Membrane Width Research Articles

Rotation Sealed Lead-in Unit of Submersible Mechanism

In this paper is reviewing rotation sealed lead-in unit of submersible mechanisms. Reviewable mechanisms are used at sea depth more than 2000 meter. The main idea of research is based on consideration of influence distance between magnetic couplings transmitting rotation through a membrane of a tough box. The emphasis was made on variation magnetic fields depending on membrane width and material. As a result is received a theoretical correlation between transferable torque and depth of submergence. Is shown a rotation sealed lead-in unit design. Is suggested a circular membrane design.

Variable Viscosity of Water as the Controlling Factor in Energetic Quantities that Control Living Systems: Physicochemical and Astronomical Interactions

The emergence of energy from the product of viscosity, volume and intrinsic or extrinsic frequency indicates that the ten fold difference in this property displayed by water could define the boundary of the physicochemical conditions of living systems. Intra-aqueous energy induced by geomagnetic variations and experimental time-varying magnetic fields within specific volumes of water maintained in static, dark conditions can be manifested as photon emissions with shifts in spectral power that approximate the width of the plasma cell membrane. Various manipulations of the viscosity of water accurately predicted the frequency required to affect intracellular organelles such as vesicles as well as the intramolecular pressures that affect interactions with photons. Application of the Smoluschowski-Einstein relation to the proton, the mediator of pH and the dynamics of the hydronium ion, potentially explained the vector characteristics of the frequency band of extremely low frequency magnetic fields that slow malignant cells. The derivation of viscosity from the inverse of the Newtonian Gravitational Constant, diffusivity and the square of the applied frequency indicates that resonant oscillations between the solid earth and the atmosphere and unit variations in solar flux density may be relevant variables.

Introduction to fluorescence probing of biological membranes.

Fluorescence is one of the most powerful and commonly used tools in biophysical studies of biomembrane structure and dynamics that can be applied on different levels, from lipid monolayers and bilayers to living cells, tissues, and whole animals. Successful application of this method relies on proper design of fluorescence probes with optimized photophysical properties. These probes are efficient for studying the microscopic analogs of viscosity, polarity, and hydration, as well as the molecular order, environment relaxation, and electrostatic potentials at the sites of their location. Being smaller than the membrane width they can sense the gradients of these parameters across the membrane. We present examples of novel dyes that achieve increased spatial resolution and information content of the probe responses. In this respect, multiparametric environment-sensitive probes feature considerable promise.

In patients with type 1 diabetes simultaneous pancreas and kidney transplantation preserves long-term kidney graft ultrastructure and function better than transplantation of kidney alone.

In patients with type 1 diabetes and end-stage renal disease (ESRD) we aimed to determine whether long-term normoglycaemia, as achieved by successful simultaneous pancreas and kidney (SPK) transplantation, would preserve kidney graft structure and function better than live donor kidney (LDK) transplantation alone. Estimated GFR (eGFR) was calculated in SPK (n = 25) and LDK (n = 17) recipients in a stable phase 3months after transplantation and annually during follow-up. Kidney graft biopsies were obtained at follow-up for measurement of glomerular volume (light microscopy), glomerular basement membrane (GBM) and podocyte foot process widths and mesangial volume fraction (electron microscopy). SPK and LDK recipients were similar in age and diabetes duration at engraftment. Donor age was higher in the LDK group. Median follow-up time was 10.1years. Mean HbA1c levels during follow-up were 5.5 ± 0.4% (37 ± 5mmol/mol) and 8.3 ± 1.5% (68 ± 16mmol/mol) in the SPK and LDK group, respectively (p < 0.001). Compared with SPK recipients, LDK recipients had wider GBM (369 ± 109nm vs 281 ± 57nm; p = 0.008) and increased mesangial volume fraction (median 0.23 [range 0.13-0.59] vs 0.16 [0.10-0.41]; p = 0.007) at follow-up. Absolute eGFR change from baseline was -11 ± 21 and -23 ± 15mlmin(-1) 1.73m(-2) (p = 0.060), whereas eGFR slope was -1.1 (95% CI -1.7, -0.5) and -2.6 (95% CI -3.1, -2.1) mlmin(-1) 1.73m(-2) per year in the SPK and LDK group, respectively (p = 0.001). In patients with type 1 diabetes and long-term normoglycaemia after successful SPK transplantation, kidney graft ultrastructure and function were better preserved compared with LDK transplantation alone.

