood sustaining 2 billion pulsations of blood pressure with minor deterioration depends on unique construction of the arterial wall. Viscoelastic properties of this construction enable to re-seal the occuring damages apparently without direct immediate participance of the constituent cells. Collagen structures are considered to be the elements that determine the mechanoelastic properties of the wall in parallel with elastin responsible for elasticity and resilience. Collagen scaffold architecture is the function-dependent dynamic arrangement of a dozen different collagen types composing three distinct interacting forms inside the extracellular matrix of the wall. Tightly packed molecules of collagen types I, III, V provide high tensile strength along collagen fibrils but toughness of the collagen scaffold as a whole depends on molecular bonds between distinct fibrils. Apart of other macromolecules in the extracellular matrix (ECM), collagen-specific interlinks involve microfilaments of collagen type VI, meshwork-organized collagen type VIII, and FACIT collagen type XIV. Basement membrane collagen types IV, XV, XVIII and cell-associated collagen XIII enable transmission of mechanical signals between cells and whole artery matrix. Collagen scaffold undergoes continuous remodeling by decomposition promoted with MMPs and reconstitution from newly produced collagen molecules. Pulsatile stress-strain load modulates both collagen synthesis and MMP-dependent collagen degradation. In this way the ECM structure becomes adoptive to mechanical challenges. The mechanoelastic properties of the arterial wall are changed in atherosclerosis concomitantly with collagen turnover both type-specific and dependent on the structure. Improving the feedback could be another approach to restore sufficient blood circulation.

Nanoengineered membranes for controlled transport

Science.gov (United States)

Doktycz, Mitchel J [Oak Ridge, TN; Simpson, Michael L [Knoxville, TN; McKnight, Timothy E [Greenback, TN; Melechko, Anatoli V [Oak Ridge, TN; Lowndes, Douglas H [Knoxville, TN; Guillorn, Michael A [Knoxville, TN; Merkulov, Vladimir I [Oak Ridge, TN

2010-01-05

A nanoengineered membrane for controlling material transport (e.g., molecular transport) is disclosed. The membrane includes a substrate, a cover definining a material transport channel between the substrate and the cover, and a plurality of fibers positioned in the channel and connected to an extending away from a surface of the substrate. The fibers are aligned perpendicular to the surface of the substrate, and have a width of 100 nanometers or less. The diffusion limits for material transport are controlled by the separation of the fibers. In one embodiment, chemical derivitization of carbon fibers may be undertaken to further affect the diffusion limits or affect selective permeability or facilitated transport. For example, a coating can be applied to at least a portion of the fibers. In another embodiment, individually addressable carbon nanofibers can be integrated with the membrane to provide an electrical driving force for material transport.

Radon mitigation experience in houses with basements and adjoining crawl spaces

International Nuclear Information System (INIS)

Messing, M.; Henschel, D.B.

1990-01-01

Active soil depressurization systems were installed in four basement houses with adjoining crawl spaces in Maryland. In addition, existing soil depressurization systems were modified in two additional basement-plus-crawl-space houses. These six houses were selected to include both good and poor communication beneath the basement slab, and different degrees of importance of the crawl space as a source of the indoor radon. The radon reduction effectiveness was compared for: depressurization only under the basement slab; depressurization only under a polyethylene liner over the unpaved crawl-space floor; and simultaneous depressurization under both the basement slab and the crawl-space liner. The objective of this paper is to identify under what conditions treatment of the basement alone might provide sufficient radon reductions in houses of this substructure, and what incremental benefits might be achieved by also treating the crawl space

Crucial Role of Mesangial Cell-derived Connective Tissue Growth Factor in a Mouse Model of Anti-Glomerular Basement Membrane Glomerulonephritis.

Science.gov (United States)

Toda, Naohiro; Mori, Kiyoshi; Kasahara, Masato; Ishii, Akira; Koga, Kenichi; Ohno, Shoko; Mori, Keita P; Kato, Yukiko; Osaki, Keisuke; Kuwabara, Takashige; Kojima, Katsutoshi; Taura, Daisuke; Sone, Masakatsu; Matsusaka, Taiji; Nakao, Kazuwa; Mukoyama, Masashi; Yanagita, Motoko; Yokoi, Hideki

2017-02-13

Connective tissue growth factor (CTGF) coordinates the signaling of growth factors and promotes fibrosis. Neonatal death of systemic CTGF knockout (KO) mice has hampered analysis of CTGF in adult renal diseases. We established 3 types of CTGF conditional KO (cKO) mice to investigate a role and source of CTGF in anti-glomerular basement membrane (GBM) glomerulonephritis. Tamoxifen-inducible systemic CTGF (Rosa-CTGF) cKO mice exhibited reduced proteinuria with ameliorated crescent formation and mesangial expansion in anti-GBM nephritis after induction. Although CTGF is expressed by podocytes at basal levels, podocyte-specific CTGF (pod-CTGF) cKO mice showed no improvement in renal injury. In contrast, PDGFRα promoter-driven CTGF (Pdgfra-CTGF) cKO mice, which predominantly lack CTGF expression by mesangial cells, exhibited reduced proteinuria with ameliorated histological changes. Glomerular macrophage accumulation, expression of Adgre1 and Ccl2, and ratio of M1/M2 macrophages were all reduced both in Rosa-CTGF cKO and Pdgfra-CTGF cKO mice, but not in pod-CTGF cKO mice. TGF-β1-stimulated Ccl2 upregulation in mesangial cells and macrophage adhesion to activated mesangial cells were decreased by reduction of CTGF. These results reveal a novel mechanism of macrophage migration into glomeruli with nephritis mediated by CTGF derived from mesangial cells, implicating the therapeutic potential of CTGF inhibition in glomerulonephritis.

Abnormalities in the basement membrane structure promote basal keratinocytes in the epidermis of hypertrophic scars to adopt a proliferative phenotype.

Science.gov (United States)

Yang, Shaowei; Sun, Yexiao; Geng, Zhijun; Ma, Kui; Sun, Xiaoyan; Fu, Xiaobing

2016-05-01

The majority of studies on scar formation have mainly focused on the dermis and little is known of the involvement of the epidermis. Previous research has demonstrated that the scar tissue-derived keratinocytes are different from normal cells at both the genetic and cell biological levels; however, the mechanisms responsible for the fundamental abnormalities in keratinocytes during scar development remain elusive. For this purpose, in this study, we used normal, wound edge and hypertrophic scar tissue to examine the morphological changes which occur during epidermal regeneration as part of the wound healing process and found that the histological structure of hypertrophic scar tissues differed from that of normal skin, with a significant increase in epidermal thickness. Notably, staining of the basement membrane (BM) appeared to be absent in the scar tissues. Moreover, immunofluorescence staining for cytokeratin (CK)10, CK14, CK5, CK19 and integrin-β1 indicated the differential expression of cell markers in the epidermal keratinocytes among the normal, wound edge and hypertrophic scar tissues, which corresponded with the altered BM structures. By using a panel of proteins associated with BM components, we validated our hypothesis that the BM plays a significant role in regulating the cell fate decision of epidermal keratinocytes during skin wound healing. Alterations in the structure of the BM promote basal keratinocytes to adopt a proliferative phenotype both in vivo and in vitro.

Influence of a reconstituted basement membrane and its components on casein gene expression and secretion in mouse mammary epithelial cells

International Nuclear Information System (INIS)

Li, M.L.; Aggeler, J.; Farson, D.A.; Hatier, C.; Hassell, J.; Bissell, M.J.

1987-01-01

When primary mouse mammary epithelial cells are cultured on plastic, they rapidly lose their ability to synthesize and secrete most milk proteins even in the presence of lactogenic hormones, whereas cells cultured on release type I collagen gels show greatly enhanced mRNA levels and secretion rates of β-casein and of some other milk proteins. The authors show here that culture on a reconstituted basement membrane from Engelbreth-Holm-Swarm tumor (EHS) allows > 90% of cells to produce high levels of β-casein. By comparison, 30-40% of cells on released type 1 gels and only 2-10% of cells on plastic express β-casein after 6 days in culture. Because only 40% of cells from late pregnant gland produced β-casein before culture, the EHS matrix can both induce and maintain an increased level of casein gene expression. Individual basal lamina components were also evaluated. Type IV collagen and fibronectin had little effect on morphology and β-casein mRNA levels. In contrast, both laminin and heparan sulfate proteoglycan increased β-casein mRNA levels. Profound morphological differences were evident between cells cultured on plastic and on EHS matrix, the latter cells forming ducts, ductules, and lumina and resembling secretory alveoli. These results emphasize the vital role of the extracellular matrix in receiving and integrating structural and functional signals that can direct specific gene expression in differentiated tissues

Basement depressurization using dwelling mechanical exhaust ventilation system

International Nuclear Information System (INIS)

Collignan, B.; O'Kelly, P.; Pilch, E.

2004-01-01

The mechanical ventilation exhaust system is commonly used in France to generate air renewal into building and especially into dwelling. It consists of a permanent mechanical air extraction from technical rooms (kitchen, bathrooms and toilets) using a unique fan connected to exhaust ducts. Natural air inlets in living room and bed rooms ensure an air flow from living spaces towards technical rooms. To fight against radon into building, the most recognised efficient technique is the Soil Depressurization System (S.D.S.) consisting in depressurizing the house basement. The aim of this study is to test the ability of the dwelling mechanical ventilation system to depressurize the basement in conjunction with air renewal of a house. For that purpose, a S.D.S. has been installed in an experimental house at CSTB during its construction. At first, tests undertaken with a variable velocity fan connected to the S.D.S. have characterised the permeability of the basement. It is shown that basement can be depressurized adequately with a relatively low air flow rate. At a second stage, S.D.S. has been connected to the exhaust ventilation fan used for the mechanical ventilation of the house. Results obtained show the ability of such ventilation system to generate sufficient depressurization in the basement and to ensure simultaneously adequate air change rate in the dwelling. (author)

Grenville age of basement rocks in Cape May NJ well: New evidence for Laurentian crust in U.S. Atlantic Coastal Plain basement Chesapeake terrane

Science.gov (United States)

Sheridan, R.E.; Maguire, T.J.; Feigenson, M.D.; Patino, L.C.; Volkert, R.A.

1999-01-01

The Chesapeake terrane of the U.S. mid-Atlantic Coastal Plain basement is bounded on the northwest by the Salisbury positive gravity and magnetic anomaly and extends to the southeast as far as the Atlantic coast. It underlies the Coastal Plain of Virginia, Maryland, Delaware and southern New Jersey. Rubidium/Strontium dating of the Chesapeake terrane basement yields an age of 1.025 ?? 0.036 Ga. This age is typical of Grenville province rocks of the Middle to Late Proterozoic Laurentian continent. The basement lithologies are similar to some exposed Grenville-age rocks of the Appalachians. The TiO2 and Zr/P2O5 composition of the metagabbro from the Chesapeake terrane basement is overlapped by those of the Proterozoic mafic dikes in the New Jersey Highlands. These new findings support the interpretation that Laurentian basement extends southeast as far as the continental shelf in the U.S. mid-Atlantic region. The subcrop of Laurentian crust under the mid-Atlantic Coastal Plain implies unroofing by erosion of the younger Carolina (Avalon) supracrustal terrane. Dextral-transpression fault duplexes may have caused excessive uplift in the Salisbury Embayment area during the Alleghanian orogeny. This extra uplift in the Salisbury area may have caused the subsequent greater subsidence of the Coastal Plain basement in the embayment.

Radionuclide distribution in TMI-2 reactor building basement liquids and solids

International Nuclear Information System (INIS)

Horan, J.T.; McIsaac, C.V.; Keefer, D.G.

1984-01-01

As a result of the TMI-2 accident, approximately 2.46 x 10 6 L of contaminated water were released to the Reactor Building basement. The principal fission product release pathway from the damaged core was through the reactor coolant system (RCS) to the pressurizer, through the pressure-operated relief valve (PORV) on the pressurizer to the Reactor Coolant Drain Tank (RCDT), and then through the RCDT rupture disk to the Reactor Building basement. Since August 1979, a number of efforts have been made to determine the location, quantity, and composition of fission products released to the Reactor Building basement. These efforts have included sampling of the basement water and solids, the basement sump pump recirculation line, the RCDT, and visual surveys using a closed circuit television (CCTV) system. The analysis of basement samples has provided data on the physical and radioisotopic characteristics of the liquids and solids. This paper describes the sample collection techniques and discusses radiochemical analyses results

Depth-To-Basement Mapping Using Fractal Technique: Application ...

African Journals Online (AJOL)

... and can thus be obtained at source level. Application to aeromagnetic data from the Chad basin north eastern Nigeria produced a basement relief which range from depths of 2.47 km to 5.40 km with an average of 3.92 +- 0.66 km. Keywords: Fractal, depth, basement, spectra, aeromagnetic. Nigerian Journal of Physics Vol ...

Small RNAs controlling outer membrane porins

DEFF Research Database (Denmark)

Valentin-Hansen, Poul; Johansen, Jesper; Rasmussen, Anders A

2007-01-01

are key regulators of environmental stress. Recent work has revealed an intimate interplay between small RNA regulation of outer membrane proteins and the stress-induced sigmaE-signalling system, which has an essential role in the maintenance of the integrity of the outer membrane.......Gene regulation by small non-coding RNAs has been recognized as an important post-transcriptional regulatory mechanism for several years. In Gram-negative bacteria such as Escherichia coli and Salmonella, these RNAs control stress response and translation of outer membrane proteins and therefore...

Measure Guideline: Basement Insulation Basics

Energy Technology Data Exchange (ETDEWEB)

Aldrich, R.; Mantha, P.; Puttagunta, S.

2012-10-01

This guideline is intended to describe good practices for insulating basements in new and existing homes, and is intended to be a practical resources for building contractors, designers, and also to homeowners.

Divergent mechanisms underlie Smad4-mediated positive regulation of the three genes encoding the basement membrane component laminin-332 (laminin-5)

International Nuclear Information System (INIS)

Zboralski, Dirk; Böckmann, Miriam; Zapatka, Marc; Hoppe, Sabine; Schöneck, Anna; Hahn, Stephan A; Schmiegel, Wolff; Schwarte-Waldhoff, Irmgard

2008-01-01

Functional inactivation of the tumor suppressor Smad4 in colorectal and pancreatic carcinogenesis occurs coincident with the transition to invasive growth. Breaking the basement membrane (BM) barrier, a prerequisite for invasive growth, can be due to tumor induced proteolytic tissue remodeling or to reduced synthesis of BM molecules by incipient tumor cells. Laminin-332 (laminin-5), a heterotrimeric BM component composed of α3-, β3- and γ2-chains, has recently been identified as a target structure of Smad4 and represents the first example for expression control of an essential BM component by a tumor and invasion suppressor. Biochemically Smad4 is a transmitter of signals of the TGFβ superfamily of cytokines. We have reported previously, that Smad4 functions as a positive transcriptional regulator of constitutive and of TGFβ-induced transcription of all three genes encoding Laminin-332, LAMA3, LAMB3 and LAMC2. Promoter-reporter constructs harboring 4 kb upstream regions, each of the three genes encoding Laminin-322 as well as deletion and mutations constructs were established. Promoter activities and TGFβ induction were assayed through transient transfections in Smad4-negative human cancer cells and their stable Smad4-positive derivatives. Functionally relevant binding sites were subsequently confirmed through chromatin immunoprecipitation. Herein, we report that Smad4 mediates transcriptional regulation through three different mechanisms, namely through Smad4 binding to a functional SBE site exclusively in the LAMA3 promoter, Smad4 binding to AP1 (and Sp1) sites presumably via interaction with AP1 family components and lastly a Smad4 impact on transcription of AP1 factors. Whereas Smad4 is essential for positive regulation of all three genes, the molecular mechanisms are significantly divergent between the LAMA3 promoter as compared to the LAMB3 and LAMC2 promoters. We hypothesize that this divergence in modular regulation of the three promoters may lay the

Reactivated basement structures in the central Savannah River area and their relationship to coastal plain deformation

International Nuclear Information System (INIS)

Cumbest, R.J.; Price, V.; Temples, T.J.; Fallaw, W.C.; Snipes, D.S.

1993-01-01

Structural surface mapping and geophysical studies have identified several faults in the crystalline basement and overlying Coastal Plain sedimentary sequences in the central Savannah River area. Major subsurface basement shear zones occur parallel to and near Upper Three Runs Creek and Tinker Creek and are associated with linear aeromagnetic anomalies. Reflection seismic imaging of the basement shows a band of southeast dipping events parallel to Upper Three Runs Creek. Drill core from basement contain phyllonites, mylonites, fault breccia and pseudotachylite. The magnetic anomalies also mark the boundary separating greenschist facies metavolcanic rocks from amphibolite facies felsic gneiss, schist, and amphibolite. These features are similar to those that characterize other Paleozoic faults of the Eastern Piedmont Fault system. Reflection seismic imaging shows the sub-Cretaceous unconformity as well defined and easily identified event as well as easily traced laterally extensive events in Coastal Plain sequences. The unconformity and sedimentary sequences are faulted or deformed in several locations which also coincide with changes in dip of the unconformity. In the vicinity of Upper Three Runs Creek the unconformity shows a broad warping across which the elevation drops to the southeast and sedimentary sequences show a marked rate of thickening southeast. This indicates deformation of the basement exerted a control on deposition of the Coastal Plain sediments with down to the southeast movement. The basement shear zones are closely associated with the Dunbarton basin and are probable reactivated Paleozoic structures associated with extensional basin development as commonly seen associated with extensional basins on the east coast of North America

Effect of basement structure and salt tectonics on deformation styles along strike: An example from the Kuqa fold-thrust belt, West China

Science.gov (United States)

Neng, Yuan; Xie, Huiwen; Yin, Hongwei; Li, Yong; Wang, Wei

2018-04-01

The Kuqa fold-thrust belt (KFTB) has a complex thrust-system geometry and comprises basement-involved thrusts, décollement thrusts, triangle zones, strike-slip faults, transpressional faults, and pop-up structures. These structures, combined with the effects of Paleogene salt tectonics and Paleozoic basement uplift form a complex structural zone trending E-W. Interpretation and comprehensive analysis of recent high-quality seismic data, field observations, boreholes, and gravity data covering the KFTB has been performed to understand the characteristics and mechanisms of the deformation styles along strike. Regional sections, fold-thrust system maps of the surface and the sub-salt layer, salt and basement structure distribution maps have been created, and a comprehensive analysis of thrust systems performed. The results indicate that the thrust-fold system in Paleogene salt range can be divided into five segments from east to west: the Kela-3, Keshen, Dabei, Bozi, and Awate segments. In the easternmost and westernmost parts of the Paleogene salt range, strike-slip faulting and basement-involved thrusting are the dominant deformation styles, as basement uplift and the limits of the Cenozoic evaporite deposit are the main controls on deformation. Salt-core detachment fold-thrust systems coincide with areas of salt tectonics, and pop-up, imbricate, and duplex structures are associated with the main thrust faults in the sub-salt layer. Distribution maps of thrust systems, basement structures, and salt tectonics show that Paleozoic basement uplift controlled the Paleozoic foreland basin morphology and the distribution of Cenozoic salt in the KFTB, and thus had a strong influence on the segmented structural deformation and evolution of the fold-thrust belt. Three types of transfer zone are identified, based on the characteristics of the salt layer and basement uplift, and the effects of these zones on the fault systems are evaluated. Basement uplift and the boundary of

Structural Controls on Groundwater Flow in Basement Terrains: Geophysical, Remote Sensing, and Field Investigations in Sinai

KAUST Repository

Mohamed, Lamees

2015-07-09

An integrated [very low frequency (VLF) electromagnetic, magnetic, remote sensing, field, and geographic information system (GIS)] study was conducted over the basement complex in southern Sinai (Feiran watershed) for a better understanding of the structural controls on the groundwater flow. The increase in satellite-based radar backscattering values following a large precipitation event (34 mm on 17–18 January 2010) was used to identify water-bearing features, here interpreted as preferred pathways for surface water infiltration. Findings include: (1) spatial analysis in a GIS environment revealed that the distribution of the water-bearing features (conductive features) corresponds to that of fractures, faults, shear zones, dike swarms, and wadi networks; (2) using VLF (43 profiles), magnetic (7 profiles) techniques, and field observations, the majority (85 %) of the investigated conductive features were determined to be preferred pathways for groundwater flow; (3) northwest–southeast- to north–south-trending conductive features that intersect the groundwater flow (southeast to northwest) at low angles capture groundwater flow, whereas northeast–southwest to east–west features that intersect the flow at high angles impound groundwater upstream and could provide potential productive well locations; and (4) similar findings are observed in central Sinai: east–west-trending dextral shear zones (Themed and Sinai Hinge Belt) impede south to north groundwater flow as evidenced by the significant drop in hydraulic head (from 467 to 248 m above mean sea level) across shear zones and by reorientation of regional flow (south–north to southwest–northeast). The adopted integrated methodologies could be readily applied to similar highly fractured basement arid terrains elsewhere. © 2015 Springer Science+Business Media Dordrecht

Poliomyelitis in MuLV-infected ICR-SCID mice after injection of basement membrane matrix contaminated with lactate dehydrogenase-elevating virus.

Science.gov (United States)

Carlson Scholz, Jodi A; Garg, Rohit; Compton, Susan R; Allore, Heather G; Zeiss, Caroline J; Uchio, Edward M

2011-10-01

The arterivirus lactate dehydrogenase-elevating virus (LDV) causes life-long viremia in mice. Although LDV infection generally does not cause disease, infected mice that are homozygous for the Fv1(n) allele are prone to develop poliomyelitis when immunosuppressed, a condition known as age-dependent poliomyelitis. The development of age-dependent poliomyelitis requires coinfection with endogenous murine leukemia virus. Even though LDV is a common contaminant of transplantable tumors, clinical signs of poliomyelitis after inadvertent exposure to LDV have not been described in recent literature. In addition, LDV-induced poliomyelitis has not been reported in SCID or ICR mice. Here we describe the occurrence of poliomyelitis in ICR-SCID mice resulting from injection of LDV-contaminated basement membrane matrix. After exposure to LDV, a subset of mice presented with clinical signs including paresis, which was associated with atrophy of the hindlimb musculature, and tachypnea; in addition, some mice died suddenly with or without premonitory signs. Mice presenting within the first 6 mo after infection had regions of spongiosis, neuronal necrosis and astrocytosis of the ventral spinal cord, and less commonly, brainstem. Axonal degeneration of ventral roots prevailed in more chronically infected mice. LDV was identified by RT-PCR in 12 of 15 mice with typical neuropathology; positive antiLDV immunolabeling was identified in all PCR-positive animals (n = 7) tested. Three of 8 mice with neuropathology but no clinical signs were LDV negative by RT-PCR. RT-PCR yielded murine leukemia virus in spinal cords of all mice tested, regardless of clinical presentation or neuropathology.

Anti-nucleosome antibodies complexed to nucleosomal antigens show anti-DNA reactivity and bind to rat glomerular basement membrane in vivo.

Science.gov (United States)

Kramers, C; Hylkema, M N; van Bruggen, M C; van de Lagemaat, R; Dijkman, H B; Assmann, K J; Smeenk, R J; Berden, J H

1994-01-01

Histones can mediate the binding of DNA and anti-DNA to the glomerular basement membrane (GBM). In ELISA histone/DNA/anti-DNA complexes are able to bind to heparan sulfate (HS), an intrinsic constituent of the GBM. We questioned whether histone containing immune complexes are able to bind to the GBM, and if so, whether the ligand in the GBM is HS. Monoclonal antibodies (mAbs) complexed to nucleosomal antigens and noncomplexed mAbs were isolated from culture supernatants of four IgG anti-nuclear mAbs. All noncomplexed mAbs showed strong anti-nucleosome reactivity in ELISA. One of them showed in addition anti-DNA reactivity in noncomplexed form. The other three mAbs only showed anti-DNA reactivity when they were complexed to nucleosomal antigens. After renal perfusion a fine granular binding of complexed mAbs to the glomerular capillary wall and activation of complement was observed in immunofluorescence, whereas noncomplexed mAbs did not bind. Immuno-electron microscopy showed binding of complexes to the whole width of the GBM. When HS in the GBM was removed by renal heparinase perfusion the binding of complexed mAb decreased, but did not disappear completely. We conclude that anti-nucleosome mAbs, which do not bind DNA, become DNA reactive once complexed to nucleosomal antigens. These complexed mAbs can bind to the GBM. The binding ligand in the GBM is partly, but not solely, HS. Binding to the GBM of immune complexes containing nucleosomal material might be an important event in the pathogenesis of lupus nephritis. Images PMID:8040312

Experiments on pollutant transport from soil into residential basements by pressure-driven airflow

International Nuclear Information System (INIS)

Nazaroff, W.W.; Lewis, S.R.; Doyle, S.M.; Moed, B.A.; Nero, A.V.

1987-01-01

At two residences in Portland, OR, they have investigated (1) the coupling between residential basements and the air in nearby soil and (2) the influence of basement depressurization on the migration of air in soil. With the basements depressurized 25-50 Pa relative to outdoor air, underpressures as great as 20-40% of those in the basement were observed at sampling points in the soil. Sulfur hexafluoride was injected into the soil near the houses and its concentration monitored in soil air and in the house over time, both with and without basement depressurization. Depressurization was seen to have a substantial effect on the migration of the tracer within the soil. For basement depressurizations of 25-50 Pa, effective transport velocities through the soil and into the houses were observed to exceed 1 m h -1 . Airborne 222 Rn concentration was monitored in the basement of one house during the 6-day investigation and was seen to increase substantially on each of the seven occasions that the house was depressurized. The techniques employed are applicable to the study of problems of excessive radon entry into buildings and the migration of toxic vapors from waste dumps and landfills

Control of membrane fouling during hyperhaline municipal wastewater treatment using a pilot-scale anoxic/aerobic-membrane bioreactor system

Institute of Scientific and Technical Information of China (English)

Jingmei Sun; Jiangxiu Rong; Lifeng Dai; Baoshan Liu; Wenting Zhu

2011-01-01

Membrane fouling limits the effects of long-term stable operation of membrane bioreactor (MBR).Control of membrane foulin can extend the membrane life and reduce water treatment cost effectively.A pilot scale anoxic/aerobic-membrane bioreactor (A/O MBR,40 L/hr) was used to treat the hyperhaline municipal sewage from a processing zone of Tianjin,China.Impact factors including mixed liquid sludge suspension (MLSS),sludge viscosity (μ),microorganisms,extracellular polymeric substances (EPS),aeration intensity and suction/suspended time on membrane fouling and pollution control were studied.The relationships among various factors associated with membrane fouling were analyzed.Results showed that there was a positive correlation among MLSS,sludge viscosity and trans-membrane pressure (TMP).Considering water treatment efficiency and stable operation of the membrane module,MLSS of 5 g/L was suggested for the process.There was a same trend among EPS,sludge viscosity and TMP.Numbers and species of microorganisms affected membrane fouling.Either too high or too low aeration intensity was not conducive to membrane fouling control.Aeration intensity of 1.0 m3/hr (gas/water ratio of 25:1) is suggested for the process.A long suction time caused a rapid increase in membrane resistance.However,long suspended time cannot prevent the increase of membrane resistance effectively even though a suspended time was necessary for scale off particles from the membrane surface.The suction/suspended time of 12 min/3 min was selected for the process.The interaction of various environmental factors and operation conditions must be considered synthetically.

Controlling the shape of membrane protein polyhedra

Science.gov (United States)

Li, Di; Kahraman, Osman; Haselwandter, Christoph A.

2017-03-01

Membrane proteins and lipids can self-assemble into membrane protein polyhedral nanoparticles (MPPNs). MPPNs have a closed spherical surface and a polyhedral protein arrangement, and may offer a new route for structure determination of membrane proteins and targeted drug delivery. We develop here a general analytic model of how MPPN self-assembly depends on bilayer-protein interactions and lipid bilayer mechanical properties. We find that the bilayer-protein hydrophobic thickness mismatch is a key molecular control parameter for MPPN shape that can be used to bias MPPN self-assembly towards highly symmetric and uniform MPPN shapes. Our results suggest strategies for optimizing MPPN shape for structural studies of membrane proteins and targeted drug delivery.

Asymmetric Effects of Subaerial and Subaqueous Basement Slopes on Self-Similar Morphology of Prograding Deltas

Science.gov (United States)

Lai, Steven Yueh Jen; Hsiao, Yung-Tai; Wu, Fu-Chun

2017-12-01

Deltas form over basements of various slope configurations. While the morphodynamics of prograding deltas over single-slope basements have been studied previously, our understanding of delta progradation over segmented basements is still limited. Here we use experimental and analytical approaches to investigate the deltaic morphologies developing over two-slope basements with unequal subaerial and subaqueous slopes. For each case considered, the scaled profiles of the evolving delta collapse to a single profile for constant water and sediment influxes, allowing us to use the analytical self-similar profiles to investigate the individual effects of subaerial/subaqueous slopes. Individually varying the subaerial/subaqueous slopes exerts asymmetric effects on the morphologies. Increasing the subaerial slope advances the entire delta; increasing the subaqueous slope advances the upstream boundary of the topset yet causes the downstream boundary to retreat. The delta front exhibits a first-retreat-then-advance migrating trend with increasing subaqueous slope. A decrease in subaerial topset length is always accompanied by an increase in subaqueous volume fraction, no matter which segment is steepened. Applications are presented for estimating shoreline retreat caused by steepening of basement slopes, and estimating subaqueous volume and delta front using the observed topset length. The results may have implications for real-world delta systems subjected to upstream tectonic uplift and/or downstream subsidence. Both scenarios would exhibit reduced topset lengths, which are indicative of the accompanied increases in subaqueous volume and signal tectonic uplift and/or subsidence that are at play. We highlight herein the importance of geometric controls on partitioning of sediment between subaerial and subaqueous delta components.

Discussion on the basement topography and its relation with the uranium mineralization in Xiangshan basin

International Nuclear Information System (INIS)

Long Qihua; Liu Qingcheng

2002-01-01

The depth of the basement and the relation between the basement relief shape and uranium mineralization are discussed by forward and inverse computation for large-scale gravity data in Xiangshan basin. The difference of basement topography result in the inhomogeneous distribution of uranium mineralization. The margin of the basement upheaval section and the variation place of basement topography are the favorable place for uranium mineralization. It's helpful to prospect deep and blind uranium deposit in Xiangshan basin

Examination of the Basement of Historic Buildings in Investment Activity

Directory of Open Access Journals (Sweden)

Ulybin Aleksey

2016-01-01

Full Text Available The process and methodology of the survey of basements rarely mentioned in the various construction rules and regulations. Basically describes the procedure of conducting a detailed survey of some of the individual elements. These surveys are fundamental in nature, include a large number of estimates and require significant financial and time costs. Usually the purpose of these surveys is to check the state of the building as a whole, it’s safe operation or before starting of reconstruction. In the process of selecting areas of investment activity such large-scale survey is not possible. Needed a quick and inexpensive method intended for decision about investment in a particular object. At the same time, the survey should cover all the elements of the basement significantly affect the cost of reconstruction of the basement associated with his penetration. The article presents the general conception of conducting a rapid survey. The described methods and technologies applicable to the examination for the purpose of making decisions about investments in reconstruction of a basement level rooms. The composition of the works and their sequence. A comparison of the advantages and disadvantages of different methods. The practical examples. Scheme of conducting a rapid survey of the basement. The article analyzes the materials used in the construction of historic buildings in St. Petersburg.

Investigation of the subsurface features of the basement complex of ...

African Journals Online (AJOL)

3D seismic reflection survey was recently carried out within the Zaria area of the basement complex of northern Nigeria, in order to investigate the complexity of the subsurface features within the basement. The geology of the survey area was characterized by gneisses and low grade meta-sedimentary rocks that form the ...

Basement Surface Faulting and Topography for Savannah River Site and Vicinity

International Nuclear Information System (INIS)

Cumbest, R.J.

1998-01-01

This report integrates the data from more than 60 basement borings and over 100 miles of seismic reflection profiling acquired on the Savannah River Site to map the topography of the basement (unweathered rock) surface and faulting recorded on this surface

Control of distributed heat transfer mechanisms in membrane distillation plants

KAUST Repository

Laleg-Kirati, Taous-Meriem

2017-01-05

Various examples are provided that are related to boundary control in membrane distillation (MD) processes. In one example, a system includes a membrane distillation (MD) process comprising a feed side and a permeate side separated by a membrane boundary layer; and processing circuitry configured to control a water production rate of the MD process based at least in part upon a distributed heat transfer across the membrane boundary layer. In another example, a method includes determining a plurality of estimated temperature states of a membrane boundary layer separating a feed side and a permeate side of a membrane distillation (MD) process; and adjusting inlet flow rate or inlet temperature of at least one of the feed side or the permeate side to maintain a difference temperature along the membrane boundary layer about a defined reference temperature based at least in part upon the plurality of estimated temperature states.

Biological control of biofilms on membranes by metazoans.

Science.gov (United States)

Klein, Theresa; Zihlmann, David; Derlon, Nicolas; Isaacson, Carl; Szivak, Ilona; Weissbrodt, David G; Pronk, Wouter

2016-01-01

Traditionally, chemical and physical methods have been used to control biofouling on membranes by inactivating and removing the biofouling layer. Alternatively, the permeability can be increased using biological methods while accepting the presence of the biofouling layer. We have investigated two different types of metazoans for this purpose, the oligochaete Aelosoma hemprichi and the nematode Plectus aquatilis. The addition of these grazing metazoans in biofilm-controlled membrane systems resulted in a flux increase of 50% in presence of the oligochaetes (Aelosoma hemprichi), and a flux increase of 119-164% in presence of the nematodes (Plectus aquatilis) in comparison to the control system operated without metazoans. The change in flux resulted from (1) a change in the biofilm structure, from a homogeneous, cake-like biofilm to a more heterogeneous, porous structure and (2) a significant reduction in the thickness of the basal layer. Pyrosequencing data showed that due to the addition of the predators, also the community composition of the biofilm in terms of protists and bacteria was strongly affected. The results have implications for a range of membrane processes, including ultrafiltration for potable water production, membrane bioreactors and reverse osmosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Membranous glomerulonephritis in a child asymptomatic for hepatitis B virus. Concomitant seropositivity for HBsAG and anti-HBs.

Science.gov (United States)

Hirsch, H Z; Ainsworth, S K; DeBeukelaer, M; Brissie, R M; Hennigar, G R

1981-04-01

The presence of hepatitis B surface antigen (HBsAg) in association with immunoglobulins and complement components within the glomerular basement membranes of adults having chronic active hepatitis has been well documented. In addition, investigators in Poland have demonstrated HBsAg immune complexes in glomeruli of children who did not have clinical evidence of hepatitis. More recently, a single case of childhood membranous glomerulonephritis in an asymptomatic carrier of hepatitis B virus was cited by observers in Canada. Reported here is the deposition of HBsAg immune complexes in the glomerular basement membranes of a 13-year-old black boy who had membranous glomerulopathy but not clinical evidence of hepatitis. This may be the first reported case in the United States of HbsAg-associated membranous glomerulonephritis in a child asymptomatic for hepatitis B virus, and only the second such case in North America. However, unlike previous studies of childhood glomerulopathy in association with hepatitis B virus, this patient is seropositive for both HBsAg and anti-HBs (antibody for hepatitis B surface antigen). Similar "rare" serologic findings were found for the patient's eldest male sib.

Geology of the Pan-African basement Complex in Ube-Wulko area ...

African Journals Online (AJOL)

The Ube-Wulko area of southeast Akwanga falls within the Pan-African remobilized Basement Complex of northcentral Nigeria. It consists of intensely multi-deformed high grade polymetamorphic basement rocks, predominantly composed of migmatitic gneisses and schists and subordinate quartzites, marbles, and ...

Membranous glomerulopathy with spherules: an uncommon variant with obscure pathogenesis.

Science.gov (United States)

Kowalewska, Jolanta; Smith, Kelly D; Hudkins, Kelly L; Chang, Anthony; Fogo, Agnes B; Houghton, Donald; Leslie, Deena; Aitchison, John; Nicosia, Roberto F; Alpers, Charles E

2006-06-01

Occasional case reports of membranous glomerulopathy described unique subepithelial accumulations of an unusual type of immune deposit composed of spherular structures. The identity of such structures as nuclear pores has been suggested, but not established. We identified a cohort of patients (n = 14, including 1 patient with disease recurrence in an allograft) who presented with nephrotic syndrome and had renal biopsy specimens with light and immunofluorescence microscopic findings characteristic of membranous glomerulopathy. These patients were distinguished by ultrastructural studies that showed glomerular capillary wall accumulations of subepithelial immune deposits composed of uniform spherular structures, while lacking the typical granular electron-dense deposits seen in membranous glomerulopathy. The molecular identity of these spherular structures as nuclear pores was tested by using immunofluorescence microscopy and immunohistochemistry with mouse monoclonal antinuclear pore antibodies (Covance, Princeton, NJ) and anti-Nuclear Pore-O-Linked Glycoprotein (Affinity BioReagents Inc, Golden, CO) antibodies. Measurement of spherular structures by using high-magnification electron microscopy showed an average diameter of 84.5 nm, which correlated well with accepted diameters of nuclear pores (80 to 120 nm). Immunofluorescence microscopy and immunoperoxidase staining with both antibodies showed characteristic beaded staining of nuclear membranes of multiple cell types within normal control kidney, but no staining of immune-type deposits within glomerular basement membranes. These cases form a rare, but distinctive, morphological subclass of membranous glomerulopathy. The antigenic specificity of immune deposits in these cases remains elusive.

Control of distributed heat transfer mechanisms in membrane distillation plants

KAUST Repository

Laleg-Kirati, Taous-Meriem; Eleiwi, Fadi; Karam, Ayman M.

2017-01-01

Various examples are provided that are related to boundary control in membrane distillation (MD) processes. In one example, a system includes a membrane distillation (MD) process comprising a feed side and a permeate side separated by a membrane

Design and simulation of the surface shape control system for membrane mirror

Science.gov (United States)

Zhang, Gengsheng; Tang, Minxue

2009-11-01

The surface shape control is one of the key technologies for the manufacture of membrane mirror. This paper presents a design of membrane mirror's surface shape control system on the basis of fuzzy logic control. The system contains such function modules as surface shape design, surface shape control, surface shape analysis, and etc. The system functions are realized by using hybrid programming technology of Visual C# and MATLAB. The finite element method is adopted to simulate the surface shape control of membrane mirror. The finite element analysis model is established through ANSYS Parametric Design Language (APDL). ANSYS software kernel is called by the system in background running mode when doing the simulation. The controller is designed by means of controlling the sag of the mirror's central crosssection. The surface shape of the membrane mirror and its optical aberration are obtained by applying Zernike polynomial fitting. The analysis of surface shape control and the simulation of disturbance response are performed for a membrane mirror with 300mm aperture and F/2.7. The result of the simulation shows that by using the designed control system, the RMS wavefront error of the mirror can reach to 142λ (λ=632.8nm), which is consistent to the surface accuracy of the membrane mirror obtained by the large deformation theory of membrane under the same condition.

development in a basement terrain

African Journals Online (AJOL)

2004-05-17

May 17, 2004 ... especially as a reconnaissance tool (de Jong et al., 1981; de. Rooy et al., 1986; ... ful naval radio transmitters in the very low frequency range. (15-25kHz). ... involved partial curve matching and computer iteration tech- niques. .... result predicted depth to fresh basement bedrock to be 46m whilst drilling ...

