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In water, the surfactant dioctyl sulfosuccinate (Aerosol-OT or AOT) exhibits diverse aggregate structures, ranging from micelles to lamella. An atomic-level understanding, however, of the formation and structure of these aggregates is lacking. Herein, using atomistic molecular dynamics (MD) with microsecond-long simulations, self-assembly of AOT in water is studied for concentrations of 1, 7.2, and 20 wt % at 293 K and for 7.2 wt % at 353 K. Assembly proceeds through stepwise association and dissociation of single AOT molecules, and the fusion and fission of AOT clusters. At 293 K, AOT self-assembles into either (i) spherical micelles (1 wt %), (ii) biphasic systems consisting of rod-like and prolate spheroidal micelles (7.2 wt %), or (iii) bilayers (20 wt %). We hypothesize that the observed rod-like structure is a precursor to lamellar microdomains found experimentally in biphasic dispersions. Increasing temperature to 353 K at 7.2 wt % results in a system consisting of prolate micelles but no rod-like micelles. Simulated phase behavior agrees with previously published experimental observations. Individual aggregates formed during self-assembly are identified using graph theory. Structural metrics of these aggregates like the radius of gyration, shape anisotropy, and prolateness are presented. Trends in structural metrics quantitatively reflect how shapes and sizes of AOT aggregates vary with surfactant concentration and temperature. These simulations provide deeper insight into open questions in the scientific community and demonstrate a method to generate physics-based micelle structures that can be used to rationalize experimental observations.

Post-stroke neurological deficits and mortality are often associated with vascular disruption and neuronal apoptosis. Galectin-3 (Gal3) is a potent pro-survival and angiogenic factor. However, little is known about its protective role in the cerebral ischemia/reperfusion (I/R) injury. We have previously shown significant up-regulation of Gal3 in the post-stroke rat brain, and that blocking of Gal3 with neutralizing antibody decreases the cerebral blood vessel density. Our current study demonstrates that intracerebral local delivery of the Gal3 into rat brain at the time of reperfusion exerts neuroprotection. Ischemic lesion volume and neuronal cell death were significantly reduced as compared with the vehicle-treated MCAO rat brains. Gal3 increased vessel density and neuronal survival after I/R in rat brains. Importantly, Gal3-treated groups showed significant improvement in motor and sensory functional recovery. Gal3 increased neuronal cell viability under in vitro oxygen–glucose deprivation conditions in association with increased phosphorylated-Akt, decreased phosphorylated-ERK1/2, and reduced caspase-3 activity. Gene expression analysis showed down regulation of pro-apoptotic and inflammatory genes including Fas-ligand, and upregulation of pro-survival and pro-angiogenic genes including Bcl-2, PECAM, and occludin. These results indicate a key role for Gal3 in neuro-vascular protection and functional recovery following ischemic stroke through modulation of angiogenic and apoptotic pathways.

Technicians in a commercial laboratory manually uncap up to 700 sample tubes daily in preparation for bioanalytical testing. Manually twisting off sample tube caps not only is a time-consuming task, but also poses increased risk for muscle fatigue and repetitive-motion injuries. An automated device capable of uncapping sample tubes at a rate faster than the current workflow would be valuable for minimizing strain on technicians' hands and saving time. Although several commercial sample tube-uncapping products exist, they are not always usable for a workload that uses a mix of tube sizes and specific workflow. A functioning uncapping device was developed that can semi-automatically uncap sample tubes with three different heights and diameters and was compatible with the workflow in a commercial laboratory setting. Under limited testing, the average success rate with uncapping each of the three sample tube sizes or a mix of them was 90% or more, more than three times faster than manual uncapping, and met standard acceptance criteria using mass spectrometry. Our device with its current performance is still a prototype, requiring further development. It showed promise for ergonomic benefit to the laboratory technicians, however, reducing the necessity to manually unscrew caps.

Aging and dysregulated immuno-regulatory molecules amplify the stroke incidence, and poor post-stroke outcome. Adipokine imbalance is linked to inflammation and cerebro-vascular diseases, emphasizing a need to better understand the adipokines in aging and post-stroke brains. Lipocalin2 (LCN2) is an acute response adipokine involved in immune functions and apoptosis. MicroRNAs modulate genes involved in the immune response, aging, and stroke. We examined the role of LCN2 in aging and post-stroke brain, and examined if microRNAs regulate LCN2 expression and function. Proteomic profiling was used to examine the expression of adipokines in pre- and post-stroke brains of 3 and 12 months rats. Stroke was induced by middle cerebral artery occlusion. Immunohistochemistry, real-time PCR, and biochemical analysis were employed. LCN2 was downregulated by SiRNA using cat-ionic lipid-particle transfection. MTT assay and TMRE staining detected cell viability and mitochondrial potential. Immunomodulatory miRNAs were identified using profiler qPCR arrays. MicroRNA target prediction software identified the microRNAs able to modulate the expression of LCN2. LCN2 levels were significantly elevated in the brains of older naïve rats, and in ipsilateral brains of both young and older rats during the acute phase of ischemia/re-perfusion. Circulating plasma LCN2 levels were increased as a result of aging and ischemic stroke. LCN2 was predominantly expressed in neurons of ischemic brain. LCN2 mRNA levels correlated with protein levels. Under oxygen glucose deprivation - in vitro ischemia, LCN2 decreased mitochondrial potential and augmented neuronal apoptosis. However, silencing of LCN2 by siRNA caused a significant reduction in LCN2 levels, and an increase in neuronal cell viability. Mechanistic studies in post-stroke brain identified down regulation of microRNAs 125, 138, and 383 that target 3’-UTR of LCN2. MicroRNA 138 and 383 were also decreased significantly in response to aging. This inverse correlation between these microRNAs and LCN2 expression strongly indicated miRNA-mediated regulation of LCN2. Potential downregulation of LCN2 by immunomodulatory miRNAs 125 and 383 may attenuate pro-inflammatory status, and may improve post-stroke outcome.