Fracture property and quantitative strain evaluation of hetero-epitaxial single crystal 3C-SiC membrane

The following paper explores the development of a combined bulge test/micro-Raman analysis. This analysis, together with a refined load-deflection model (valid in both small and large deformation regimes, defined as the regimes in which the ratio between membrane deflection and width is smaller or larger than 1:10), allowed the determination of the elastic and optical properties of high quality single-crystal 3C-SiC squared membranes. Specifically we have evaluated the breaking strain of the membranes by measuring the breaking pressure for various membrane widths. The relation between the shift of the Raman Transverse Optical (TO) mode and the total residual strain (Δa/a) has been determined by measuring the TO shift for different membrane deflections. This relation, which allows determination of the residual strain by simply measuring the TO shift, was known only for thick samples (Olego et al) and high-oriented (100) thin films (Rohmfeld et al). Finally, we have calculated the TO stress-free value of high-quality thin single-crystal 3C-SiC/Si(100) films as 796.71 ± 0.04 cm−1.

Cantilever arrayed blood pressure sensor for arterial applanation tonometry.

The authors developed a cantilever-arrayed blood pressure sensor array fabricated by (111) silicon bulk-micromachining for the non-invasive and continuous measurement of blood pressure. The blood pressure sensor measures the blood pressure based on the change in the resistance of the piezoresistor on a 5-microm-thick-arrayed perforated membrane and 20-microm-thick metal pads. The length and the width of the unit membrane are 210 and 310 microm, respectively. The width of the insensible zone between the adjacent units is only 10 microm. The resistance change over contact force was measured to verify the performance. The good linearity of the result confirmed that the polydimethylsiloxane package transfers the forces appropriately. The measured sensitivity was about 4.5%/N. The maximum measurement range and the resolution of the fabricated blood pressure sensor were greater than 900 mmHg (= 120 kPa) and less than 1 mmHg (= 133.3 Pa), respectively.

Implicit membrane treatment of buried charged groups: Application to peptide translocation across lipid bilayers

The energetic cost of burying charged groups in the hydrophobic core of lipid bilayers has been controversial, with simulations giving higher estimates than certain experiments. Implicit membrane approaches are usually deemed too simplistic for this problem. Here we challenge this view. The free energy of transfer of amino acid side chains from water to the membrane center predicted by IMM1 is reasonably close to all-atom free energy calculations. The shape of the free energy profile, however, for the charged side chains needs to be modified to reflect the all-atom simulation findings (IMM1-LF). Membrane thinning is treated by combining simulations at different membrane widths with an estimate of membrane deformation free energy from elasticity theory. This approach is first tested on the voltage sensor and the isolated S4 helix of potassium channels. The voltage sensor is stably inserted in a transmembrane orientation for both the original and the modified model. The transmembrane orientation of the isolated S4 helix is unstable in the original model, but a stable local minimum in IMM1-LF, slightly higher in energy than the interfacial orientation. Peptide translocation is addressed by mapping the effective energy of the peptide as a function of vertical position and tilt angle, which allows identification of minimum energy pathways and transition states. The barriers computed for the S4 helix and other experimentally studied peptides are low enough for an observable rate. Thus, computational results and experimental studies on the membrane burial of peptide charged groups appear to be consistent. This article is part of a Special Issue entitled: Interfacially Active Peptides and Proteins. Guest Editors: William C. Wimley and Kalina Hristova.