Depth of magnetic basement in Iran based on fractal spectral analysis of aeromagnetic data

Science.gov (United States)

Teknik, Vahid; Ghods, Abdolreza

2017-06-01

To estimate the shape of sedimentary basins, a critical parameter in hydrocarbon exploration, we calculated the depth of magnetic basement by applying a fractal spectral method to the aeromagnetic map of Iran. The depth of magnetic basement is a close proxy for the shape of sedimentary basins provided that igneous basement is strongly magnetized relative to the overlying sediments and there is no interbedding magnetic layer in the sediments. The shape of the power spectrum of magnetic anomalies is sensitive to the depth of magnetic basement, the thickness of the magnetic layer, the fractal parameter of magnetization and the size of the window used for the calculation of the power spectrum. Using a suite of synthetic tests, we have shown that the estimation of the depth of magnetic basement of up to 20 km is not very sensitive to the often unknown fractal parameter and thus the spectral method is a reliable tool to calculate the depth of magnetic basement. The depth of magnetic basement is in the range of 7-16 km in the Zagros, east Alborz, Tabas, Jazmurian and Makran regions, showing a close correlation with depths estimated from the maximum thickness of stratigraphic columns. We have also found new sedimentary basins in Bostan Abad, Bijar and south of Orumiyeh Lake. The significant depth of the magnetic basement in the Makran, Jazmurain depression, southeast Caspian Sea, Tabas, Great Kavir, south of Orumiyeh Lake, Bostan Abad and Bijar sedimentary basins makes them future prospects for hydrocarbon explorations. The depth of magnetic basement is strongly reduced over the Neyriz and Kermanshah Ophiolites, but it does not show any meaningful correlation with other outcrops of ophiolitic rocks in Iran.

Myosin IIA interacts with the spectrin-actin membrane skeleton to control red blood cell membrane curvature and deformability.

Science.gov (United States)

Smith, Alyson S; Nowak, Roberta B; Zhou, Sitong; Giannetto, Michael; Gokhin, David S; Papoin, Julien; Ghiran, Ionita C; Blanc, Lionel; Wan, Jiandi; Fowler, Velia M

2018-05-08

The biconcave disk shape and deformability of mammalian RBCs rely on the membrane skeleton, a viscoelastic network of short, membrane-associated actin filaments (F-actin) cross-linked by long, flexible spectrin tetramers. Nonmuscle myosin II (NMII) motors exert force on diverse F-actin networks to control cell shapes, but a function for NMII contractility in the 2D spectrin-F-actin network of RBCs has not been tested. Here, we show that RBCs contain membrane skeleton-associated NMIIA puncta, identified as bipolar filaments by superresolution fluorescence microscopy. MgATP disrupts NMIIA association with the membrane skeleton, consistent with NMIIA motor domains binding to membrane skeleton F-actin and contributing to membrane mechanical properties. In addition, the phosphorylation of the RBC NMIIA heavy and light chains in vivo indicates active regulation of NMIIA motor activity and filament assembly, while reduced heavy chain phosphorylation of membrane skeleton-associated NMIIA indicates assembly of stable filaments at the membrane. Treatment of RBCs with blebbistatin, an inhibitor of NMII motor activity, decreases the number of NMIIA filaments associated with the membrane and enhances local, nanoscale membrane oscillations, suggesting decreased membrane tension. Blebbistatin-treated RBCs also exhibit elongated shapes, loss of membrane curvature, and enhanced deformability, indicating a role for NMIIA contractility in promoting membrane stiffness and maintaining RBC biconcave disk cell shape. As structures similar to the RBC membrane skeleton exist in many metazoan cell types, these data demonstrate a general function for NMII in controlling specialized membrane morphology and mechanical properties through contractile interactions with short F-actin in spectrin-F-actin networks.

Ultrasonic control of ceramic membrane fouling: Effect of particle characteristics.

Science.gov (United States)

Chen, Dong; Weavers, Linda K; Walker, Harold W

2006-02-01

In this study, the effect of particle characteristics on the ultrasonic control of membrane fouling was investigated. Ultrasound at 20 kHz was applied to a cross-flow filtration system with gamma-alumina membranes in the presence of colloidal silica particles. Experimental results indicated that particle concentration affected the ability of ultrasound to control membrane fouling, with less effective control of fouling at higher particle concentrations. Measurements of sound wave intensity and images of the cavitation region indicated that particles induced additional cavitation bubbles near the ultrasonic source, which resulted in less turbulence reaching the membrane surface and subsequently less effective control of fouling. When silica particles were modified to be hydrophobic, greater inducement of cavitation bubbles near the ultrasonic source occurred for a fixed concentration, also resulting in less effective control of fouling. Particle size influenced the cleaning ability of ultrasound, with better permeate recovery observed with larger particles. Particle size did not affect sound wave intensity, suggesting that the more effective control of fouling by large particles was due to greater lift and cross-flow drag forces on larger particles compared to smaller particles.

Magnetically controlled permeability membranes

KAUST Repository

Kosel, Jurgen

2013-10-31

A bioactive material delivery system can include a thermoresponsive polymer membrane and nanowires distributed within the thermoresponsive polymer membrane. Magnetic activation of a thermoresponsive polymer membrane can take place via altering the magnetization or dimensions of nanowires dispersed or ordered within the membrane matrix.

Magnetically controlled permeability membranes

KAUST Repository

Kosel, Jü rgen; Khashab, Niveen M.; Zaher, Amir

2013-01-01

A bioactive material delivery system can include a thermoresponsive polymer membrane and nanowires distributed within the thermoresponsive polymer membrane. Magnetic activation of a thermoresponsive polymer membrane can take place via altering the magnetization or dimensions of nanowires dispersed or ordered within the membrane matrix.

Controlled release of curcumin from poly(HEMA-MAPA) membrane.

Science.gov (United States)

Caka, Müşerref; Türkcan, Ceren; Aktaş Uygun, Deniz; Uygun, Murat; Akgöl, Sinan; Denizli, Adil

2017-05-01

In this work, poly(HEMA-MAPA) membranes were prepared by UV-polymerization technique. These membranes were characterized by SEM, FTIR, and swelling studies. Synthesized membranes had high porous structure. These membranes were used for controlled release of curcumin which is already used as folk remedy and used as drug for some certain diseases and cancers. Curcumin release was investigated for various pHs and temperatures. Optimum drug release yield was found to be as 70% at pH 7.4 and 37 °C within 2 h period. Time-depended release of curcumin was also investigated and its slow release from the membrane demonstrated within 48 h.

Periplasmic quality control in biogenesis of outer membrane proteins.

Science.gov (United States)

Lyu, Zhi Xin; Zhao, Xin Sheng

2015-04-01

The β-barrel outer membrane proteins (OMPs) are integral membrane proteins that reside in the outer membrane of Gram-negative bacteria and perform a diverse range of biological functions. Synthesized in the cytoplasm, OMPs must be transported across the inner membrane and through the periplasmic space before they are assembled in the outer membrane. In Escherichia coli, Skp, SurA and DegP are the most prominent factors identified to guide OMPs across the periplasm and to play the role of quality control. Although extensive genetic and biochemical analyses have revealed many basic functions of these periplasmic proteins, the mechanism of their collaboration in assisting the folding and insertion of OMPs is much less understood. Recently, biophysical approaches have shed light on the identification of the intricate network. In the present review, we summarize recent advances in the characterization of these key factors, with a special emphasis on the multifunctional protein DegP. In addition, we present our proposed model on the periplasmic quality control in biogenesis of OMPs.

Hydrogen concentration control utilizing a hydrogen permeable membrane

International Nuclear Information System (INIS)

Keating, S.J. Jr.

1976-01-01

The concentration of hydrogen in a fluid mixture is controlled to a desired concentration by flowing the fluid through one chamber of a diffusion cell separated into two chambers by a hydrogen permeable membrane. A gradient of hydrogen partial pressure is maintained across the membrane to cause diffusion of hydrogen through the membrane to maintain the concentration of hydrogen in the fluid mixture at the predetermined level. The invention has particular utility for the purpose of injecting into and/or separating hydrogen from the reactor coolant of a nuclear reactor system

Possible options for reducing occupational dose from the TMI-2 basement

International Nuclear Information System (INIS)

Munson, L.F.; Harty, R.

1985-11-01

The major sources of exposure in the basement include the enclosed stairwell/elevator shaft structure, water and sludge in the elevator shaft, cast concrete walls, concrete floor slab, water and sludge on the floor, and activity in the paint and loose surface contamination. The sources were identified using data obtained by the utility from water processing, water and solid samples, remote video inspections and radiation monitoring with a robot, and strings of thermoluminescent dosimeters lowered from upper elevations. The area dose rates in the basement range from approximately 4 R/hr (in the NE quadrant) to over 1100 R/hr (near the enclosed stairwell/elevator shaft structure). It is estimated that the basement contains between 11,000 and 21,000 curies of 137 Cs. Specific decontamination and cleanup techniques are discussed. These techniques include flushing with water, high-pressure water blasting, leaching, scabbling and chemical cleaning. The applicability of these techniques to the major sources of radiation are discussed, and possible approaches and work sequences for basement cleanup are given

Thick-skinned tectonics in a Late Cretaceous-Neogene intracontinental belt (High Atlas Mountains, Morocco): The flat-ramp fault control on basement shortening and cover folding

Science.gov (United States)

Fekkak, A.; Ouanaimi, H.; Michard, A.; Soulaimani, A.; Ettachfini, E. M.; Berrada, I.; El Arabi, H.; Lagnaoui, A.; Saddiqi, O.

2018-04-01

Most of the structural studies of the intracontinental High Atlas belt of Morocco have dealt with the central part of the belt, whose basement does not crop out. Here we study the Alpine deformation of the North Subatlas Zone, which is the part of the Western High Atlas (WHA) Paleozoic Massif that involves both Paleozoic basement units and remnants of their Mesozoic-Cenozoic cover formations. Our aim is to better constrain the geometry and kinematics of the basement faults during the Alpine shortening. Based on detail mapping, satellite imagery and field observations, we describe an array of sub-equatorial, transverse and oblique faults between the WHA Axial Zone and the Haouz Neogene basin. They define a mosaic of basement blocks pushed upon one another and upon the Haouz basement along the North Atlas Fault (NAF). The Axial Zone makes up the hanging-wall of the Adassil-Medinet Fault (AMF) south of this mosaic. The faults generally presents flat-ramp-flat geometry linked to the activation of multiple décollement levels, either within the basement where its foliation is subhorizontal or within favourable cover formations (Jurassic evaporites, Lower Cretaceous silty red beds, Upper Cretaceous evaporitic marls, Neogene basal argillites). The occurrence of the North Atlas detachment (NAD) allowed folded pop-up units to develop in front of the propagating NAF. Shortening began as early as the Campanian-Maastrichtian along the AMF. The direction of the maximum horizontal stress rotated from NNE-SSW to NNW-SSE from the Maastrichtian-Paleocene to the Neogene. The amount of shortening reaches 20% in the Azegour transect. This compares with the shortening amount published for the central-eastern High Atlas, suggesting that similar structures characterize the Paleozoic basement all along the belt. The WHA thick-skinned tectonics evokes that of the frontal Sevier belt and of the external Western Alps, although with a much minor pre-inversion burial.

Detection of gelatinolytic activity in developing basement membranes of the mouse embryo head by combining sensitive in situ zymography with immunolabeling.

Science.gov (United States)

Gkantidis, Nikolaos; Katsaros, Christos; Chiquet, Matthias

2012-10-01

Genetic evidence indicates that the major gelatinases MMP-2 and MMP-9 are involved in mammalian craniofacial development. Since these matrix metalloproteinases are secreted as proenzymes that require activation, their tissue distribution does not necessarily reflect the sites of enzymatic activity. Information regarding the spatial and temporal expression of gelatinolytic activity in the head of the mammalian embryo is sparse. Sensitive in situ zymography with dye-quenched gelatin (DQ-gelatin) has been introduced recently; gelatinolytic activity results in a local increase in fluorescence. Using frontal sections of wild-type mouse embryo heads from embryonic day 14.5-15.5, we optimized and validated a simple double-labeling in situ technique for combining DQ-gelatin zymography with immunofluorescence staining. MMP inhibitors were tested to confirm the specificity of the reaction in situ, and results were compared to standard SDS-gel zymography of tissue extracts. Double-labeling was used to show the spatial relationship in situ between gelatinolytic activity and immunostaining for gelatinases MMP-2 and MMP-9, collagenase 3 (MMP-13) and MT1-MMP (MMP-14), a major activator of pro-gelatinases. Strong gelatinolytic activity, which partially overlapped with MMP proteins, was confirmed for Meckel's cartilage and developing mandibular bone. In addition, we combined in situ zymography with immunostaining for extracellular matrix proteins that are potential gelatinase substrates. Interestingly, gelatinolytic activity colocalized precisely with laminin-positive basement membranes at specific sites around growing epithelia in the developing mouse head, such as the ducts of salivary glands or the epithelial fold between tongue and lower jaw region. Thus, this sensitive method allows to associate, with high spatial resolution, gelatinolytic activity with epithelial morphogenesis in the embryo.

Coating of reverse osmosis membranes with amphiphilic copolymers for biofouling control

KAUST Repository

Bucs, Szilard

2017-05-30

Surface coating of membranes may be a promising option to control biofilm development and biofouling impact on membrane performance of spiral-wound reverse osmosis (RO) systems. The objective of this study was to investigate the impact of an amphiphilic copolymer coating on biofilm formation and biofouling control. The coating was composed of both hydrophilic and hydrophobic monomers hydroxyethyl methacrylate (HEMA) and perfluorodecyl acrylate (PFA), respectively. Commercial RO membranes were coated with HEMA-PFA copolymer film. Long and short term biofouling studies with coated and uncoated membranes and feed spacer were performed using membrane fouling simulators (MFSs) operated in parallel, fed with water containing nutrients. For the long-term studies pressure drop development in time was monitored and after eight days the MFSs were opened and the accumulated biofilm on the membrane and spacer sheets was quantified and characterized. The presence of the membrane coating was determined using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Results showed that the amphiphilic coating (i) delayed biofouling (a lower pressure drop increase by a factor of 3 and a lower accumulated active biomass amount by a factor of 6), (ii) influenced the biofilm composition (23% lower polysaccharides and 132% higher protein content) and (iii) was still completely present on the membrane at the end of the biofouling study, showing that the coating was strongly attached to the membrane surface. Using coated membranes and feed spacers in combination with advanced cleaning strategies may be a suitable way to control biofouling.

Coating of reverse osmosis membranes with amphiphilic copolymers for biofouling control

KAUST Repository

Bucs, Szilard; Valladares Linares, Rodrigo; Siddiqui, Amber; Matin, Asif; Khan, Zafarullah; van Loosdrecht, Mark C.M.; Yang, Rong; Wang, Minghui; Gleason, Karen K.; Kruithof, Joop C.; Vrouwenvelder, Johannes S.

2017-01-01

Surface coating of membranes may be a promising option to control biofilm development and biofouling impact on membrane performance of spiral-wound reverse osmosis (RO) systems. The objective of this study was to investigate the impact of an amphiphilic copolymer coating on biofilm formation and biofouling control. The coating was composed of both hydrophilic and hydrophobic monomers hydroxyethyl methacrylate (HEMA) and perfluorodecyl acrylate (PFA), respectively. Commercial RO membranes were coated with HEMA-PFA copolymer film. Long and short term biofouling studies with coated and uncoated membranes and feed spacer were performed using membrane fouling simulators (MFSs) operated in parallel, fed with water containing nutrients. For the long-term studies pressure drop development in time was monitored and after eight days the MFSs were opened and the accumulated biofilm on the membrane and spacer sheets was quantified and characterized. The presence of the membrane coating was determined using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Results showed that the amphiphilic coating (i) delayed biofouling (a lower pressure drop increase by a factor of 3 and a lower accumulated active biomass amount by a factor of 6), (ii) influenced the biofilm composition (23% lower polysaccharides and 132% higher protein content) and (iii) was still completely present on the membrane at the end of the biofouling study, showing that the coating was strongly attached to the membrane surface. Using coated membranes and feed spacers in combination with advanced cleaning strategies may be a suitable way to control biofouling.

3D depth-to-basement and density contrast estimates using gravity and borehole data

Science.gov (United States)

Barbosa, V. C.; Martins, C. M.; Silva, J. B.

2009-05-01

We present a gravity inversion method for simultaneously estimating the 3D basement relief of a sedimentary basin and the parameters defining the parabolic decay of the density contrast with depth in a sedimentary pack assuming the prior knowledge about the basement depth at a few points. The sedimentary pack is approximated by a grid of 3D vertical prisms juxtaposed in both horizontal directions, x and y, of a right-handed coordinate system. The prisms' thicknesses represent the depths to the basement and are the parameters to be estimated from the gravity data. To produce stable depth-to-basement estimates we impose smoothness on the basement depths through minimization of the spatial derivatives of the parameters in the x and y directions. To estimate the parameters defining the parabolic decay of the density contrast with depth we mapped a functional containing prior information about the basement depths at a few points. We apply our method to synthetic data from a simulated complex 3D basement relief with two sedimentary sections having distinct parabolic laws describing the density contrast variation with depth. Our method retrieves the true parameters of the parabolic law of density contrast decay with depth and produces good estimates of the basement relief if the number and the distribution of boreholes are sufficient. We also applied our method to real gravity data from the onshore and part of the shallow offshore Almada Basin, on Brazil's northeastern coast. The estimated 3D Almada's basement shows geologic structures that cannot be easily inferred just from the inspection of the gravity anomaly. The estimated Almada relief presents steep borders evidencing the presence of gravity faults. Also, we note the existence of three terraces separating two local subbasins. These geologic features are consistent with Almada's geodynamic origin (the Mesozoic breakup of Gondwana and the opening of the South Atlantic Ocean) and they are important in understanding

Effects of ionizing radiation on glycerolated amniotic membranes as a substract for cultured human epithelium

International Nuclear Information System (INIS)

Paggiaro, Andre Oliveira

2011-01-01

The amniotic membrane (AM) is a biomaterial with biological properties that are beneficial to tissue repair. It has been used as a temporary coverage to threat burns and chronic wounds. Recently, it has been served as a substrate for keratinocytes culture to construct a living skin equivalent. However, MA is a biological material, and its transplantation could cause infectious disease for receptors. So, it must be preserved and sterilized before clinical use. The aim of this study was to evaluate the radiation effects on glycerol-preserved MA, considering its compatibility to support human keratinocytes culture. Four MA were stored in high concentrations of glycerol (> 85%) and half of them were radio sterilized with a dose of 25 kGy. Then, we established two groups: nonirradiated MA (MA-ni) and irradiated MA (MA-i). Both groups was deepithelialized by a standardized protocol and was investigated morphologically, immunohistochemical and ultrastructural. Subsequently human keratinocytes were cultivated immersed and in air-liquid interface on denuded surface of MA-i and MA-ni. The results were compared at 14 and 21 days of culture by light and electron microscopy. After epithelial denudation, analyses demonstrated the continuity of the basement membrane in MA-ni group, whereas in the irradiated group, there was no indication of the basement membrane’s presence on the surface of MA. The cell cultures showed that in the non-irradiated group, there was growth of a multi-layered and differentiated epithelium, with a stratum corneum’s formation in air-liquid interface. In the irradiated group, the epithelium had only two or three layer, little cell differentiation, with the same results immersed or air-liquid interface system. Glycerol-preserved MA was biocompatible with the growth of a cultivated epithelium, showing its potential as a skin substitute. Irradiation at 25 kGy cause structural damage to the tissue, making changes in basement membrane, that facilitates

Does Chlorination of Seawater Reverse Osmosis Membranes Control Biofouling?

KAUST Repository

Khan, Muhammad Tariq; Hong, Pei-Ying; Nada, Nabil; Croue, Jean Philippe

2015-01-01

Biofouling is the major problem of reverse osmosis (RO) membranes used for desalting seawater (SW). The use of chlorine is a conventional and common practice to control/prevent biofouling. Unlike polyamide RO membranes, cellulose triacetate (CTA) RO membranes display a high chlorine tolerance. Due to this characteristic, CTA membranes are used in most of the RO plants located in the Middle East region where the elevated seawater temperature and water quality promote the risk of membrane biofouling. However, there is no detailed study on the investigation/characterization of CTA-RO membrane fouling. In this investigation, the fouling profile of a full–scale SWRO desalination plant operating with not only continuous chlorination of raw seawater but also intermittent chlorination of CTA-RO membranes was studied. Detailed water quality and membrane fouling analyses were conducted. Profiles of microbiological, inorganic, and organic constituents of analysed fouling layers were extensively discussed. Our results clearly identified biofilm development on these membranes. The incapability of chlorination on preventing biofilm formation on SWRO membranes could be assigned to its failure in effectively reaching throughout the different regions of the permeators. This failure could have occurred due to three main factors: plugging of membrane fibers, chlorine consumption by organics accumulated on the front side fibers, or chlorine adaptation of certain bacterial populations.

Does Chlorination of Seawater Reverse Osmosis Membranes Control Biofouling?

KAUST Repository

Khan, Muhammad Tariq

2015-04-01

Biofouling is the major problem of reverse osmosis (RO) membranes used for desalting seawater (SW). The use of chlorine is a conventional and common practice to control/prevent biofouling. Unlike polyamide RO membranes, cellulose triacetate (CTA) RO membranes display a high chlorine tolerance. Due to this characteristic, CTA membranes are used in most of the RO plants located in the Middle East region where the elevated seawater temperature and water quality promote the risk of membrane biofouling. However, there is no detailed study on the investigation/characterization of CTA-RO membrane fouling. In this investigation, the fouling profile of a full–scale SWRO desalination plant operating with not only continuous chlorination of raw seawater but also intermittent chlorination of CTA-RO membranes was studied. Detailed water quality and membrane fouling analyses were conducted. Profiles of microbiological, inorganic, and organic constituents of analysed fouling layers were extensively discussed. Our results clearly identified biofilm development on these membranes. The incapability of chlorination on preventing biofilm formation on SWRO membranes could be assigned to its failure in effectively reaching throughout the different regions of the permeators. This failure could have occurred due to three main factors: plugging of membrane fibers, chlorine consumption by organics accumulated on the front side fibers, or chlorine adaptation of certain bacterial populations.

Mapping magnetic lineaments and subsurface basement beneath ...

Indian Academy of Sciences (India)

65

studied the basement structures beneath parts of the Lower Benue Trough (LBT). Anudu et .... order vertical derivatives can be calculated respectively using the relations below: 145. ( ) ... minerals as in the case of the FVD-RTP-TMI (Figure 6).

Reactor-building-basement radionuclide and source distribution studies. Volume 3

International Nuclear Information System (INIS)

Cox, T.E.; Horan, J.T.; Worku, G.

1983-06-01

The Three Mile Island Unit 2 (TMI-2) Reactor Building basement has been sampled several times since August 1979. This report compiles the analytical results and sample history for the liquid and solid samples obtained to date. In addition, basement radiation levels were also obtained using thermoluminescent dosimeters (TLDs). The data obtained will provide information to support ongoing mass balance and source term studies and will aid in characterizing the 282-ft elevation for decontamination planning and dose reduction

Nanomaterials for membrane fouling control: accomplishments and challenges.

Science.gov (United States)

Yang, Qian; Mi, Baoxia

2013-11-01

We report a review of recent research efforts on incorporating nanomaterials-including metal/metal oxide nanoparticles, carbon-based nanomaterials, and polymeric nanomaterials-into/onto membranes to improve membrane antifouling properties in biomedical or potentially medical-related applications. In general, nanomaterials can be incorporated into/onto a membrane by blending them into membrane fabricating materials or by attaching them to membrane surfaces via physical or chemical approaches. Overall, the fascinating, multifaceted properties (eg, high hydrophilicity, superparamagnetic properties, antibacterial properties, amenable functionality, strong hydration capability) of nanomaterials provide numerous novel strategies and unprecedented opportunities to fully mitigate membrane fouling. However, there are still challenges in achieving a broader adoption of nanomaterials in the membrane processes used for biomedical applications. Most of these challenges arise from the concerns over their long-term antifouling performance, hemocompatibility, and toxicity toward humans. Therefore, rigorous investigation is still needed before the adoption of some of these nanomaterials in biomedical applications, especially for those nanomaterials proposed to be used in the human body or in contact with living tissue/body fluids for a long period of time. Nevertheless, it is reasonable to predict that the service lifetime of membrane-based biomedical devices and implants will be prolonged significantly with the adoption of appropriate fouling control strategies. Copyright © 2013 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Relationship of Basal laminar deposit and membranous debris to the clinical presentation of early age-related macular degeneration.

Science.gov (United States)

Sarks, Shirley; Cherepanoff, Svetlana; Killingsworth, Murray; Sarks, John

2007-03-01

To correlate basal laminar deposit (BLamD) and membranous debris, including basal linear deposit (BLinD), with the evolution of early age-related macular degeneration (AMD). A clinicopathologic collection of 132 eyes with a continuous layer of BLamD was reviewed. The thickness and type of BLamD and the sites of membranous debris deposition were correlated with the clinical progression of the disease. Two types of BLamD, termed early and late, were identified based on light microscopic appearance by using the picro-Mallory stain. The progressive accumulation of late type BLamD correlated well with increasing BLamD thickness, advancing RPE degeneration, poorer vision, increasing age, and clinically evident pigment changes. Membranous debris initially accumulated diffusely as BLinD, most eyes with BLinD and early BLamD remaining funduscopically normal. However, membranous debris also formed focal collections as basal mounds internal to the RPE basement membrane and as soft drusen external to the basement membrane. Eyes in which membranous debris remained confined to basal mounds belonged to older patients with poorer vision, whereas patients with soft drusen were younger and had better vision. The presence of BLinD and early BLamD define threshold AMD, which manifests clinically as a normal fundus. Although late BLamD correlates most closely with clinical pigment abnormalities, it is the quantity and sites of membranous debris accumulation that appear to determine whether the disease develops pigment changes only or follows the alternative pathway of soft drusen formation with its attendant greater risk of choroidal neovascularization (CNV).

Modeling radon entry into houses with basements: Model description and verification

International Nuclear Information System (INIS)

Revzan, K.L.; Fisk, W.J.; Gadgil, A.J.

1991-01-01

We model radon entry into basements using a previously developed three-dimensional steady-state finite difference model that has been modified in the following ways: first, cylindrical coordinates are used to take advantage of the symmetry of the problem in the horizontal plant; second, the configuration of the basement has been made more realistic by incorporating the concrete footer; third, a quadratic relationship between the pressure and flow in the L-shaped gap between slab, footer, and wall has been employed; fourth, the natural convection of the soil gas which follows from the heating of the basement in winter has been taken into account. The temperature field in the soil is determined from the equation of energy conservation, using the basement, surface, and deep-soil temperatures as boundary conditions. The pressure field is determined from Darcy's law and the equation of mass conservation (continuity), assuming that there is no flow across any boundary except the soil surface (atmospheric pressure) and the opening in the basement shell (fixed pressure). After the pressure and temperatures field have been obtained the velocity field is found from Darcy's law. Finally, the radon concentration field is found from the equation of mass-transport. The convective radon entry rate through the opening or openings is then calculated. In this paper we describe the modified model, compare the predicted radon entry rates with and without the consideration of thermal convection, and compare the predicted rates with determined from data from 7 houses in the Spokane River valley of Washington and Idaho. Although the predicted rate is much lower than the mean of the rates determined from measurements, errors in the measurement of soil permeability and variations in the permeability of the area immediately under the basement slab, which has a significant influence on the pressure field, can account for the range of entry rates inferred from the data. 25 refs., 8 figs

The basement control on Xiazhuang uranium ore field in south sector of Wuyi tumescence and relevant geological problems

International Nuclear Information System (INIS)

Xu Dazhong; Xue Zhenhua

1994-01-01

Based on the two rift-trench tectonic framework in Wuyi as well as its adjacent areas proposed previously, this study takes Yingtan-Nancheng-Anyuan-Heyuan tenacity fracture belt as the geological boundary between two types of uranium deposits (granite and volcanic rock). It is noted that the distinct function of Caledonian movement in this area is the formation of the linear migmatization and granitization on the basis of rift and tumescence basement. Simultaneously, according to the new discovery of hypometamorphic rock and large scaled ductile mylonitized zone in Xiazhuang uranium ore field and its adjacent area, it is concluded that the Xiazhuang uranium ore field is the result of multiple tectonism and magmatic activations on the Caledonian hot dome on the basis of ancient basement. Because the uranium mineralization is present in two kinds of rocks (ductile and brittle), it is suggested that the types of mineralization in Xiazhuang can be considered in order to guide the further prospecting

Controlled change of transport properties of poly(ethylene terephthalate) track membranes by plasma method

International Nuclear Information System (INIS)

Kravets, L I; Dmitriev, S N; Drachev, A I; Gilman, A B; Lazea, A; Dinescu, G

2007-01-01

A process of plasma polymerization of dimethylaniline and acrylic acid vapours on the surface of poly(ethylene terephthalate) track membranes has been investigated. The surface and hydrodynamic properties of the composite membranes produced in this case have been studied. It is shown that the water permeability of the obtained polymeric membranes can be controlled by changing the filtrate pH. Membranes with such properties can be used for controllable drug delivery and in sensor control

Prostate-specific membrane antigen (PSMA)-mediated laminin proteolysis generates a pro-angiogenic peptide

Czech Academy of Sciences Publication Activity Database

Conway, R. E.; Rojas, C.; Alt, J.; Nováková, Zora; Richardson, S. M.; Rodrick, T. C.; Fuentes, J. L.; Richardson, N. H.; Attalla, J.; Stewart, S.; Fahmy, B.; Bařinka, Cyril; Ghosh, M.; Shapiro, L. H.; Slusher, B. S.

2016-01-01

Roč. 19, č. 4 (2016), s. 487-500 ISSN 0969-6970 R&D Projects: GA ČR GAP301/12/1513; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:86652036 Keywords : TUMOR-ASSOCIATED NEOVASCULATURE * BASEMENT-MEMBRANE * DISTINCT ANTITUMOR PROPERTIES Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 5.253, year: 2016

Circulating Vascular Basement Membrane Fragments are Associated with the Diameter of the Abdominal Aorta and Their Expression Pattern is Altered in AAA Tissue.

Science.gov (United States)

Holsti, Mari; Wanhainen, Anders; Lundin, Christina; Björck, Martin; Tegler, Gustaf; Svensson, Johan; Sund, Malin

2018-04-12

Abdominal aortic aneurysm (AAA) is characterised by enhanced proteolytic activity, and extracellular matrix (ECM) remodelling in the vascular wall. Type IV and XVIII collagen/endostatin are structural proteins in vascular basement membrane (VBM), a specialised ECM structure. Here the association between plasma levels of these collagens with the aortic diameter and expansion rate is studied, and their expression in aortic tissue characterised. This was a retrospective population based cohort study. Type IV and XVIII collagen/endostatin were analysed in plasma by ELISA assay in 615 men, divided into three groups based on the aortic diameter: 1) normal aorta ≤ 25 mm, 2) sub-aneurysmal aorta (SAA) 26-29 mm, and 3) AAA ≥ 30 mm. Follow up data were available for 159 men. The association between collagen levels and aortic diameter at baseline, and with the expansion rate at follow up were analysed in ordinal logistic regression and linear regression models, controlling for common confounding factors. Tissue expression of the collagens was analysed in normal aorta (n = 6) and AAA (n = 6) by immunofluorescence. Plasma levels of type XVIII collagen/endostatin (136 ng/mL [SD 29] in individuals with a normal aorta diameter, 154 ng/ml [SD 45] in SAA, and 162 ng/ml [SD 46] in AAA; p = .001) and type IV collagen (105 ng/mL [SD 42] normal aorta, 124 ng/ml [SD 46] SAA, and 127 ng/ml [SD 47] AAA; p = .037) were associated with a larger aortic diameter. A significant association was found between the baseline levels of type XVIII/endostatin and the aortic expansion rate (p = .035), but in the multivariable model, only the initial aortic diameter remained significantly associated with expansion (p = .005). Altered expression patterns of both collagens were observed in AAA tissue. Plasma levels of circulating type IV and XVIII collagen/endostatin increase with AAA diameter. The expression pattern of VBM proteins is altered in the aneurysm wall. Copyright �

Basement inheritance and salt tectonics in the SE Barents Sea: Insights from new potential field data

Science.gov (United States)

Gernigon, L.; Broenner, M.; Dumais, M. A.; Gradmann, S.; Grønlie, A.; Nasuti, A.; Roberts, D.

2017-12-01

The tectonic evolution of the former `grey zone' between Russia and Norway has so far remained poorly constrained due to a lack of geophysical data. In 2014, we carried out a new aeromagnetic survey (BASAR-14) in the southern part of the new Norwegian offshore territory. Caledonian and Timanian structures, highlighted by the new potential field data, dominate the basement patterns and have exerted a strong influence on the structure and development of the overlying basins and basement highs. Clearly associated with NW-SE-oriented Timanian trends, the Tiddlybanken Basin represents an atypical sag basin that developed at the southern edge of the Fedynsky High. Regional extension and rapid sedimentation initiated the salt tectonics in the Barents Sea in the Early Triassic. Some of the pillows became diapiric during the Early Triassic and rejuvenated during subsequent Jurassic-Tertiary episodes of regional extension and/or compression. At present, quite a few large diapiric salt domes along the Nordkapp and Tiddlybanken basins are relatively shallow, locally reaching the seabed and thus show a clear bathymetric and magnetic signature. Quantitative modelling along 2D seismic transects was also carried out to constrain the structural and basement composition of the study area. The predominant NE-SW Mesozoic trend of the Nordkapp Basin represents a major crustal hinge zone between the Finnmark Platform, poorly affected by major crustal deformation, and the Bjarmeland Platform where Late Palaeozoic rifting controlled the widespread accumulation of salt deposits in Late Carboniferous-Early Permian time. The entire structure and segmentation of the Nordkapp Basin have been influenced by the inherited basement configuration highlighted by the new aeromagnetic data. Both the Nordkapp and the Tiddlybanken basins appear to lie at the edge of a peculiar thick and rigid crustal feature that coincides with a highly magnetic region. The abrupt termination of the eastern Nordkapp

The metamorphic basement of the Cordillera Frontal of Mendoza: New geochronologic and isotopic data

International Nuclear Information System (INIS)

Basei, Miguel; Ramos, Victor A.; Vujovich, Graciela I.; Poma, Stella

1998-01-01

The metamorphic rocks of the Cordillera Frontal exposed in the Cordon del Portillo, Mendoza were examined by Rb/Sr geochronology and Nd/Sm isotopic analysis. The Rb/Sr data defined a Devonian age for the last metamorphic episode, similar to the previous K/Ar and Ar/Ar ages obtained in this region and western Precordillera. The isotopic analysis identified three sets of model ages: 1.- The oldest corresponds to a set of meta sedimentary rocks with a model age of 1,400 to 1,700 Ma; 2.- A monzogranodiorite with a model age of 1,000 Ma; and 3.- Metabasites with model ages between 577 and 330 Ma. These rocks are interpreted as 1.- A typical Grenvillian derived basement; 2.- Late Paleozoic granitoids derived from a different Proterozoic basement; and 3.- Some Eopaleozoic metabasites tectonically inter fingered with the Grenvillian basement. These new data are coherent with the existence of a Laurentia derived terrane, Chilenia, that was separated by oceanic rocks from the basement of Pre cordillera during Eopaleozoic times. This last basement known as the Cuyania terrane, was also derived from Laurentia. (author)

Synthesis and localization of two sulphated glycoproteins associated with basement membranes and the extracellular matrix

DEFF Research Database (Denmark)

Hogan, B L; Taylor, A; Kurkinen, M

1982-01-01

's membrane by mouse embryo parietal endoderm cells (Hogan, B. L.M., A. Taylor, and A.R. Cooper, 1982, Dev. Biol., 90:210-214). Both the Mr 180,000 and 150,000 sgps are deposited in the detergent-insoluble matrix of cultured cells, but they do not apparently undergo any disulphide-dependent intermolecular...... interactions and are not precursors or products of each other. They contain asparagine-linked oligosaccharides, but these are not the exclusive sites of sulphate labeling. Antiserum raised against the Mr 150,000 sgp C of Reichert's membranes has been used in an immunohistochemical analysis of rat skin...

Structural and Geophysical Characterization of Oklahoma Basement

Science.gov (United States)

Morgan, C.; Johnston, C. S.; Carpenter, B. M.; Reches, Z.

2017-12-01

Oklahoma has experienced a large increase in seismicity since 2009 that has been attributed to wastewater injection. Most earthquakes, including four M5+ earthquakes, nucleated at depths > 4 km, well within the pre-Cambrian crystalline basement, even though wastewater injection occurred almost exclusively in the sedimentary sequence above. To better understand the structural characteristics of the rhyolite and granite that makeup the midcontinent basement, we analyzed a 150 m long core recovered from a basement borehole (Shads 4) in Rogers County, NE Oklahoma. The analysis of the fracture network in the rhyolite core included measurements of fracture inclination, aperture, and density, the examination fracture surface features and fill minerology, as well as x-ray diffraction analysis of secondary mineralization. We also analyzed the highly fractured and faulted segments of the core with a portable gamma-ray detector, magnetometer, and rebound hammer. The preliminary analysis of the fractures within the rhyolite core showed: (1) Fracture density increasing with depth by a factor of 10, from 4 fractures/10m in the upper core segment to 40 fracture/10m at 150 m deeper. (2) The fractures are primarily sub-vertical, inclined 10-20° from the axis of the vertical core. (3) The secondary mineralization is dominated by calcite and epidote. (4) Fracture aperture ranges from 0.35 to 2.35mm based on the thickness of secondary filling. (5) About 8% of the examined fractures display slickenside striations. (6) Increases of elasticity (by rebound hammer) and gamma-ray emissions are systematically correlated with a decrease in magnetic susceptibility in core segments of high fracture density and/or faulting; this observation suggests diagenetic fracture re-mineralization.

Primary cellular meningeal defects cause neocortical dysplasia and dyslamination

Science.gov (United States)

Hecht, Jonathan H.; Siegenthaler, Julie A.; Patterson, Katelin P.; Pleasure, Samuel J.