To evaluate stool habits and associated quality of life (QoL) in a matched pair analysis of patients who underwent continent cutaneous diversion using the ileocecal segment [Mainz pouch I (MzPI)] with an intussuscepted ileal nipple as efferent segment with those receiving an ileal conduit (IC) after radical cystectomy. We identified 250 patients who underwent radical cystectomy and urinary diversion (UD) with either MzPI with an ileal nipple or IC in our database. A detailed history of stool habits using the modified Wexner score was obtained, and questions addressing general lifestyle, comparison of symptom differences before and after surgery considering bowel function as well as bowel-associated QoL were assessed. Forty-five age- and sex-matched pairs could be compared. Overall, stool incontinence (p = 0.481) and the Wexner score (p = 0.464) revealed no differences between both groups. However, patients with MzPI as compared to those with IC had significant higher rates of stool frequency (53 vs 31 %), softer stool consistencies (60 vs 13 %), diarrhea (62 vs 20 %) and a lower rate of constipation (4 vs 22 %). Patients with MzPI had a trend toward lower bowel-associated QoL compared with patients with IC. Similarly, the MzPI group reported a significantly impaired overall postoperative QoL (51 %) compared to the IC group (29 %) (p = 0.024). Patients following UD by MzPI have an increased stool frequency and softer stool consistency. However, there is no difference between both groups in terms of de novo stool incontinence. Change in bowel habits should be part of preoperative informed consent in any kind of UD. Careful patient selection is of paramount importance.

This paper deals with the assessment of an innovative decay heat removal system for the MYRRHA reactor, based on the analysis of the selected transients with two different system codes. The application to liquid metal cooled reactors has the disadvantage of adding overcooling transients to the transient spectrum. Under these circumstances, freezing of the coolant can occur if no corrective or operator actions are taken in the medium and long term. Therefore, ANSALDO Nucleare invented an enhanced decay heat removal system which avoids the risk of freezing. The numerical assessment and proof of operational principles are performed by KIT and ENEA. The simulation results show that the freezing can be avoided. Moreover, both institutions calculate similar behavior during overcooling transients. This study will help to implement the novel decay heat removal system and the overall safety philosophy of innovative reactor concepts. © 2016 Elsevier B.V.

Turmeric is a yellowish orange spice, widely used in Asian cuisine and obtained from the rhizome of Curcuma longa. It is a mixture of three curcuminoids namely, curcumin, demethoxycurcumin and bisdemethoxycurcumin. Turmeric has been used as a medicinal substance since ancient times for respiratory and gastrointestinal problems. The aim of the present study was to investigate which curcuminoid contributes to the observed pharmacological activities, all three curcuminoids, the major curcumin metabolite tetrahydrocurcumin, and the non-enzymatic curcumin hydrolysis products ferulic acid, feruloyl methane and vanillin were analyzed for spasmolytic, inotropic and chronotropic activity. Furthermore, their uptake in respective tissue samples was also investigated and correlated with activity. Spasmolytic activity was determined in guinea pig ileum, aorta and pulmonary artery. Inotropic and chronotropic activity was determined on guinea pig papillary muscles and right atrium respectively, while tissue uptake was quantified by using high-performance liquid chromatography (HPLC). All the curcuminoids exhibited significant spasmolytic activity with highest EC