Augmenting podocyte injury promotes advanced diabetic kidney disease in Akita mice

To determine if augmenting podocyte injury promotes the development of advanced diabetic nephropathy (DN), we created mice that expressed the enzyme cytosine deaminase (CD) specifically in podocytes of diabetic Akita mice (Akita-CD mice). In these mice, treatment with the prodrug 5-flucytosine (5-FC) causes podocyte injury as a result of conversion to the toxic metabolite 5-fluorouracil (5-FU). We found that treatment of 4–5week old Akita mice with 5-FC for 5days caused robust albuminuria at 16 and 20weeks of age compared to 5-FC treated Akita controls, which do not express CD (Akita CTLs). By 20weeks of age, there was a significant increase in mesangial expansion in Akita-CD mice compared to Akita CTLs, which was associated with a variable increase in glomerular basement membrane (GBM) width and interstitial fibrosis. At 20weeks of age, podocyte number was similarly reduced in both groups of Akita mice, and was inversely correlated with the albuminuria and mesangial expansion. Thus, enhancing podocyte injury early in the disease process promotes the development of prominent mesangial expansion, interstitial fibrosis, increased GBM thickness and robust albuminuria. These data suggest that podocytes play a key role in the development of advanced features of diabetic kidney disease.

Diabetic dermangiopathy - A micrometric study

Aim Diabetes mellitus (DM) is the most common endocrine disorder and cutaneous disorders associated with DM are thought to occur in about one-third of patients. The present study was undertaken to assess the alterations in the small blood vessels. Methods Skin biopsies from 100 type 2 diabetic patients and 15 non-diabetic controls were studied to observe the dermangiopathic changes. The lumen diameter and basement membrane width were measured. Depending on deposition of PAS-positive material in the vessel wall, the dermangiopathic changes were graded as 1 +, 2 + and 3 +. Results 80% of the cases showed 2 + (69%) or 3 + (11%) changes. The other 20% cases showed 1 + change and were not taken as positive evidence of microangiopathy. Mean BMT was measured as 6.06 microns and mean LD was 53.9 microns. The mean BMT:LD ratio was 0.11. No correlation was observed between age, duration of diabetes, severity of disease, diabetic complications and microangiopathy. A positive correlation was observed between the grades of microangiopathy and the basement membrane thickness. Discussion Characteristic angiopathy is demonstrable in vessels of diabetic patients and the vessel basement membrane thickness is an important criterion to grade diabetic dermangiopathy.

The Round Window Diameter in Congenital Aural Atresia and Comparison With Sensorineural Hearing Loss and Control Group

The aim of this study was to measure round window (RW) diameters in patients with congenital aural atresia (CAA) or sensorineural hearing loss (SNHL) and a normal control group and to analyze whether differences exist between these groups. Temporal bone computed tomographic scans of 12 patients with CAA (5 males, 7 females) aged 1 to 50 years (median age, 6 years), 12 patients with SNHL (8 males, 4 females) aged 2 to 32 years (median age, 5 years), and 11 patients (3 males, 7 females) aged 2 months to 53 years (median age, 8 years) randomly selected from a pool of patients with unilateral chronic otitis media or cholesteatoma were reviewed. We measured RW diameter on oblique reconstruction planes. To prevent possible individual differences, skull width was measured. There were no statistically significant differences between all groups for skull width. Both RW diameter and RW membrane width were found smaller in the CAA group than both SNHL group and control group with statistical significance, whereas there were no statistically significant differences between the SNHL group and the control group. We found that both the RW diameter and RW membrane width in CAA were smaller than those in the control group. If this finding is supported in future studies, the production of floating mass transducer with different sizes may be useful. We suggest that RW diameter should be measured in each patient before operation and thus a floating mass transducer with the appropriate caliber should be chosen.

Out-of-plane ion concentration polarization for scalable water desalination

We present a scalable, out-of-plane desalination approach using ion concentration polarization. A depletion boundary separates salt ions and purified water into distinct vertical layers. The out-of-plane design enables multiplexing in three dimensions, providing the functional density required for practical application. For membrane widths of 125-200 μm, and applied voltage of 5 V, the energy requirement is 4.6 Wh L(-1) for 20 mM solution, and 13.8 Wh L(-1) for 200 mM. Energy efficiency is found to be insensitive to flow rate as the depletion boundary adjusts to yield a commensurate volume of purified water. Scaled-up devices are presented, which have a 3-fold improvement in functional density over planar systems.