2010-01-01

Objective Cortical malformations are important causes of neurological morbidity, but in many cases their etiology is poorly understood. Mice with Foxc1 mutations have cellular defects in meningeal development. We use hypomorphic and null alleles of Foxc1 to study the effect of meningeal defects on neocortical organization. Methods Embryos with loss of Foxc1 activity were generated using the hypomorphic Foxc1hith allele and the null Foxc1lacZ allele. Immunohistologic analysis was used to assess cerebral basement membrane integrity, marginal zone heterotopia formation, neuronal overmigration, meningeal defects, and changes in basement membrane composition. Dysplasia severity was quantified using two measures. Results Cortical dysplasia resembling cobblestone cortex, with basement membrane breakdown and lamination defects, is seen in Foxc1 mutants. As Foxc1 activity was reduced, abnormalities in basement membrane integrity, heterotopia formation, neuronal overmigration, and meningeal development appeared earlier in gestation and were more severe. Surprisingly, the basement membrane appeared intact at early stages of development in the face of severe deficits in meningeal development. Prominent defects in basement membrane integrity appeared as development proceeded. Molecular analysis of basement membrane laminin subunits demonstrated that loss of the meninges led to changes in basement membrane composition. Interpretation Cortical dysplasia can be caused by cellular defects in the meninges. The meninges are not required for basement membrane establishment but are needed for remodeling as the brain expands. Specific changes in basement membrane composition may contribute to subsequent breakdown. Our study raises the possibility that primary meningeal defects may cortical dysplasia in some cases. PMID:20976766

The significance of strike-slip faulting in the basement of the Zagros fold and thrust belt

Energy Technology Data Exchange (ETDEWEB)

Hessami, K.; Koyi, H.A.; Talbot, C.J. [Uppsala University (Sweden). Institute of Earth Sciences

2000-01-01

Lateral offsets in the pattern of seismicity along the Zagros fold and thrust belt indicate that transverse faults segmenting the Arabian basement are active deep-seated strike-slip faults. The dominant NW-SE trending features of the belt have undergone repeated horizontal displacements along these transverse faults. These reactivated basement faults, which are inherited from the Pan-African construction phase, controlled both deposition of the Phanerozoic cover before Tertiary-Recent deformation of the Zagros and probably the entrapment of hydrocarbons on the NE margin of Arabia and in the Zagros area. We have used observations of faulting recognized on Landsat satellite images, in conjunction with the spatial distribution of earthquakes and their focal mechanism solutions, to infer a tectonic model for the Zagros basement. Deformation in the NW Zagros appears to be concentrated on basement thrusts and a few widely-spaced north-south trending strike-slip faults which separate major structural segments. In the SE Zagros, two main structural domains can be distinguished. A domain of NNW-trending right-lateral faults in the northern part of the SE Zagros implies that fault-bounded blocks are likely to have rotated anticlockwise about vertical axes relative to both Arabia and Central Iran. In contrast, the predominance of NNE-trending left-lateral faults in the southern part of the SE Zagros implies that fault-bounded blocks may have rotated clockwise about vertical axes. We propose a tectonic model in which crustal blocks bounded by strike-slip faults in a zone of simple shear rotate about vertical axes relative to both Arabia and Central Iran. The presence of domains of strike-slip and thrust faulting in the Zagros basement suggest that some of the convergence between Arabia and Central Iran is accommodated by rotation and possible lateral movement of crust along the belt by strike-slip faults, as well as by obvious crustal shortening and thickening along thrust

Basement radon entry and stack driven moisture infiltration reduced by active soil depressurization

Science.gov (United States)

C.R. Boardman; Samuel V. Glass

2015-01-01

This case study presents measurements of radon and moisture infiltration from soil gases into the basement of an unoccupied research house in Madison, Wisconsin, over two full years. The basement floor and exterior walls were constructed with preservative-treated lumber and plywood. In addition to continuous radon monitoring, measurements included building air...

Indoors and health: results of a systematic literature review assessing the potential health effects of living in basements.

Science.gov (United States)

Mezzoiuso, Angelo Giosué; Gola, Marco; Rebecchi, Andrea; Riccò, Matteo; Capolongo, Stefano; Buffoli, Maddalena; Tirani, Marcello; Odone, Anna; Signorelli, Carlo

2017-10-23

A new law approved in March 2017 in the Lombardy Region makes it possible to live in basements. Basements are defined as buildings partly below curb level but with at least one-half of its height above the curb. Basements' features and structural characteristics might pose risks to human health. In this paper we adopt a multidisciplinary approach to assess the potential health effects of living in basements. In particular, we define a conceptual framework to describe basements' structural characteristics which are risk factors, as well as the mechanisms through which they impact on human health. We also conduct a systematic review on the scientific databases PubMed,Embase, DOAJ, Proquest and EBSCO to retrieve, pool and critically analyze all available research that quantified the risk of living in basements for different health outcomes. Available evidence suggests living in basements increases the risk of respiratory diseases (asthma and allergic disorders); more heterogeneous data are available for cancers and cardiovascular diseases. As more quantitative data need to be prospectively retrieved to assess and monitor the risk of living in basements for human health, clear minimum requirements for light, air, sanitation and egress are to be defined by technical experts and enforced by policy makers.

How membrane lipids control the 3D structure and function of receptors

Directory of Open Access Journals (Sweden)

Jacques Fantini

2018-02-01

Full Text Available The cohabitation of lipids and proteins in the plasma membrane of mammalian cells is controlled by specific biochemical and biophysical rules. Lipids may be either constitutively tightly bound to cell-surface receptors (non-annular lipids or less tightly attached to the external surface of the protein (annular lipids. The latter are exchangeable with surrounding bulk membrane lipids on a faster time scale than that of non-annular lipids. Not only do non-annular lipids bind to membrane proteins through stereoselective mechanisms, they can also help membrane receptors acquire (or maintain a functional 3D structure. Cholesterol is the prototype of membrane lipids that finely controls the 3D structure and function of receptors. However, several other lipids such as sphingolipids may also modulate the function of membrane proteins though conformational adjustments. All these concepts are discussed in this review in the light of representative examples taken from the literature.

Nitric oxide treatment for the control of reverse osmosis membrane biofouling.

Science.gov (United States)

Barnes, Robert J; Low, Jiun Hui; Bandi, Ratnaharika R; Tay, Martin; Chua, Felicia; Aung, Theingi; Fane, Anthony G; Kjelleberg, Staffan; Rice, Scott A

2015-04-01

Biofouling remains a key challenge for membrane-based water treatment systems. This study investigated the dispersal potential of the nitric oxide (NO) donor compound, PROLI NONOate, on single- and mixed-species biofilms formed by bacteria isolated from industrial membrane bioreactor and reverse osmosis (RO) membranes. The potential of PROLI NONOate to control RO membrane biofouling was also examined. Confocal microscopy revealed that PROLI NONOate exposure induced biofilm dispersal in all but two of the bacteria tested and successfully dispersed mixed-species biofilms. The addition of 40 μM PROLI NONOate at 24-h intervals to a laboratory-scale RO system led to a 92% reduction in the rate of biofouling (pressure rise over a given period) by a bacterial community cultured from an industrial RO membrane. Confocal microscopy and extracellular polymeric substances (EPS) extraction revealed that PROLI NONOate treatment led to a 48% reduction in polysaccharides, a 66% reduction in proteins, and a 29% reduction in microbial cells compared to the untreated control. A reduction in biofilm surface coverage (59% compared to 98%, treated compared to control) and average thickness (20 μm compared to 26 μm, treated compared to control) was also observed. The addition of PROLI NONOate led to a 22% increase in the time required for the RO module to reach its maximum transmembrane pressure (TMP), further indicating that NO treatment delayed fouling. Pyrosequencing analysis revealed that the NO treatment did not significantly alter the microbial community composition of the membrane biofilm. These results present strong evidence for the application of PROLI NONOate for prevention of RO biofouling. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Evaluation of Human Amniotic Membrane as a Wound Dressing for Split-Thickness Skin-Graft Donor Sites

Directory of Open Access Journals (Sweden)

Denys J. Loeffelbein

2014-01-01

Full Text Available Human amniotic membrane (HAM has been used as a biomaterial in various surgical procedures and exceeds some qualities of common materials. We evaluated HAM as wound dressing for split-thickness skin-graft (STSG donor sites in a swine model (Part A and a clinical trial (Part B. Part A: STSG donor sites in 4 piglets were treated with HAM or a clinically used conventional polyurethane (PU foil (n=8 each. Biopsies were taken on days 5, 7, 10, 20, 40, and 60 and investigated immunohistochemically for alpha-smooth muscle actin (αSMA: wound contraction marker, von Willebrand factor (vWF: angiogenesis, Ki-67 (cell proliferation, and laminin (basement membrane integrity. Part B: STSG donor sites in 45 adult patients (16 female/29 male were treated with HAM covered by PU foam, solely by PU foam, or PU foil/paraffin gauze (n=15 each. Part A revealed no difference in the rate of wound closure between groups. HAM showed improved esthetic results and inhibitory effects on cicatrization. Angioneogenesis was reduced, and basement membrane formation was accelerated in HAM group. Part B: no difference in re-epithelialization/infection rate was found. HAM caused less ichor exudation and less pruritus. HAM has no relevant advantage over conventional dressings but might be a cost-effective alternative.

Glutathione S-transferase Mu 2-transduced mesenchymal stem cells ameliorated anti-glomerular basement membrane antibody-induced glomerulonephritis by inhibiting oxidation and inflammation.

Science.gov (United States)

Li, Yajuan; Yan, Mei; Yang, Jichen; Raman, Indu; Du, Yong; Min, Soyoun; Fang, Xiangdong; Mohan, Chandra; Li, Quan-Zhen

2014-01-30

Oxidative stress is implicated in tissue inflammation, and plays an important role in the pathogenesis of immune-mediated nephritis. Using the anti-glomerular basement membrane antibody-induced glomerulonephritis (anti-GBM-GN) mouse model, we found that increased expression of glutathione S-transferase Mu 2 (GSTM2) was related to reduced renal damage caused by anti-GBM antibodies. Furthermore, mesenchymal stem cell (MSC)-based therapy has shed light on the treatment of immune-mediated kidney diseases. The aim of this study was to investigate if MSCs could be utilized as vehicles to deliver the GSTM2 gene product into the kidney and to evaluate its potential therapeutic effect on anti-GBM-GN. The human GSTM2 gene (hGSTM2) was transduced into mouse bone marrow-derived MSCs via a lentivirus vector to create a stable cell line (hGSTM2-MSC). The cultured hGSTM2-MSCs were treated with 0.5 mM H2O2, and apoptotic cells were measured by terminal dUTP nick-end labeling (TUNEL) assay. The 129/svj mice, which were challenged with anti-GBM antibodies, were injected with 10⁶ hGSTM2-MSCs via the tail vein. Expression of hGSTM2 and inflammatory cytokines in the kidney was assayed by quantitative PCR and western blotting. Renal function of mice was evaluated by monitoring proteinuria and levels of blood urea nitrogen (BUN), and renal pathological changes were analyzed by histochemistry. Immunohistochemical analysis was performed to measure inflammatory cell infiltration and renal cell apoptosis. MSCs transduced with hGSTM2 exhibited similar growth and differentiation properties to MSCs. hGSTM2-MSCs persistently expressed hGSTM2 and resisted H2O2-induced apoptosis. Upon injection into 129/svj mice, hGSTM2-MSCs migrated to the kidney and expressed hGSTM2. The anti-GBM-GN mice treated with hGSTM2-MSCs exhibited reduced proteinuria and BUN (58% and 59% reduction, respectively) and ameliorated renal pathological damage, compared with control mice. Mice injected with hGSTM2-MSCs showed

Surface analogue outcrops of deep fractured basement reservoirs in extensional geological settings. Examples within active rift system (Uganda) and proximal passive margin (Morocco).

Science.gov (United States)

Walter, Bastien; Géraud, Yves; Diraison, Marc

2014-05-01

The important role of extensive brittle faults and related structures in the development of reservoirs has already been demonstrated, notably in initially low-porosity rocks such as basement rocks. Large varieties of deep-seated resources (e.g. water, hydrocarbons, geothermal energy) are recognized in fractured basement reservoirs. Brittle faults and fracture networks can develop sufficient volumes to allow storage and transfer of large amounts of fluids. Development of hydraulic model with dual-porosity implies the structural and petrophysical characterization of the basement. Drain porosity is located within the larger fault zones, which are the main fluid transfer channels. The storage porosity corresponds both to the matrix porosity and to the volume produced by the different fractures networks (e.g. tectonic, primary), which affect the whole reservoir rocks. Multi-scale genetic and geometric relationships between these deformation features support different orders of structural domains in a reservoir, from several tens of kilometers to few tens of meters. In subsurface, 3D seismic data in basement can be sufficient to characterize the largest first order of structural domains and bounding fault zones (thickness, main orientation, internal architecture, …). However, lower order structural blocks and fracture networks are harder to define. The only available data are 1D borehole electric imaging and are used to characterize the lowest order. Analog outcrop studies of basement rocks fill up this resolution gap and help the understanding of brittle deformation, definition of reservoir geometries and acquirement of reservoir properties. These geological outcrop studies give information about structural blocks of second and third order, getting close to the field scale. This allows to understand relationships between brittle structures geometry and factors controlling their development, such as the structural inheritance or the lithology (e.g. schistosity, primary

Magnetic basement in the central Bay of Bengal

Digital Repository Service at National Institute of Oceanography (India)

Sarma, K.V.L.N.S.; Ramana, M.V.; Ramprasad, T.; Desa, M.; Subrahmanyam, V.; Krishna, K.S.; Rao, M.M.M.

Analyses of about 6000 km of processed magnetic data in the central Bay of Bengal using Analytical Signal Processing and Werner Deconvolution techniques revealed that the depth to top of the magnetic basement varies between 5 and 12 km from the sea...

Improved Access To Aging Ocean Basement Biosphere For Microbial Geochemical Studies

Science.gov (United States)

Cowen, J. P.; Glazer, B.; Rappe, M.; Kenig, F.; Fisher, A.; Copson, D.; Harris, D.; Jolly, J.; Nuzzio, D.

2005-12-01

CORK observatories affixed to Integrated Ocean Drilling Program (IODP) boreholes offer an unprecedented opportunity to study biogeochemical properties and microbial diversity in circulating fluids from sediment-buried ocean basement. Preliminary 16S rRNA gene sequence data from 65 degrees C fluids escaping from the top of the over-pressured ODP borehole 1026B, on the flanks of the Juan de Fuca Ridge indicated the presence of diverse Bacteria and Archaea, including gene clones with varying degrees of relatedness to known dissimilatory nitrate reducers (with ammonia production), thermophilic sulfate reducers, and thermophilic fermentative heterotrophs, consistent with fluid chemistry measurements. However, questions remain regarding microbial community structure, key metabolic pathways and rates, and redox chemistry of the basement fluids, along with concerns for contamination issues. We describe ongoing developments intended to address key in situ analytical and sampling challenges including: 1) The new generation CORKs' dedicated microbiological/geochemical fluid delivery system specifically designed to minimize chemical contamination and surface biofouling; and 2) Development of a seafloor instrument sled for coupling to the CORK's bio-fluid delivery system for acquisition of real-time, in situ electrochemical (voltammetry) redox chemistry data on basement fluids, in addition to in situ particle filtration of basement fluids for molecular genetics, culturing and biogeochemical studies. Results of the first deployment of this instrument sled to new CORK observatory 1301A in Cascadia Basin, on the flanks of the Juan de Fuca Ridge, will be described.

The application of nitric oxide to control biofouling of membrane bioreactors.

Science.gov (United States)

Luo, Jinxue; Zhang, Jinsong; Barnes, Robert J; Tan, Xiaohui; McDougald, Diane; Fane, Anthony G; Zhuang, Guoqiang; Kjelleberg, Staffan; Cohen, Yehuda; Rice, Scott A

2015-05-01

A novel strategy to control membrane bioreactor (MBR) biofouling using the nitric oxide (NO) donor compound PROLI NONOate was examined. When the biofilm was pre-established on membranes at transmembrane pressure (TMP) of 88-90 kPa, backwashing of the membrane module with 80 μM PROLI NONOate for 45 min once daily for 37 days reduced the fouling resistance (Rf ) by 56%. Similarly, a daily, 1 h exposure of the membrane to 80 μM PROLI NONOate from the commencement of MBR operation for 85 days resulted in reduction of the TMP and Rf by 32.3% and 28.2%. The microbial community in the control MBR was observed to change from days 71 to 85, which correlates with the rapid TMP increase. Interestingly, NO-treated biofilms at 85 days had a higher similarity with the control biofilms at 71 days relative to the control biofilms at 85 days, indicating that the NO treatment delayed the development of biofilm bacterial community. Despite this difference, sequence analysis indicated that NO treatment did not result in a significant shift in the dominant fouling species. Confocal microscopy revealed that the biomass of biopolymers and microorganisms in biofilms were all reduced on the PROLI NONOate-treated membranes, where there were reductions of 37.7% for proteins and 66.7% for microbial cells, which correlates with the reduction in TMP. These results suggest that NO treatment could be a promising strategy to control biofouling in MBRs. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Membrane morphology and topology for fouling control in Reverse Osmosis filtration systems

Science.gov (United States)

Ling, Bowen; Battiato, Ilenia

2017-11-01

Reverse Osmosis Membrane (ROM) filtration systems are widely utilized in waste-water recovery, seawater desalination, landfill water treatment, etc. During filtration, the system performance is dramatically affected by membrane fouling which causes a significant decrease in permeate flux as well as an increase in the energy input required to operate the system. Design and optimization of ROM filtration systems aim at reducing membrane fouling by studying the coupling between membrane structure, local flow field and foulant adsorption patterns. Yet, current studies focus exclusively on oversimplified steady-state models that ignore any dynamic coupling between fluid flow and transport through the membrane. In this work, we develop a customized solver (SUMembraneFoam) under OpenFOAM to solve the transient equations. The simulation results not only predict macroscopic quantities (e.g. permeate flux, pressure drop, etc.) but also show an excellent agreement with the fouling patterns observed in experiments. It is observed that foulant deposition is strongly controlled by the local shear stress on the membrane, and channel morphology or membrane topology can be modified to control the shear stress distribution and reduce fouling. Finally, we identify optimal regimes for design.

Vesicle fusion with bilayer lipid membrane controlled by electrostatic interaction

Directory of Open Access Journals (Sweden)

Azusa Oshima

2017-09-01

Full Text Available The fusion of proteoliposomes is a promising approach for incorporating membrane proteins in artificial lipid membranes. In this study, we employed an electrostatic interaction between vesicles and supported bilayer lipid membranes (s-BLMs to control the fusion process. We combined large unilamellar vesicles (LUVs containing anionic lipids, which we used instead of proteoliposomes, and s-BLMs containing cationic lipids to control electrostatic interaction. Anionic LUVs were never adsorbed or ruptured on the SiO2 substrate with a slight negative charge, and selectively fused with cationic s-BLMs. The LUVs can be fused effectively to the target position. Furthermore, as the vesicle fusion proceeds and some of the positive charges are neutralized, the attractive interaction weakens and finally the vesicle fusion saturates. In other words, we can control the number of LUVs fused with s-BLMs by controlling the concentration of the cationic lipids in the s-BLMs. The fluidity of the s-BLMs after vesicle fusion was confirmed to be sufficiently high. This indicates that the LUVs attached to the s-BLMs were almost completely fused, and there were few intermediate state vesicles in the fusion process. We could control the position and amount of vesicle fusion with the s-BLMs by employing an electrostatic interaction.

Osmotically driven drug delivery through remote-controlled magnetic nanocomposite membranes

KAUST Repository

Zaher, A.

2015-09-29

Implantable drug delivery systems can provide long-term reliability, controllability, and biocompatibility, and have been used in many applications, including cancer pain and non-malignant pain treatment. However, many of the available systems are limited to zero-order, inconsistent, or single burst event drug release. To address these limitations, we demonstrate prototypes of a remotely operated drug delivery device that offers controllability of drug release profiles, using osmotic pumping as a pressure source and magnetically triggered membranes as switchable on-demand valves. The membranes are made of either ethyl cellulose, or the proposed stronger cellulose acetate polymer, mixed with thermosensitive poly(N-isopropylacrylamide) hydrogel and superparamagnetic iron oxide particles. The prototype devices\\' drug diffusion rates are on the order of 0.5–2 μg/h for higher release rate designs, and 12–40 ng/h for lower release rates, with maximum release ratios of 4.2 and 3.2, respectively. The devices exhibit increased drug delivery rates with higher osmotic pumping rates or with magnetically increased membrane porosity. Furthermore, by vapor deposition of a cyanoacrylate layer, a drastic reduction of the drug delivery rate from micrograms down to tens of nanograms per hour is achieved. By utilizing magnetic membranes as the valve-control mechanism, triggered remotely by means of induction heating, the demonstrated drug delivery devices benefit from having the power source external to the system, eliminating the need for a battery. These designs multiply the potential approaches towards increasing the on-demand controllability and customizability of drug delivery profiles in the expanding field of implantable drug delivery systems, with the future possibility of remotely controlling the pressure source.

Osmotically driven drug delivery through remote-controlled magnetic nanocomposite membranes

KAUST Repository

Zaher, Amir; Li, S.; Wolf, K. T.; Pirmoradi, F. N.; Yassine, Omar; Lin, L.; Khashab, Niveen M.; Kosel, Jü rgen

2015-01-01

Implantable drug delivery systems can provide long-term reliability, controllability, and biocompatibility, and have been used in many applications, including cancer pain and non-malignant pain treatment. However, many of the available systems are limited to zero-order, inconsistent, or single burst event drug release. To address these limitations, we demonstrate prototypes of a remotely operated drug delivery device that offers controllability of drug release profiles, using osmotic pumping as a pressure source and magnetically triggered membranes as switchable on-demand valves. The membranes are made of either ethyl cellulose, or the proposed stronger cellulose acetate polymer, mixed with thermosensitive poly(N-isopropylacrylamide) hydrogel and superparamagnetic iron oxide particles. The prototype devices' drug diffusion rates are on the order of 0.5–2 μg/h for higher release rate designs, and 12–40 ng/h for lower release rates, with maximum release ratios of 4.2 and 3.2, respectively. The devices exhibit increased drug delivery rates with higher osmotic pumping rates or with magnetically increased membrane porosity. Furthermore, by vapor deposition of a cyanoacrylate layer, a drastic reduction of the drug delivery rate from micrograms down to tens of nanograms per hour is achieved. By utilizing magnetic membranes as the valve-control mechanism, triggered remotely by means of induction heating, the demonstrated drug delivery devices benefit from having the power source external to the system, eliminating the need for a battery. These designs multiply the potential approaches towards increasing the on-demand controllability and customizability of drug delivery profiles in the expanding field of implantable drug delivery systems, with the future possibility of remotely controlling the pressure source.

Radio-iodination of plasma membranes of toad bladder epithelium

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, H J; Edelman, I S [California Univ., San Francisco (USA). Cardiovascular Research Inst.; California Univ., San Francisco (USA). Dept. of Medicine; California Univ., San Francisco (USA). Dept. of Biochemistry and Biophysics)

1979-01-01

The present report describes high yield enzymatic radio-iodination of the apical and basal-lateral plasma membranes of toad bladder epithelium with /sup 125/I-Na, by a procedure that does not breach the functional integrity of the epithelium, as assessed by the basal and vasopressin-sensitive short-circuit current (SCC). Iodination of basal-lateral plasma membranes, at a yield comparable to that obtained with apical labelling, was attained after about 30 min of exposure of the intact bladder to the labelling solutions. Approximately 25% of the basal-lateral labeling was lost when the epithelial cells were harvested after collagenase treatment, implying that some iodination of the basement membrane had taken place. Less than 10% of iodination of the apical or basal-lateral surfaces was accounted for by lipid-labeling. Analysis of the labeled apical and basal-lateral species by enzymatic digestion and thin layer chromatography disclosed that virtually all the radioactivity was present as mono-iodotyrosine (MIT). (orig./AJ).

Ion-Exchanged SAPO-34 Membranes for Krypton-Xenon Separation: Control of Permeation Properties and Fabrication of Hollow Fiber Membranes.

Science.gov (United States)

Kwon, Yeon Hye; Min, Byunghyun; Yang, Shaowei; Koh, Dong-Yeun; Bhave, Ramesh R; Nair, Sankar

2018-02-21

Separation of radioisotope 85 Kr from 136 Xe is of importance in used nuclear fuel reprocessing. Membrane separation based on zeolite molecular sieves such as chabazite SAPO-34 is an attractive alternative to energy-intensive cryogenic distillation. We report the synthesis of SAPO-34 membranes with considerably enhanced performance via thickness reduction based upon control of a steam-assisted vapor-solid conversion technique followed by ion exchange with alkali metal cations. The reduction of membrane thickness leads to a large increase in Kr permeance from 7.5 to 26.3 gas permeation units (GPU) with ideal Kr/Xe selectivities >20 at 298 K. Cation-exchanged membranes show large (>50%) increases in selectivity at ambient or slight subambient conditions. The adsorption, diffusion, and permeation characteristics of ion-exchanged SAPO-34 materials and membranes are investigated in detail, with potassium-exchanged SAPO-34 membranes showing particularly attractive performance. We then demonstrate the fabrication of selective SAPO-34 membranes on α-alumina hollow fibers.

Natural-basement ventilation as a radon-mitigation technique. Final report Jun 89-Feb 91

International Nuclear Information System (INIS)

Cavallo, A.; Gadsby, K.; Reddy, T.A.

1992-04-01

The report documents a study of natural basement ventilation in two research houses during both the summer cooling season and the winter heating season. (NOTE: Natural basement ventilation has always been recommended as a way to reduce radon levels in houses. However, its efficacy has never been documented. It has generally been assumed to be a very inefficient mitigation strategy since it was believed that dilution was the mechanism by which radon levels were reduced.) Ventilation rates, environmental and house operating parameters, and radon levels have been monitored; it can be concluded that natural ventilation can reduce radon levels two ways: (1) by simple dilution, and (2) although less obvious, by providing a pressure break that reduces basement depressurization and thus the amount of radon-contaminated soil gas drawn into the house. Thus, basement ventilation can be a much more effective mitigation strategy than was previously believed. It might be especially useful in houses with low radon concentrations (of the order of 10 pCi/L) or those with low levels that cannot be mitigated cost-effectively with conventional technology

Basement characterization and crustal structure beneath the Arabia-Eurasia collision (Iran): A combined gravity and magnetic study

Science.gov (United States)

Mousavi, Naeim; Ebbing, Jörg

2018-04-01

We present a study on the depth to basement and magnetic crustal domains beneath the Iranian Plateau by modeling aeromagnetic and gravity data. First, field processing of the aeromagnetic data was undertaken to estimate the general characteristics of the magnetic basement. Afterwards, inverse modeling of aeromagnetic data was carried out to estimate the depth to basement. The obtained model of basement was refined using combined gravity and magnetic forward modeling. Hereby, we were able to distinguish different magnetic domains in the uppermost crust (10-20 km depths) influencing the medium to long wavelength trends of the magnetic anomalies. Magnetic basement mapping shows that prominent shallow magnetic features are furthermore located in the volcanic areas, e.g. the Urumieh Dokhtar Magmatic Assemblage. The presence of ophiolite outcrops in SE Iran implies that shallow oceanic crust (with high magnetization) is the main source of one of the biggest magnetic anomalies in entire Iran area located north of the Makran.

Analisis Risiko pada Proyek Pembangunan Parkir Basement Jalan Sulawesi Denpasar

Directory of Open Access Journals (Sweden)

I Wayan Muka

2015-04-01

Full Text Available Construction of Basement Parking Sulawesi Road Denpasar is a government attempt to tackle congestion and parking problems in the city of Denpasar. This activity is highly correlated with the location of Badung Market. This study aims to identify risks arising, assess the level of acceptance of risk analysis, risk mitigation and ownership of dominant risk. The results showed 25 risks identified. Of the risks identified are 24 risk dominant with 5 risk category is unacceptable occurrence of accidents in the project, the landslide during basement excavation, the lack of security fence project that can cause accidents especially hazard fell during basement excavation, the damage caused by natural disasters and the workers were not using safety equipment. Additionally identified 19 risk category is undesirable, one acceptable risk category. Dominant risk is unacceptable risks do 11 mitigation measures such as building damage due to natural disasters (force majeure, which is also a risk with follow-up by reducing the risk that anticipated early preparing for disasters and transfer risk to another party by insuring the work to others. Ownership is the most dominant risk of the contractor. The parties should consider the risks unacceptable category and also should pay attention to the risks classified as undesirable.

PH-triggered micellar membrane for controlled release microchips

KAUST Repository

Yang, Xiaoqiang

2011-01-01

A pH-responsive membrane based on polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) block copolymer was developed on a model glass microchip as a promising controlled polymer delivery system. The PS-b-P4VP copolymer assembles into spherical and/or worm-like micelles with styrene block cores and pyridine coronas in selective solvents. The self-assembled worm-like morphology exhibited pH-responsive behaviour due to the protonation of the P4VP block at low pH and it\\'s deprotonation at high pH and thus constituting a switchable "off/on" system. Doxorubicin (Dox) was used as cargo to test the PS-b-P4VP membrane. Luminescence experiments indicated that the membrane was able to store Dox molecules within its micellar structure at neutral pH and then release them as soon as the pH was raised to 8.0. The performance of the cast membrane was predictable and most importantly reproducible. The physiochemical and biological properties were also investigated carefully in terms of morphology, cell viability and cell uptake. This journal is © The Royal Society of Chemistry.

On controllability of an integrated bioreactor and periodically operated membrane separation process

DEFF Research Database (Denmark)

Prado Rubio, Oscar Andres; Jørgensen, Sten Bay; Jonsson, Gunnar Eigil

the influence of membrane fouling. Previously, the REED and fermentation processes have been modeled and investigated separately (Prado- Rubio et al., 2011a; Boonmee, 2003). Additionally, a simple quasi-sequential strategy for integrated process design and control structure development has been proposed (Prado...... to understand the controlled operation of the integrated process, it is convenient to use a model based approach supported by experimental evidence. Recently, an integrated bioreactor and electrically driven membrane separation process (Reverse Electro- Enhanced Dialysis - REED) has been proposed as a method...... at a certain lactate concentration level. Hence, productivity can be enhanced by the in situ lactate removal from the cultivation broth during pH controlled fermentation. This can be done by means of ion exchange membranes and electrical potential gradients. The novelty of the integrated process lies...

Control of directed cell migration in vivo by membrane-to-cortex attachment.

Directory of Open Access Journals (Sweden)

Alba Diz-Muñoz

2010-11-01

Full Text Available Cell shape and motility are primarily controlled by cellular mechanics. The attachment of the plasma membrane to the underlying actomyosin cortex has been proposed to be important for cellular processes involving membrane deformation. However, little is known about the actual function of membrane-to-cortex attachment (MCA in cell protrusion formation and migration, in particular in the context of the developing embryo. Here, we use a multidisciplinary approach to study MCA in zebrafish mesoderm and endoderm (mesendoderm germ layer progenitor cells, which migrate using a combination of different protrusion types, namely, lamellipodia, filopodia, and blebs, during zebrafish gastrulation. By interfering with the activity of molecules linking the cortex to the membrane and measuring resulting changes in MCA by atomic force microscopy, we show that reducing MCA in mesendoderm progenitors increases the proportion of cellular blebs and reduces the directionality of cell migration. We propose that MCA is a key parameter controlling the relative proportions of different cell protrusion types in mesendoderm progenitors, and thus is key in controlling directed migration during gastrulation.

PH-triggered micellar membrane for controlled release microchips

KAUST Repository

Yang, Xiaoqiang; Moosa, Basem; Deng, Lin; Zhao, Lan; Khashab, Niveen M.

2011-01-01

A pH-responsive membrane based on polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) block copolymer was developed on a model glass microchip as a promising controlled polymer delivery system. The PS-b-P4VP copolymer assembles into spherical and

Survey of Jaemtland county (basement rock part). Geologic conditions

International Nuclear Information System (INIS)

Antal, I.; Bergman, S.; Freden, C.; Gierup, J.; Stoelen, L.K.; Thunholm, B.; Stephens, M.

1999-06-01

A broad survey of the geologic conditions in Jaemtland county is presented, with the aim to give background for the location of a repository for spent fuels. The study is restricted to the basement rock part of the county

Survey of Dalarna county (basement rock part). Geologic conditions

International Nuclear Information System (INIS)

Gierup, J.; Kuebler, L.; Linden, A.; Ripa, M.; Stoelen, L.K.; Thunholm, B.; Stephens, M.

1999-06-01

A broad survey of the geologic conditions in Dalarna county is presented, with the aim to give background for the location of a repository for spent fuels. The study is restricted to the basement rock part of the county

Survey of Scania county (basement rock part). Geologic conditions

International Nuclear Information System (INIS)

Gierup, J.; Kuebler, L.; Pamnert, M.; Persson, Magnus; Thunholm, B.; Wahlgren, C.H.; Wikman, H.; Stephens, M.

1999-06-01

A broad survey of the geologic conditions in Scania county is presented, with the aim to give background for the location of a repository for spent fuels. The study is restricted to the basement rock part of the county

Control-oriented model of a membrane humidifier for fuel cell applications

International Nuclear Information System (INIS)

Solsona, Miguel; Kunusch, Cristian; Ocampo-Martinez, Carlos

2017-01-01

Highlights: • A control-oriented model of a Nafion® membrane gas humidifier has been developed. • The control-oriented model has been experimentally validated. • A non-linear control strategy has been used to test its suitability for control purposes. - Abstract: Improving the humidification of polymer electrolyte membrane fuel-cells (PEMFC) is essential to optimize its performance and stability. Therefore, this paper presents an experimentally validated model of a low temperature PEMFC cathode humidifier for control/observation design purposes. A multi-input/multi-output non-linear fourth order model is derived, based on the mass and heat dynamics of circulating air. In order to validate the proposed model and methodology, experimental results are provided. Finally, a non-linear control strategy based on second order sliding mode is designed and analyzed in order to show suitability and usefulness of the approach.

Testing of indoor radon-reduction techniques in basement houses having adjoining wings. Final report, August 1988-September 1989

International Nuclear Information System (INIS)

Messing, M.

1990-11-01

The report gives results of tests of indoor radon reduction techniques in 12 existing Maryland houses, with the objective of determining when basement houses with adjoining wings require active soil depressurization (ASD) treatment of both wings, and when treatment of the basement alone is sufficient. In five basement houses with adjoining slabs on grade, ASD treatment of both wings provided an incremental additional radon reduction of 0 to 5.2 pCi/L, compared to ASD treatment of either one of the slabs alone. However, basement-only treatment reduced radon to <4 pCi/L in all five houses. In six basement houses having adjoining crawl spaces, ASD treatment of both wings (including sub-liner depressurization of the crawl space) provided little additional reduction compared to basement-only treatment, when sub-slab communication was good. When communication was not good, treatment of both wings was required to achieve <4 pCi/L. Tests of one fully slab-on-grade house showed that, when there is good aggregate under the slab, a one-pipe sub-slab depressurization system can achieve <1-2 pCi/L, even when there are forced-air supply ducts under the slab

Basement configuration of KG offshore basin from magnetic anomalies

Indian Academy of Sciences (India)

of charnockites of neighbouring EGMB and onshore K–G basin areas indicates that EGMB geology. (charnockites ... Marine magnetic anomalies; offshore K–G basin; magnetic basement; extension of EGMB geology; continent– oceanic boundary. ..... of India; J. Australian Petroleum Exploration Association. 14 29–41.

Performance Evaluation of Waterproofing Membrane Systems Subject to the Concrete Joint Load Behavior of Below-Grade Concrete Structures

Directory of Open Access Journals (Sweden)

Jaeyoung Song

2017-11-01

Full Text Available Below-grade structures such as parking lots, underground subway tunnels, and basements are growing in scale and reaching deeper below-ground levels. In this type of environment, they become subject to higher water pressure. The concrete material of the structures is exposed to wet conditions for longer periods of time, which makes the proper adhesion of waterproofing membranes difficult. Joint movements from increased structural settlement, thermal expansion/shrinkage, and physical loads from external sources (e.g., vehicles make securing durable waterproofing challenging. While ASTM Guides, Korean Codes, and BS Practice Codes on below-grade waterproofing stress the importance of manufacturer specification for quality control, ensuring high quality waterproofing for the ever-changing scale of construction remains a challenge. This study proposes a new evaluation method and criteria which allow for the selection of waterproofing membranes based on specific performance attributes and workmanship. It subjects six different waterproofing membrane systems (installed on dry and wet surface conditioned mortar slab specimens with an artificial joint to different cyclic movement widths to 300 cycles in water to demonstrate that inadequate material properties and workmanship are key causes for leakages.

Ultra-thin and strong formvar-based membranes with controlled porosity for micro- and nano-scale systems

Science.gov (United States)

Auchter, Eric; Marquez, Justin; Stevens, Garrison; Silva, Rebecca; Mcculloch, Quinn; Guengerich, Quintessa; Blair, Andrew; Litchfield, Sebastian; Li, Nan; Sheehan, Chris; Chamberlin, Rebecca; Yarbro, Stephen L.; Dervishi, Enkeleda

2018-05-01

We present a methodology for developing ultra-thin and strong formvar-based membranes with controlled morphologies. Formvar is a thin hydrophilic and oleophilic polymer inert to most chemicals and resistant to radiation. The formvar-based membranes are viable materials as support structures in micro- and macro-scale systems depending on thinness and porosity control. Tunable sub-micron thick porous membranes with 20%–65% porosity were synthesized by controlling the ratios of formvar, glycerol, and chloroform. This synthesis process does not require complex separation or handling methods and allows for the production of strong, thin, and porous formvar-based membranes. An expansive array of these membrane characterizations including chemical compatibility, mechanical responses, wettability, as well as the mathematical simulations as a function of porosity has been presented. The wide range of chemical compatibility allows for membrane applications in various environments, where other polymers would not be suitable. Our formvar-based membranes were found to have an elastic modulus of 7.8 GPa, a surface free energy of 50 mN m‑1 and an average thickness of 125 nm. Stochastic model simulations indicate that formvar with the porosity of ∼50% is the optimal membrane formulation, allowing the most material transfer across the membrane while also withstanding the highest simulated pressure loadings before tearing. Development of novel, resilient and versatile membranes with controlled porosity offers a wide range of exciting applications in the fields of nanoscience, microfluidics, and MEMS.

Controllable synthesis of single-walled carbon nanotube framework membranes and capsules.

Science.gov (United States)

Song, Changsik; Kwon, Taeyun; Han, Jae-Hee; Shandell, Mia; Strano, Michael S

2009-12-01

Controlling the morphology of membrane components at the nanometer scale is central to many next-generation technologies in water purification, gas separation, fuel cell, and nanofiltration applications. Toward this end, we report the covalent assembly of single-walled carbon nanotubes (SWNTs) into three-dimensional framework materials with intertube pores controllable by adjusting the size of organic linker molecules. The frameworks are fashioned into multilayer membranes possessing linker spacings from 1.7 to 3.0 nm, and the resulting framework films were characterized, including transport properties. Nanoindentation measurements by atomic force microscopy show that the spring constant of the SWNT framework film (22.6 +/- 1.2 N/m) increased by a factor of 2 from the control value (10.4 +/- 0.1 N/m). The flux ratio comparison in a membrane-permeation experiment showed that larger spacer sizes resulted in larger pore structures. This synthetic method was equally efficient on silica microspheres, which could then be etched to create all-SWNT framework, hollow capsules approximately 5 mum in diameter. These hollow capsules are permeable to organic and inorganic reagents, allowing one to form inorganic nanoparticles, for example, that become entrapped within the capsule. The ability to encapsulate functional nanomaterials inside perm-selective SWNT cages and membranes may find applications in new adsorbents, novel catalysts, and drug delivery vehicles.

Dissolution of biogenic ooze over basement edifices in the equatorial Pacific with implications for hydrothermal ventilation of the oceanic crust

Science.gov (United States)

Bekins, B.A.; Spivack, A.J.; Davis, E.E.; Mayer, L.A.

2007-01-01

Recent observations indicate that curious closed depressions in carbonate sediments overlying basement edifices are widespread in the equatorial Pacific. A possible mechanism for their creation is dissolution by fluids exiting basement vents from off-axis hydrothermal flow. Quantitative analysis based on the retrograde solubility of calcium carbonate and cooling of basement fluids during ascent provides an estimate for the dissolution capacity of the venting fluids. Comparison of the dissolution capacity and fluid flux with typical equatorial Pacific carbonate mass accumulation rates shows that this mechanism is feasible. By maintaining sediment-free basement outcrops, the process may promote widespread circulation of relatively unaltered seawater in the basement in an area where average sediment thicknesses are 300-500 m. The enhanced ventilation can explain several previously puzzling observations in this region, including anomalously low heat flux, relatively unaltered seawater in the basement, and aerobic and nitrate-reducing microbial activity at the base of the sediments. ?? 2007 The Geological Society of America.

Folding DNA into a Lipid-Conjugated Nanobarrel for Controlled Reconstitution of Membrane Proteins.

Science.gov (United States)

Dong, Yuanchen; Chen, Shuobing; Zhang, Shijian; Sodroski, Joseph; Yang, Zhongqiang; Liu, Dongsheng; Mao, Youdong

2018-02-19

Building upon DNA origami technology, we introduce a method to reconstitute a single membrane protein into a self-assembled DNA nanobarrel that scaffolds a nanodisc-like lipid environment. Compared with the membrane-scaffolding-protein nanodisc technique, our approach gives rise to defined stoichiometry, controlled sizes, as well as enhanced stability and homogeneity in membrane protein reconstitution. We further demonstrate potential applications of the DNA nanobarrels in the structural analysis of membrane proteins. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

How membrane lipids control the 3D structure and function of receptors

OpenAIRE

Jacques Fantini; Francisco J. Barrantes

2018-01-01

The cohabitation of lipids and proteins in the plasma membrane of mammalian cells is controlled by specific biochemical and biophysical rules. Lipids may be either constitutively tightly bound to cell-surface receptors (non-annular lipids) or less tightly attached to the external surface of the protein (annular lipids). The latter are exchangeable with surrounding bulk membrane lipids on a faster time scale than that of non-annular lipids. Not only do non-annular lipids bind to membrane prote...

Soil inertia and shallow basement envelope impact on cellar internal temperature

Directory of Open Access Journals (Sweden)

Naima Sakami

2016-06-01

Full Text Available This work deals with a three dimensional numerical study of heat transfer by conduction between the soil and the shallow basement in the city of Marrakech (Morocco. The heat transfer equation is solved by the finite difference method using the implicit alternative direction (ADI. The internal temperature of the cellar is computed by using energy balance equation in the cellar. The objective of this work is to evaluate the effects of the nature of the soil, the nature of the walls, the thickness of the walls of the cellar and the distance L far from the cellar on the internal temperature and the heat exchanged between the soil and the shallow basement

Biofouling Control in Spiral-Wound Membrane Systems: Impact of Feed Spacer Modification and Biocides

KAUST Repository

Siddiqui, Amber

2016-12-01

High-quality drinking water can be produced with membrane-based filtration processes like reverse osmosis and nanofiltration. One of the major problems in these membrane systems is biofouling that reduces the membrane performance, increasing operational costs. Current biofouling control strategies such as pre-treatment, membrane modification, and chemical cleaning are not sufficient in all cases. Feed spacers are thin (0.8 mm), complex geometry meshes that separate membranes in a module. The main objective of this research was to evaluate whether feed spacer modification is a suitable strategy to control biofouling. Membrane fouling simulator studies with six feed spacers showed differences in biofouled spacer performance, concluding that (i) spacer geometry influences biofouling impact and (ii) biofouling studies are essential for evaluation of spacer biofouling impact. Computed tomography (CT) was found as a suitable technique to obtain three-dimensional (3D) measurements of spacers, enabling more representative mathematical modeling of hydraulic behavior of spacers in membrane systems. A strategy for developing, characterizing, and testing of spacers by numerical modeling, 3D printing of spacers and experimental membrane fouling simulator studies was developed. The combination of modeling and experimental testing of 3D printed spacers is a promising strategy to develop advanced spacers aiming to reduce the impact of biofilm formation on membrane performance and to improve the cleanability of spiral-wound membrane systems.

Percolation of diagenetic fluids in the Archaean basement of the Franceville basin

Science.gov (United States)

Mouélé, Idalina Moubiya; Dudoignon, Patrick; Albani, Abderrazak El; Cuney, Michel; Boiron, Marie-Christine; Gauthier-Lafaye, François

2014-01-01

The Palaeoproterozoic Franceville basin, Gabon, is mainly known for its high-grade uranium deposits, which are the only ones known to act as natural nuclear fission reactors. Previous work in the Kiéné region investigated the nature of the fluids responsible for these natural nuclear reactors. The present work focuses on the top of the Archaean granitic basement, specifically, to identify and date the successive alteration events that affected this basement just below the unconformity separating it from the Palaeoproterozoic basin. Core from four drill holes crosscutting the basin-basement unconformity have been studied. Dating is based on U-Pb isotopic analyses performed on monazite. The origin of fluids is discussed from the study of fluid inclusion planes (FIP) in quartz from basement granitoids. From the deepest part of the drill holes to the unconformable boundary with the basin, propylitic alteration assemblages are progressively replaced by illite and locally by a phengite + Fe chlorite ± Fe oxide assemblage. Illitic alteration is particularly strong along the sediment-granitoid contact and is associated with quartz dissolution. It was followed by calcite and anhydrite precipitation as fracture fillings. U-Pb isotopic dating outlines three successive events: a 3.0-2.9-Ga primary magmatic event, a 2.6-Ga propylitic alteration and a late 1.9-Ga diagenetic event. Fluid inclusion microthermometry suggests the circulation of three types of fluids: (1) a Na-Ca-rich diagenetic brine, (2) a moderately saline (diagenetic + meteoric) fluid, and (3) a low-salinity fluid of probable meteoric origin. These fluids are similar to those previously identified within the overlying sedimentary rocks of the Franceville basin. Overall, the data collected in this study show that the Proterozoic-Archaean unconformity has operated as a major flow corridor for fluids circulation, around 1.9 Ga. highly saline diagenetic brines; hydrocarbon-rich fluids derived from organic matter

G-protein signaling leverages subunit-dependent membrane affinity to differentially control βγ translocation to intracellular membranes.

Science.gov (United States)

O'Neill, Patrick R; Karunarathne, W K Ajith; Kalyanaraman, Vani; Silvius, John R; Gautam, N

2012-12-18

Activation of G-protein heterotrimers by receptors at the plasma membrane stimulates βγ-complex dissociation from the α-subunit and translocation to internal membranes. This intermembrane movement of lipid-modified proteins is a fundamental but poorly understood feature of cell signaling. The differential translocation of G-protein βγ-subunit types provides a valuable experimental model to examine the movement of signaling proteins between membranes in a living cell. We used live cell imaging, mathematical modeling, and in vitro measurements of lipidated fluorescent peptide dissociation from vesicles to determine the mechanistic basis of the intermembrane movement and identify the interactions responsible for differential translocation kinetics in this family of evolutionarily conserved proteins. We found that the reversible translocation is mediated by the limited affinity of the βγ-subunits for membranes. The differential kinetics of the βγ-subunit types are determined by variations among a set of basic and hydrophobic residues in the γ-subunit types. G-protein signaling thus leverages the wide variation in membrane dissociation rates among different γ-subunit types to differentially control βγ-translocation kinetics in response to receptor activation. The conservation of primary structures of γ-subunits across mammalian species suggests that there can be evolutionary selection for primary structures that confer specific membrane-binding affinities and consequent rates of intermembrane movement.

Gravitational sliding of the Mt. Etna massif along a sloping basement

Science.gov (United States)

Murray, John B.; van Wyk de Vries, Benjamin; Pitty, Andy; Sargent, Phil; Wooller, Luke

2018-04-01

Geological field evidence and laboratory modelling indicate that volcanoes constructed on slopes slide downhill. If this happens on an active volcano, then the movement will distort deformation data and thus potentially compromise interpretation. Our recent GPS measurements demonstrate that the entire edifice of Mt. Etna is sliding to the ESE, the overall direction of slope of its complex, rough sedimentary basement. We report methods of discriminating the sliding vector from other deformation processes and of measuring its velocity, which averaged 14 mm year-1 during four intervals between 2001 and 2012. Though sliding of one sector of a volcano due to flank instability is widespread and well-known, this is the first time basement sliding of an entire active volcano has been directly observed. This is important because the geological record shows that such sliding volcanoes are prone to devastating sector collapse on the downslope side, and whole volcano migration should be taken into account when assessing future collapse hazard. It is also important in eruption forecasting, as the sliding vector needs to be allowed for when interpreting deformation events that take place above the sliding basement within the superstructure of the active volcano, as might occur with dyke intrusion or inflation/deflation episodes.

Combination of Electrochemical Processes with Membrane Bioreactors for Wastewater Treatment and Fouling Control: A Review

OpenAIRE

Ensano, Benny M. B.; Borea, Laura; Naddeo, Vincenzo; Belgiorno, Vincenzo; de Luna, Mark D. G.; Ballesteros, Florencio C.

2016-01-01

This paper provides a critical review about the integration of electrochemical processes into membrane bioreactors (MBR) in order to understand the influence of these processes on wastewater treatment performance and membrane fouling control. The integration can be realized either in an internal or an external configuration. Electrically enhanced membrane bioreactors or electro membrane bioreactors (eMBRs) combine biodegradation, electrochemical and membrane filtration processes into one syst...

Combination of electrochemical processes with membrane bioreactors for wastewater treatment and fouling control: A review

OpenAIRE

Benny Marie B. Ensano; Laura Borea; Vincenzo Naddeo; Vincenzo Belgiorno; Mark Daniel G. de Luna; Mark Daniel G. de Luna; Florencio C. Ballesteros, Jr.; Florencio C. Ballesteros, Jr.

2016-01-01

This paper provides a critical review about the integration of electrochemical processes into membrane bioreactors (MBR) in order to understand the influence of these processes on wastewater treatment performance and membrane fouling control. The integration can be realized either in an internal or an external configuration. Electrically enhanced membrane bioreactors or electro membrane bioreactors (eMBRs) combine biodegradation, electrochemical and membrane filtration processes into one syst...

Geology of the plutonic basement rocks of Stewart Island, New Zealand

International Nuclear Information System (INIS)

Allibone, A.H.; Tulloch, A.J.

2004-01-01

Exposures of basement rocks on Stewart Island provide a c. 70 km long by 50 km wide map of part of the Median Batholith that spans the margin of the Western Province. Because of their distance from the present plate boundary, these rocks are relatively unaffected by Cenozoic tectonism, allowing examination of unmodified Carboniferous-Cretaceous relationships within the Median Batholith. Thirty individual plutons (>c.20 km 2 ) have been mapped along with numerous relatively small intrusions ( 2 ). The large plutons form 85-90% of the Median Batholith on Stewart Island while the many smaller intrusions comprise 10-15%, mostly in the north. Lithologies include: biotite ± minor hornblende granodiorite, granite and leucogranite with accessory titanite - magmatic epidote and allanite (c. 50%); biotite ± muscovite ± garnet granite with S-type affinities (c. 10%); alkaline quartz monzonite, granite, and alkali feldspar granite with rare aegirine and blue-green amphibole (c. 3%); quartz monzodiorite and diorite with hornblende > biotite (c. 23%); gabbro and anorthosite (c. 12%) and ultramafic rocks (c. 2%). U-Pb zircon and monazite dating indicates that c. 12% of these plutonic rocks were emplaced during the Carboniferous between 345 and 290 Ma, c. 20% in the Early-Middle Jurassic at c. 170-165 Ma, c. 30% in the latest Jurassic to earliest Cretaceous between 152 and 128 Ma, and c. 38% in the Early Cretaceous between 128 and 100 Ma. The distribution of Pegasus Group schists and peraluminous granitoid rocks indicates that the northern limit of extensive early Paleozoic Western Province basement is located either within the Gutter Shear Zone or at the Escarpment Fault, 10-15 km south of the Freshwater Fault System previously thought to mark this boundary. Carboniferous and Middle Jurassic magmatism extended plutonic basement northwards as far as the Freshwater Fault System, while further magmatism during the latest Jurassic and earliest Cretaceous produced the basement

lithologic characterisation of the basement aquifers of awe and ...

African Journals Online (AJOL)

Global Journal

resistivity exceeded 3000 ohm-m, then the bedrock is fresh and prospect for water is low (Olayinka and. Olorunfemi, 1992; Olorunfemi and Olorunniwo, 1990). Groundwater zones are found in the weathered and fractured zones in basement areas. In Ibarapa area of SW, Nigeria the associated fractured bedrock aquifers.

Investigation of humidity control via membrane separation for advanced Extravehicular Mobility Unit (EMU) application

Science.gov (United States)

Newbold, D. D.; Ray, R. J.; Pledger, W. A.; Mccray, S. B.; Brown, M. F.

1989-01-01

This paper describes the development of a membrane-based process for dehumidifying the Extravehicular Mobility Unit (EMU). The membrane process promises to be smaller, lighter, and more energy efficient than the other technologies for dehumidification. The dehydration membranes were tested for 90 days at conditions expected to be present in the EMU. The results of these tests indicate that membrane-based technology can effectively control humidity in the EMU.

Filtration behavior of casein glycomacropeptide (CGMP) in an enzymatic membrane reactor: fouling control by membrane selection and threshold flux operation

DEFF Research Database (Denmark)

Luo, Jianquan; Morthensen, Sofie Thage; Meyer, Anne S.

2014-01-01

. In this study, the filtration performance and fouling behavior during ultrafiltration (UF) of CGMP for the enzymatic production of 3′-sialyllactose were investigated. A 5kDa regenerated cellulose membrane with high anti-fouling performance, could retain CGMP well, permeate 3′-sialyllactose, and was found...... to be the most suitable membrane for this application. Low pH increased CGMP retention but produced more fouling. Higher agitation and lower CGMP concentration induced larger permeate flux and higher CGMP retention. Adsorption fouling and pore blocking by CGMP in/on membranes could be controlled by selecting...... a highly hydrophilic membrane with appropriate pore size. Operating under threshold flux could minimize the concentration polarization and cake/gel/scaling layers, but might not avoid irreversible fouling caused by adsorption and pore blocking. The effects of membrane properties, pH, agitation and CGMP...

Membrane tension controls adhesion positioning at the leading edge of cells.

Science.gov (United States)

Pontes, Bruno; Monzo, Pascale; Gole, Laurent; Le Roux, Anabel-Lise; Kosmalska, Anita Joanna; Tam, Zhi Yang; Luo, Weiwei; Kan, Sophie; Viasnoff, Virgile; Roca-Cusachs, Pere; Tucker-Kellogg, Lisa; Gauthier, Nils C

2017-09-04

Cell migration is dependent on adhesion dynamics and actin cytoskeleton remodeling at the leading edge. These events may be physically constrained by the plasma membrane. Here, we show that the mechanical signal produced by an increase in plasma membrane tension triggers the positioning of new rows of adhesions at the leading edge. During protrusion, as membrane tension increases, velocity slows, and the lamellipodium buckles upward in a myosin II-independent manner. The buckling occurs between the front of the lamellipodium, where nascent adhesions are positioned in rows, and the base of the lamellipodium, where a vinculin-dependent clutch couples actin to previously positioned adhesions. As membrane tension decreases, protrusion resumes and buckling disappears, until the next cycle. We propose that the mechanical signal of membrane tension exerts upstream control in mechanotransduction by periodically compressing and relaxing the lamellipodium, leading to the positioning of adhesions at the leading edge of cells. © 2017 Pontes et al.

Stress rotation along pre-Cenozoic basement structures

Science.gov (United States)

Reiter, K.; Heidbach, O.; Henk, A.

2017-12-01

The in-situ stress state of the Earth's crust is under investigation since decades for both, scientific and economic purposes. Several methods have been established to indicate the contemporary orientation of the maximum compressive horizontal stress (SHmax). It is assumed that the same forces that drive plate motion are the first order stress sources and one could presume that SHmax is always parallel to plate motion, which is the case for some regions. However, deviations from this general trend occur in many regions. Therefore, second and third order sources of stress have been identified that potentially cause regional and local stress rotation with respect to the long wave-length trend imposed by plate tectonic forces. One group of such subordinate stress sources are lateral heterogeneities based on structures, petrothermal or petrophysical properties. The World Stress Map (WSM) project compiles systematically data records of the present day SHmax orientation. The increasing amount of stress orientation data allows to investigate areas with consistent stress rotation, divergent to the regional stress pattern. In our work we analyse the stress pattern variability and its causes beneath Germany. In the Molasse Basin in the Alpine foreland the SHmax orientation is perpendicular to the Alpine front as a consequence of gravitational potential energy of the orogen. SHmax is oriented in N-S direction in the central Alpine foreland and within the North German Basin. Between both, within the Mid-German Crystalline High, SHmax is divergent oriented in SE-NW direction. Neither gravitational potential energy nor petrothermal effects can be indicated as stress source. But when comparing the stress pattern with the Variscan basement structures it is obvious that SHmax is perpendicular oriented to this Palaeozoic basement structures. Therefore, petrophysical heterogeneities can be expected as reason for the observed stress rotation. Two assumptions can be made for the Mid

Air dehumidification by membrane with cold water for manned spacecraft environmental control

Directory of Open Access Journals (Sweden)

Shang Yonghong

2017-01-01

Full Text Available The traditional condensation dehumidification method requires additional gas-liquid separation and water recovery process in the manned spacecraft humidity control system, which would increase weight and complexity of systems. A new membrane dehumidification with cold water is proposed, which uses water vapor partial pressure difference to promote water vapor transmembrane mass transfer for dehumidification. The permeability of the membrane was measured and the experimental results agree well with the theoretical calculations. Based on the simulation of dehumidification process of cold water-membrane, the influence of module structure and working condition on dehumidification performance was analyzed, which provided reference for the design of membrane module construct. It can be seen from the simulation and experiments that the cold water-membrane dehumidification can effectively reduce the thermal load of the manned spacecraft.

Natural material-decorated mesoporous silica nanoparticle container for multifunctional membrane-controlled targeted drug delivery

Directory of Open Access Journals (Sweden)

Hu Y

2017-11-01

Full Text Available Yan Hu,1 Lei Ke,2 Hao Chen,1 Ma Zhuo,1 Xinzhou Yang,1 Dan Zhao,1 Suying Zeng,1 Xincai Xiao1 1Department of Pharmaceutics, School of Pharmaceutical Science, South-Central University for Nationalities, 2Department of Medicinal Chemistry, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People’s Republic of China Abstract: To avoid the side effects caused by nonspecific targeting, premature release, weak selectivity, and poor therapeutic efficacy of current nanoparticle-based systems used for drug delivery, we fabricated natural material-decorated nanoparticles as a multifunctional, membrane-controlled targeted drug delivery system. The nanocomposite material coated with a membrane was biocompatible and integrated both specific tumor targeting and responsiveness to stimulation, which improved transmission efficacy and controlled drug release. Mesoporous silica nanoparticles (MSNs, which are known for their biocompatibility and high drug-loading capacity, were selected as a model drug container and carrier. The membrane was established by the polyelectrolyte composite method from chitosan (CS which was sensitive to the acidic tumor microenvironment, folic acid-modified CS which recognizes the folate receptor expressed on the tumor cell surface, and a CD44 receptor-targeted polysaccharide hyaluronic acid. We characterized the structure of the nanocomposite as well as the drug release behavior under the control of the pH-sensitive membrane switch and evaluated the antitumor efficacy of the system in vitro. Our results provide a basis for the design and fabrication of novel membrane-controlled nanoparticles with improved tumor-targeting therapy. Keywords: multifunctional, membrane-controlled, natural materials, mesoporous silica nanoparticles, targeted drug delivery

Tectonic inheritage from adjacent basement, north of the Campos Basin; Heranca tectonica no embasamento adjacente no norte da Bacia de Campos

Energy Technology Data Exchange (ETDEWEB)

Ferroni, Felipe R. [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil); Castro, Joel C. de [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil). Inst. de Geociencias e Ciencias Exatas. Dept. de Geologia Aplicada; Souza, Iata A. de; Castro, Joel C. de [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil). Inst. de Geociencias e Ciencias Exatas

2008-07-01

The evolution of the Atlantic Brazilian basins is a target of researches since the firth discovery of oil deposits. With the advance of the geophysical methods the understanding of the structures in depth became possible. The objective of this paper is to determine if the adjacent basement in the north of Campos Basin has significant influence in the identification of areas that can contain hydrocarbons. Therefore, lineaments had been extracted with SRTM images of continental basement and the main alignment was correlated with gravimetric anomalies map and seismic data. Eight levels on seismic data had been interpreted (basement, top rift, shallow water Albian, Albian, mid-Oligocene and mid-Miocene). In all levels were identified a fault normal system, which cut sediments since basement until the Recent. The main direction of the basement is NE-SW, and the alignments formed for basin basement faults coincide with this direction, what indicates that the system is active and also genetically related. (author)

Uranium deposits in the metamorphic basement of the Rouergue massif. Genesis and extension of related albitization processes

International Nuclear Information System (INIS)

Schmitt, J.M.

1982-02-01

Albitization processes in the Rouergue metamorphic basement, probably Permian aged is evidenced. Late development of uranium orebodies occured within albitized zones. The detection of the latter serves as a highly valuable indirect guide for prospecting this type of deposits in a metamorphic basement [fr

Alkali-assisted membrane cleaning for fouling control of anaerobic ceramic membrane bioreactor.

Science.gov (United States)

Mei, Xiaojie; Quek, Pei Jun; Wang, Zhiwei; Ng, How Yong

2017-09-01

In this study, a chemically enhanced backflush (CEB) cleaning method using NaOH solution was proposed for fouling mitigation in anaerobic membrane bioreactors (AnMBRs). Ex-situ cleaning tests revealed that NaOH dosages ranging from 0.05 to 1.30mmol/L had positive impacts on anaerobic biomass, while higher dosages (>1.30mmol/L) showed inhibition and/or toxic impacts. In-situ cleaning tests showed that anaerobic biomass could tolerate much higher NaOH concentrations due to the alkali consumption by anaerobic process and/or the buffering role of mixed liquor. More importantly, 10-20mmol-NaOH/L could significantly reduce membrane fouling rates (4-5.5 times over the AnMBR with deionized water backflush) and slightly improve methanogenic activities. COD removal efficiencies were over 87% and peaked at 20mmol-NaOH/L. However, extremely high NaOH concentration had adverse effects on filtration and treatment performance. Economic analysis indicated that 12mmol/L of NaOH was the cost-efficient and optimal fouling-control dosage for the CEB cleaning. Copyright © 2017 Elsevier Ltd. All rights reserved.

KUALITAS UDARA DALAM RUANG DI DAERAH PARKIR BASEMENT DAN PARKIR UPPERGROUND (STUDI KASUS DI SUPERMARKET SEMARANG

Directory of Open Access Journals (Sweden)

Haryono S Huboyo

2016-03-01

Full Text Available Ever increasing building growth in urban areas is limited by land availability. Lack of space in this area lead to build high rise building rather landed building. In this type of building, parking area is built in the basement and or upperground inside the building. Within this enclosed space, indoor air quality might a problem. This study focus to compare emerged pollutants between basement parking area and upperground parking area in supermarket building. The dust sampler, the impinger and the CO monitor were used to measure TSP, NO2 and CO concentrations respectively in these areas during supermarket operations. In the basement area, in particular, the TSP concentrations tend to exceeds 300 µg/m3 mainly at weekend period. While for NO2 and CO concentrations still meet the air quality standard. Based on these findings it seems the main source of pollutants was derived from dust resuspension. Thus, the mitigation measures to reduce this dust resuspension should be emphasized in order to prevent air quality deterioration in the basement parking area.

Ion sieving in graphene oxide membranes via cationic control of interlayer spacing

Science.gov (United States)

Chen, Liang; Shi, Guosheng; Shen, Jie; Peng, Bingquan; Zhang, Bowu; Wang, Yuzhu; Bian, Fenggang; Wang, Jiajun; Li, Deyuan; Qian, Zhe; Xu, Gang; Liu, Gongping; Zeng, Jianrong; Zhang, Lijuan; Yang, Yizhou; Zhou, Guoquan; Wu, Minghong; Jin, Wanqin; Li, Jingye; Fang, Haiping

2017-10-01

Graphene oxide membranes—partially oxidized, stacked sheets of graphene—can provide ultrathin, high-flux and energy-efficient membranes for precise ionic and molecular sieving in aqueous solution. These materials have shown potential in a variety of applications, including water desalination and purification, gas and ion separation, biosensors, proton conductors, lithium-based batteries and super-capacitors. Unlike the pores of carbon nanotube membranes, which have fixed sizes, the pores of graphene oxide membranes—that is, the interlayer spacing between graphene oxide sheets (a sheet is a single flake inside the membrane)—are of variable size. Furthermore, it is difficult to reduce the interlayer spacing sufficiently to exclude small ions and to maintain this spacing against the tendency of graphene oxide membranes to swell when immersed in aqueous solution. These challenges hinder the potential ion filtration applications of graphene oxide membranes. Here we demonstrate cationic control of the interlayer spacing of graphene oxide membranes with ångström precision using K+, Na+, Ca2+, Li+ or Mg2+ ions. Moreover, membrane spacings controlled by one type of cation can efficiently and selectively exclude other cations that have larger hydrated volumes. First-principles calculations and ultraviolet absorption spectroscopy reveal that the location of the most stable cation adsorption is where oxide groups and aromatic rings coexist. Previous density functional theory computations show that other cations (Fe2+, Co2+, Cu2+, Cd2+, Cr2+ and Pb2+) should have a much stronger cation-π interaction with the graphene sheet than Na+ has, suggesting that other ions could be used to produce a wider range of interlayer spacings.

A PtdIns(4)P-driven electrostatic field controls cell membrane identity and signalling in plants.

Science.gov (United States)

Simon, Mathilde Laetitia Audrey; Platre, Matthieu Pierre; Marquès-Bueno, Maria Mar; Armengot, Laia; Stanislas, Thomas; Bayle, Vincent; Caillaud, Marie-Cécile; Jaillais, Yvon

2016-06-20

Many signalling proteins permanently or transiently localize to specific organelles. It is well established that certain lipids act as biochemical landmarks to specify compartment identity. However, they also influence membrane biophysical properties, which emerge as important features in specifying cellular territories. Such parameters include the membrane inner surface potential, which varies according to the lipid composition of each organelle. Here, we found that the plant plasma membrane (PM) and the cell plate of dividing cells have a unique electrostatic signature controlled by phosphatidylinositol-4-phosphate (PtdIns(4)P). Our results further reveal that, contrarily to other eukaryotes, PtdIns(4)P massively accumulates at the PM, establishing it as a critical hallmark of this membrane in plants. Membrane surface charges control the PM localization and function of the polar auxin transport regulator PINOID as well as proteins from the BRI1 KINASE INHIBITOR1 (BKI1)/MEMBRANE ASSOCIATED KINASE REGULATOR (MAKR) family, which are involved in brassinosteroid and receptor-like kinase signalling. We anticipate that this PtdIns(4)P-driven physical membrane property will control the localization and function of many proteins involved in development, reproduction, immunity and nutrition.

Regional trends in radiogenic heat generation in the Precambrian basement of the Western Canadian Basin

Science.gov (United States)

Jones, F. W.; Majorowicz, J. A.

Radiogenic heat generation values for 381 basement samples from 229 sites in the western Canadian basin exhibit a lognormal frequency distribution. The mean value = 2.06 (S.D. = 1.22) µWm-3 is larger than the radiogenic heat generation values reported for the shield in the Superior (ca. 1.2 µWm-3, Jessop and Lewis, 1978) and Churchill (ca. 0.7 µWm-3, Drury, 1985) provinces. When equal Log A contour intervals are used to map the basement heat generation, three large zones of relatively high heat generation are found. One coincides with the Peace River Arch basement structure and one with the Athabasca axis (Darnley, 1981). There is no apparent indication of increased heat flow through the Paleozoic formations associated with these two zones. The third zone, in southwestern Saskatchewan, coincides with a high heat flow zone in the Swift Current area. The lack of correlation between heat flow and heat generation in Alberta may be due to the disturbance to the heat flow in the Paleozoic formations by water motion, or may indicate that the heat is from uranium, thorium and potassium isotope enrichment near the basement surface rather than enrichment throughout the entire upper crust.

Impact of climate changes during the last 5 million years on groundwater in basement aquifers.

Science.gov (United States)

Aquilina, Luc; Vergnaud-Ayraud, Virginie; Les Landes, Antoine Armandine; Pauwels, Hélène; Davy, Philippe; Pételet-Giraud, Emmanuelle; Labasque, Thierry; Roques, Clément; Chatton, Eliot; Bour, Olivier; Ben Maamar, Sarah; Dufresne, Alexis; Khaska, Mahmoud; Le Gal La Salle, Corinne; Barbecot, Florent

2015-09-22

Climate change is thought to have major effects on groundwater resources. There is however a limited knowledge of the impacts of past climate changes such as warm or glacial periods on groundwater although marine or glacial fluids may have circulated in basements during these periods. Geochemical investigations of groundwater at shallow depth (80-400 m) in the Armorican basement (western France) revealed three major phases of evolution: (1) Mio-Pliocene transgressions led to marine water introduction in the whole rock porosity through density and then diffusion processes, (2) intensive and rapid recharge after the glacial maximum down to several hundred meters depths, (3) a present-day regime of groundwater circulation limited to shallow depth. This work identifies important constraints regarding the mechanisms responsible for both marine and glacial fluid migrations and their preservation within a basement. It defines the first clear time scales of these processes and thus provides a unique case for understanding the effects of climate changes on hydrogeology in basements. It reveals that glacial water is supplied in significant amounts to deep aquifers even in permafrosted zones. It also emphasizes the vulnerability of modern groundwater hydrosystems to climate change as groundwater active aquifers is restricted to shallow depths.

The Drosophila inner-membrane protein PMI controls crista biogenesis and mitochondrial diameter.

Science.gov (United States)

Macchi, Marc; El Fissi, Najla; Tufi, Roberta; Bentobji, Mélanie; Liévens, Jean-Charles; Martins, L Miguel; Royet, Julien; Rival, Thomas

2013-02-01

Cristae are mitochondrial inner-membrane structures that concentrate respiratory chain complexes and hence regulate ATP production. Mechanisms controlling crista morphogenesis are poorly understood and few crista determinants have been identified. Among them are the Mitofilins that are required to establish crista junctions and ATP-synthase subunits that bend the membrane at the tips of the cristae. We report here the phenotypic consequences associated with the in vivo inactivation of the inner-membrane protein Pantagruelian Mitochondrion I (PMI) both at the scale of the whole organism, and at the level of mitochondrial ultrastructure and function. We show that flies in which PMI is genetically inactivated experience synaptic defects and have a reduced life span. Electron microscopy analysis of the inner-membrane morphology demonstrates that loss of PMI function increases the average length of mitochondrial cristae in embryonic cells. This phenotype is exacerbated in adult neurons in which cristae form a dense tangle of elongated membranes. Conversely, we show that PMI overexpression is sufficient to reduce crista length in vivo. Finally, these crista defects are associated with impaired respiratory chain activity and increases in the level of reactive oxygen species. Since PMI and its human orthologue TMEM11 are regulators of mitochondrial morphology, our data suggest that, by controlling crista length, PMI influences mitochondrial diameter and tubular shape.

Uranium deposits in the Beaverlodge area, northern Saskatchewan: their relationship to the Martin Group (Proterozoic) and the underlying basement

International Nuclear Information System (INIS)

Mazimhaka, P.K.; Hendry, H.E.

1989-01-01

The rocks of the Martin Group crop out in an area 60 km by 50 km north of Lake Athabasca near Uranium City, northern Saskatchewan. This area has numerous uranium showings within a few kilometres of the unconformity below the Martin Group. Mineralization occurs in fault zones, in basement rocks and in sedimentary and volcanic rocks of the Martin Group. Martin Group sediments accumulated in alluvial fans, braided streams, and ephemeral lakes. The thickest sequence (8 km to 10 km) is preserved in the Beaverlodge area, near Uranium City. The style of sedimentation changed through time as the basin evolved from deposition of conglomeratic detritus along fault scarps to the accumulation of silt in ephemeral lakes. The uneven nature of the sub-Martin unconformity surface, the lithotype of the lowermost conglomerates and breccias (Beaverlodge Formation), and the shape of the basin fill indicate deposition in fault-controlled basins. The earliest economic uranium mineralization in the rocks of the Martin Group was epigenetic. The mineralization was coeval with that in basement rocks. Economic mineralization in basement rocks and in the lowermost formation of the Martin Group is close to the unconformity. Epigenetic uranium mineralization thus appears to have resulted from processes that were related, in time and space, to either the formation of the unconformity or the deposition of the Martin Group or both. (author). 29 refs, 5 figs

Self-ordered, controlled structure nanoporous membranes using constant current anodization.

Science.gov (United States)

Lee, Kwan; Tang, Yun; Ouyang, Min

2008-12-01

We report a constant current (CC) based anodization technique to fabricate and control structure of mechanically stable anodic aluminum oxide (AAO) membranes with a long-range ordered hexagonal nanopore pattern. For the first time we show that interpore distance (Dint) of a self-ordered nanopore feature can be continuously tuned over a broad range with CC anodization and is uniquely defined by the conductivity of sulfuric acid as electrolyte. We further demonstrate that this technique can offer new degrees of freedom for engineering planar nanopore structures by fine tailoring the CC based anodization process. Our results not only facilitate further understanding of self-ordering mechanism of alumina membranes but also provide a fast, simple (without requirement of prepatterning or preoxide layer), and flexible methodology for controlling complex nanoporous structures, thus offering promising practical applications in nanotechnology.

Zeta potential control in decontamination with inorganic membranes and inorganic adsorbents

Energy Technology Data Exchange (ETDEWEB)

Andalaft, E; Vega, R; Correa, M; Araya, R; Loyola, P [Comision Chilena de Energia Nuclear, Santiago (Chile)

1997-02-01

The application of some advanced separation processes such as microfiltration and ultrafiltration, electroosmosis and electrodialysis for treating nuclear waste from different aqueous streams is under examination at the Chilean Commission for Nuclear Energy. The application of these techniques can be extended to regular industrial wastes when economically advisable. This report deals mainly with electrodialysis, electroosmosis and adsorption with inorganic materials. Special attention is paid to zeta potential control as a driving factor to electroosmosis. For radioactive contaminants that are present in the form of cations, anions, non-ionic solutions, colloids and suspended matter, appropriate combination of the processes may considerably increase the efficiency of processes used. As an example, colloids and suspended particles may be retained in porous ceramic membranes by nanofiltration, ultrafiltration or microfiltration depending on the particle size of the particles. The control of zeta potential by acting in the solid phase or else on the liquid phase has been studied; a mathematical model to predict electrodialysis data has been developed, and finally, the use of a home-made inorganic adsorbent illustrated. The effect of gamma irradiation on the membranes has also been studied. Properties such as salt retention, water flux and pore size diameter determined on both organic and inorganic membranes before and after irradiation indicate deterioration of the organic membrane. (author). 13 refs, 15 figs, 2 tabs.

Zeta potential control in decontamination with inorganic membranes and inorganic adsorbents

International Nuclear Information System (INIS)

Andalaft, E.; Vega, R.; Correa, M.; Araya, R.; Loyola, P.

1997-01-01

The application of some advanced separation processes such as microfiltration and ultrafiltration, electroosmosis and electrodialysis for treating nuclear waste from different aqueous streams is under examination at the Chilean Commission for Nuclear Energy. The application of these techniques can be extended to regular industrial wastes when economically advisable. This report deals mainly with electrodialysis, electroosmosis and adsorption with inorganic materials. Special attention is paid to zeta potential control as a driving factor to electroosmosis. For radioactive contaminants that are present in the form of cations, anions, non-ionic solutions, colloids and suspended matter, appropriate combination of the processes may considerably increase the efficiency of processes used. As an example, colloids and suspended particles may be retained in porous ceramic membranes by nanofiltration, ultrafiltration or microfiltration depending on the particle size of the particles. The control of zeta potential by acting in the solid phase or else on the liquid phase has been studied; a mathematical model to predict electrodialysis data has been developed, and finally, the use of a home-made inorganic adsorbent illustrated. The effect of gamma irradiation on the membranes has also been studied. Properties such as salt retention, water flux and pore size diameter determined on both organic and inorganic membranes before and after irradiation indicate deterioration of the organic membrane. (author). 13 refs, 15 figs, 2 tabs

Nonlinear observer-based Lyapunov boundary control of distributed heat transfer mechanisms for membrane distillation plant

KAUST Repository

Eleiwi, Fadi

2016-09-19

This paper presents a nonlinear observer-based Lyapunov control for a membrane distillation (MD) process. The control considers the inlet temperatures of the feed and the permeate solutions as inputs, transforming it to boundary control process, and seeks to maintain the temperature difference along the membrane boundaries around a sufficient level to promote water production. MD process is modeled with advection diffusion equation model in two dimensions, where the diffusion and convection heat transfer mechanisms are best described. Model analysis, effective order reduction and parameters physical interpretation, are provided. Moreover, a nonlinear observer has been designed to provide the control with estimates of the temperature evolution at each time instant. In addition, physical constraints are imposed on the control to have an acceptable range of feasible inputs, and consequently, better energy consumption. Numerical simulations for the complete process with real membrane parameter values are provided, in addition to detailed explanations for the role of the controller and the observer. (C) 2016 Elsevier Ltd. All rights reserved.

Basement tectonics and flexural subsidence along western continental margin of India

Directory of Open Access Journals (Sweden)

D.K. Pandey

2017-09-01

Full Text Available The Paleocene-recent post-rift subsidence history recorded in the Mumbai Offshore Basin off western continental margin of India is examined. Results obtained through 2-D flexural backstripping modelling of new seismic data reveal considerable thermo-tectonic subsidence over last ca. 56 Myr. Reverse post-rift subsidence modelling with variable β stretching factor predicts residual topography of ca. 2000 m to the west of Shelf Margin Basin and fails to restore late Paleocene horizon and the underlying igneous basement to the sea level. This potentially implies that: (1 either the igneous basement formed during the late Cretaceous was emplaced under open marine environs; or (2 a laterally varying cumulative subsidence occurred within Mumbai Offshore Basin (MOB during ca. 68 to ca. 56 Ma. Pre-depositional topographic variations at ca. 56 Ma across the basin could be attributed to the extensional processes such as varied lower crustal underplating along Western Continental Margin of India (WCMI. Investigations about basement tectonics after unroofing of sediments since late Paleocene from this region support a transitional and heavily stretched nature of crust with high to very high β factors. Computations of past sediment accumulation rates show that the basin sedimentation peaked during late Miocene concurrently with uplift of Himalayan–Tibetan Plateau and intensification of Indian monsoon system. Results from basin subsidence modelling presented here may have significant implications for further studies attempting to explore tectono–climatic interactions in Asia.

Geochemical variability of the Yucatan basement: Constraints from crystalline clasts in Chicxulub impactites

Science.gov (United States)

Kettrup, B.; Deutsch, A.

2003-07-01

The 65 Ma old Chicxulub impact structure with a diameter of about 180 km is again in the focus of the geosciences because of the recently commenced drilling of the scientific well Yaxcopoil- 1. Chicxulub is buried beneath thick post-impact sediments, yet samples of basement lithologies in the drill cores provide a unique insight into age and composition of the crust beneath Yucatan. This study presents major element, Sr, and Nd isotope data for Chicxulub impact melt lithologies and clasts of basement lithologies in impact breccias from the PEMEX drill cores C-1 and Y-6, as well as data for ejecta material from the K/T boundaries at La Lajilla, Mexico, and Furlo, Italy. The impact melt lithologies have an andesitic composition with significantly varying contents of Al, Ca, and alkali elements. Their present day 87Sr/86Sr ratios cluster at about 0.7085, and 143Nd/144Nd ratios range from 0.5123 to 0.5125. Compared to the melt lithologies that stayed inside the crater, data for ejecta material show larger variations. The 87Sr/86Sr ratios range from 0.7081 for chloritized spherules from La Lajilla to 0.7151 for sanidine spherules from Furlo. The 143Nd/144Nd ratio is 0.5126 for La Lajilla and 0.5120 for the Furlo spherules. In an tCHUR(Nd)-tUR(Sr) diagram, the melt lithologies plot in a field delimited by Cretaceous platform sediments, various felsic lithic clasts and a newly found mafic fragment from a suevite. Granite, gneiss, and amphibolite have been identified among the fragments from crystalline basement gneiss. Their 87Sr/86Sr ratios range from 0.7084 to 0.7141, and their 143Nd/144Nd ratios range from 0.5121 to 0.5126. The TNdDM model ages vary from 0.7 to 1.4 Ga, pointing to different source terranes for these rocks. This leads us to believe that the geological evolution and the lithological composition of the Yucatàn basement is probably more complex than generally assumed, and Gondwanan as well as Laurentian crust may be present in the Yucatàn basement.