The effect of spiral wound membrane element design characteristics on its performance in steady state desalination — A parametric study

The spiral-wound membrane (SWM) element design variables include retentate- and permeate-spacer characteristics and number of membrane envelopes (or sheet width) for constant total area, in addition to membrane surface properties. The effect of these parameters (varying within realistic ranges) on the operating variables, comprising two-dimensional distribution of permeate flux, trans-membrane pressure (TMP), retentate- and permeate-side pressures and velocities, is systematically assessed. Advanced software is employed, capable of simulating SWM desalination performance with no recourse to empirical parameters. The parametric study involves typical cases of desalinating brackish and sea-water with 2000mg/L and 40,000mg/L TDS, respectively, in pressure vessels with seven 8-inch SWM-elements. The results show that low-pressure desalination modules are most sensitive to variations of geometric parameters. The effect of permeate-side fabric is significant, directly affecting TMP and module productivity. In both low- and high-pressure desalination, the effect of retentate-side spacer manifests itself mainly in the pressure drop across the element. The results confirm that the membrane width is very important, with short sheets exhibiting the best overall performance. Noteworthy is the insensitivity of high-pressure SWM-module productivity to significantly different design parameter-values, including envelope width. These results are helpful in guiding SWM element optimization and in setting priorities for related R&D work.

Early Progression of Diabetic Nephropathy Correlates With Methylglyoxal-Derived Advanced Glycation End Products

OBJECTIVEIncreased advanced glycation end products (AGEs) and oxidation products (OPs) are proposed to lead to progression of diabetic nephropathy (DN). We investigated the relationship between AGEs, OPs, and progression of DN in 103 subjects with type 1 diabetes participating in the Natural History of Diabetic Nephropathy Study.RESEARCH DESIGN AND METHODSMean age of subjects was 17.6 ± 7.4 years, and mean duration of diabetes was 8.3 ± 4.9 years. All patients were normoalbuminuric. Change in glomerular basement membrane (GBM) width from baseline to 5 years, measured using electron micrographs of renal biopsies, was our primary end point, and mesangial fractional volume was a secondary end point. Fast progressors (FPs) were defined as those in the upper quartile of GBM change, and the remaining patients were classified as slow progressors (SPs). AGEs (3-deoxyglucosone and methylglyoxal hydroimidazolones [MGHI]), carboxymethyl lysine (CML), carboxyethyl lysine (CEL), and OPs (methionine sulfoxide and 2-aminoadipic acid) were measured at year 5 by liquid chromatography/triple-quadruple mass spectroscopy on 10-K plasma filtrates.RESULTSWe found that MGHI, CEL, and CML levels were significantly higher in FPs relative to SPs. No product predicted mesangial expansion. A model containing only HbA1c accounted for 4.7% of GBM width variation, with the total variability explained by the model increasing to 11.6% when MGHI, CEL, and CML were added to the regression model (7.9% increase). MGHI was a significant independent predictor of FP. Using a logistic regression model to relate each biomarker to the probability of a subject’s classification as an FP, CML, CEL, and MGHI, but not HbA1c, showed a significant relationship to the probability of FP.CONCLUSIONSThe results suggest that these three major AGEs may be early indicators of progression of important DN lesions.