Fracture Analysis of basement rock: A case example of the Eastern Part of the Peninsular Malaysia

International Nuclear Information System (INIS)

Shamsuddin, A; Ghosh, D

2015-01-01

In general, reservoir rocks can be defined into carbonates, tight elastics and basement rocks. Basement rocks came to be highlighted as their characteristics are quite complicated and remained as a significant challenge in exploration and production area. Motivation of this research is to solve the problem in some area in the Malay Basin which consist fractured basement reservoirs. Thus, in order to increase understanding about their characteristic, a study was conducted in the Eastern part of the Peninsular Malaysia. The study includes the main rock types that resemble the offshore rocks and analysis on the factors that give some effect on fracture characteristic that influence fracture systems and fracture networks. This study will allow better fracture prediction which will be beneficial for future hydrocarbon prediction in this region

Polymeric and Lipid Membranes-From Spheres to Flat Membranes and vice versa.

Science.gov (United States)

Saveleva, Mariia S; Lengert, Ekaterina V; Gorin, Dmitry A; Parakhonskiy, Bogdan V; Skirtach, Andre G

2017-08-15

Membranes are important components in a number of systems, where separation and control of the flow of molecules is desirable. Controllable membranes represent an even more coveted and desirable entity and their development is considered to be the next step of development. Typically, membranes are considered on flat surfaces, but spherical capsules possess a perfect "infinite" or fully suspended membranes. Similarities and transitions between spherical and flat membranes are discussed, while applications of membranes are also emphasized.

Analogue modelling of a reactivated, basement controlled strike-slip zone, Sierra de Albarracín, Spain: application of sandbox modelling to polyphase deformation

NARCIS (Netherlands)

Merten, S.; Smit, W.G.; Nieuwland, D.A.; Rondeel, H.E.

2006-01-01

This paper presents the results of an analogue modelling study on the reactivation of Riedel shears generated by basement-induced sinistral strike-slip faulting. It is based on a natural example in the Sierra de Albarracín, Iberian Range (Spain). The area has a polyphase deformation history, defined

Aeromagnetic imaging of the basement morphology in part of the ...

African Journals Online (AJOL)

Aeromagnetic imaging of the basement morphology in part of the middle Benue trough, Nigeria. GC Onyedim, MO Awoyemi, EA Ariyibi, JB Arubayi. Abstract. No Abstract. Journal of Mining and Geology Vol. 42 (2) 2006: pp. 157-163. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD ...

Impact of feed spacer and membrane modification by hydrophilic, bactericidal and biocidal coating on biofouling control

KAUST Repository

Araújo, Paula A.

2012-06-01

The influence of polydopamine- and polydopamine-. graft-poly(ethylene glycol)-coated feed spacers and membranes, copper-coated feed spacers, and commercially-available biostatic feed spacers on biofouling has been studied in membrane fouling simulators. Feed spacers and membranes applied in practical membrane filtration systems were used; biofouling development was monitored by feed channel pressure drop increase and biomass accumulation. Polydopamine and polydopamine-. g-PEG are hydrophilic surface modification agents expected to resist protein and bacterial adhesion, while copper feed spacer coatings and biocides infused in feed spacers are expected to restrict biological growth. Our studies showed that polydopamine and polydopamine-. g-PEG coatings on feed spacers and membranes, copper coatings on feed spacers, and a commercial biostatic feed spacer did not have a significant impact on feed channel pressure drop increase and biofilm accumulation as measured by ATP and TOC content. The studied spacer and membrane modifications were not effective for biofouling control; it is doubtful that feed spacer and membrane modification, in general, may be effective for biofouling control regardless of the type of applied coating. © 2012 Elsevier B.V.

System and method for air temperature control in an oxygen transport membrane based reactor

Science.gov (United States)

Kelly, Sean M

2016-09-27

A system and method for air temperature control in an oxygen transport membrane based reactor is provided. The system and method involves introducing a specific quantity of cooling air or trim air in between stages in a multistage oxygen transport membrane based reactor or furnace to maintain generally consistent surface temperatures of the oxygen transport membrane elements and associated reactors. The associated reactors may include reforming reactors, boilers or process gas heaters.

Nonlinear Lyapunov-based boundary control of distributed heat transfer mechanisms in membrane distillation plant

KAUST Repository

Eleiwi, Fadi

2015-07-01

This paper presents a nonlinear Lyapunov-based boundary control for the temperature difference of a membrane distillation boundary layers. The heat transfer mechanisms inside the process are modeled with a 2D advection-diffusion equation. The model is semi-descretized in space, and a nonlinear state-space representation is provided. The control is designed to force the temperature difference along the membrane sides to track a desired reference asymptotically, and hence a desired flux would be generated. Certain constraints are put on the control law inputs to be within an economic range of energy supplies. The effect of the controller gain is discussed. Simulations with real process parameters for the model, and the controller are provided. © 2015 American Automatic Control Council.

Superhydrophilic Thin-Film Composite Forward Osmosis Membranes for Organic Fouling Control: Fouling Behavior and Antifouling Mechanisms

KAUST Repository

Tiraferri, Alberto

2012-10-16

This study investigates the fouling behavior and fouling resistance of superhydrophilic thin-film composite forward osmosis membranes functionalized with surface-tailored nanoparticles. Fouling experiments in both forward osmosis and reverse osmosis modes are performed with three model organic foulants: alginate, bovine serum albumin, and Suwannee river natural organic matter. A solution comprising monovalent and divalent salts is employed to simulate the solution chemistry of typical wastewater effluents. Reduced fouling is consistently observed for the superhydrophilic membranes compared to control thin-film composite polyamide membranes, in both reverse and forward osmosis modes. The fouling resistance and cleaning efficiency of the functionalized membranes is particularly outstanding in forward osmosis mode where the driving force for water flux is an osmotic pressure difference. To understand the mechanism of fouling, the intermolecular interactions between the foulants and the membrane surface are analyzed by direct force measurement using atomic force microscopy. Lower adhesion forces are observed for the superhydrophilic membranes compared to the control thin-film composite polyamide membranes. The magnitude and distribution of adhesion forces for the different membrane surfaces suggest that the antifouling properties of the superhydrophilic membranes originate from the barrier provided by the tightly bound hydration layer at their surface, as well as from the neutralization of the native carboxyl groups of thin-film composite polyamide membranes. © 2012 American Chemical Society.

Superhydrophilic thin-film composite forward osmosis membranes for organic fouling control: fouling behavior and antifouling mechanisms.

Science.gov (United States)

Tiraferri, Alberto; Kang, Yan; Giannelis, Emmanuel P; Elimelech, Menachem

2012-10-16

This study investigates the fouling behavior and fouling resistance of superhydrophilic thin-film composite forward osmosis membranes functionalized with surface-tailored nanoparticles. Fouling experiments in both forward osmosis and reverse osmosis modes are performed with three model organic foulants: alginate, bovine serum albumin, and Suwannee river natural organic matter. A solution comprising monovalent and divalent salts is employed to simulate the solution chemistry of typical wastewater effluents. Reduced fouling is consistently observed for the superhydrophilic membranes compared to control thin-film composite polyamide membranes, in both reverse and forward osmosis modes. The fouling resistance and cleaning efficiency of the functionalized membranes is particularly outstanding in forward osmosis mode where the driving force for water flux is an osmotic pressure difference. To understand the mechanism of fouling, the intermolecular interactions between the foulants and the membrane surface are analyzed by direct force measurement using atomic force microscopy. Lower adhesion forces are observed for the superhydrophilic membranes compared to the control thin-film composite polyamide membranes. The magnitude and distribution of adhesion forces for the different membrane surfaces suggest that the antifouling properties of the superhydrophilic membranes originate from the barrier provided by the tightly bound hydration layer at their surface, as well as from the neutralization of the native carboxyl groups of thin-film composite polyamide membranes.

Light-activated control of protein channel assembly mediated by membrane mechanics

Science.gov (United States)

Miller, David M.; Findlay, Heather E.; Ces, Oscar; Templer, Richard H.; Booth, Paula J.

2016-12-01

Photochemical processes provide versatile triggers of chemical reactions. Here, we use a photoactivated lipid switch to modulate the folding and assembly of a protein channel within a model biological membrane. In contrast to the information rich field of water-soluble protein folding, there is only a limited understanding of the assembly of proteins that are integral to biological membranes. It is however possible to exploit the foreboding hydrophobic lipid environment and control membrane protein folding via lipid bilayer mechanics. Mechanical properties such as lipid chain lateral pressure influence the insertion and folding of proteins in membranes, with different stages of folding having contrasting sensitivities to the bilayer properties. Studies to date have relied on altering bilayer properties through lipid compositional changes made at equilibrium, and thus can only be made before or after folding. We show that light-activation of photoisomerisable di-(5-[[4-(4-butylphenyl)azo]phenoxy]pentyl)phosphate (4-Azo-5P) lipids influences the folding and assembly of the pentameric bacterial mechanosensitive channel MscL. The use of a photochemical reaction enables the bilayer properties to be altered during folding, which is unprecedented. This mechanical manipulation during folding, allows for optimisation of different stages of the component insertion, folding and assembly steps within the same lipid system. The photochemical approach offers the potential to control channel assembly when generating synthetic devices that exploit the mechanosensitive protein as a nanovalve.

Smart membranes for monitoring membrane based desalination processes

KAUST Repository

Laleg-Kirati, Taous-Meriem

2017-10-12

Various examples are related to smart membranes for monitoring membrane based process such as, e.g., membrane distillation processes. In one example, a membrane, includes a porous surface and a plurality of sensors (e.g., temperature, flow and/or impedance sensors) mounted on the porous surface. In another example, a membrane distillation (MD) process includes the membrane. Processing circuitry can be configured to monitor outputs of the plurality of sensors. The monitored outputs can be used to determine membrane degradation, membrane fouling, or to provide an indication of membrane replacement or cleaning. The sensors can also provide temperatures or temperature differentials across the porous surface, which can be used to improve modeling or control the MD process.

Disease: H01721 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available H01721 Anti-glomerular basement membrane (GBM) disease; Goodpasture syndrome Goodp...asture syndrome (GS), or anti-glomerular basement membrane (anti-GBM) disease, is a rare and organ-specific ...n of the alpha 3 chain of type IV collagen [alpha3(IV)NC1], found in the glomerular and alveolar basement me

Impact of sludge flocs on membrane fouling in membrane bioreactors

DEFF Research Database (Denmark)

Christensen, Morten Lykkegaard; Niessen, Wolfgang; Jørgensen, Mads Koustrup

Membrane bioreactors (MBR) are widely used for wastewater treatment, but membrane fouling reduces membrane performance and thereby increases the cost for membranes and fouling control. Large variation in filtration properties measured as flux decline was observed for the different types of sludges....... Further, the flux could partly be reestablished after the relaxation period depending on the sludge composition. The results underline that sludge properties are important for membrane fouling and that control of floc properties, as determined by the composition of the microbial communities...... and the physico-chemical properties, is an efficient method to reduce membrane fouling in the MBR. High concentration of suspended extracellular substances (EPS) and small particles (up to 10 µm) resulted in pronounced fouling propensity. The membrane fouling resistance was reduced at high concentration...

Model-Based Control of a Continuous Coating Line for Proton Exchange Membrane Fuel Cell Electrode Assembly

Directory of Open Access Journals (Sweden)

Vikram Devaraj

2015-01-01

Full Text Available The most expensive component of a fuel cell is the membrane electrode assembly (MEA, which consists of an ionomer membrane coated with catalyst material. Best-performing MEAs are currently fabricated by depositing and drying liquid catalyst ink on the membrane; however, this process is limited to individual preparation by hand due to the membrane’s rapid water absorption that leads to shape deformation and coating defects. A continuous coating line can reduce the cost and time needed to fabricate the MEA, incentivizing the commercialization and widespread adoption of fuel cells. A pilot-scale membrane coating line was designed for such a task and is described in this paper. Accurate process control is necessary to prevent manufacturing defects from occurring in the coating line. A linear-quadratic-Gaussian (LQG controller was developed based on a physics-based model of the coating process to optimally control the temperature and humidity of the drying zones. The process controller was implemented in the pilot-scale coating line proving effective in preventing defects.

Reliability of residential basements as blast shelters

International Nuclear Information System (INIS)

Longinow, A.; Mohammadi, J.

1983-01-01

This paper describes an analysis method for predicting the probability of failure of a wood-framed basement when subjected to a static, uniformly distributed load. The analysis considers the primary failure modes of each framing member and determines the probability of failure for each mode acting alone. The failure probability of the system as a whole is then bounded. The upper bound is determined on the assumption that the failure modes are independent, while the lower bound is determined on the assumption that the failure modes are perfectly correlated. The analysis is described with reference to an example problem

Numerical analysis of temperature distribution due to basement radiogenic heat production, St. Lawrence Lowlands, eastern Canada

Science.gov (United States)

Liu, Hejuan; Giroux, Bernard; Harris, Lyal B.; Mansour, John

2017-04-01

Although eastern Canada is considered as having a low potential for high-temperature geothermal resources, the possibility for additional localized radioactive heat sources in Mesoproterozoic Grenvillian basement to parts of the Palaeozoic St. Lawrence Lowlands in Quebec, Canada, suggests that this potential should be reassessed. However, such a task remains hard to achieve due to scarcity of heat flow data and ambiguity about the nature of the basement. To get an appraisal, the impact of radiogenic heat production for different Grenville Province crystalline basement units on temperature distribution at depth was simulated using the Underworld Geothermal numerical modelling code. The region south of Trois-Rivières was selected as representative for the St. Lawrence Lowlands. An existing 3D geological model based on well log data, seismic profiles and surface geology was used to build a catalogue of plausible thermal models. Statistical analyses of radiogenic element (U, Th, K) concentrations from neighbouring outcropping Grenville domains indicate that the radiogenic heat production of rocks in the modelled region is in the range of 0.34-3.24 μW/m3, with variations in the range of 0.94-5.83 μW/m3 for the Portneuf-Mauricie (PM) Domain, 0.02-4.13 μW/m3 for the Shawinigan Domain (Morin Terrane), and 0.34-1.96 μW/m3 for the Parc des Laurentides (PDL) Domain. Various scenarios considering basement characteristics similar to the PM domain, Morin Terrane and PDL Domain were modelled. The results show that the temperature difference between the scenarios can be as much as 12 °C at a depth of 5 km. The results also show that the temperature distribution is strongly affected by both the concentration of radiogenic elements and the thermal conductivity of the basement rocks. The thermal conductivity in the basement affects the trend of temperature change between two different geological units, and the spatial extent of thermal anomalies. The validity of the results was

Effects of ionizing radiation on glycerolated amniotic membranes as a substract for cultured human epithelium; Efeitos da radiacao ionizante em membranas amnioticas gliceroladas empregadas como substrato ao cultivo de epitelio humano

Energy Technology Data Exchange (ETDEWEB)

Paggiaro, Andre Oliveira

2011-07-01

The amniotic membrane (AM) is a biomaterial with biological properties that are beneficial to tissue repair. It has been used as a temporary coverage to threat burns and chronic wounds. Recently, it has been served as a substrate for keratinocytes culture to construct a living skin equivalent. However, MA is a biological material, and its transplantation could cause infectious disease for receptors. So, it must be preserved and sterilized before clinical use. The aim of this study was to evaluate the radiation effects on glycerol-preserved MA, considering its compatibility to support human keratinocytes culture. Four MA were stored in high concentrations of glycerol (> 85%) and half of them were radio sterilized with a dose of 25 kGy. Then, we established two groups: nonirradiated MA (MA-ni) and irradiated MA (MA-i). Both groups was deepithelialized by a standardized protocol and was investigated morphologically, immunohistochemical and ultrastructural. Subsequently human keratinocytes were cultivated immersed and in air-liquid interface on denuded surface of MA-i and MA-ni. The results were compared at 14 and 21 days of culture by light and electron microscopy. After epithelial denudation, analyses demonstrated the continuity of the basement membrane in MA-ni group, whereas in the irradiated group, there was no indication of the basement membrane’s presence on the surface of MA. The cell cultures showed that in the non-irradiated group, there was growth of a multi-layered and differentiated epithelium, with a stratum corneum’s formation in air-liquid interface. In the irradiated group, the epithelium had only two or three layer, little cell differentiation, with the same results immersed or air-liquid interface system. Glycerol-preserved MA was biocompatible with the growth of a cultivated epithelium, showing its potential as a skin substitute. Irradiation at 25 kGy cause structural damage to the tissue, making changes in basement membrane, that facilitates

Where are uranium and thorium stored in the Archean basement

Energy Technology Data Exchange (ETDEWEB)

Schwinner, R

1949-01-01

The author advances a theory which makes it possible to predict where prospecting for new deposits of uranium and thorium should prove successful. According to this theory, such deposits occur chiefly where the equatorial and the meridional branches of the oldest primitive rock systems cross one another. An outline of the earth's Archean basement is included.

[Pollution prevention and control of aqueous extract of astragali radix processed with ZrO2 inorganic ceramic membrane micro-filtration].

Science.gov (United States)

Pan, Lin-Men; Huang, Min-Yan; Guo, Li-Wei

2012-11-01

To study the measures for preventing and controlling the pollution of aqueous extract of Astragali Radix proceeded with inorganic ceramic membrane micro-filtration, in order to find effective measures for preventing and controlling the membrane pollution. The resistance distribution, polymer removal and changes in physical and chemical parameters of the zirconium oxide film of different pore diameters were determined to analyze the state or location of pollutants as well as the regularity of formation. Meanwhile, recoil and ultrasonic physical measures were adopted to strengthen the membrane process, in order to explore the methods for preventing and controlling the membrane pollution. When 0.2 microm of ZrO2 micro-filtrated aqueous extract of Astragali Radix, the rate of pollution was as high as 44.9%. The hole blocking resistance and the concentration polarization resistance were the main filtration resistances, while the surface deposit resistance decreased with the increase in the membrane's hold diameter; after micro-filtration, the liquid turbidity significantly reduced, with slight changes in both pH and viscosity. The 0.2 microm ZrO2 micro-filtration membrane performed better than the 0.05 microm pore size membrane in terms of conductivity. The 0. 2 microm and 0.05 microm pore diameter membranes showed better performance in the removal of pectin. The ultrasonic measure to strengthen membranes is more suitable to this system, with a flux rate up by 41.7%. The membrane optimization process adopts appropriate measures for preventing and controlling the membrane pollution, in order to reduce the membrane pollution, recover membrane performance and increase filtration efficiency.

The Effect of Mechanical Characteristics of Basal Decollement and Basement Structures on Deformation of the Zagros Basin

OpenAIRE

Bahroudi, Abbas

2003-01-01

Two fundamental structural elements, basement architecture and basal decollement, play a significant role in the evolution of a tectonically active region. Using different approaches (field data, literature review and analogue models) this thesis demonstrates that these two elements affected the deformation style in the Zagros fold-thrust belt during Mesozoic extensional and Cenozoic contractional episodes. Reassessment of available data suggests a new configuration for the basement to Zagro...

Disease: H00579 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available to the missense mutations in the COL4A1 in basement membranes. The renal manifestations include hematuria an...erited diseases of the glomerular basement membrane. ... JOURNAL ... Nat Clin Pract N

The anterior lens capsule used as support material in RPE cell-transplantation

DEFF Research Database (Denmark)

Nicolini, J; Kiilgaard, Jens Folke; Wiencke, A K

2000-01-01

To investigate the use of an ocular basement membrane as support material for transplanted porcine RPE cells.......To investigate the use of an ocular basement membrane as support material for transplanted porcine RPE cells....

Geochemical interpretation of the Precambrian basement and overlying Cambrian sandstone on Bornholm, Denmark: Implications for the weathering history

Science.gov (United States)

Zhou, Lingli; Friis, Henrik; Yang, Tian; Nielsen, Arne Thorshøj

2017-08-01

A geochemical study of the Precambrian basement granites from the Borggård borehole on Bornholm, Denmark, suggests that the granites were moderately weathered (Chemical Index of Alteration-CIA = 66-71) during subaerial exposure in a humid climate. The microcline is well preserved, whereas plagioclase was thoroughly altered to clay minerals (Plagioclase Index of Alteration-PIA = 93-99) which is likely due to its original Ca-rich composition. The primary Fe-Ti accessory minerals were oxidized to hematite and anatase. Evidence from REE distribution patterns and immobile element ratios, e.g. Zr/Hf and Nb/Ta, between the weathered basement granite from the Borggård borehole and regional granitoids on Bornholm, constrains the Svaneke Granite as the original basement lithology. A tau (τ) mass transport model (assuming immobile Ti) was applied to quantify the mass transfer during weathering of the basement granite. The results show a depletion of major elements in the following order: Na > Ca > Mg > Si; Al and Ti are immobile and stay constant; K shows sample dependent enrichment or depletion; Fe is slightly enriched. The Cambrian sandstone overlying the basement in the Borggård borehole, assigned to the Gadeby Member of the Nexø Formation, is feldspathic litharenite-litharenite in composition. Provenance indicators including (Gd/Yb)N, Zr/Hf and Nb/Ta ratios and petrological features indicate that source material was derived from both weathered and fresh basement granite of intermediate composition. The Gadeby Member equivalents in Germany, the basal lower Cambrian Adlergrund Konglomerat Member (AKM) in the offshore G-14 well north of Rügen, and the approximately coeval Lubmin Sandstein Formation (LSF) from the Loissin-1 borehole, mainland Germany, must have been sourced from a basement with compositions comparable to the intermediate group of the regional granitoids on Bornholm. The source materials for the AKM (CIA = 71-72, PIA = 94-96), the Gadeby Member in the

Halogens are key cofactors in building of collagen IV scaffolds outside the cell.

Science.gov (United States)

Brown, Kyle L; Hudson, Billy G; Voziyan, Paul A

2018-05-01

The purpose of this review is to highlight recent advances in understanding the molecular assembly of basement membranes, as exemplified by the glomerular basement membrane (GBM) of the kidney filtration apparatus. In particular, an essential role of halogens in the basement membrane formation has been discovered. Extracellular chloride triggers a molecular switch within non collagenous domains of collagen IV that induces protomer oligomerization and scaffold assembly outside the cell. Moreover, bromide is an essential cofactor in enzymatic cross-linking that reinforces the stability of scaffolds. Halogenation and halogen-induced oxidation of the collagen IV scaffold in disease states damage scaffold function. Halogens play an essential role in the formation of collagen IV scaffolds of basement membranes. Pathogenic damage of these scaffolds by halogenation and halogen-induced oxidation is a potential target for therapeutic interventions.

Graphene oxide enrichment of collagen membranes improves DPSCs differentiation and controls inflammation occurrence.

Science.gov (United States)

Radunovic, Milena; De Colli, Marianna; De Marco, Patrizia; Di Nisio, Chiara; Fontana, Antonella; Piattelli, Adriano; Cataldi, Amelia; Zara, Susi

2017-08-01

Collagen membranes are used in oral surgery for bone defects treatment acting as a barrier that does not allow the invasion of soft tissue into the growing bone. To improve biocompatibility collagen membranes were coated with graphene oxide (GO), a graphene derivative. The aim of this study was to investigate the biocompatibility of GO coated collagen membranes on human dental pulp stem cells (DPSCs) focusing on biomaterial cytotoxicity, ability to promote DPSCs differentiation process and to control inflammation event induction. DPSCs were cultured on uncoated membranes and on both 2 and 10 μg mL -1 GO coated membranes up to 28 days. Alamar blue and LDH cytotocicity assay, PGE2 ELISA assay, real time RT-PCR for RUNX2, BMP2, SP7, TNFα and COX2 genes expression were performed. Proliferation is higher on GO coated membranes at days 14 and 28. LDH assay evidences no cytotoxicity. BMP2 and RUNX2 expression is higher on coated membranes, BMP2 at early and RUNX2 and SP7 at late experimental times. PGE2 levels are lower on GO coated membranes at days 14 and 28, both TNFα and COX2 expression is significantly decreased when GO is applied. GO coated membranes are not toxic for DPSCs, induce a faster DPSCs differentiation into odontoblasts/osteoblasts and may represent good alternative to conventional membranes thus ensuring more efficient bone formation and improving the clinical performance. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2312-2320, 2017. © 2017 Wiley Periodicals, Inc.

Preliminary analysis of a membrane-based atmosphere-control subsystem

Science.gov (United States)

Mccray, Scott B.; Newbold, David D.; Ray, Rod; Ogle, Kathryn

1993-01-01

Controlled ecological life supprot systems will require subsystems for maintaining the consentrations of atmospheric gases within acceptable ranges in human habitat chambers and plant growth chambers. The goal of this work was to develop a membrane-based atmosphere comntrol (MBAC) subsystem that allows the controlled exchange of atmospheric componets (e.g., oxygen, carbon dioxide, and water vapor) between these chambers. The MBAC subsystem promises to offer a simple, nonenergy intensive method to separate, store and exchange atmospheric components, producing optimal concentrations of components in each chamber. In this paper, the results of a preliminary analysis of the MBAC subsystem for control of oxygen and nitrogen are presented. Additionally, the MBAC subsystem and its operation are described.

Age of Izu-Bonin-Mariana arc basement

Science.gov (United States)

Ishizuka, Osamu; Hickey-Vargas, Rosemary; Arculus, Richard J.; Yogodzinski, Gene M.; Savov, Ivan P.; Kusano, Yuki; McCarthy, Anders; Brandl, Philipp A.; Sudo, Masafumi

2018-01-01

Documenting the early tectonic and magmatic evolution of the Izu-Bonin-Mariana (IBM) arc system in the Western Pacific is critical for understanding the process and cause of subduction initiation along the current convergent margin between the Pacific and Philippine Sea plates. Forearc igneous sections provide firm evidence for seafloor spreading at the time of subduction initiation (52 Ma) and production of "forearc basalt". Ocean floor drilling (International Ocean Discovery Program Expedition 351) recovered basement-forming, low-Ti tholeiitic basalt crust formed shortly after subduction initiation but distal from the convergent margin (nominally reararc) of the future IBM arc (Amami Sankaku Basin: ASB). Radiometric dating of this basement gives an age range (49.3-46.8 Ma with a weighted average of 48.7 Ma) that overlaps that of basalt in the present-day IBM forearc, but up to 3.3 m.y. younger than the onset of forearc basalt activity. Similarity in age range and geochemical character between the reararc and forearc basalts implies that the ocean crust newly formed by seafloor spreading during subduction initiation extends from fore- to reararc of the present-day IBM arc. Given the age difference between the oldest forearc basalt and the ASB crust, asymmetric spreading caused by ridge migration might have taken place. This scenario for the formation of the ASB implies that the Mesozoic remnant arc terrane of the Daito Ridges comprised the overriding plate at subduction initiation. The juxtaposition of a relatively buoyant remnant arc terrane adjacent to an oceanic plate was more favourable for subduction initiation than would have been the case if both downgoing and overriding plates had been oceanic.

Controlled growth of CNT in mesoporous AAO through optimized conditions for membrane preparation and CVD operation

Energy Technology Data Exchange (ETDEWEB)

Ciambelli, P; Sarno, M; Leone, C; Sannino, D [Department of Chemical and Food Engineering, University of Salerno, I-84084 Fisciano (Italy); Arurault, L; Fontorbes, S; Datas, L; Lenormand, P; Le Blond Du Plouy, S, E-mail: msarno@unisa.it, E-mail: arurault@chimie.ups-tlse.fr [Universite de Toulouse, CIRIMAT, UPS/INPT/CNRS, LCMIE, F-31062 Toulouse Cedex 9 (France)

2011-07-01

Anodic aluminium oxide (RAAO) membranes with a mesoporous structure were prepared under strictly controlling experimental process conditions, and physically and chemically characterized by a wide range of experimental techniques. Commercial anodic aluminium oxide (CAAO) membranes were also investigated for comparison. We demonstrated that RAAO membranes have lower content of both water and phosphorus and showed better porosity shape than CAAO. The RAAO membranes were used for template growth of carbon nanotubes (CNT) inside its pores by ethylene chemical vapour deposition (CVD) in the absence of a catalyst. A composite material, containing one nanotube for each channel, having the same length as the membrane thickness and an external diameter close to the diameter of the membrane holes, was obtained. Yield, selectivity and quality of CNTs in terms of diameter, length and arrangement (i.e. number of tubes for each channel) were optimized by investigating the effect of changing the experimental conditions for the CVD process. We showed that upon thermal treatment RAAO membranes were made up of crystallized allotropic alumina phases, which govern the subsequent CNT growth, because of their catalytic activity, likely due to their Lewis acidity. The strict control of experimental conditions for membrane preparation and CNT growth allowed us to enhance the carbon structural order, which is a critical requisite for CNT application as a substitute for copper in novel nano-interconnects.

Effect of Graphene and Fullerene Nanofillers on Controlling the Pore Size and Physicochemical Properties of Chitosan Nanocomposite Mesoporous Membranes

Directory of Open Access Journals (Sweden)

Irene S. Fahim

2015-01-01

Full Text Available Chitosan (CS nanocomposite mesoporous membranes were fabricated by mixing CS with graphene (G and fullerene (F nanofillers, and the diffusion properties through CS membranes were studied. In addition, in order to enhance the binding between the internal CS chains, physical cross-linking of CS by sodium tripolyphosphate (TPP was carried out. F and G with different weight percentages (0.1, 0.5, and 1 wt.% were added on physically cross-linked chitosan (CLCS and non-cross-linked chitosan (NCLCS membranes by wet mixing. Permeability and diffusion time of CLCS and NCLCS membranes at different temperatures were investigated. The results revealed that the pore size of all fabricated CS membranes is in the mesoporous range (i.e., 2–50 nm. Moreover, the addition of G and F nanofillers to CLCS and NCLCS solutions aided in controlling the CS membranes’ pore size and was found to enhance the barrier effect of the CS membranes either by blocking the internal pores or decreasing the pore size. These results illustrate the significant possibility of controlling the pore size of CS membranes by cross-linking and more importantly the careful selection of nanofillers and their percentage within the CS membranes. Controlling the pore size of CS membranes is a fundamental factor in packaging applications and membrane technology.

A fall-out shelter or basement structure

International Nuclear Information System (INIS)

Blatchford, J.M.A.

1982-01-01

A strong structure of precast concrete for use as a fallout shelter, tank, basement structure, blast-proof garage is described. It consists of several upright, concrete wall elements, including L-shaped sections, and at least one concrete roof element. The concrete elements are preferably encased in, and may also be supported on, a concrete surround which is formed in situ and which may be secured to the elements by projecting links. The structure may be assembled as an underground or above-ground building. This invention provides a strong structure of quite large span which is relatively simple in construction and can be rapidly assembled. (U.K.)

Membranous glomerulopathy and massive cervical lymphadenopathy due to immunoglobulin G4-disease

Directory of Open Access Journals (Sweden)

Kamel El-Reshaid

2017-01-01

Full Text Available A 32-year-old male presented with acute and severe nephrotic syndrome as well as massive right cervical lymphadenopathy for <2 years. Computed tomography scan of the chest, abdomen, and pelvis did not reveal any lymphadenopathy. Histopathology and immunohistochemical testing of his lymph node biopsy showed infiltrate enriched with immunoglobulin G4 (IgG4-positive plasma cells. His kidney biopsy showed granular membranous deposits of IgG4 in the basement membrane without interstitial infiltrate. Antiphospholipid 2 receptor antibodies were absent excluding its "idiopathic" nature. Since he was allergic to rituximab, he was treated with corticosteroids for two months and a combination of tacrolimus and mycophenolate. His lymphadenopathy disappeared, and his proteinuria abated. The dose of the latter two medications was reduced to half after four months and will be maintained for a minimum of two years to prevent relapse of his disease.

Integrated Wireless Monitoring and Control System in Reverse Osmosis Membrane Desalination Plants

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Al Haji Ahmad

2015-01-01

Full Text Available The operational processes of the Reverse Osmosis (RO membrane desalination plants require continuous monitoring through the constant attendance of operators to ensure proper productivity and minimize downtime and prevent membrane failure. Therefore, the plant must be equipped with a control system that monitors and controls the operational variables. Monitoring and controlling the affecting parameters are critical to the evaluation of the performance of the desalination plant, which will help the operator find and resolve problems immediately. Therefore, this paper was aimed at developing an RO unit by utilizing a wireless sensor network (WSN system. Hence, an RO pilot plant with a feed capacity of 1.2 m3/h was utilized, commissioned, and tested in Kuwait to assess and verify the performance of the integrated WSN in RO membrane desalination system. The investigated system allowed the operators to remotely monitor the operational process of the RO system. The operational data were smoothly recorded and monitored. Furthermore, the technical problems were immediately determined, which reduced the time and effort in rectifying the technical problems relevant to the RO performance. The manpower requirements of such treatment system were dramatically reduced by about 50%. Based on a comparison between manual and wireless monitoring operational processes, the availability of the integrated RO unit with a wireless monitoring was increased by 10%

Identification of Zones and Areal Extent of Weathered Crystalline Basement in the Archean-Lower Proterozoic Crust of the South Tatar Arch

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N.B. Amelchenko

2017-08-01

Full Text Available Based on the data of geophysical surveys and deep drilling the depth to the crystalline basement and its weathered upper layer at the eastern flank of the South Tartar Arch varies from 1650 to 2500 m. Against the ongoing depletion of hydrocarbon reserves in the Paleozoic reservoirs of the region the basement becomes a promising exploration target. However the study of its architecture, composition and areal extent is largely hindered by so far very limited coring in this interval. In previous research correlation of core data and wireline logs was used for petrophysical characterization and identification of zones in a vertical profile of the upper weathered layer of the basement in the deep parametric test wells 50 Novournyak and 2000 Tyimazy with most complete core recovery. These characterization criteria have been utilized for analysis of 750 deep wells drilled in Bashkortostan within the South Tatar Arch which is bounded in the south by the Serafimovsko-Baltaevskiy Graben. In 340 wells based on wireline and production logs the upper weathered layer of the basement revealed certain distinct features of vertical zonation. The analysis resulted in thickness maps for Zone B and combined thickness maps for Zones B + C where the weathered basement is characterized by two morphological types – linear-areal and linear-fractured. The findings support the initial assumption that the obtained petrophysical characteristics may be applied to identify the weathered crystalline basement in wells with no core.

Effect of fibrin glue on the biomechanical properties of human Descemet's membrane.

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Shyam S Chaurasia

Full Text Available BACKGROUND: Corneal transplantation has rapidly evolved from full-thickness penetrating keratoplasty (PK to selective tissue corneal transplantation, where only the diseased portions of the patient's corneal tissue are replaced with healthy donor tissue. Descemet's membrane endothelial keratoplasty (DMEK performed in patients with corneal endothelial dysfunction is one such example where only a single layer of endothelial cells with its basement membrane (10-15 µm in thickness, Descemet's membrane (DM is replaced. It is challenging to replace this membrane due to its intrinsic property to roll in an aqueous environment. The main objective of this study was to determine the effects of fibrin glue (FG on the biomechanical properties of DM using atomic force microscopy (AFM and relates these properties to membrane folding propensity. METHODOLOGY/PRINCIPAL FINDINGS: Fibrin glue was sprayed using the EasySpray applicator system, and the biomechanical properties of human DM were determined by AFM. We studied the changes in the "rolling up" tendency of DM by examining the changes in the elasticity and flexural rigidity after the application of FG. Surface topography was assessed using scanning electron microscopy (SEM and AFM imaging. Treatment with FG not only stabilized and stiffened DM but also led to a significant increase in hysteresis of the glue-treated membrane. In addition, flexural or bending rigidity values also increased in FG-treated membranes. CONCLUSIONS/SIGNIFICANCE: Our results suggest that fibrin glue provides rigidity to the DM/endothelial cell complex that may aid in subsequent manipulation by maintaining tissue integrity.

Effect of Fibrin Glue on the Biomechanical Properties of Human Descemet's Membrane

Science.gov (United States)

Chaurasia, Shyam S.; Champakalakshmi, Ravi; Li, Ang; Poh, Rebekah; Tan, Xiao Wei; Lakshminarayanan, Rajamani; Lim, Chwee T.; Tan, Donald T.; Mehta, Jodhbir S.

2012-01-01

Background Corneal transplantation has rapidly evolved from full-thickness penetrating keratoplasty (PK) to selective tissue corneal transplantation, where only the diseased portions of the patient's corneal tissue are replaced with healthy donor tissue. Descemet's membrane endothelial keratoplasty (DMEK) performed in patients with corneal endothelial dysfunction is one such example where only a single layer of endothelial cells with its basement membrane (10–15 µm in thickness), Descemet's membrane (DM) is replaced. It is challenging to replace this membrane due to its intrinsic property to roll in an aqueous environment. The main objective of this study was to determine the effects of fibrin glue (FG) on the biomechanical properties of DM using atomic force microscopy (AFM) and relates these properties to membrane folding propensity. Methodology/Principal Findings Fibrin glue was sprayed using the EasySpray applicator system, and the biomechanical properties of human DM were determined by AFM. We studied the changes in the “rolling up” tendency of DM by examining the changes in the elasticity and flexural rigidity after the application of FG. Surface topography was assessed using scanning electron microscopy (SEM) and AFM imaging. Treatment with FG not only stabilized and stiffened DM but also led to a significant increase in hysteresis of the glue-treated membrane. In addition, flexural or bending rigidity values also increased in FG-treated membranes. Conclusions/Significance Our results suggest that fibrin glue provides rigidity to the DM/endothelial cell complex that may aid in subsequent manipulation by maintaining tissue integrity. PMID:22662156

Metasomatic tourmalinite formation along basement-cover decollements, Orobic Alps, Italy

Science.gov (United States)

Slack, J.F.; Passchier, C.W.; Zhang, J.S.

1996-01-01

Cryptocrystalline tourmalinites that occur discontinuously for ???30 km along basement-cover de??collements of the Orohic Alps (Italy) formed by the metasomatism of aluminous cataclasites derived from Permian conglomerates and/or feldspathic sandstones. Using Al as an immobile element monitor, calculations show that the majority of tourmalinites in the region formed through the addition of moderate to significant amounts of B, Mg, Na, Sr, and Be, and the loss of moderate to significant Mn, Ca, K, P, Rb, Ba, and Cr; minor Si, Ti, V, light REE, and Eu also were lost. Data tor relatively immobile Al, Zr, Th, Sc, Nb, and heavy REE indicate that, on average, these tourmalinites formed through ???12% net mass loss assuming an original conglomerate protolith, or through ???7% net mass loss assuming a sandstone protolith. The B and other introduced constituents in the tourmalinites were deposited by hydrothermal fluids focused along and near basement-cover de??collements. These fluids, believed to be associated with late Hercynian felsic magmatism, probably are related to fluids that formed the tourmaline-rich U-Mo-Zn deposits at the nearby Novazza mine and the U-Zn deposits at the nearby Val Vedello mine.

Time variation of 222Rn concentration and gamma level in a half-basement room

International Nuclear Information System (INIS)

Iimoto, Takeshi; Eguchi, Hoshio; Kosako, Toshiso; Sugiura, Nobuyuki

1998-01-01

Correlation between 222 Rn (radon) concentration and gamma level in a half-basement has been discussed. In order to decrease the background count of a whole-body counter (WBC), a ventilation blower of 72 m 2 h -1 was installed. The device succeeded in a big reduction of radon concentration in the half-basement and then the background of WBC (NaI(Tl)) decreased to the 76.5% of the saturated value. Through a radon saturation test the exhalation rate of radon from concrete wall was estimated as 2.1 Bqm -2 h -1 by a simple model calculation. In addition, through a ventilation test, the procedure was analyzed by another simple model. (author)

Disease: H01221 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available H01221 Epithelial basement membrane corneal dystrophy (EBMD); Cogan microcystic ep...ithelial dystrophy; Map-dot-fingerprint dystrophy Epithelial basement membrane corneal dystrophy (EBMD) is a...e known to cause various forms of corneal dystrophies, have been identified. Sheet-like areas of basement me...on J, Menasche M, Munier FL, Laroche L, Abitbol M, Schorderet DF ... TITLE ... A subset of patients with epithelial basemen

Podocyte expression of membrane transporters involved in puromycin aminonucleoside-mediated injury.

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Cristina Zennaro

Full Text Available Several complex mechanisms contribute to the maintenance of the intricate ramified morphology of glomerular podocytes and to interactions with neighboring cells and the underlying basement membrane. Recently, components of small molecule transporter families have been found in the podocyte membrane, but expression and function of membrane transporters in podocytes is largely unexplored. To investigate this complex field of investigation, we used two molecules which are known substrates of membrane transporters, namely Penicillin G and Puromycin Aminonucleoside (PA. We observed that Penicillin G pre-administration prevented both in vitro and in vivo podocyte damage caused by PA, suggesting the engagement of the same membrane transporters by the two molecules. Indeed, we found that podocytes express a series of transporters which are known to be used by Penicillin G, such as members of the Organic Anion Transporter Polypeptides (OATP/Oatp family of influx transporters, and P-glycoprotein, a member of the MultiDrug Resistance (MDR efflux transporter family. Expression of OATP/Oatp transporters was modified by PA treatment. Similarly, in vitro PA treatment increased mRNA and protein expression of P-glycoprotein, as well as its activity, confirming the engagement of the molecule upon PA administration. In summary, we have characterized some of the small molecule transporters present at the podocyte membrane, focusing on those used by PA to enter and exit the cell. Further investigation will be needed to understand precisely the role of these transporter families in maintaining podocyte homeostasis and in the pathogenesis of podocyte injury.

Biofouling of Water Treatment Membranes: A Review of the Underlying Causes, Monitoring Techniques and Control Measures

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Felicity A. Roddick

2012-11-01

Full Text Available Biofouling is a critical issue in membrane water and wastewater treatment as it greatly compromises the efficiency of the treatment processes. It is difficult to control, and significant economic resources have been dedicated to the development of effective biofouling monitoring and control strategies. This paper highlights the underlying causes of membrane biofouling and provides a review on recent developments of potential monitoring and control methods in water and wastewater treatment with the aim of identifying the remaining issues and challenges in this area.

Combination of electrochemical processes with membrane bioreactors for wastewater treatment and fouling control: A review

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Benny Marie B. Ensano

2016-08-01

Full Text Available This paper provides a critical review about the integration of electrochemical processes into membrane bioreactors (MBR in order to understand the influence of these processes on wastewater treatment performance and membrane fouling control. The integration can be realized either in an internal or an external configuration. Electrically enhanced membrane bioreactors or electro membrane bioreactors (eMBRs combine biodegradation, electrochemical and membrane filtration processes into one system providing higher effluent quality as compared to conventional MBRs and activated sludge plants. Furthermore, electrochemical processes, such as electrocoagulation, electrophoresis and electroosmosis, help to mitigate deposition of foulants into the membrane and enhance sludge dewaterability by controlling the morphological properties and mobility of the colloidal particles and bulk liquid. Intermittent application of minute electric field has proven to reduce energy consumption and operational cost as well as minimize the negative effect of direct current field on microbial activity which are some of the main concerns in eMBR technology. The present review discusses important design considerations of eMBR, its advantages as well as its applications to different types of wastewater. It also presents several challenges that need to be addressed for future development of this hybrid technology which include treatment of high strength industrial wastewater and removal of emerging contaminants, optimization study, cost benefit analysis and the possible combination with microbial electrolysis cell for biohydrogen production.

Optimal design and control of solar driven air gap membrane distillation desalination systems

International Nuclear Information System (INIS)

Chen, Yih-Hang; Li, Yu-Wei; Chang, Hsuan

2012-01-01

Highlights: ► Air gap membrane distillation unit was used in the desalination plants. ► Aspen Custom Molder was used to simulate each unit of desalination plants. ► Design parameters were investigated to obtain the minimum total annual cost. ► The control structure was proposed to operate desalination plants all day long. -- Abstract: A solar heated membrane distillation desalination system is constructed of solar collectors and membrane distillation devices for increasing pure water productivity. This technically and economically feasible system is designed to use indirect solar heat to drive membrane distillation processes to overcome the unstable supply of solar radiation from sunrise to sunset. The solar heated membrane distillation desalination system in the present study consisted of hot water storage devices, heat exchangers, air gap membrane distillation units, and solar collectors. Aspen Custom Molder (ACM) software was used to model and simulate each unit and establish the cost function of a desalination plant. From Design degree of freedom (DOF) analysis, ten design parameters were investigated to obtain the minimum total annual cost (TAC) with fixed pure water production rate. For a given solar energy density profile of typical summer weather, the minimal TAC per 1 m 3 pure water production can be found at 500 W/m 2 by varying the solar energy intensity. Therefore, we proposed two modes for controlling the optimal design condition of the desalination plant; day and night. In order to widen the operability range of the plant, the sensitivity analysis was used to retrofit the original design point to lower the effluent temperature from the solar collector by increasing the hot water recycled stream. The simulation results show that the pure water production can be maintained at a very stable level whether in sunny or cloudy weather.

Influence of pre-existing basement faults on the structural evolution of the Zagros Simply Folded belt: 3D numerical modelling

Science.gov (United States)

Ruh, Jonas B.; Gerya, Taras

2015-04-01

The Simply Folded Belt of the Zagros orogen is characterized by elongated fold trains symptomatically defining the geomorphology along this mountain range. The Zagros orogen results from the collision of the Arabian and the Eurasian plates. The Simply Folded Belt is located southwest of the Zagros suture zone. An up to 2 km thick salt horizon below the sedimentary sequence enables mechanical and structural detachment from the underlying Arabian basement. Nevertheless, deformation within the basement influences the structural evolution of the Simply Folded Belt. It has been shown that thrusts in form of reactivated normal faults can trigger out-of-sequence deformation within the sedimentary stratigraphy. Furthermore, deeply rooted strike-slip faults, such as the Kazerun faults between the Fars zone in the southeast and the Dezful embayment and the Izeh zone, are largely dispersing into the overlying stratigraphy, strongly influencing the tectonic evolution and mechanical behaviour. The aim of this study is to reveal the influence of basement thrusts and strike-slip faults on the structural evolution of the Simply Folded Belt depending on the occurrence of intercrustal weak horizons (Hormuz salt) and the rheology and thermal structure of the basement. Therefore, we present high-resolution 3D thermo-mechnical models with pre-existing, inversively reactivated normal faults or strike-slip faults within the basement. Numerical models are based on finite difference, marker-in-cell technique with (power-law) visco-plastic rheology accounting for brittle deformation. Preliminary results show that deep tectonic structures present in the basement may have crucial effects on the morphology and evolution of a fold-and-thrust belt above a major detachment horizon.

Geologic setting of the St. Catherine basement rocks, Sinai, Egypt

OpenAIRE

Abdel Maksoud, M. A. [محمد علي عبدالمقصود; Khalek, M. L. Abdel; Oweiss, K. A.

1993-01-01

St. Catherine area, some 900 km in size, is dominated by basement rocks Encompassing old continental gneisses, metasediments, greenstone belt, calc-alkaline granites (G-II-granites), rift-related volcanics (RV), and anorogenic within plate granites (G-III-granites). The greenstone belt is composed of subduction-related volcanics (SV) intercalated with metasediments. These volcanics split into older group (moderately metamorphosed) and younger group (slightly metamorphosed). The calc-alkaline ...

Disease: H00582 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available H00582 Benign familial hematuria; Thin basement membrane nephropathy Benign famili...hildhood. The glomerular basement membrane is uniformly thin, but renal function is normal. Heterozygous mut...ations in COL4A3 or COL4A4 lead to reduced collagen network levels in the basemen...MIM: 141200 PMID:18094725 (gene, description) ... AUTHORS ... Gubler MC ... TITLE ... Inherited diseases of the glomerular basemen...Wang YY ... TITLE ... Thin basement membrane nephropathy. ... JOURNAL ... Kidney Int 64:1169-78 (2003) DOI:10.1046/j.1523-1755.2003.00234.x

A Coincidence Detection Mechanism Controls PX-BAR Domain-Mediated Endocytic Membrane Remodeling via an Allosteric Structural Switch.

Science.gov (United States)

Lo, Wen-Ting; Vujičić Žagar, Andreja; Gerth, Fabian; Lehmann, Martin; Puchkov, Dymtro; Krylova, Oxana; Freund, Christian; Scapozza, Leonardo; Vadas, Oscar; Haucke, Volker

2017-11-20

Clathrin-mediated endocytosis occurs by bending and remodeling of the membrane underneath the coat. Bin-amphiphysin-rvs (BAR) domain proteins are crucial for endocytic membrane remodeling, but how their activity is spatiotemporally controlled is largely unknown. We demonstrate that the membrane remodeling activity of sorting nexin 9 (SNX9), a late-acting endocytic PX-BAR domain protein required for constriction of U-shaped endocytic intermediates, is controlled by an allosteric structural switch involving coincident detection of the clathrin adaptor AP2 and phosphatidylinositol-3,4-bisphosphate (PI(3,4)P 2 ) at endocytic sites. Structural, biochemical, and cell biological data show that SNX9 is autoinhibited in solution. Binding to PI(3,4)P 2 via its PX-BAR domain, and concomitant association with AP2 via sequences in the linker region, releases SNX9 autoinhibitory contacts to enable membrane constriction. Our results reveal a mechanism for restricting the latent membrane remodeling activity of BAR domain proteins to allow spatiotemporal coupling of membrane constriction to the progression of the endocytic pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

Development of nano-structure controlled polymer electrolyte fuel-cell membranes by high-energy heavy ion irradiation

International Nuclear Information System (INIS)

Yamaki, Tetsuya; Asano, Masaharu; Maekawa, Yasunari; Yoshida, Masaru; Kobayashi, Misaki; Nomura, Kumiko; Takagi, Shigeharu

2008-01-01

There is increasing interest in polymer electrolyte fuel cells (PEFCs) together with recent worldwide energy demand and environmental issues. In order to develop proton-conductive membranes for PEFCs, we have been using high-energy heavy ion beams from the cyclotron accelerator of Takasaki Ion Accelerators for Advanced Radiation Application (TIARA), JAEA. Our strategic focus is centered on using nano-scale controllability of the ion-beam processing; the membrane preparation involves (1) the irradiation of commercially-available base polymer films with MeV ions, (2) graft polymerization of vinyl monomers into electronically-excited parts along the ion trajectory, called latent tracks, and (3) sulfonation of the graft polymers. Interestingly, the resulting membranes exhibited anisotropic proton transport, i.e., higher conductivity in the thickness direction. According to microscopic observations, this is probably because the columnar electrolyte phase extended, with a width of tens-to-hundreds nanometers, through the membrane. Other excellent membrane properties, e.g., sufficient mechanical strength, high dimensional stability, and low gas permeability should be due to such a controlled structure. (author)

Integrated pyrolucite fluidized bed-membrane hybrid process for improved iron and manganese control in drinking water.

Science.gov (United States)

Dashtban Kenari, Seyedeh Laleh; Barbeau, Benoit

2017-04-15

Newly developed ceramic membrane technologies offer numerous advantages over the conventional polymeric membranes. This work proposes a new configuration, an integrated pyrolucite fluidized bed (PFB)-ceramic MF/UF hybrid process, for improved iron and manganese control in drinking water. A pilot-scale study was undertaken to evaluate the performance of this process with respect to iron and manganese control as well as membrane fouling. In addition, the fouling of commercially available ceramic membranes in conventional preoxidation-MF/UF process was compared with the hybrid process configuration. In this regard, a series of experiments were conducted under different influent water quality and operating conditions. Fouling mechanisms and reversibility were analyzed using blocking law and resistance-in-series models. The results evidenced that the flux rate and the concentration of calcium and humic acids in the feed water have a substantial impact on the filtration behavior of both membranes. The model for constant flux compressible cake formation well described the rise in transmembrane pressure. The compressibility of the filter cake substantially increased in the presence of 2 mg/L humic acids. The presence of calcium ions caused significant aggregation of manganese dioxide and humic acid which severely impacted the extent of membrane fouling. The PFB pretreatment properly alleviated membrane fouling by removing more than 75% and 95% of iron and manganese, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Geochronology of the basement rocks, Amazonas Territory, Venezuela and the tectonic evolution of the western Guiana Shield

Energy Technology Data Exchange (ETDEWEB)

Gaudette, H E; Olszewski, Jr, W J

1985-01-01

The Amazonas Territory of Venezuela is a large area of Precambrian basement rocks overlain in some locales by the supracrustal sedimentary and volcanic rocks of the Roraima Formation. The basement rocks are medium to high grade gneisses with both igneous and sedimentary protoliths, plutonic rocks ranging in composition from granite to tonalite, and meta-volcanic rocks. Rb-Sr whole rock, and U-Pb isotopic analyses of zircons indicate a period of medium to high grade metamorphism and intrusion from 1860 to 1760 Ma. Post-tectonic plutonic activity continued to 1550 Ma. The volcanic rocks of the Roraima Formation in Venezuela give an age of 1746 Ma comparable to volcanic rocks of the Roraima Formation in other parts of the Guiana Shield. The ages and distribution of the basement rocks suggest the presence of a tectonic zone, approximately coincident with the Venezuelan-Colombian border, representing an active orogenic boundary between distinct tectonic provinces. The rocks to the northeast of this zone are part of the Trans-Amazonian of the Guiana Shield, while to the southwest and in adjacent Brazil and Colombia, new younger continental crust has been developed and cratonized. We suggest a model of collision and subduction followed by a chan0140n tectonic style to extensional-vertical to produce the basement rocks of the western Guiana Shield in the Amazonas Territory. (Auth.). 20 refs.; 13 figs.; 2 tabs.

Provenance of Austroalpine basement metasediments: tightening up Early Palaeozoic connections between peri-Gondwanan domains of central Europe and Northern Africa

Science.gov (United States)

Siegesmund, S.; Oriolo, S.; Heinrichs, T.; Basei, M. A. S.; Nolte, N.; Hüttenrauch, F.; Schulz, B.

2018-03-01

New U-Pb and Lu-Hf detrital zircon data together with whole-rock geochemical and Sm-Nd data were obtained for paragneisses of the Austroalpine basement south of the Tauern Window. Geochemically immature metasediments of the Northern-Defereggen-Petzeck (Ötztal-Bundschuh nappe system) and Defereggen (Drauzug-Gurktal nappe system) groups contain zircon age populations which indicate derivation mainly from Pan-African orogens. Younger, generally mature metasediments of the Gailtal Metamorphic Basement (Drauzug-Gurktal nappe system), Thurntaler Phyllite Group (Drauzug-Gurktal nappe system) and Val Visdende Formation (South Alpine Basement) were possibly derived from more distant sources. Their significantly larger abundances of pre-Pan-African zircons record a more advanced stage of downwearing of the Pan-African belts and erosion of older basement when the Austroalpine terrane was part of the Early Palaeozoic Northern Gondwana passive margin. Most zircon age spectra are dominated by Ediacaran sources, with lesser Cryogenian, Tonian and Stenian contributions and subordinate Paleoproterozoic and Neoarchean ages. These age patterns are similar to those recorded by Cambro-Ordovician sedimentary sequences in northeastern Africa between Libya and Jordan, and in some pre-Variscan basement inliers of Europe (e.g. Dinarides-Hellenides, Alboran microplate). Therefore, the most likely sources seem to be in the northeastern Saharan Metacraton and the Northern Arabian-Nubian Shield (Sinai), further supported by whole-rock Sm-Nd and zircon Lu-Hf data.

Disease: H00576 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available a deficiency of 2-laminin in the basement membrane. Developmental disorder; Kidn... AUTHORS ... Gubler MC ... TITLE ... Inherited diseases of the glomerular basement membrane. ... JOURNAL ... Nat Clin Pract Nephrol 4:24-37 (2008) DOI:10.1038/ncpneph0671 ...

Rb-Sr and K-Ar isotopic evidence for neoproterozoic (Pan-African) granulite metamorphism from the basement of Mumbai offshore basin, India

International Nuclear Information System (INIS)

Rathore, S.S.; Vijan, A.R.; Singh, M.P.; Misra, K.N.; Prabhu, B.N.

2000-01-01

Precambrian basement from well HBM-1 in the Heera oil field of Mumbai offshore basin has been dated by Rb-Sr and K-Ar methods. Five granulitic basement samples from three conventional drill cores have yielded Rb-Sr isochron age of 502±25 Ma with an initial Sr ratio of 0.70855±0.00013. This age has been interpreted as the time of granulite facies metamorphism of the basement rocks in the region. Two whole rock samples from the basement of this well have yielded mutually concordant K-Ar ages of 505±16 Ma and 507±17 Ma. The K-Ar ages are significantly similar to Rb-Sr age obtained from this well, suggesting complete isotopic reequilibration around 500 Ma ago. The time of secondary thermal heating around 500 Ma ago in the basement of Heera field coincides with the widespread neoproterozoic (Pan-African) thermo-tectonic event extending from the Arabian Peninsula and eastern Africa covering Madagascar, southern India. Sri Lanka and East Antarctica. This study widens the limit of the Pan-African zone, which hitherto was thought to be confined to the western part (presently southern part) of the Indian subcontinent, towards further east. (author)

The cataclasis in the crystalline basement of Northern Switzerland

International Nuclear Information System (INIS)

Meyer, J.

1987-01-01

In the crystalline basement of Northern Switzerland two main phases of cataclastic deformation can be distinguished: a 'cataclasis 1' in a higher temperature hydrothermal regime, as a consequence of tectonic and magmatic-hydrothermal events in Upper Carboniferous time and a lower temperature 'cataclasis 2', which can be related to Permian tectonics at the northern margin of the Paleozoic Konstanz-Frick trough. These cataclases are interpreted as a result of longlasting and complex tectonic processes at shallow crustal levels. (author) 30 refs., 4 figs

Risk of a large amount of high-radioactive contaminated water leaking into the reactor building basement of Fukushima Daiichi nuclear power station

International Nuclear Information System (INIS)

Ebisawa, Toru; Sawai, Masako

2013-01-01

In November 2012 about one and half year after the accident at units 1, 2 and 3 of Fukushima Daiichi nuclear power station, some 405 m 3 /day cooling water was being injected into the melt damaged core and leaked as highly-radioactive contaminated water from damaged lower part of containment into the basement of turbine hall. To treat a large amount of contaminated water in the basement, waste processing plant to remove cesium was installed in June 2011 with desalination plant, which produced clean water for circulating coolant system of damaged nuclear fuel while the rest went to storage. Radioactivity of contaminated water in the basement accumulated at initial almost 80 days of the accident was evaluated about 20% for Cs-137 of core inventory of units 1, 2 and 3 and 2.3% for Sr-90 of core inventory of units 2 and 3. Sr-90 from unit 1 was not released into the basement and almost remained at suppression chamber. By November 2012, Cs-137 released into the basement was evaluated to total about 40% of core inventory and stored contaminated water amounted to about 360 kilotons, while Cs-137 released into the atmosphere was estimated about 3.6% of core inventory with its one third contributed for land contamination. Sr-90 released into the basement was estimated as 6.3% or 4.4% of core inventory based on Sr-90 measured activity of treated water in December or September 2011 with stored contaminated water of 300 kilotons. Cs-137 and Sr-90 contaminated water kept continuously releasing into the basement as long as melt damaged core existed and cooling water washed out Cs-137 and Sr-90 attached on containment walls. Safe store of released radioactivity was highly important and acquired important data was recommended to publish for check and review. (T. Tanaka)

Microfluidic Device for Controllable Chemical Release via Field-Actuated Membrane Incorporating Nanoparticles

Directory of Open Access Journals (Sweden)

Xiang Wang

2013-01-01

Full Text Available We report a robust magnetic-membrane-based microfluidic platform for controllable chemical release. The magnetic membrane was prepared by mixing polydimethylsiloxane (PDMS and carbonyl-iron nanoparticles together to obtain a flexible thin film. With combined, simultaneous regulation of magnetic stimulus and mechanical pumping, the desired chemical release rate can easily be realized. For example, the dose release experimental data was well fitted by a mathematical sigmoidal model, exhibiting a typical dose-response relationship, which shows promise in providing significant guidance for on-demand drug delivery. To test the platform’s feasibility, our microfluidic device was employed in an experiment involving Escherichia coli culture under controlled antibiotic ciprofloxacin exposure, and the expected outcomes were successfully obtained. Our experimental results indicate that such a microfluidic device, with high accuracy and easy manipulation properties, can legitimately be characterized as active chemical release system.

Microfluidic Device for Controllable Chemical Release via Field-Actuated Membrane Incorporating Nanoparticles

KAUST Repository

Wang, Xiang; Li, Shunbo; Wang, Limu; Yi, Xin; Hui, Yu Sanna; Qin, Jianhua; Wen, Weijia

2013-01-01

We report a robust magnetic-membrane-based microfluidic platform for controllable chemical release. The magnetic membrane was prepared by mixing polydimethylsiloxane (PDMS) and carbonyl-iron nanoparticles together to obtain a flexible thin film. With combined, simultaneous regulation of magnetic stimulus and mechanical pumping, the desired chemical release rate can easily be realized. For example, the dose release experimental data was well fitted by a mathematical sigmoidal model, exhibiting a typical dose-response relationship, which shows promise in providing significant guidance for on-demand drug delivery. To test the platform’s feasibility, our microfluidic device was employed in an experiment involving Escherichia coli culture under controlled antibiotic ciprofloxacin exposure, and the expected outcomes were successfully obtained. Our experimental results indicate that such a microfluidic device, with high accuracy and easy manipulation properties, can legitimately be characterized as active chemical release system.

Microfluidic Device for Controllable Chemical Release via Field-Actuated Membrane Incorporating Nanoparticles

KAUST Repository

Wang, Xiang

2013-01-01

We report a robust magnetic-membrane-based microfluidic platform for controllable chemical release. The magnetic membrane was prepared by mixing polydimethylsiloxane (PDMS) and carbonyl-iron nanoparticles together to obtain a flexible thin film. With combined, simultaneous regulation of magnetic stimulus and mechanical pumping, the desired chemical release rate can easily be realized. For example, the dose release experimental data was well fitted by a mathematical sigmoidal model, exhibiting a typical dose-response relationship, which shows promise in providing significant guidance for on-demand drug delivery. To test the platform’s feasibility, our microfluidic device was employed in an experiment involving Escherichia coli culture under controlled antibiotic ciprofloxacin exposure, and the expected outcomes were successfully obtained. Our experimental results indicate that such a microfluidic device, with high accuracy and easy manipulation properties, can legitimately be characterized as active chemical release system.

Basement of Structure, Main Power and Design Parameters of Mechanism of Removing Sections of Mechanized Sets of Knife Plane Installation

Science.gov (United States)

Sysoev, N. I.; Turuk, Yu V.; Kolesnichenko, I. Y.; Lugantsev, B. B.

2017-10-01

The reasons for the failure of the pitch stability of the knife-plane installation due to the action of extreme effort in the plane of the seam from the conveyor side on the mechanism of removing sections of mechanized sets are shown. The technique for determining this effort is presented. The constructions of the adaptive mechanisms of the removing sections of mechanized sets with the basements of catamaran type, in the constrictions of which elastic elements (rods) are used, are considered. The constructions of the mechanism of removing a section of the mechanized set with the basement of catamaran type in which the stock of the hydraulic jack is connected with the band loop through the movable rods intermediate basement with a link are worked out. The intermediate basement unloads the stock of the hydraulic jack of the moving installation from the side curving efforts, caused by the action of lateral forces in the plane of the seam on the conveyor side. It increases the reliability and efficiency of work of the knife plane mechanized complex.

Glomerular matrix: synthesis, turnover and role in mesangial expansion

DEFF Research Database (Denmark)

Couchman, J R; Beavan, L A; McCarthy, K J

1994-01-01

The extracellular matrix has an integral role in development, homeostasis and pathology of the glomerulus. Three spatially distinct matrices are present in the glomerulus: the mesangium, and basement membranes of the capillary loops and Bowman's capsule. Each is dominated by basement membrane com...

The role of basement inheritance faults in the recent fracture system of the inner shelf around Alboran Island, Western Mediterranean

Science.gov (United States)

Maestro-González, A.; Bárcenas, P.; Vázquez, J. T.; Díaz-Del-Río, V.

2008-02-01

Fractures associated with volcanic rock outcrops on the inner shelf of Alboran Island, Western Mediterranean, were mapped on the basis of a side-scan sonar mosaic. Absolute maximum fracture orientation frequency is NW SE to NNW SSE, with several sub-maxima oriented NNE SSW, NE SW and ENE WSW. The origin of the main fracture systems in Neogene and Quaternary rocks of the Alboran Basin (south Spain) appears to be controlled by older structures, namely NE SW and WNW ESE to NW SE faults which cross-cut the basement. These faults, pre-Tortonian in origin, have been reactivated since the early Neogene in the form of strike-slip and extensional movements linked to the recent stress field in this area. Fracture analysis of volcanic outcrops on the inner continental shelf of Alboran Island suggests that the shelf has been deformed into a narrow shear zone limited by two NE SW-trending, sub-parallel high-angle faults, the main orientation and density of which have been influenced by previous WNW ESE to NW SE basement fractures.

Application of electrochemical processes to membrane bioreactors for improving nutrient removal and fouling control.

Science.gov (United States)

Borea, Laura; Naddeo, Vincenzo; Belgiorno, Vincenzo

2017-01-01

Membrane bioreactor (MBR) technology is becoming increasingly popular as wastewater treatment due to the unique advantages it offers. However, membrane fouling is being given a great deal of attention so as to improve the performance of this type of technology. Recent studies have proven that the application of electrochemical processes to MBR represents a promising technological approach for membrane fouling control. In this work, two intermittent voltage gradients of 1 and 3 V/cm were applied between two cylindrical perforated electrodes, immersed around a membrane module, at laboratory scale with the aim of investigating the treatment performance and membrane fouling formation. For comparison purposes, the reactor also operated as a conventional MBR. Mechanisms of nutrient removal were studied and membrane fouling formation evaluated in terms of transmembrane pressure variation over time and sludge relative hydrophobicity. Furthermore, the impact of electrochemical processes on transparent exopolymeric particles (TEP), proposed as a new membrane fouling precursor, was investigated in addition to conventional fouling precursors such as bound extracellular polymeric substances (bEPS) and soluble microbial products (SMP). All the results indicate that the integration of electrochemical processes into a MBR has the advantage of improving the treatment performance especially in terms of nutrient removal, with an enhancement of orthophosphate (PO 4 -P) and ammonia nitrogen (NH 4 -N) removal efficiencies up to 96.06 and 69.34 %, respectively. A reduction of membrane fouling was also observed with an increase of floc hydrophobicity to 71.72 %, a decrease of membrane fouling precursor concentrations, and, thus, of membrane fouling rates up to 54.33 %. The relationship found between TEP concentration and membrane fouling rate after the application of electrochemical processes confirms the applicability of this parameter as a new membrane fouling indicator.

Punta del este terrane: meso proterozoic basement and neo proterozoic cover

International Nuclear Information System (INIS)

Preciozzi, F.; Sanchez Bettucci, L.; Basei, M.; Peel, E.; Oyhantcabal, P.; Cordani, U.

2003-01-01

Full text: Eastern basement of Uruguay consists of Meso and Neoproterozoic rocks. Mesoproterozoic basement had been deformed by pre-Brasiliano and Brasiliano events. Regional variations in this basement and in the Neoproterozoic cover show equivalent deformation styles and intensities. Models proposed for tectonic evolution have been scarce and confusing. Specially, the ones that concern the moment of collision and/or juxtaposition of blocks. The Punta del Este Terrane (PET) is composed of gneisses and migmatites formed between 1000 Ma to 900 Ma (Preciozzi et al., 2001). These rocks had been strongly reworked during Brasiliano and Rio Doce orogenesis (ca. 900-500 Ma). This crustal segment represents a high grade metamorphic terrane, which is correlated to some gneissic complexes southwest of Africa. Particularly, it is correlated to Kibaran-Namaqua Belt in Namibia. U-Pb ages between 1000 Ma and 900 Ma, obtained in zircons from tonalitic granitoids, are interpreted as indicative of their crystallization (Fig. 1). Besides, anatectic fluids related to migmatites leucosomes yielded ages of ca. 520 to 540 Ma. This denotes that superimposed metamorphic conditions during Brasiliano orogenesis reached, at least, lower amphibolite facies. PET basement gneisses present Sm-Nd model ages (TDM) between 2.4 to 1.8 Ga, showing long crustal residence, corroborated by the very negative εNd values of –1.3 and –14.3. During Brazilian orogenesy they were affected by deformation processes and anatexis. Metasedimentary PET cover occurs near La Paloma and Rocha towns. It is represented by a siliciclastic metasedimentary succession corresponding to the Rocha formation. In La Pedrera town recognized three sedimentary facies were (1-3): (1) sandstones and pelites; (2) green pelites; and (3) rhytmites. The transition from facies (1) to facies (3) shows the passage from fluvial environment with tidal influence to tidal flat with predominance of sub tidal deposits (Pazos and S�

Antimetastatic effect of PSK, a protein-bound polysaccharide, against the B16-BL6 mouse melanoma.

Science.gov (United States)

Matsunaga, K; Ohhara, M; Oguchi, Y; Iijima, H; Kobayashi, H

1996-01-01

We examined the effect of PSK, a protein-bound polysaccharide, upon in vivo metastasis and in vitro invasion of the B16-BL6 mouse melanoma cells. (1) PSK suppressed in vivo artificial and spontaneous lung metastases of B16-BL6 in C57BL/6 mice. (2) PSK in a dose-dependent fashion suppressed in vitro invasion and chemotaxis of the tumor cells using filters coated with a reconstituted basement membrane. (3) PSK had little effect on DNA synthesis in tumor cells in vitro, but suppressed tumor cell adhesion to, degradation of, and haptotaxis to components of the basement membrane. (4) PSK suppressed the binding of tumor cells to components of the basement membrane. These findings suggest that PSK may suppress metastasis through inhibition of tumor cell invasion and that this effect is the result of interactions between PSK and components of the basement membrane.

Model cell membranes

DEFF Research Database (Denmark)

Günther-Pomorski, Thomas; Nylander, Tommy; Cardenas Gomez, Marite

2014-01-01

The high complexity of biological membranes has motivated the development and application of a wide range of model membrane systems to study biochemical and biophysical aspects of membranes in situ under well defined conditions. The aim is to provide fundamental understanding of processes control...

Basement configuration of KG offshore basin from magnetic anomalies

Digital Repository Service at National Institute of Oceanography (India)

Subrahmanyam, V.; Swamy, K.V.; Raj, N.

to Dept. of Science & Technology, New Delhi for granting the Junior Research Fel- lowship through Inspire Programme. This is NIO (CSIR) contribution no. 7132. References Aftalion M, Bowes D R, Dash B and Dempster T J 1988 Late proterozoic charnockites... anomaly map in figure 1. Keywords. Marine magnetic anomalies; offshore K–G basin; magnetic basement; extension of EGMB geology; continent– oceanic boundary. J. Earth Syst. Sci. 125, No. 3, April 2016, pp. 663–668 c© Indian Academy of Sciences 663 664 V...

Late Cretaceous and Cenozoic seafloor and oceanic basement roughness: Spreading rate, crustal age and sediment thickness correlations

Science.gov (United States)

Bird, Robert T.; Pockalny, Robert A.

1994-05-01

Single-channel seismic data from the South Australian Basin and Argentine Basin, and bathymetry data from the flanks of the Mid-Atlantic Ridge, East Pacific Rise and Southwest Indian Ridge are analysed to determine the root-mean-square (RMS) roughness of the seafloor and oceanic basement created at seafloor spreading rates ranging from 3 to 80 km/Ma (half-rate). For these data, crustal ages range from near zero to 85 Ma and sediment thicknesses range from near zero to over 2 km. Our results are consistent with a negative correlation of basement roughness and spreading rate where roughness decreases dramatically through the slow-spreading regime (oceanic basement roughness and spreading rate appears to have existed since the late Cretaceous for slow and intermediate spreading rates, suggesting that the fundamental processes creating abyssal hill topography may have remained the same for this time period. Basement roughness does not appear to decrease (smooth) with increasing crustal age, and therefore off-ridge degradation of abyssal hill topography by mass wasting is not detected by our data. Seismic data reveal that sediment thickness increases with increasing crustal age in the South Australian Basin and Argentine Basin, but not monotonically and with significant regional variation. We show that minor accumulations of sediment can affect roughness significantly. Average sediment accumulations of less that 50 m (for our 100 km long sample seismic profiles and half-spreading rates ocean ridges.

Effect of Hedera helix on lung histopathology in chronic asthma.

Science.gov (United States)

Hocaoglu, Arzu Babayigit; Karaman, Ozkan; Erge, Duygu Olmez; Erbil, Guven; Yilmaz, Osman; Kivcak, Bijen; Bagriyanik, H Alper; Uzuner, Nevin

2012-12-01

Hedera helix is widely used to treat bronchial asthma for many years. However, effects of this herb on lung histopathology is still far from clear. We aimed to determine the effect of oral administration of Hedera helix on lung histopathology in a murine model of chronic asthma.BALB/c mice were divided into four groups; I (Placebo), II (Hedera helix), III (Dexamethasone) and IV (Control). All mice except controls were sensitized and challenged with ovalbumin. Then, mice in group I received saline, group II 100 mg/kg Hedera helix and group III 1 mg/kg dexamethasone via orogastic gavage once daily for one week. Airway histopathology was evaluated by using light and electron microscopy in all groups.Goblet cell numbers and thicknesses of basement membrane were found significantly lower in group II, but there was no statistically significant difference in terms of number of mast cells, thicknesses of epithelium and subepithelial smooth muscle layers between group I and II. When Hedera helix and dexamethasone groups were compared with each other, thickness of epithelium, subepithelial muscle layers, number of mast cells and goblet cells of group III were significantly ameliorated when compared with the group II. Although Hedera helix administration reduced only goblet cell counts and the thicknesses of basement membrane in the asthmatic airways, dexamethasone ameliorated all histopathologic parameters except thickness of basement membrane better than Hedera helix.

"We Dominate the Basement!": How Asian American Girls Construct a Borderland Community

Science.gov (United States)

Tokunaga, Tomoko

2016-01-01

This article, based on two years of ethnographic fieldwork, explores the ways in which eight Asian American immigrant high school girls construct a borderland community, which they call the "Basement Group," after the place where they gather at school. While the girls struggle with displacement in the borderlands, including isolation in…

Mass transfer rate through liquid membranes: interfacial chemical reactions and diffusion as simultaneous permeability controlling factors

International Nuclear Information System (INIS)

Danesi, P.R.; Horwitz, E.P.; Vandegrift, G.F.; Chiarizia, R.

1981-01-01

Equations describing the permeability of a liquid membrane to metal cations have been derived taking into account aqueous diffusion, membrane diffusion, and interfacial chemical reactions as simultaneous permeability controlling factors. Diffusion and chemical reactions have been coupled by a simple model analogous to the one previously described by us to represent liquid-liquid extraction kinetics. The derived equations, which make use of experimentally determined interfacial reaction mechanisms, qualitatively fit unexplained literature data regarding Cu 2+ transfer through liquid membranes. Their use to predict and optimize membrane permeability in practical separation processes by setting the appropriate concentration of the membrane carrier [LIX 64 (General Mills), a commercial β-hydroxy-oxime] and the pH of the aqueous copper feed solution is briefly discussed. 4 figures

Autoradiographic study of the penetration of radiolabelled dextrans and inulin through non-keratinized oral mucosa in vitro

International Nuclear Information System (INIS)

Alfano, M.C.; Chasens, A.I.; Masi, C.W.

1977-01-01

Although a well known barrier effect against the penetration of macromolecules exists at the basement membrane region of epithelial tissues, recent reports suggest that the penetration of smaller molecules may be impeded by this region. Considering the probable importance of the permeability of gingival crevicular tissues in the etiology of inflammatory periodontal disease, the present study was designed to evaluate the barrier function of the basement membrane region of non-keratinized oral mucosal epithelium to a series of radiolabelled penetrating molecules of increasing molecular weight. Tritium labeled inulin (Mw 5,000), dextran 20 (Mw 20,000) and dextran 70 (Mw 70,000) were used as penetrating molecules, and autoradiographic tracer techniques were used to evaluate the barrier function. The study was conducted in vitro to eliminate vascular ''wash-out'' effects and to facilitate study of penetration across the basement membrane region in both directions. The results indicated that although the penetration of inulin and dextran 70 was impeded by the basement membrane region, the penetration of dextran 20 was not affected. Therefore, the barrier function of the basement membrane region is not solely dependent on the molecular weight of the penetration molecule. Mechanisms to account for the findings are described and the significance to periodontal disease is discussed. (author)

Autoradiographic study of the penetration of radiolabelled dextrans and inulin through non-keratinized oral mucosa in vitro

Energy Technology Data Exchange (ETDEWEB)

Alfano, M C; Chasens, A I; Masi, C W [Block Periodontal Research Laboratories, Department of Periodontics and Oral Medicine, Fairleigh Dickinson University, School of Dentistry, Hackensack, New Jersey, U.S.A.

1977-01-01

Although a well known barrier effect against the penetration of macromolecules exists at the basement membrane region of epithelial tissues, recent reports suggest that the penetration of smaller molecules may be impeded by this region. Considering the probable importance of the permeability of gingival crevicular tissues in the etiology of inflammatory periodontal disease, the present study was designed to evaluate the barrier function of the basement membrane region of non-keratinized oral mucosal epithelium to a series of radiolabelled penetrating molecules of increasing molecular weight. Tritium labeled inulin (Mw 5,000), dextran 20 (Mw 20,000) and dextran 70 (Mw 70,000) were used as penetrating molecules, and autoradiographic tracer techniques were used to evaluate the barrier function. The study was conducted in vitro to eliminate vascular ''wash-out'' effects and to facilitate study of penetration across the basement membrane region in both directions. The results indicated that although the penetration of inulin and dextran 70 was impeded by the basement membrane region, the penetration of dextran 20 was not affected. Therefore, the barrier function of the basement membrane region is not solely dependent on the molecular weight of the penetration molecule. Mechanisms to account for the findings are described and the significance to periodontal disease is discussed.

Flow restrictor silicon membrane microvalve actuated by optically controlled paraffin phase transition

International Nuclear Information System (INIS)

Kolari, K; Havia, T; Stuns, I; Hjort, K

2014-01-01

Restrictor valves allow proportional control of fluid flow but are rarely integrated in microfluidic systems. In this study, an optically actuated silicon membrane restrictor microvalve is demonstrated. Its actuation is based on the phase transition of paraffin, using a paraffin wax mixed with a suitable concentration of optically absorbing nanographite particles. Backing up the membrane with oil (the melted paraffin) allows for a compliant yet strong contact to the valve seat, which enables handling of high pressures. At flow rates up to 30 µL min −1 and at a pressure of 2 bars, the valve can successfully be closed and control the flow level by restriction. The use of this paraffin composite as an adhesive layer sandwiched between the silicon valve and glass eases fabrication. This type of restrictor valve is best suited for high pressure, low volume flow silicon-based nanofluidic systems. (paper)

Insights into early extracellular matrix evolution: spongin short chain collagen-related proteins are homologous to basement membrane type IV collagens and form a novel family widely distributed in invertebrates.