Detection of diabetic nephropathy from advanced glycation endproducts (AGEs) differs in plasma and urine, and is dependent on the method of preparation

Increased advanced glycation endproducts (AGEs) and oxidation products (OPs) have been proposed as pathogenic for diabetic nephropathy (DN). We investigated the relationship between AGEs and OPs measured in different plasma and urine preparations, and progression of DN in 103 young, normoalbuminuric, normotensive participants with type 1 diabetes in the Natural History of Diabetic Nephropathy Study. The primary endpoint was electron microscopy-measured change in glomerular basement membrane (GBM) width from baseline to 5 years; change in mesangial fractional volume was a secondary endpoint. Fast progressors (FP) were defined as the upper quartile (n = 24) of rate of GBM thickening; slow progressors (SP) were the remainder (n = 79). Four AGEs [3-deoxyglucosone and methylglyoxal hydroimidazolones (DG3H1, MGH1) and carboxymethyl and ethyl lysine (CML, CEL)], and two oxidation products methionine sulfoxide and aminoadipic acid were measured by liquid chromatography, triple quadrupole mass spectrometry. Measurements were done on 10 K plasma filtrates and plasma proteolytic digests (PPD) at year 5, and at four time points over 5 years for urinary 10 K filtrates. Urinary filtrate CEL levels were significantly higher in FP, but not after adjustment for HbA1c, sex, and duration of diabetes. MGHI, CEL, and CML plasma filtrate levels were significantly higher in FP relative to SP (p < 0.05). In PPD, only MGHI showed borderline significantly higher levels in FP relative to SP (p = 0.067), while no other product showed correlation. AGE and OP measurements were not correlated with mesangial expansion. In plasma filtrates, HbA1c at year 5 accounted for 4.7 % of the variation in GBM width. The proportion of variation in GBM width was increased to 11.6 % when MGHI, CEL, and CML were added to the model (6.9 % increase).

Renal Lesions Predict Progression of Diabetic Nephropathy in Type 1 Diabetes

Whether early glomerular, tubulointerstitial, vascular, and global glomerulosclerotic lesions can predict progression of diabetic nephropathy is not well defined. Here, we sought to determine whether renal structural parameters predict the development of proteinuria or ESRD after long-term follow-up. We measured several renal structures in kidney biopsies from 94 normoalbuminuric patients with longstanding type 1 diabetes using unbiased morphometric methods. Greater width of the glomerular basement membrane and higher levels of glycated hemoglobin were independent predictors of progression to diabetic nephropathy in this normoalbuminuric cohort. Moreover, none of these patients with type 1 diabetes who had glomerular basement membrane widths within the normal range developed proteinuria and/or ESRD. In conclusion, careful quantitative assessment of kidney biopsies in normoalbuminuric patients with type 1 diabetes adds substantially to the prediction of progression to clinical diabetic nephropathy.

A lumped model with phase analysis for inline RF MEMS power sensor applications

This paper proposes a microwave lumped model with attenuation and phase mechanisms for GaAs monolithic microwave integrated circuits (MMIC)-compatible inline RF MEMS power sensors, in order to evaluate reflection and insertion losses and phase characteristics of the sensors. The purpose of the power sensors is measuring a certain percentage of the incident RF power coupled by a MEMS membrane, and their model is achieved based on the microwave port network theory. During the inline power detection, an undesired phase shift is generated by the MEMS membrane. Using this model, the additional phase shift is analyzed to show the phase change of the detected RF signal, with the effects of the membrane height and width on the phase. The three power sensors with the MEMS membrane 50μm, 100μm and 147μm in width are measured to validate the lumped model up to 13.5GHz, and the sources of small errors are discussed. Furthermore, experiments show that the inline RF MEMS power sensors with the membrane 100μm and 147μm in width have resulted in average phase changes of about 14% and 35% over the entire frequency compared with that 50μm above the same coplanar waveguide (CPW) lines, respectively.

Effect of basilar membrane radial velocity profile on fluid coupling in the cochlea

The effects of different radial distributions of basilar membrane velocity on the fluid coupling in the cochlea are studied. Different mode shapes across the width of the basilar membrane, modeled as a beam, are simulated by assuming various boundary conditions. The results suggest that the fluid coupling is insensitive to the resulting differences in mode shape. This validates the assumption commonly made in cochlear models that the fluid coupling can be reasonably well predicted by assuming a single modal shape across the basilar membrane width, even if the exact form of the radial profile is not known.