Science.gov (United States)

Aouacheria, Abdel; Geourjon, Christophe; Aghajari, Nushin; Navratil, Vincent; Deléage, Gilbert; Lethias, Claire; Exposito, Jean-Yves

2006-12-01

Collagens are thought to represent one of the most important molecular innovations in the metazoan line. Basement membrane type IV collagen is present in all Eumetazoa and was found in Homoscleromorpha, a sponge group with a well-organized epithelium, which may represent the first stage of tissue differentiation during animal evolution. In contrast, spongin seems to be a demosponge-specific collagenous protein, which can totally substitute an inorganic skeleton, such as in the well-known bath sponge. In the freshwater sponge Ephydatia mülleri, we previously characterized a family of short-chain collagens that are likely to be main components of spongins. Using a combination of sequence- and structure-based methods, we present evidence of remote homology between the carboxyl-terminal noncollagenous NC1 domain of spongin short-chain collagens and type IV collagen. Unexpectedly, spongin short-chain collagen-related proteins were retrieved in nonsponge animals, suggesting that a family related to spongin constitutes an evolutionary sister to the type IV collagen family. Formation of the ancestral NC1 domain and divergence of the spongin short-chain collagen-related and type IV collagen families may have occurred before the parazoan-eumetazoan split, the earliest divergence among extant animal phyla. Molecular phylogenetics based on NC1 domain sequences suggest distinct evolutionary histories for spongin short-chain collagen-related and type IV collagen families that include spongin short-chain collagen-related gene loss in the ancestors of Ecdyzosoa and of vertebrates. The fact that a majority of invertebrates encodes spongin short-chain collagen-related proteins raises the important question to the possible function of its members. Considering the importance of collagens for animal structure and substratum attachment, both families may have played crucial roles in animal diversification.

HeatBar Final Report 2010, Basement Heat Generation and Heat Flow in the western Barents Sea - importance for hydrocarbon systems

International Nuclear Information System (INIS)

Pascal, Christophe; Balling, Niels; Barrere, Cecile; Davidsen, Boerre; Ebbing, Joerg; Elvebakk, Harald; Mesli, Melani; Roberts, David; Slagstad, Trond; Willemoes-Wissing, Bjoern

2011-01-01

The HeatBar project aimed to determine the relative proportion of heat originating in the basement of the western Barents Sea and, as such, followed the methodologies and scientific approach developed in the course of the 2005-2008 Kontiki Project. We proposed to shed new lights on the thermal state of the basins of the western Barents Sea by (1) determining the heat flow and the relative content in heat-producing elements of the basement onshore northern Norway, (2) building 3D structural models of the basement offshore based on extensive geophysical information and (3) building 3D thermal models of the basins offshore. The present report summarizes the work accomplished in the framework of the project since 2006.(Au)

Muskelbiopsier hos patienter med fibromyalgi. En undersøgelse baseret på lys- og elektronmikroskopi

DEFF Research Database (Denmark)

Drewes, A M; Andreasen, A; Schrøder, H D

1994-01-01

of muscle disease. Nevertheless, we subjected biopsies from nine of the patients and five other controls for further ultrastructural evaluations and demonstrated pathologic findings e.g. empty sleeves of basement membrane, many lipofuscin bodies and other degenerative changes. We conclude...

Observations of hydrotectonic stress/strain events at a basement high at the Nicoya outer rise

Science.gov (United States)

Tryon, M. D.; Brown, K. M.

2005-12-01

There is substantial and growing evidence from heat flow and coring investigations that the oceanic plate off Costa Rica is highly hydrologically active and that this activity is responsible for one of the most anomalously cold thermal environments encountered in the oceanic environment. Recent work by Fisher, et al. has identified limited regions above certain topographic highs with extremely high heat flows. Pore water profiles from cores above these thinly sedimented basement highs suggest upward flow on the order of ~1 cm/yr. These highs may be the principal regions of out-flow from the basement in this region and, thus, can potentially be used to constrain the general level of hydrologic activity. The nine Chemical and Aqueous Transport (CAT) meters we deployed at one of the highest heatflow sites provide a temporal record of both in-flow and out-flow of aqueous fluids at rates as low as 0.1 mm/yr. Our objective was to provide a direct measurement of long term flow rates to address the following questions: (1) What are the characteristic fluid fluxes at basement highs of the low heat flow region of the northern Costa Rican incoming plate, and (2) is this flow temporally variable? The results of the instrument deployments agree quite closely in general with the coring results in that the background rates are on the order of 1 cm/yr or less. There is, however, considerable detail in the temporal records which suggest small scale tectonic stress transients causing temporary increases in flow rate. While this is certainly not an area of major tectonic activity, the site is located at the top of the outer rise where one would expect bending-related stress and fault reactivation to occur. The CAT meters are capable of detecting minute strain events in the underlying sediments and therefore may be detecting small localized strain events. Two periods of increased flow lasting a few weeks each occur during the 5 month deployment and are indicated on all of the

Polymetamorphic evolution of the granulite-facies Paleoproterozoic basement of the Kabul Block, Afghanistan

Science.gov (United States)

Collett, Stephen; Faryad, Shah Wali; Mosazai, Amir Mohammad

2015-08-01

The Kabul Block is an elongate crustal fragment which cuts across the Afghan Central Blocks, adjoining the Indian and Eurasian continents. Bounded by major strike slip faults and ophiolitic material thrust onto either side, the block contains a strongly metamorphosed basement consisting of some of the only quantifiably Proterozoic rocks south of the Herat-Panjshir Suture Zone. The basement rocks crop-out extensively in the vicinity of Kabul City and consist predominantly of migmatites, gneisses, schists and small amounts of higher-grade granulite-facies rocks. Granulite-facies assemblages were identified in felsic and mafic siliceous rocks as well as impure carbonates. Granulite-facies conditions are recorded by the presence of orthopyroxene overgrowing biotite in felsic rocks; by orthopyroxene overgrowing amphibole in mafic rocks and by the presence of olivine and clinohumite in the marbles. The granulite-facies assemblages are overprinted by a younger amphibolite-facies event that is characterized by the growth of garnet at the expense of the granulite-facies phases. Pressure-temperature (P-T) conditions for the granulite-facies event of around 850 °C and up to 7 kbar were calculated through conventional thermobarometry and phase equilibria modeling. The younger, amphibolite-facies event shows moderately higher pressures of up to 8.5 kbar at around 600 °C. This metamorphism likely corresponds to the dominant metamorphic event within the basement of the Kabul Block. The results of this work are combined with the litho-stratigraphic relations and recent geochronological dating to analyze envisaged Paleoproterozoic and Neoproterozoic metamorphic events in the Kabul Block.

Flow and fouling in membrane filters: Effects of membrane morphology

Science.gov (United States)

Sanaei, Pejman; Cummings, Linda J.

2015-11-01

Membrane filters are widely-used in microfiltration applications. Many types of filter membranes are produced commercially, for different filtration applications, but broadly speaking the requirements are to achieve fine control of separation, with low power consumption. The answer to this problem might seem obvious: select the membrane with the largest pore size and void fraction consistent with the separation requirements. However, membrane fouling (an inevitable consequence of successful filtration) is a complicated process, which depends on many parameters other than membrane pore size and void fraction; and which itself greatly affects the filtration process and membrane functionality. In this work we formulate mathematical models that can (i) account for the membrane internal morphology (internal structure, pore size & shape, etc.); (ii) fouling of membranes with specific morphology; and (iii) make some predictions as to what type of membrane morphology might offer optimum filtration performance.

Assessing the geo-electric characteristics of Basement Complex rocks and its implication for groundwater prospecting in Ilorin Metropolis, Nigeria

Directory of Open Access Journals (Sweden)

I. P. Ifabiyi

2016-12-01

Full Text Available In Basement Complex rocks where rainfall is seasonal, water provision in dry season depends on regolith aquifer. For effective exploitation of groundwater resources, it is reasonable that geophysical investigation be conducted before development of well. In many instances, geophysical surveys may be expensive or nonexistent. Hence, there is a need for spatial analysis which might advise water engineers within such environments. Vertical Electrical Soundings (VES data of 53 locations conducted with ABEM SAS-1000 terrameter using Schlumberger electrode configuration were obtained from the hydrogeology Department of Kwara state Ministry of Water Resources and Lower Niger River Basin and Rural Development Authority, Ilorin. VES locational coordinates were recorded using handheld GPS device. Sound curves were evaluated by partial curve matching approach and computer iteration using WinResist. The results depict six geo-electric regional successions, namely: top soil, lateritic clay, weathered basement, fairly-hard basement, thin fractured and hard basement. The geo-electric succession identified was plotted in Surfer 12 environment, using kriging interpolation method to show spatial distribution pattern of this zone. The spatial pattern is expected to give an insight to the nature of spatial variability of geo-electric layers and assist drillers as well as water resources policy makers in their operations.

Geochemical interpretation of the Precambrian basement and overlying Cambrian sandstone on Bornholm, Denmark: Implications for the weathering history

DEFF Research Database (Denmark)

Zhou, Lingli; Friis, Henrik; Yang, Tian

2017-01-01

show a depletion of major elements in the following order: Na N Ca N Mg N Si; Al and Ti are immobile and stay constant; K shows sample dependent enrichment or depletion; Fe is slightly enriched. The Cambrian sandstone overlying the basement in the Borggård borehole, assigned to the Gadeby Member...... but lost most of the plagioclase. The LSF has a comparable weathering history (CIA = 63–73), but the plagioclase is better preserved (PIA = 65–78). The significant variation of weathering rates of plagioclase and K-feldspar in the basement granite and the provenance of sandstone from the Borggård borehole...... are likely due to the different permeability developed within the internal crystal structures, a Ca- rich plagioclase original composition of the plagioclase, and the occurrence of weathering in a very humid climate. K metasomatism occurred in the basement granite and sandstone in both the Borggård and the G...

Inefficacy of osmotic backwash induced by sodium chloride salt solution in controlling SWRO membrane fouling

Science.gov (United States)

Farooque, A. Mohammed; Al-Jeshi, Subhi; Saeed, Mohamed O.; Alreweli, Ali

2014-12-01

A study was conducted to evaluate the efficacy of osmotic backwash induced by high salt (NaCl) concentration solution on feed side of seawater reverse osmosis (SWRO) membranes, online and offline, in controlling membrane fouling and therefore minimizing/eliminating the need for chemical cleaning. SWRO membranes were deliberately fouled by feeding seawater from an open intake located on the Arabian Gulf Coast without dosing chemicals. The fouled membranes were subjected to offline cleaning with the salt solution of up to 25 % concentration. Despite the partial removal of foulants from the membrane surface, SWRO membrane performance could not be restored, indicating the ineffectiveness of osmotic backwash in aiding offline salt cleaning. Similarly, online osmotic backwash was found to be not only ineffective in removing foulants from membrane surfaces but actually increased the fouling rate, as indicated by faster fouling rates compared to other cases. Although the driving force required for the osmotic backwash existed, the generated back flow proved to be insufficient to detach foulants from membrane surfaces. During the study period, the average SWRO membrane flux was maintained between 19 and 23 LMH, whereas the average generated back flow flux by high salt concentration solution was only 11 LMH, which was not adequate to remove foulants from membrane surfaces. Moreover, it seems that the membrane configuration as well as inherent microstructure of SWRO membrane places certain constraints on the osmotic backwash process and renders osmotic backwash ineffective in tackling SWRO membrane fouling. Hence, chemical cleaning is essential to restore SWRO membrane performance whenever fouling occurs, and the use of highly concentrated salt solution does not have any significant benefit. Membrane autopsy revealed only an insignificant accumulation of biofouling layer despite the absence of disinfection. However, it was shown that culturable biofilm bacteria species

Potentiometric determination of trypsin using a polymeric membrane polycation-sensitive electrode based on current-controlled reagent delivery.

Science.gov (United States)

Chen, Yan; Ding, Jiawang; Qin, Wei

2012-12-01

A potentiometric biosensor for the determination of trypsin is described based on current-controlled reagent delivery. A polymeric membrane protamine-sensitive electrode with dinonylnaphthalene sulfonate as cation exchanger is used for in situ generation of protamine. Diffusion of protamine across the polymeric membrane can be controlled precisely by applying an external current. The hydrolysis catalyzed with trypsin in sample solution decreases the concentration of free protamine released at the sample-membrane interface and facilitates the stripping of protamine out of the membrane surface via the ion-exchange process with sodium ions from the sample solution, thus decreasing the membrane potential, by which the protease can be sensed potentiometrically. The influences of anodic current amplitude, current pulse duration and protamine concentration in the inner filling solution on the membrane potential response have been studied. Under optimum conditions, the proposed protamine-sensitive electrode is useful for continuous and reversible detection of trypsin over the concentration range of 0.5-5UmL(-1) with a detection limit of 0.3UmL(-1). The proposed detection strategy provides a rapid and reagentless way for the detection of protease activities and offers great potential in the homogeneous immunoassays using proteases as labels. Copyright © 2012 Elsevier B.V. All rights reserved.

Hemocompatible control of sulfobetaine-grafted polypropylene fibrous membranes in human whole blood via plasma-induced surface zwitterionization.

Science.gov (United States)

Chen, Sheng-Han; Chang, Yung; Lee, Kueir-Rarn; Wei, Ta-Chin; Higuchi, Akon; Ho, Feng-Ming; Tsou, Chia-Chun; Ho, Hsin-Tsung; Lai, Juin-Yih

2012-12-21

In this work, the hemocompatibility of zwitterionic polypropylene (PP) fibrous membranes with varying grafting coverage of poly(sulfobetaine methacrylate) (PSBMA) via plasma-induced surface polymerization was studied. Charge neutrality of PSBMA-grafted layers on PP membrane surfaces was controlled by the low-pressure and atmospheric plasma treatment in this study. The effects of grafting composition, surface hydrophilicity, and hydration capability on blood compatibility of the membranes were determined. Protein adsorption onto the different PSBMA-grafted PP membranes from human fibrinogen solutions was measured by enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies. Blood platelet adhesion and plasma clotting time measurements from a recalcified platelet-rich plasma solution were used to determine if platelet activation depends on the charge bias of the grafted PSBMA layer. The charge bias of PSBMA layer deviated from the electrical balance of positively and negatively charged moieties can be well-controlled via atmospheric plasma-induced interfacial zwitterionization and was further tested with human whole blood. The optimized PSBMA surface graft layer in overall charge neutrality has a high hydration capability and keeps its original blood-inert property of antifouling, anticoagulant, and antithrmbogenic activities when it comes into contact with human blood. This work suggests that the hemocompatible nature of grafted PSBMA polymers by controlling grafting quality via atmospheric plasma treatment gives a great potential in the surface zwitterionization of hydrophobic membranes for use in human whole blood.

Evaluation of the layering of rock strata and basement rock depth of ...

African Journals Online (AJOL)

The layering of rock strata and depth to the basement rocks of a Federal University Teaching Hospital premises in Northern Nigeria was investigated in this study with the aim of providing 2D geo-electrical resistivity images of the subsurface for geotechnical development using a modern and state-of-the-art field instrument, ...

Attosecond control of electron beams at dielectric and absorbing membranes

Science.gov (United States)

Morimoto, Yuya; Baum, Peter

2018-03-01

Ultrashort electron pulses are crucial for time-resolved electron diffraction and microscopy of the fundamental light-matter interaction. In this work, we study experimentally and theoretically the generation and characterization of attosecond electron pulses by optical-field-driven compression and streaking at dielectric or absorbing interaction elements. The achievable acceleration and deflection gradient depends on the laser-electron angle, the laser's electric and magnetic field directions, and the foil orientation. Electric and magnetic fields have similar contributions to the final effect and both need to be considered. Experiments and theory agree well and reveal the optimum conditions for highly efficient, velocity-matched electron-field interactions in the longitudinal or transverse direction. We find that metallic membranes are optimum for light-electron control at mid-infrared or terahertz wavelengths, but dielectric membranes are excellent in the visible and near-infrared regimes and are therefore ideal for the formation of attosecond electron pulses.

Dimensional and Structural Control of Silica Aerogel Membranes for Miniaturized Motionless Gas Pumps.

Science.gov (United States)

Zhao, Shanyu; Jiang, Bo; Maeder, Thomas; Muralt, Paul; Kim, Nayoung; Matam, Santhosh Kumar; Jeong, Eunho; Han, Yen-Lin; Koebel, Matthias M

2015-08-26

With growing public interest in portable electronics such as micro fuel cells, micro gas total analysis systems, and portable medical devices, the need for miniaturized air pumps with minimal electrical power consumption is on the rise. Thus, the development and downsizing of next-generation thermal transpiration gas pumps has been investigated intensively during the last decades. Such a system relies on a mesoporous membrane that generates a thermomolecular pressure gradient under the action of an applied temperature bias. However, the development of highly miniaturized active membrane materials with tailored porosity and optimized pumping performance remains a major challenge. Here we report a systematic study on the manufacturing of aerogel membranes using an optimized, minimal-shrinkage sol-gel process, leading to low thermal conductivity and high air conductance. This combination of properties results in superior performance for miniaturized thermomolecular air pump applications. The engineering of such aerogel membranes, which implies pore structure control and chemical surface modification, requires both chemical processing know-how and a detailed understanding of the influence of the material properties on the spatial flow rate density. Optimal pumping performance was found for devices with integrated membranes with a density of 0.062 g cm(-3) and an average pore size of 142.0 nm. Benchmarking of such low-density hydrophobic active aerogel membranes gave an air flow rate density of 3.85 sccm·cm(-2) at an operating temperature of 400 °C. Such a silica aerogel membrane based system has shown more than 50% higher pumping performance when compared to conventional transpiration pump membrane materials as well as the ability to withstand higher operating temperatures (up to 440 °C). This study highlights new perspectives for the development of miniaturized thermal transpiration air pumps while offering insights into the fundamentals of molecular pumping in

A simple approach to uniform PdAg alloy membranes: Comparative study of conventional and silver concentration-controlled co-plating

KAUST Repository

Zeng, Gaofeng

2014-03-01

An Ag-controlled co-plating method was developed for the preparation of palladium/silver alloy membranes on porous tubular alumina supports. By controlling the feed rate of Ag to the Pd bath, the concentration of the silver in the plating bath was restricted during the course of plating. As a result, preferential deposition of silver at the beginning was suppressed and uniform dispersion of silver inside the membrane with silver composition in the desired range was achieved. Ultrathin (∼2.5 μm) PdAg alloy membranes with uniform silver composition of ∼25% were successfully obtained. The membrane showed a hydrogen permeance of 0.88 mol m-2 s-1 and pure-gas H2/N2 selectivity of 2140 at 823 K with ΔP = 100 kPa. Only one hydride phase existed in the studied temperature range from 373 to 823 K with ΔPH=100kPa. Direct comparisons with the conventional simply-mixed co-plating method showed that membranes made by the novel Ag-controlled co-plating method had much more uniform silver distribution, smoother surface, denser membrane structure, higher utilization rate of metal sources, and shorter alloying time. © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

A simple approach to uniform PdAg alloy membranes: Comparative study of conventional and silver concentration-controlled co-plating

KAUST Repository

Zeng, Gaofeng; Shi, Lei; Liu, Yunyang; Zhang, Yanfeng; Sun, Yuhan

2014-01-01

An Ag-controlled co-plating method was developed for the preparation of palladium/silver alloy membranes on porous tubular alumina supports. By controlling the feed rate of Ag to the Pd bath, the concentration of the silver in the plating bath was restricted during the course of plating. As a result, preferential deposition of silver at the beginning was suppressed and uniform dispersion of silver inside the membrane with silver composition in the desired range was achieved. Ultrathin (∼2.5 μm) PdAg alloy membranes with uniform silver composition of ∼25% were successfully obtained. The membrane showed a hydrogen permeance of 0.88 mol m-2 s-1 and pure-gas H2/N2 selectivity of 2140 at 823 K with ΔP = 100 kPa. Only one hydride phase existed in the studied temperature range from 373 to 823 K with ΔPH=100kPa. Direct comparisons with the conventional simply-mixed co-plating method showed that membranes made by the novel Ag-controlled co-plating method had much more uniform silver distribution, smoother surface, denser membrane structure, higher utilization rate of metal sources, and shorter alloying time. © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Nature of the Yucatan Block Basement as Derived From Study of Granitic Clasts in the Impact Breccias of Chicxulub Crater

Science.gov (United States)

Vera-Sanchez, P.; Rebolledo-Vieyra, M.; Perez-Cruz, L.; Urrutia-Fucugauchi, J.

2008-05-01

The tectonic and petrologic nature of the basement of the Yucatan Block is studied from analyses of basement clasts present in the impact suevitic breccias of Chicxulub crater. The impact breccias have been sampled as part of the drilling projects conducted in the Yucatan peninsula by Petroleos Mexicanos, the National University of Mexico and the Chicxulub Scientific Drilling Project. Samples analyzed come mainly from the Yaxcopoil-1, Tekax, and Santa Elena boreholes, and partly from Pemex boreholes. In this study we concentrate on clasts of the granites, granodiorites and quartzmonzonites in the impact breccias. We report major and trace element geochemical and petrological data, which are compared with data from the granitic and volcanic rocks from the Maya Mountains in Belize and from the Swannee terrane in Florida. Basement granitic clasts analyzed present intermediate to acidic sub-alkaline compositions. Plots of major oxides (e.g., Al2O3, Fe2O3, TiO2 and CaO) and trace elements (e.g., Th, Y, Hf, Nb and Zr) versus silica allow separation of samples into two major groups, which can be compared to units in the Maya Mountains and in Florida basement. The impact suevitic breccia samples have been affected by alteration likely related to the hydrothermal processes associated with the crater melt sheet. Cloritization, seritization and fenitization alterations are recognized, due to the long term hydrothermalism. Krogh et al. (1993) reported U-Pb dates on zircons from the suevitic breccias, which gave dates of 545 +/- 5 Ma and 418 +/- 6 Ma, which were interpreted in terms of the deep granitic metamorphic Yucatan basement. The younger date correlates with the age for the Osceola Granite and the St. Lucie metamorphic complex of the Swannee terrane in the Florida peninsula. The intrusive rocks in the Yucatan basement may be related to approx. 418 Ma ago collisional event in the Late Silurian.

The membrane-topogenic vectorial behaviour of Nrf1 controls its post-translational modification and transactivation activity.

Science.gov (United States)

Zhang, Yiguo; Hayes, John D

2013-01-01

The integral membrane-bound Nrf1 transcription factor fulfils important functions in maintaining cellular homeostasis and organ integrity, but how it is controlled vectorially is unknown. Herein, creative use of Gal4-based reporter assays with protease protection assays (GRAPPA), and double fluorescence protease protection (dFPP), reveals that the membrane-topogenic vectorial behaviour of Nrf1 dictates its post-translational modification and transactivation activity. Nrf1 is integrated within endoplasmic reticulum (ER) membranes through its NHB1-associated TM1 in cooperation with other semihydrophobic amphipathic regions. The transactivation domains (TADs) of Nrf1, including its Asn/Ser/Thr-rich (NST) glycodomain, are transiently translocated into the ER lumen, where it is glycosylated in the presence of glucose to become a 120-kDa isoform. Thereafter, the NST-adjoining TADs are partially repartitioned out of membranes into the cyto/nucleoplasmic side, where Nrf1 is subject to deglycosylation and/or proteolysis to generate 95-kDa and 85-kDa isoforms. Therefore, the vectorial process of Nrf1 controls its target gene expression.

Catalytic nanoporous membranes

Science.gov (United States)

Pellin, Michael J; Hryn, John N; Elam, Jeffrey W

2013-08-27

A nanoporous catalytic membrane which displays several unique features Including pores which can go through the entire thickness of the membrane. The membrane has a higher catalytic and product selectivity than conventional catalysts. Anodic aluminum oxide (AAO) membranes serve as the catalyst substrate. This substrate is then subjected to Atomic Layer Deposition (ALD), which allows the controlled narrowing of the pores from 40 nm to 10 nm in the substrate by deposition of a preparatory material. Subsequent deposition of a catalytic layer on the inner surfaces of the pores reduces pore sizes to less than 10 nm and allows for a higher degree of reaction selectivity. The small pore sizes allow control over which molecules enter the pores, and the flow-through feature can allow for partial oxidation of reactant species as opposed to complete oxidation. A nanoporous separation membrane, produced by ALD is also provided for use in gaseous and liquid separations. The membrane has a high flow rate of material with 100% selectivity. Also provided is a method for producing a catalytic membrane having flow-through pores and discreet catalytic clusters adhering to the inside surfaces of the pores.

Proteome array identification of bioactive soluble proteins/peptides in matrigel; relevance to stem cell responses

Science.gov (United States)

Matrigel and similar commercial products are extracts of the Engelbreth-Holm-Swarm sarcoma that provide a basement-membrane-like attachment factor or gel that is used to grow cells on or in. To ascertain further what proteins may be present in Matrigel, besides its major basement-membrane constitue...

Thermochronology and geochemistry of the Pan-African basement below the Sab'atayn Basin, Yemen

Science.gov (United States)

Veeningen, Resi; Rice, A. Hugh N.; Schneider, David A.; Grasemann, Bernhard

2015-02-01

Three important lithologies occur in two drill wells from the Pan-African basement underlying the Mesozoic Sab'atayn Basin, in a previously undocumented area of the Pan-African, 83 and 90 km NE of known exposures in Yemen. Cores from well 1 include amphibolite, with basaltic to andesitic compositions, affected by crustal contamination during emplacement into a thickened crust. Deeper in the well, an unfoliated dark red monzogranite has a U-Pb zircon age of 628.8 ± 3.1 Ma and a Rb-Sr biotite cooling age of 591.6 ± 5.8 Ma (∼300 °C). Regional constraints suggest emplacement in a transitional tectonic setting with compressional terrane amalgamation followed by extensional collapse. Sm-Nd isotope analysis yields a TDM model age of 1.24 Ga with negative εNd values, suggesting the monzogranite is part of the Al Bayda island arc terrane. Cores from well 2 contains a weakly deformed, massive (unbedded) medium grey meta-arkose exhibiting essentially no geochemical signature of weathering and with an almost pure dacitic composition. This rock may have been directly derived from an (extrusive) granitoid that was emplaced prior to, or during terrane amalgamation. A (U-Th-Sm)/He zircon age of 156 ± 14 Ma constrains the time of basement cooling to ∼180 °C, synchronous with basin formation. These lithologies provide new insights in the development of the Pan-African basement of Yemen, extending our knowledge of the nearby surface geology to the subsurface.

A link between mitotic entry and membrane growth suggests a novel model for cell size control.

Science.gov (United States)

Anastasia, Steph D; Nguyen, Duy Linh; Thai, Vu; Meloy, Melissa; MacDonough, Tracy; Kellogg, Douglas R

2012-04-02

Addition of new membrane to the cell surface by membrane trafficking is necessary for cell growth. In this paper, we report that blocking membrane traffic causes a mitotic checkpoint arrest via Wee1-dependent inhibitory phosphorylation of Cdk1. Checkpoint signals are relayed by the Rho1 GTPase, protein kinase C (Pkc1), and a specific form of protein phosphatase 2A (PP2A(Cdc55)). Signaling via this pathway is dependent on membrane traffic and appears to increase gradually during polar bud growth. We hypothesize that delivery of vesicles to the site of bud growth generates a signal that is proportional to the extent of polarized membrane growth and that the strength of the signal is read by downstream components to determine when sufficient growth has occurred for initiation of mitosis. Growth-dependent signaling could explain how membrane growth is integrated with cell cycle progression. It could also control both cell size and morphogenesis, thereby reconciling divergent models for mitotic checkpoint function.

Chondroitin-6-sulfate-containing proteoglycan: a new component of human skin dermoepidermal junction

DEFF Research Database (Denmark)

Fine, J D; Couchman, J R

1988-01-01

chondroitin sulfate proteoglycan is present in adult, neonatal, and/or fetal skin, and if present, its ultrastructural localization. Indirect immunofluorescence was performed on human adult, neonatal, and fetal skin. To detect the antigen, specimens were pretreated with chondroitinase ABC; absence of enzyme...... treatment served as negative control. Chondroitin sulfate proteoglycan was detectable in linear homogeneous array along the dermoepidermal junction and within vascular (and when present, adnexal) basement membranes in both adult and neonatal skin. In fetal skin, basement membrane staining was noted as early...... as 54 gestational days. Indirect immunoelectron microscopy and NaCl-split skin studies were performed to ultrastructurally localize the antigen; immune deposits were detectable within the lamina densa in chondroitinase-treated skin. These findings demonstrate that chondroitin sulfate proteoglycan...

Dynamic water management of polymer electrolyte membrane fuel cells using intermittent RH control

KAUST Repository

Hussaini, I.S.

2010-06-01

A novel method of water management of polymer electrolyte membrane (PEM) fuel cells using intermittent humidification is presented in this study. The goal is to maintain the membrane close to full humidification, while eliminating channel flooding. The entire cycle is divided into four stages: saturation and de-saturation of the gas diffusion layer followed by de-hydration and hydration of membrane. By controlling the duration of dry and humid flows, it is shown that the cell voltage can be maintained within a narrow band. The technique is applied on experimental test cells using both plain and hydrophobic materials for the gas diffusion layer and an improvement in performance as compared to steady humidification is demonstrated. Duration of dry and humid flows is determined experimentally for several operating conditions. © 2010 Elsevier B.V. All rights reserved.

Alternative energy efficient membrane bioreactor using reciprocating submerged membrane.

Science.gov (United States)

Ho, J; Smith, S; Roh, H K

2014-01-01

A novel membrane bioreactor (MBR) pilot system, using membrane reciprocation instead of air scouring, was operated at constant high flux and daily fluctuating flux to demonstrate its application under peak and diurnal flow conditions. Low and stable transmembrane pressure was achieved at 40 l/m(2)/h (LMH) by use of repetitive membrane reciprocation. The results reveal that the inertial forces acting on the membrane fibers effectively propel foulants from the membrane surface. Reciprocation of the hollow fiber membrane is beneficial for the constant removal of solids that may build up on the membrane surface and inside the membrane bundle. The membrane reciprocation in the reciprocating MBR pilot consumed less energy than coarse air scouring used in conventional MBR systems. Specific energy consumption for the membrane reciprocation was 0.072 kWh/m(3) permeate produced at 40 LMH flux, which is 75% less than for a conventional air scouring system as reported in literature without consideration of energy consumption for biological aeration (0.29 kWh/m(3)). The daily fluctuating flux test confirmed that the membrane reciprocation is effective to handle fluctuating flux up to 50 LMH. The pilot-scale reciprocating MBR system successfully demonstrated that fouling can be controlled via 0.43 Hz membrane reciprocation with 44 mm or higher amplitude.

Heterogeneity of groundwater storage properties in the critical zone of Irish metamorphic basement from geophysical surveys and petrographic analyses

Science.gov (United States)

Comte, Jean-Christophe; Cassidy, Rachel; Caulfield, John; Nitsche, Janka; Ofterdinger, Ulrich; Wilson, Christopher

2016-04-01

Weathered/fractured bedrock aquifers contain groundwater resources that are crucial in hard rock basement regions for rural water supply and maintaining river flow and ecosystem resilience. Groundwater storage in metamorphic rocks is subject to high spatial variations due to the large degree of heterogeneity in fracture occurrence and weathering patterns. Point measurements such as borehole testing are, in most cases, insufficient to characterise and quantify those storage variations because borehole sampling density is usually much lower than the scale of heterogeneities. A suite of geophysical and petrographic investigations was implemented in the weathered/fractured micaschist basement of Donegal, NW Ireland. Electrical Resistivity Tomography provided a high resolution 2D distribution of subsurface resistivities. Resistivity variations were transferred into storage properties (i.e. porosities) in the saturated critical zone of the aquifer through application of a petrophysical model derived from Archie's Law. The petrophysical model was calibrated using complementary borehole gamma logging and clay petrographic analysis at multi-depth well clusters distributed along a hillslope transect at the site. The resulting distribution of porosities shows large spatial variations along the studied transect. With depth, porosities rapidly decrease from about a few % in the uppermost, highly weathered basement to less than 0.5% in the deep unweathered basement, which is encountered at depths of between 10 and 50m below the ground surface. Along the hillslope, porosities decrease with distance from the river in the valley floor, ranging between 5% at the river to less than 1% at the top of the hill. Local traces of regional fault zones that intersect the transect are responsible for local increases in porosity in relation to deeper fracturing and weathering. Such degrees of spatial variation in porosity are expected to have a major impact on the modality of the response of

Elucidating the role of Cyclooxygenase-2 in the pathogenesis of oral lichen planus - an immunohistochemical study with supportive histochemical analysis.

Science.gov (United States)

Singh, Pratyush; Grover, Jasleen; Byatnal, Aditi Amit; Guddattu, Vasudeva; Radhakrishnan, Raghu; Solomon, Monica Charlotte

2017-05-01

Oral lichen planus (OLP) is a chronic, inflammatory disorder that affects the oral mucous membrane. During an inflammatory response, several chemokines and cytokines are released by the cells of the immune system. Activation of MMPs, along with mast cell-derived chymase and tryptase, degrades the basement membrane structural proteins, resulting in basement membrane breaks. To investigate the association between the COX-2 expressions, presence of intact or degranulating mast cells within the connective tissue and the extent of basement membrane discontinuity in OLP cases. This study included a total of 50 formalin-fixed paraffin-embedded specimens (FFPE) of histologically confirmed cases of idiopathic oral lichen planus. A retrospective cross-sectional analysis was carried out by immunohistochemistry to study the epithelial expression of COX-2 and by the use of special stains such as toluidine blue and periodic acid-Schiff (PAS) to study the mast cell count and basement membrane changes in the oral mucosal tissue, respectively. There was a significant (P = 0.03) association between the COX-2 expressions and mast cell count. As the intensity of COX-2 expression increased from mild to moderate or severe, the number of mast cell count almost doubled. Interaction between upregulation of COX-2, mast cell and basement membrane sets a vicious cycle which relates to the chronic nature of the disease. Inhibitors of COX-2 may reduce the inflammatory process preceding the immune dysregulation in OLP. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Trans-membrane area asymmetry controls the shape of cellular organelles

NARCIS (Netherlands)

Beznoussenko, Galina V; Pilyugin, Sergei S; Geerts, Willie J C; Kozlov, Michael M; Burger, Koert N J; Luini, Alberto; Derganc, Jure; Mironov, Alexander A

2015-01-01

Membrane organelles often have complicated shapes and differ in their volume, surface area and membrane curvature. The ratio between the surface area of the cytosolic and luminal leaflets (trans-membrane area asymmetry (TAA)) determines the membrane curvature within different sites of the organelle.

The use of allodermis prepared from Euro skin bank to prepare autologous tissue engineered skin for clinical use.

Science.gov (United States)

Deshpande, P; Ralston, D R; MacNeil, S

2013-09-01

Over the past two decades a range of 3D models for human skin have been described. Some include native collagen and intrinsic basement membrane proteins and fibroblasts, others are based on xenogeneic collagen or synthetic supports often without fibroblasts. The aim of this study was to look at the influence of media calcium, basement membrane and fibroblasts on the quality of 3D tissue engineered skin produced using human de-epidermized acellular dermis. In this study we deliberately used Euro skin as the source of the donor dermis to examine to what extent this could provide an effective dermal substrate for producing 3D skin for clinical use. Keratinocytes were cultured in the presence and absence of fibroblasts and both with and without basement membrane on decellularized dermis at calcium concentrations ranging from 250μM to 1.6mM over a period of 14 days. Results showed the formation of a well attached epithelium with many of the features of normal skin in the presence of a basement membrane. This was largely independent of the presence of fibroblasts and not greatly influenced by the concentration of calcium in the media. However there was a clear requirement for physiological levels of calcium in the formation of a stratified epithelium in the absence of a basement membrane. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

A Highly Controllable Electrochemical Anodization Process to Fabricate Porous Anodic Aluminum Oxide Membranes

Science.gov (United States)

Lin, Yuanjing; Lin, Qingfeng; Liu, Xue; Gao, Yuan; He, Jin; Wang, Wenli; Fan, Zhiyong

2015-12-01

Due to the broad applications of porous alumina nanostructures, research on fabrication of anodized aluminum oxide (AAO) with nanoporous structure has triggered enormous attention. While fabrication of highly ordered nanoporous AAO with tunable geometric features has been widely reported, it is known that its growth rate can be easily affected by the fluctuation of process conditions such as acid concentration and temperature during electrochemical anodization process. To fabricate AAO with various geometric parameters, particularly, to realize precise control over pore depth for scientific research and commercial applications, a controllable fabrication process is essential. In this work, we revealed a linear correlation between the integrated electric charge flow throughout the circuit in the stable anodization process and the growth thickness of AAO membranes. With this understanding, we developed a facile approach to precisely control the growth process of the membranes. It was found that this approach is applicable in a large voltage range, and it may be extended to anodization of other metal materials such as Ti as well.

Retinal Damage Induced by Internal Limiting Membrane Removal

Directory of Open Access Journals (Sweden)

Rachel Gelman

2015-01-01

Full Text Available The internal limiting membrane (ILM, the basement membrane of the Müller cells, serves as the interface between the vitreous body and the retinal nerve fiber layer. It has a fundamental role in the development, structure, and function of the retina, although it also is a pathologic component in the various vitreoretinal disorders, most notably in macular holes. It was not until understanding of the evolution of idiopathic macular holes and the advent of idiopathic macular hole surgery that the idea of adjuvant ILM peeling in the treatment of tractional maculopathies was explored. Today intentional ILM peeling is a commonly applied surgical technique among vitreoretinal surgeons as it has been found to increase the rate of successful macular hole closure and improve surgical outcomes in other vitreoretinal diseases. Though ILM peeling has refined surgery for tractional maculopathies, like all surgical procedures it is not immune to perioperative risk. The essential role of the ILM to the integrity of the retina and risk of trauma to retinal tissue spurs suspicion with regard to its routine removal. Several authors have investigated the retinal damage induced by ILM peeling and these complications have been manifested across many different diagnostic studies.

Application of Cauchy-type integrals in developing effective methods for depth-to-basement inversion of gravity and gravity gradiometry data

DEFF Research Database (Denmark)

Cai, Hongzhu; Zhdanov, Michael

2015-01-01

to be discretized for the calculation of gravity field. This was especially significant in the modeling and inversion of gravity data for determining the depth to the basement. Another important result was developing a novel method of inversion of gravity data to recover the depth to basement, based on the 3D...... Cauchy-type integral representation. Our numerical studies determined that the new method is much faster than conventional volume discretization method to compute the gravity response. Our synthetic model studies also showed that the developed inversion algorithm based on Cauchy-type integral is capable......One of the most important applications of gravity surveys in regional geophysical studies is determining the depth to basement. Conventional methods of solving this problem are based on the spectrum and/or Euler deconvolution analysis of the gravity field and on parameterization of the earth...

Forms of iron in soils on basement complex rocks of Kaduna state in ...

African Journals Online (AJOL)

The forms of iron extracted by different methods were studied in soils developed on four basement complex rocks within Northern Guinea Savanna of Nigeria namely: migmatite gneisses, older granite, quartzites and mica schists. The study shows that forms of iron generally decreased in the order of total elemental iron ...