뉴트라비딘 검출용 간이 진단키트의 성능향상을 위한 기본 플랫폼 선정

This study was performed to optimize the basic platform of a lateral flow immunoassay. Improvement of the limit of detection (LOD) was evaluated according to the width of a nitrocellulose membrane with varying concentrations of analyte. The analyte, neutravidin was detected based on the avidin-biotin interaction. The antibody-Au nanoparticle conjugation was mostly stabled in a PBS buffer of pH 7.3. The optimal widths of a nitrocellulose membrane were 4 and 6 mm considering the sample flow rate and signal strength of the test line on the membrane. The LOD of neutravidin was 0.001 mg/ml in the optimum conditions.

Aliskiren alleviates doxorubicin-induced nephrotoxicity by inhibiting oxidative stress and podocyte injury

Doxorubicin (DXR) is one of the most effective and widely used anthracycline antibiotics. However, its clinical application is hampered by toxic effects in many organs. Nephrotoxicity is one of the major side effects of anthracycline antibiotics. This study was designed to investigate the possible protective effects of aliskiren (a direct renin inhibitor) in DXR-induced nephrotoxicity in rats. Wistar albino rats were intraperitoneally (ip) injected with DXR and renin activity, albumin, total protein, urea, creatinine levels in plasma and ultrastructural changes in podocytes were assessed. Rats subjected to DXR administration had significant (p<0.01) increases in systolic blood pressure, plasma renin activity, plasma concentration of urea, creatinine and tissue malondialdehyde and significant (p<0.01) reductions in plasma concentrations of albumin, total protein and antioxidant defense (reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT)) in renal tissues. Furthermore, DXR-induced nephrotoxicity has also been characterized by broadening of podocyte foot processes, enlargement of glomerular basement membrane width and reduction in slit pore diameter. The above effects of DXR were significantly (p<0.01) prevented by aliskiren treatment. These findings revealed that the blockade of renin activity by aliskiren is a promising approach in the treatment of DXR-induced nephrotoxicity.

Discovery and Description of a New Trichostrongyloid Species (Nematoda: Ostertagiinae), Abomasal Parasites in Mountain Goat, Oreamnos americanus, from the Western Cordillera of North America

Marshallagia lichtenfelsi sp. n. is a dimorphic ostertagiine nematode occurring in the abomasum of mountain goats, Oreamnos americanus, from the Western Cordillera of North America. Major and minor morphotype males and females are characterized and distinguished relative to the morphologically similar Marshallagia marshalli / Marshallagia occidentalis from North America and Marshallagia dentispicularis, along with other congeners, from the Palearctic region. The configuration of the convoluted and irregular synlophe in the cervical region of males and females of M. lichtenfelsi is apparently unique, contrasting with a continuous and parallel system of ridges among those species of Marshallagia, including M. marshalli/M. occidentalis, which have been evaluated. Specimens of M. lichtenfelsi are further defined by the rectangular form of the accessory bursal membrane (width > length) in the major morphotype and by the trapezoidal Sjöberg's organ in the minor morphotype, in addition to specific attributes of the spicules and spicule tips. We regard 12 species, including the proposed new taxon, to be valid. Primary diagnostic characters are reviewed for Marshallagia and a framework is presented for standardization of future descriptions incorporating the synlophe in males and females and the structure of the spicules and genital cone in major and minor morphotype males. The center of diversity for species of Marshallagia is the mountain-steppe region of central Eurasia where 11 species (including the Holarctic M. marshalli) are recognized in association with Caprini, Rupicaprini, and Antelopinae; only 2 species occur in the Nearctic. In this assemblage, M. lichtenfelsi is endemic to North America and limited in host distribution to mountain goats. An intricate history for refugial isolation and population fragmentation demonstrated for mountain goats and wild sheep indicates the potential for considerable cryptic diversity for Marshallagia and other nematodes. Shifting patterns of contact and sympatry among assemblages of ungulates during the Pleistocene are consistent with geographic and host colonization as a process involved in diversification of these parasites.