Structural analysis of a fractured basement reservoir, central Yemen

Science.gov (United States)

Veeningen, Resi; Rice, Hugh; Schneider, Dave; Grasemann, Bernhard; Decker, Kurt

2013-04-01

The Pan-African Arabian-Nubian Shield (ANS), within which Yemen lies, formed as a result of Neoproterozoic collisional events between c. 870-550 Ma. Several subsequent phases of extension occurred, from the Mesozoic (due to the breakup of Gondwana) to the Recent (forming the Gulf of Aden and the Red Sea). These resulted in the formation of numerous horst- and-graben structures and the development of fractured basement reservoirs in the southeast part of the ANS. Two drill cores from the Mesozoic Marib-Shabwa Basin, central Yemen, penetrated the upper part of the Pan-African basement. The cores show both a lithological and structural inhomogeneity, with variations in extension-related deformation structures such as dilatational breccias, open fractures and closed veins. At least three deformation events have been recognized: D1) Ductile to brittle NW-SE directed faulting during cooling of a granitic pluton. U-Pb zircon ages revealed an upper age limit for granite emplacement at 627±3.5 Ma. As these structures show evidence for ductile deformation, this event must have occurred during the Ediacaran, shortly after intrusion, since Rb/Sr and (U-Th)/He analyses show that subsequent re-heating of the basement did not take place. D2) The development of shallow dipping, NNE-SSW striking extensional faults that formed during the Upper Jurassic, simultaneously with the formation of the Marib-Shabwa Basin. These fractures are regularly cross-cut by D3. D3) Steeply dipping NNE-SSW to ENE-WSW veins that are consistent with the orientation of the opening of the Gulf of Aden. These faults are the youngest structures recognized. The formation of ductile to brittle faults in the granite (D1) resulted in a hydrothermally altered zone ca. 30 cm wide replacing (mainly) plagioclase with predominantly chlorite, as well as kaolinite and heavy element minerals such as pyrite. The alteration- induced porosity has an average value of 20%, indicating that the altered zone is potentially a

Separation membrane development

Energy Technology Data Exchange (ETDEWEB)

Lee, M.W. [Savannah River Technology Center, Aiken, SC (United States)

1998-08-01

A ceramic membrane has been developed to separate hydrogen from other gases. The method used is a sol-gel process. A thin layer of dense ceramic material is coated on a coarse ceramic filter substrate. The pore size distribution in the thin layer is controlled by a densification of the coating materials by heat treatment. The membrane has been tested by permeation measurement of the hydrogen and other gases. Selectivity of the membrane has been achieved to separate hydrogen from carbon monoxide. The permeation rate of hydrogen through the ceramic membrane was about 20 times larger than Pd-Ag membrane.

Electrospun Gelatin/poly(Glycerol Sebacate Membrane with Controlled Release of Antibiotics for Wound Dressing

Directory of Open Access Journals (Sweden)

Parisa Shirazaki

2017-01-01

Full Text Available Background: The most important risk that threatens the skin wounds is infections. Therefore, fabrication of a membrane as a wound dressing with the ability of antibiotic delivery in a proper delivery rate is especially important. Materials and Methods: Poly(glycerol sebacate (PGS was prepared from sebacic acid and glycerol with 1:1 ratio; then, it was added to gelatin in the 1:3 ratio and was dissolved in 80% (v/v acetic acid, and finally, ciprofloxacin was added in 10% (w/v of polymer solution. The gelatin/PGS membrane was fabricated using an electrospinning method. The membrane was cross-linked using ethyl-3-(3-dimethylaminopropyl carbodiimide ethyl-3-(3-dimethylaminopropylcarbodiim (EDC and N-hydroxysuccinimide (NHS in different time periods to achieve a proper drug release rate. Fourier-transform infrared (FTIR spectroscopy was being used to manifest the peaks of polymers and drug in the membrane. Scanning electron microscopy (SEM was used to evaluate the morphology, fibers diameter, pore size, and porosity before and after crosslinking process. Ultraviolet (UV-visible spectrophotometry was used to show the ciprofloxacin release from the cross-linked membrane. Results: FTIR analysis showed the characteristic peaks of gelatin, PGS, and ciprofloxacin without any added peaks after the crosslinking process. SEM images revealed that nanofibers' size increased during the crosslinking process and porosity was higher than 80% before and after crosslinking process. UV-visible spectrophotometry showed the proper rate of ciprofloxacin release occurred from cross-linked membrane that remaining in EDC/NHS ethanol solution for 120 min. Conclusion: The obtained results suggest that this recently developed gelatin/PGS membrane with controlled release of ciprofloxacin could be a promising biodegradable membrane for wound dressing.

Geology and petrography of basement in south extreme in Sierra Grande de San Luis, Argentina

International Nuclear Information System (INIS)

Morosini, A.; Ortiz Suarez, A.

2007-01-01

In the south of the Sierra de San Luis is recognized a basement composed by La Escalerilla and Los Puquios granites, accompanied by schist, mylonite s and mafic-ultramafic rocks. The schists, La Escalerilla granite and the mafic -ultramafic rocks are affected by a regional metamorphism in anphibolites facies, the two first present a N-S foliation di ping to east. The mylonite s correspond to a second event of deformation, distributed in thin belts of NNE-SSO direction and inclination to east, developed in green schist to anphibolites facies. Los Puquios granite represents the more young of the basement rocks and the intrusion was associated with a shear zone. Los Puquios granite forms dikes and small plutons cutting La Escalerilla granite and micas chits in high cortical levels

Use of cation selective membrane and acid addition for PH control in two-dimensional electrokinetic remediation of copper

Energy Technology Data Exchange (ETDEWEB)

Chan, M.S.M.; Lynch, R.J. [Cambridge Univ., Engineering Dept. (United Kingdom); Ilett, D.J. [AEA Technology, Harwell, Oxfordshire (United Kingdom)

2001-07-01

The feasibility of using a combination of a cation selective membrane and acid addition for pH control in electrokinetic remediation to toxic and heavy metals from low-permeability soil has been investigated. The high pH generated during the remediation process, as a result of surplus OH{sup -} ions, may cause metal ions to precipitate as hydroxides at or near the cathodes. This region of high pH is known to be associated with high electrical resistance, which limits the remediation efficiency by inhibiting current flow through the soil. One way to control pH is by adding acid to neutralize the OH{sup -} ions. However, preliminary work showed that addition of acid to the cathodic region was not effective in preventing the spread of the alkaline zone from cathodes toward anodes. Precipitates were formed before metal ions reached the cathodic region. Therefore, another method of pH control was investigated, using a cation selective membrane to enhance the electrokinetic process. The membrane was placed in front of the cathodes to contain the OH{sup -} ions generated, and confine the precipitates of metal hydroxide to a small cathodic region. The clean-up of a contaminated site was modelled in a rectangular tank, using silt as the low permeability soul and copper to simulate the contamination. The objective was to redistribute the contaminant so as to concentrate it into a small area. Three experiments were performed with the following methods of pH control: (1) acid addition, (2) use of a cation selective membrane and (3) a combination of acid addition and a cation selective membrane. Using the combined approach, it was found that 75% of the target clean-up section (bounded by the cation selective membrane and the anodes) had more than 40% of the initial copper removed. The general efficiency of remediation increased in the following order. (orig.)

Optimal operation of batch membrane processes

CERN Document Server

Paulen, Radoslav

2016-01-01

This study concentrates on a general optimization of a particular class of membrane separation processes: those involving batch diafiltration. Existing practices are explained and operational improvements based on optimal control theory are suggested. The first part of the book introduces the theory of membrane processes, optimal control and dynamic optimization. Separation problems are defined and mathematical models of batch membrane processes derived. The control theory focuses on problems of dynamic optimization from a chemical-engineering point of view. Analytical and numerical methods that can be exploited to treat problems of optimal control for membrane processes are described. The second part of the text builds on this theoretical basis to establish solutions for membrane models of increasing complexity. Each chapter starts with a derivation of optimal operation and continues with case studies exemplifying various aspects of the control problems under consideration. The authors work their way from th...

Uplift, Emergence, and Subsidence of the Gorda Escarpment Basement Ridge Offshore Cape Mendocino, CA

Science.gov (United States)

Hoover, Susan M.; Tréhu, Anne M.

2017-12-01

The Gorda Escarpment is a topographic step that characterizes the south side of the Mendocino Transform Fault east of 126oW and forms the northern edge of the Vizcaino Block. Seismic reflection data suggest that the basement beneath the northern edge of the Vizcaino is composed of east-west trending slivers of oceanic crust that form a 15 km wide band of buried ridges we call the Gorda Escarpment Basement Ridge (GEBR) to distinguish it from the northwest-trending basement structure that characterizes most of the Vizcaino Block. The history of uplift and subsidence of the GEBR is reconstructed by combining the seismic reflection profiles with age and lithological constraints from ODP Site 1022, gravity cores, and grab samples from the northern face of the Escarpment recovered using a remotely operated vehicle. Uplift of the GEBR began prior to 6 Ma, and it was above sea level 3.7-2.5 Ma. GEBR uplift and emergence coincided with sediment deposition on the southern flank of the GEBR that we interpret as indicative of strong upwelling and turbulence in the lee of a shallow ridge and island chain. A bright reflection, interpreted to be a sill, is observed south of the shallowest part of the GEBR. We speculate that this sill may reflect a larger, hidden intrusion at depth and that thermal expansion of the crust combined with tectonic forces to drive enhanced uplift of this segment of the plate boundary. The GEBR has been subsiding since 2.7 Ma, and its shallowest point is now 1,400 m below sea level.

A fluidic device for the controlled formation and real-time monitoring of soft membranes self-assembled at liquid interfaces.

Science.gov (United States)

Mendoza-Meinhardt, Arturo; Botto, Lorenzo; Mata, Alvaro

2018-02-13

Membrane materials formed at the interface between two liquids have found applications in a large variety of technologies, from sensors to drug-delivery and catalysis. However, studying the formation of these membranes in real-time presents considerable challenges, owing to the difficulty of prescribing the location and instant of formation of the membrane, the difficulty of observing time-dependent membrane shape and thickness, and the poor reproducibility of results obtained using conventional mixing procedures. Here we report a fluidic device that facilitates characterisation of the time-dependent thickness, morphology and mass transport properties of materials self-assembled at fluid-fluid interfaces. In the proposed device the membrane forms from the controlled coalescence of two liquid menisci in a linear open channel. The linear geometry and controlled mixing of the solutions facilitate real-time visualisation, manipulation and improve reproducibility. Because of its small dimensions, the device can be used in conjunction with standard microscopy methods and reduces the required volumes of potentially expensive reagents. As an example application to tissue engineering, we use the device to characterise interfacial membranes formed by supra-molecular self-assembly of peptide-amphiphiles with either an elastin-like-protein or hyaluronic acid. The device can be adapted to study self-assembling membranes for applications that extend beyond bioengineering.

Basement to surface expressions and critical factors in the genesis of unconformity-related deposits

International Nuclear Information System (INIS)

Potter, Eric

2014-01-01

Two subprojects: 1) Basement to surface expressions of deep mineralization and refinement of critical factors leading to the genesis of unconformity-related uranium deposits; and 2) Recognition of uranium ore system alteration signatures in complex terranes: IOCG vs albite-hosted uranium vs volcanic-hosted uranium.

Numerical Simulation for Mechanism of Airway Narrowing in Asthma

Science.gov (United States)

Bando, Kiyoshi; Yamashita, Daisuke; Ohba, Kenkichi

A calculation model is proposed to examine the generation mechanism of the numerous lobes on the inner-wall of the airway in asthmatic patients and to clarify luminal occlusion of the airway inducing breathing difficulties. The basement membrane in the airway wall is modeled as a two-dimensional thin-walled shell having inertia force due to the mass, and the smooth muscle contraction effect is replaced by uniform transmural pressure applied to the basement membrane. A dynamic explicit finite element method is used as a numerical simulation method. To examine the validity of the present model, simulation of an asthma attack is performed. The number of lobes generated in the basement membrane increases when transmural pressure is applied in a shorter time period. When the remodeling of the basement membrane occurs characterized by thickening and hardening, it is demonstrated that the number of lobes decreases and the narrowing of the airway lumen becomes severe. Comparison of the results calculated by the present model with those measured for animal experiments of asthma will be possible.

Fluorescent in situ folding control for rapid optimization of cell-free membrane protein synthesis.

Directory of Open Access Journals (Sweden)

Annika Müller-Lucks

Full Text Available Cell-free synthesis is an open and powerful tool for high-yield protein production in small reaction volumes predestined for high-throughput structural and functional analysis. Membrane proteins require addition of detergents for solubilization, liposomes, or nanodiscs. Hence, the number of parameters to be tested is significantly higher than with soluble proteins. Optimization is commonly done with respect to protein yield, yet without knowledge of the protein folding status. This approach contains a large inherent risk of ending up with non-functional protein. We show that fluorophore formation in C-terminal fusions with green fluorescent protein (GFP indicates the folding state of a membrane protein in situ, i.e. within the cell-free reaction mixture, as confirmed by circular dichroism (CD, proteoliposome reconstitution and functional assays. Quantification of protein yield and in-gel fluorescence intensity imply suitability of the method for membrane proteins of bacterial, protozoan, plant, and mammalian origin, representing vacuolar and plasma membrane localization, as well as intra- and extracellular positioning of the C-terminus. We conclude that GFP-fusions provide an extension to cell-free protein synthesis systems eliminating the need for experimental folding control and, thus, enabling rapid optimization towards membrane protein quality.

Ion Transport through Diffusion Layer Controlled by Charge Mosaic Membrane

Directory of Open Access Journals (Sweden)

Akira Yamauchi

2012-01-01

Full Text Available The kinetic transport behaviors in near interface of the membranes were studied using commercial anion and cation exchange membrane and charge mosaic membrane. Current-voltage curve gave the limiting current density that indicates the ceiling of conventional flux. From chronopotentiometry above the limiting current density, the transition time was estimated. The thickness of boundary layer was derived with conjunction with the conventional limiting current density and the transition time from steady state flux. On the other hand, the charge mosaic membrane was introduced in order to examine the ion transport on the membrane surface in detail. The concentration profile was discussed by the kinetic transport number with regard to the water dissociation (splitting on the membrane surface.

Electrically-controlled permeation of vapors through carbon nanotube network-based membranes

Czech Academy of Sciences Publication Activity Database

Slobodian, P.; Říha, Pavel; Olejník, R.

2018-01-01

Roč. 17, č. 2 (2018), s. 332-337 ISSN 1536-125X R&D Projects: GA MŠk ED2.1.00/19.0409 Grant - others:Ministerstvo školství, mládeže a tělovýchovy (MŠMT)(CZ) LO1504 Institutional research plan: CEZ:AV0Z20600510 Keywords : carbon nanotubes * electrically controlled membranes * permeation of chemical vapors Impact factor: 2.485, year: 2016

BSM-MBR: a benchmark simulation model to compare control and operational strategies for membrane bioreactors.

Science.gov (United States)

Maere, Thomas; Verrecht, Bart; Moerenhout, Stefanie; Judd, Simon; Nopens, Ingmar

2011-03-01

A benchmark simulation model for membrane bioreactors (BSM-MBR) was developed to evaluate operational and control strategies in terms of effluent quality and operational costs. The configuration of the existing BSM1 for conventional wastewater treatment plants was adapted using reactor volumes, pumped sludge flows and membrane filtration for the water-sludge separation. The BSM1 performance criteria were extended for an MBR taking into account additional pumping requirements for permeate production and aeration requirements for membrane fouling prevention. To incorporate the effects of elevated sludge concentrations on aeration efficiency and costs a dedicated aeration model was adopted. Steady-state and dynamic simulations revealed BSM-MBR, as expected, to out-perform BSM1 for effluent quality, mainly due to complete retention of solids and improved ammonium removal from extensive aeration combined with higher biomass levels. However, this was at the expense of significantly higher operational costs. A comparison with three large-scale MBRs showed BSM-MBR energy costs to be realistic. The membrane aeration costs for the open loop simulations were rather high, attributed to non-optimization of BSM-MBR. As proof of concept two closed loop simulations were run to demonstrate the usefulness of BSM-MBR for identifying control strategies to lower operational costs without compromising effluent quality. Copyright © 2011 Elsevier Ltd. All rights reserved.

Nonlinear Lyapunov-based boundary control of distributed heat transfer mechanisms in membrane distillation plant

KAUST Repository

Eleiwi, Fadi; Laleg-Kirati, Taous-Meriem

2015-01-01

This paper presents a nonlinear Lyapunov-based boundary control for the temperature difference of a membrane distillation boundary layers. The heat transfer mechanisms inside the process are modeled with a 2D advection-diffusion equation. The model

Detection and quantification through a lipid membrane using the molecularly controlled semiconductor resistor.

Science.gov (United States)

Bavli, Danny; Tkachev, Maria; Piwonski, Hubert; Capua, Eyal; de Albuquerque, Ian; Bensimon, David; Haran, Gilad; Naaman, Ron

2012-01-10

The detection of covalent and noncovalent binding events between molecules and biomembranes is a fundamental goal of contemporary biochemistry and analytical chemistry. Currently, such studies are performed routinely using fluorescence methods, surface-plasmon resonance spectroscopy, and electrochemical methods. However, there is still a need for novel sensitive miniaturizable detection methods where the sample does not have to be transferred to the sensor, but the sensor can be brought into contact with the sample studied. We present a novel approach for detection and quantification of processes occurring on the surface of a lipid bilayer membrane, by monitoring the current change through the n-type GaAs-based molecularly controlled semiconductor resistor (MOCSER), on which the membrane is adsorbed. Since GaAs is susceptible to etching in an aqueous environment, a protective thin film of methoxysilane was deposited on the device. The system was found to be sensitive enough to allow monitoring changes in pH and in the concentration of amino acids in aqueous solution on top of the membrane. When biotinylated lipids were incorporated into the membrane, it was possible to monitor the binding of streptavidin or avidin. The device modified with biotin-streptavidin complex was capable of detecting the binding of streptavidin antibodies to immobilized streptavidin with high sensitivity and selectivity. The response depends on the charge on the analyte. These results open the way to facile electrical detection of protein-membrane interactions.

New type of chitosan/2-hydroxypropyl-β-cyclodextrin composite membrane for gallic acid encapsulation and controlled release.

Science.gov (United States)

Paun, Gabriela; Neagu, Elena; Tache, Andreia; Radu, G L

2014-01-01

A new type of chitosan/2-hydroxypropyl-β-cyclodextrin composite membrane have been developed for the encapsulation and controlled release of gallic acid. The morphology of the composite membrane was investigated by infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM), whereas swelling gallic acid and release properties were investigated by UV-visible spectroscopy. The release behavior with pH changes was also explored. The composite membrane based on chitosan/2-hydroxypropyl-β-cyclodextrin with gallic acid included showed improved antioxidant capacities compared to plain chitosan membrane. The information obtained in this study will facilitate the design and preparation of composite membrane based on chitosan and could open a wide range of applications, particularly its use as an antioxidant in food, food packaging, biomedical (biodegradable soft porous scaffolds for enhance the surrounding tissue regeneration), pharmaceutical and cosmetics industries.

Characterization of 222Rn entry into a basement structure surrounded by low permeability soil

International Nuclear Information System (INIS)

Ward, D.C.

1992-01-01

An experimental facility has been developed to monitor the entry rate and concentration of 222 Rn in two basement type structures surrounded by soil having a permeability on the order of 1- -12 m 2 . A data acquisition system recorded environmental conditions outside and inside the structures, including basement air exchange rates, every 15 min. Indoor 222 Rn concentrations ranged from 400 to 1400 Bq m -3 . The observed 222 Rn entry rate is highly variable and has two primary components; a constant input rate caused by diffusion of 222 Rn through the concrete walls and floor, and a variable rate that depends upon indoor-soil pressure differentials of only a few pascals. Pressure differentials are dependent upon wind speed and wind direction. Stack effect was not significant. During a two week period, with relatively calm winds, diffusion through the concrete walls and floor plus the floor-wall joint accounted for more than 80% of the total 222 Rn entry

Geochemical, microtextural and petrological studies of the Samba prospect in the Zambian Copperbelt basement: a metamorphosed Palaeoproterozoic porphyry Cu deposit.

Science.gov (United States)

Master, Sharad; Mirrander Ndhlovu, N.

2015-04-01

, including potassic (biotite+sericite+ quartz), propylitic (clinozoisite+chlorite+saussuritized plagioclase), phyllic (sericite+quartz+ pyrite+hydromuscovite/illite) and argillic (kaolinite+chlorite+dolomite) alteration. The clays were identified with XRD. All the rocks show penetrative deformational textures and fabrics. Our textural studies show that phyllic zone pyrite crystals have quartz-rich pressure shadows, and they predate all phases of deformation. Similarly, in the potassic zone, fracture-controlled biotite stringers in particular orientations are deformed, and partly replaced by chlorite, again showing their pre-deformational, pre-metamorphic origin. Copper sulfide-bearing quartz veinlets are deformed. Many of the alteration assemblages containing biotite or sericite have been deformed into crenulated schists, showing that they were formed early in the deformation history. Coupled with the dating of a Samba metavolcanic rock at 1964±12 Ma (Rainaud et al., 2005, JAES, 42, 1-31), we regard the Samba deposit as a metamorphosed Palaeoproterozoic porphyry-type Cu deposit, which has undergone deformation, and retrograde metamorphism of its alteration assemblages, during the Neoproterozoic Lufilian Orogeny, followed by post-tectonic cooling, which occurred throughout the Copperbelt at about 480±20 Ma. Samba, together with the Mkushi deposits, is part of a long-lived (>100 Ma) Palaeoproterozoic porphyry-Cu province in the Zambian Copperbelt basement, and ore genetic theories for the Copperbelt mineralization must now seriously take this into account.

Membrane-bound organelles versus membrane-less compartments and their control of anabolic pathways in Drosophila

NARCIS (Netherlands)

Aguilera-Gomez, Angelica; Rabouille, Catherine

2017-01-01

Classically, we think of cell compartmentalization as being achieved by membrane-bound organelles. It has nevertheless emerged that membrane-less assemblies also largely contribute to this compartmentalization. Here, we compare the characteristics of both types of compartmentalization in term of

Controlling the Release of Indomethacin from Glass Solutions Layered with a Rate Controlling Membrane Using Fluid-Bed Processing. Part 1: Surface and Cross-Sectional Chemical Analysis.

Science.gov (United States)

Dereymaker, Aswin; Scurr, David J; Steer, Elisabeth D; Roberts, Clive J; Van den Mooter, Guy

2017-04-03

Fluid bed coating has been shown to be a suitable manufacturing technique to formulate poorly soluble drugs in glass solutions. Layering inert carriers with a drug-polymer mixture enables these beads to be immediately filled into capsules, thus avoiding additional, potentially destabilizing, downstream processing. In this study, fluid bed coating is proposed for the production of controlled release dosage forms of glass solutions by applying a second, rate controlling membrane on top of the glass solution. Adding a second coating layer adds to the physical and chemical complexity of the drug delivery system, so a thorough understanding of the physical structure and phase behavior of the different coating layers is needed. This study aimed to investigate the surface and cross-sectional characteristics (employing scanning electron microscopy (SEM) and time of flight secondary ion mass spectrometry (ToF-SIMS)) of an indomethacin-polyvinylpyrrolidone (PVP) glass solution, top-coated with a release rate controlling membrane consisting of either ethyl cellulose or Eudragit RL. The implications of the addition of a pore former (PVP) and the coating medium (ethanol or water) were also considered. In addition, polymer miscibility and the phase analysis of the underlying glass solution were investigated. Significant differences in surface and cross-sectional topography of the different rate controlling membranes or the way they are applied (solution vs dispersion) were observed. These observations can be linked to the polymer miscibility differences. The presence of PVP was observed in all rate controlling membranes, even if it is not part of the coating solution. This could be attributed to residual powder presence in the coating chamber. The distribution of PVP among the sample surfaces depends on the concentration and the rate controlling polymer used. Differences can again be linked to polymer miscibility. Finally, it was shown that the underlying glass solution layer

Analytical and numerical models for estimating the effect of exhaust ventilation on radon entry in houses with basements or crawl spaces

International Nuclear Information System (INIS)

Mowris, R.J.

1986-08-01

Mechanical exhaust ventilation systems are being installed in newer, energy-efficient houses and their operation can increase the indoor-outdoor pressure differences that drive soil gas and thus radon entry. This thesis presents simplified models for estimating the pressure driven flow of radon into houses with basements or crawl spaces, due to underpressures induced by indoor-outdoor temperature differences, wind, or exhaust ventilation. A two-dimensional finite difference model is presented and used to calculate the pressure field and soil gas flow rate into a basement situated in soil of uniform permeability. A simplified analytical model is compared to the finite difference model with generally very good agreement. Another simplified model is presented for houses with a crawl space. Literature on radon research is also reviewed to show why pressure driven flow of soil gas is considered to be the major source of radon entry in houses with higher-than-average indoor radon concentrations. Comparisons of measured vs. calculated indoor radon concentrations for a house with a basement showed the simplified basement model underpredicting on average by 25%. For a house with a crawl space the simplified crawl space model overpredicted by 23% when the crawl space vents are open and 48% when the crawl space vents are sealed

Rb/Sr and U/Pb isotopic ages in basement rocks of Mina Gonzalito and Arroyo Salado, Atlantic North-Patagonian Massif, Rio Negro, Argentina

International Nuclear Information System (INIS)

Varela, Ricardo; Sato, Ana M.; Cingolani, Carlos A.; Basei, Miguel A.S.; Siga, Oswaldo; Sato, Kei

1998-01-01

Isotopic ages from metamorphic and plutonic rocks of the Atlantic area of North Patagonian basement indicate that the main crustal tectonic events occurred during the late Proterozoic to early Paleozoic times. Rb/Sr and U/Pb data in the 550-470 Ma interval suggest an old tecto-thermal activity during the upper Brazilian Cycle (Rio Doce Orogeny). At regional scale, the comparable Neo proterozoic basement of Ventania and sedimentary for eland cover of Tandilia continues to the Northeast, in the Dom Feliciano Belt. A possible correlation of the North Patagonian basement with igneous-metamorphic relics of Central Argentina (Pampean Ranges of San Luis-Cordoba and at La Pampa province) is also indicated. (author)

Dynamics of uranium ore formation in the basement and frame of the Streltsovskaya Caldera

International Nuclear Information System (INIS)

Petrov, V.; Schukin, S.

2014-01-01

The analysis of geological-geophysical, paleo-geodynamics, mineralogical, geochemical, isotope, geochronological, and thermo-baro-geochemical data allow us to offer a model of uranium ore formation dynamics in the basement and frame of the Streltsovskaya Caldera connected to activity of the fluid-conducting fault zones network with the aim to identify prospective areas The most ancient fluid-conducting structures are inter-block NE-SW, NNE-submeridional, NW-SE and, probably, WNW-sub-latitudinal faults. The oldest NE-SW faults and schistosity zones were formed during Proterozoic tectonic cycle (TC) with reactivation in T3-J2 time due to global reorganization of stress field and reactivation of tectonic movements. The NNE-submeridional and NW-SE faults were extended with increased fluid permeability during Caledonian and Variscan TCs. They also were reactivated in the process of Late Mesozoic tectonic and magmatic activation (TMA). Thus already at early stages of geotectonic evolution within the intersection of NE-SW (N-Urulyunguyevskiy fault) and NNE-submeridional (Chindachinskaya zone) faults the areas of increased fluid and magmatic activity were formed. The dynamics of fault formation in the basement and frame of the Streltsovskaya caldera and its volcano-sedimentary cover differs. In the basement and granite framework NE-SW, NNEsubmeridional and NW-SE faults are interblock structures of the I rank. Their intersection formed areas of long-term circulation of hydrothermal solutions and telescopic appearance of multi-age metasomatites that created conditions for localizing of vein-stockwork mineralization. In volcanosedimentary cover the NE-SW and NNE-submeridional faults should be considered as interblock structures of the I rank where intersections provided inflow of ore-bearing solutions and their redistribution within the cover. Here the main ore distributing role belongs to NW-SE shears. They are intrablock II rank structures which were formed due to dextral

Induced- and alternating-current electro-osmotic control of the diffusion layer growth in a microchannel-membrane interface device

Science.gov (United States)

Park, Sinwook; Yossifon, Gilad

2014-11-01

The passage of an electric current through an ionic permselective medium under an applied electric field is characterized by the formation of ionic concentration gradients, which result in regions of depleted and enriched ionic concentration at opposite ends of the medium. Induced-current electro-osmosis (ICEO) and alternating-current-electro-osmosis (ACEO) are shown to control the growth of the diffusion layer (DL) which, in turn, controls the diffusion limited ion transport through the microchannel-membrane system. We fabricated and tested devices made of a Nafion membrane connecting two opposite PDMS microchannels. An interdigitated electrode array was embedded within the microchannel with various distances from the microchannel-membrane interface. The induced ICEO (floating electrodes) / ACEO (active electrodes) vortices formed at the electrode array stir the fluid and thereby suppress the growth of the DL. The intensity of the ACEO vortices is controlled by either varying the voltage amplitude or the frequency, each having its own unique effect. Enhancement of the limiting current by on-demand control of the diffusion length is of importance in on-chip electro-dialysis, desalination and preconcentration of analytes.

Membrane Bioreactor (MBR) Technology for Wastewater Treatment and Reclamation: Membrane Fouling.

Science.gov (United States)

Iorhemen, Oliver Terna; Hamza, Rania Ahmed; Tay, Joo Hwa

2016-06-15

The membrane bioreactor (MBR) has emerged as an efficient compact technology for municipal and industrial wastewater treatment. The major drawback impeding wider application of MBRs is membrane fouling, which significantly reduces membrane performance and lifespan, resulting in a significant increase in maintenance and operating costs. Finding sustainable membrane fouling mitigation strategies in MBRs has been one of the main concerns over the last two decades. This paper provides an overview of membrane fouling and studies conducted to identify mitigating strategies for fouling in MBRs. Classes of foulants, including biofoulants, organic foulants and inorganic foulants, as well as factors influencing membrane fouling are outlined. Recent research attempts on fouling control, including addition of coagulants and adsorbents, combination of aerobic granulation with MBRs, introduction of granular materials with air scouring in the MBR tank, and quorum quenching are presented. The addition of coagulants and adsorbents shows a significant membrane fouling reduction, but further research is needed to establish optimum dosages of the various coagulants/adsorbents. Similarly, the integration of aerobic granulation with MBRs, which targets biofoulants and organic foulants, shows outstanding filtration performance and a significant reduction in fouling rate, as well as excellent nutrients removal. However, further research is needed on the enhancement of long-term granule integrity. Quorum quenching also offers a strong potential for fouling control, but pilot-scale testing is required to explore the feasibility of full-scale application.

Exhumation of Basement-cored Uplifts: Example of the Kyrgyz Range Quantified with Apatite Fission-track Thermochronology

Science.gov (United States)

Sobel, Edward R.; Oskin, Michael; Burbank, Douglas; Mikolaichuk, Alexander

2005-01-01

The Kyrgyz Range, the northernmost portion of the Kyrgyzstan Tien Shan, displays topographic evidence for lateral propagation of surface uplift and exhumation. The highest and most deeply dissected segment lies in the center of the range. To the east, topography and relief decrease, and preserved remnants of a Cretaceous regional erosion surface imply minimal amounts of bedrock exhumation. The timing of exhumation of range segments defines the lateral propagation rate of the range-bounding reverse fault and quantifies the time and erosion depth needed to transform a mountain range from a juvenile to a mature morphology. New apatite fission-track (AFT) data from three transects from the eastern Kyrgyz Range, combined with published AFT data, demonstrate that the range has propagated over 110 km eastwards over the last 7-11 Myr. Based on the thermal and topographic evolutionary history, we present a model for a time-varying exhumation rate driven by rock uplift and changes in erodability and the time scale of geomorphic adjustment to surface uplift. Easily eroded, Cenozoic sedimentary rocks overlying resistant basement control early, rapid exhumation and slow surface upliftrates. As increasing amounts of resistant basement are exposed, exhumation rates decrease while surface uplift rates are sustained or increase, thereby growing topography. As the range becomes high enough to cause ice accumulation and develop steep river valleys, fluvial and glacial erosion become more powerful and exhumation rates once again increase. Independently determined range-noma1 shortening rates have also varied over time, suggesting a feedback between erosional efficiency and shortening rate.

Nitric oxide partitioning into mitochondrial membranes and the control of respiration at cytochrome c oxidase

Science.gov (United States)

Shiva, Sruti; Brookes, Paul S.; Patel, Rakesh P.; Anderson, Peter G.; Darley-Usmar, Victor M.

2001-06-01

An emerging and important site of action for nitric oxide (NO) within cells is the mitochondrial inner membrane, where NO binds to and inhibits members of the electron transport chain, complex III and cytochrome c oxidase. Although it is known that inhibition of cytochrome c oxidase by NO is competitive with O2, the mechanisms that underlie this phenomenon remain unclear, and the impact of both NO and O2 partitioning into biological membranes has not been considered. These properties are particularly interesting because physiological O2 tensions can vary widely, with NO having a greater inhibitory effect at low O2 tensions (mitochondrial membranes in the absence of substrate, in a nonsaturable process that is O2 dependent. This consumption modulates inhibition of cytochrome c oxidase by NO and is enhanced by the addition of exogenous membranes. From these data, it is evident that the partition of NO into mitochondrial membranes has a major impact on the ability of NO to control mitochondrial respiration. The implications of this conclusion are discussed in the context of mitochondrial lipid:protein ratios and the importance of NO as a regulator of respiration in pathophysiology.

A study of the influence of a gravel subslab layer on radon entry rate using two basement structures

International Nuclear Information System (INIS)

Robinson, A.L.; Sextro, R.G.; Fisk, W.J.; Garbesi, K.; Wooley, J.; Wollenberg, H.A.

1993-01-01

In buildings with elevated radon concentrations, the dominant transport mechanism of radon is advective flow of soil gas into the building substructure. However, the building-soil system is often complex, making detailed studies of the radon source term difficult. In order to examine radon entry into buildings, the authors have constructed two room-size, precisely-fabricated basement structures at a site with relatively homogeneous, moderately permeable soil. The basements are identical except that one lies directly on native soil whereas the other lies on a high permeability aggregate layer. The soil pressure field and radon entry rate have been measured for different basement pressures and environmental conditions. The subslab gravel layer greatly enhances the advective entry of radon into the structure; when the structures are depressurized, the radon entry rate into the structure with the subslab gravel layer is more than a factor of 3 times the radon entry rate into the other structure for the same depressurization. The gravel subslab layer also spreads the pressure field around the structure, extending the field of influence of the structure and the region from which it draws radon

A study of the influence of a gravel subslab layer on radon entry rate using two basement structures

International Nuclear Information System (INIS)

Robinson, A.L.; Sextro, R.G.; Fisk, W.J.; Garbesi, K.; Wooley, J.; Wollenberg, H.A.

1993-01-01

In buildings with elevated radon concentrations, the dominant transport mechanism of radon is advective flow of soil gas into the building substructure. However, the building-soil system is often complex, making detailed studies of the radon source term difficult. In order-to examine radon entry into buildings, we have constructed two room-size, precisely-fabricated basement structures at a site with relatively homogeneous, moderately permeable soil. The basements are identical except that one lies directly on native soil whereas the other lies on a high permeability aggregate layer. The soil pressure field and radon entry rate have been measured for different basement pressures and environmental conditions. The subslab gravel layer greatly enhances the advective entry of radon into the structure; when the structures are depressurized, the radon entry rate into the structure with the subslab gravel layer is more than a factor of 3 times the radon entry rate into the other structure for the same depressurization. The gravel subslab layer also spreads the pressure field around the structure, extending the field of influence of the structure and the region from which it draws radon. (orig.). (7 refs., 3 figs.)

Radon transport into a detached one-story house with a basement

International Nuclear Information System (INIS)

D'Ottavio, T.W.; Dietz, R.N.; Nazaroff, W.W.; California Institute of Technology

1986-01-01

The interpretation of the data presented in a paper published in 1985 on radon transport into a detached one-story house with a basement is extended by developing an improved model that can be used to predict radon concentration in this house. In particular, emphasis was placed on a more complete set of replotted sump activity data. In the author's reply, this development is welcomed but two concerns regarding the conclusions one might infer from the analysis are discussed. (UK)

Gas separation membranes

Science.gov (United States)

Schell, William J.

1979-01-01

A dry, fabric supported, polymeric gas separation membrane, such as cellulose acetate, is prepared by casting a solution of the polymer onto a shrinkable fabric preferably formed of synthetic polymers such as polyester or polyamide filaments before washing, stretching or calendering (so called griege goods). The supported membrane is then subjected to gelling, annealing, and drying by solvent exchange. During the processing steps, both the fabric support and the membrane shrink a preselected, controlled amount which prevents curling, wrinkling or cracking of the membrane in flat form or when spirally wound into a gas separation element.

A novel urinary biomarker of type VI collagen formation and endotrophin is associated with loss of kidney function in patients with diabetic nephropathy

DEFF Research Database (Denmark)

Genovese, Federica; Rasmussen, Daniel; Nielsen, Signe Holm

2017-01-01

-stage renal disease. Fibrosis is characterized by a dysregulated remodeling of the extracellular matrix (ECM). Collagen type VI (COL VI) is a crucial ECM molecule for the control of tissue organization. It is present at the interface of the glomerular basement membrane and interstitial matrix and its levels...

Enhanced ferro-actuator with a porosity-controlled membrane using the sol-gel process and the HF etching method

International Nuclear Information System (INIS)

Kim, KiSu; Ko, Seong Young; Park, Jong-Oh; Park, Sukho

2016-01-01

In this paper, we propose a ferro-actuator using a porous polyvinylidene difluoride (PVDF) membrane. In detail, we fabricated the silica-embedded PVDF membrane using a sol-gel process with PVDF solution and tetraethyl orthosilicate (TEOS) solution, where the size of the silica was determined by the ratio of the PVDF and TEOS solutions. Using hydrofluoric acid (HF) etching, the silica were removed from the silica-embedded PVDF membrane, and porous PVDF membranes with different porosities were obtained. Finally, through absorption of a ferrofluid on the porous PVDF membrane, the proposed ferro-actuator using porous PVDF membranes with different porosities was fabricated. We executed the characterization and actuation test as follows. First, the silica size of the silica-embedded PVDF membrane and the pore size of the porous PVDF membrane were analyzed using scanning electron microscopy (SEM) imaging. Second, energy-dispersive x-ray spectroscopy analysis showed that the silica had clearly been removed from the silica-embedded PVDF membrane by HF etching. Third, through x-ray photoelectron spectroscopy and vibrating sample magnetometer (VSM) of the ferro-actuators, we found that more ferrofluids were absorbed by the porous PVDF membrane when the pore of the membrane was smaller and uniformly distributed. Finally, we executed tip displacement and a blocking force test of the proposed ferro-actuator using the porous PVDF membrane. Similar to the VSM result, the ferro-actuator that used a porous PVDF membrane with smaller pores exhibited better actuation performance. The ferro-actuator that used a porous PVDF membrane displayed a tip displacement that was about 7.2-fold better and a blocking force that was about 6.5-fold better than the ferro-actuator that used a pure PVDF membrane. Thus, we controlled the pore size of the porous PVDF membrane and enhanced the actuation performance of the ferro-actuator using a porous PVDF membrane. (technical note)

Interaction between bacterial outer membrane proteins and periplasmic quality control factors: a kinetic partitioning mechanism.

Science.gov (United States)

Wu, Si; Ge, Xi; Lv, Zhixin; Zhi, Zeyong; Chang, Zengyi; Zhao, Xin Sheng

2011-09-15