Background: Carotid Atherosclerotic (CA) plaque rupture is associated with ischemic stroke. Smooth muscle cells (SMC) play key role in plaque development. SMC also produce collagen fibers and maintain the fibrous cap thickness and strength, and SMC apoptosis and inflammation can lead to plaque rupture. Molecular mechanisms leading to plaque instability and stroke are not completely understood. Our study has shown that an adipokine dipeptidyl peptidase (DPPIV) is significantly upregulated in post-stroke rat brain, and in the plasma of over 75% of CA patients, suggesting a role for DPPIV in CA and stroke. In this study, we examined the effects of DPPIV on SMC viability, apoptosis, and identified responsible signaling pathways. Methods: Mouse carotid artery SMC were exposed to oxygen glucose deprivation (OGD). Cells were treated with either physiological (200-500 ng/ml) or high (1000-2000 ng/ml) dose of DPPIV. Using transcriptome array, we examined the expression profile of apoptotic and inflammatory pathway specific genes in these cells. DPPIV levels were examined by PCR and immunofluorescence staining. MTT assay was used to assess cell viability. Live/dead cell assay detected apoptosis. Mitochondrial membrane potential was detected using tetra-methyl-rhodamine ethyl ester (TMRE). Results: Ischemia/hypoxia upregulates DPPIV mRNA and protein levels in association with increased pro-apoptotic genes including caspase 7, Nod1, and Gadd45a. Transcriptome array data demonstrated that higher dose of exogenous DPPIV results in significant increase in same pro-apoptotic pathway genes including caspase 3,7, Nod1, Trp63, and Gadd45a. On the other hand, DPPIV decreased the expression of anti-apoptotic genes including Atf5 and Birc3. Levels of pro-inflammatory cytokines including IL1-beta and Ccl26/Eotaxin were increased in both DPPIV and ischemic SMCs. Higher dose of DPPIV increased apoptosis, decreased viability and mitochondrial membrane potential in SMCs. Conclusion: Higher levels of DPP4 activates the inflammatory and apoptotic signaling cascade resulting in the apoptosis of SMC. Further research in this area will enhance our understanding of the mechanism of CA progression and may provide clues to efficient therapeutic intervention for CA.

The emergency department (ED) is a vital entry point in the health care system for children who experience maltreatment. This study fills a gap in the maltreatment literature by presenting systematic, national estimates of maltreatment-related ED visits in the United States by children ≤3 years old, from 2006 to 2011, using the Nationwide Emergency Department Sample (NEDS). Children who experienced and likely experienced maltreatment were identified via International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic codes. Maltreatment was classified as physical or sexual abuse, neglect, or poly-victimization. The clinical and demographic profiles of children who experienced maltreatment were described. Approximately 10,095 children who experienced maltreatment (0.1% of total ED visits) and 129,807 children who likely experienced maltreatment (1.2% of total ED visits) were documented each year. Maltreatment was associated with significantly greater risk of injury, hospitalization, and death in the ED setting. Physical abuse was the most common explicit maltreatment diagnosis (33 ED visits per 100,000 children ≤3 years old) and neglect was the most common likely maltreatment diagnosis (436 ED visits per 100,000 children ≤3 years old). This study established the NEDS as a valuable complement to existing surveillance efforts of child maltreatment from a public health perspective.

Innovations in communications technology, computer systems and software, and medical as well as nonmedical devices occur rapidly, and it may be difficult for clinical practice modifications to keep pace. The goals of this review are to discuss emerging technologies in emergency medical services (EMS) and to highlight studies and resources supported by the EMS for Children program. We will describe applications of new technology in the areas of EMS processes, telemedicine, patient monitoring and treatment, disaster management, and provider education.

As highly promising coolant for new generation nuclear reactors, liquid Lead–Bismuth Eutectic has been extensively worldwide investigated. With high expectation about this advanced coolant, a multi-national systematic study on LBE was proposed in 2007, which covers benchmarking of thermal hydraulic prediction models for Lead-Alloy Cooled Advanced Nuclear Energy System (LACANES). This international collaboration has been organized by OECD/NEA, and nine organizations – ENEA, ERSE, GIDROPRESS, IAEA, IPPE, KIT/IKET, KIT/INR, NUTRECK, and RRC KI – contribute their efforts to LACANES benchmarking. To produce experimental data for LACANES benchmarking, thermal–hydraulic tests were conducted by using a 12-m tall LBE integral test facility, named as Heavy Eutectic liquid metal loop for integral test of Operability and Safety of PEACER (HELIOS) which has been constructed in 2005 at the Seoul National University in the Republic of Korea. LACANES benchmark campaigns consist of a forced convection (phase-I) and a natural circulation (phase-II). In the forced convection case, the predictions of pressure losses based on handbook correlations and that obtained by Computational Fluid Dynamics code simulation were compared with the measured data for various components of the HELIOS test facility. Based on comparative analyses of the predictions and the measured data, recommendations for the prediction methods of a pressure loss in LACANES were obtained. In this paper, results for the forced convection case (phase-I) of LACANES benchmarking are described.

Introduction: Glioblastoma Multiforme (GBM) is the most aggressive type of brain cancer and progresses at a rapid rate. The major obstacle in the treatment of GBM is selective survival of a subpopulation of GBM derived stem cells (GSC) which are highly proliferative and resistant to drug induced apoptosis. The proteins involved in the regulation of the cell cycle impact survival potential of GBM and GSCs. Pentraxin 3 (PTX3), an angiogenic and survival factor plays a key role in cell proliferation, angiogenesis and invasion. However, little is known about the association of PTX3 and cell cycle regulation in GBM derived stem cells. Mehods: GBM patient tumor lines, and GSC derived from the same GBM lines were used. These cell lines were exposed to hypoxia and re-oxygenation. Cell cycle profiling and analysis were carried out using flow cytometry and FlowJo Single Cell Data Analysis Software. Xeno-transplanted mouse brain sections were used for PTX3 expression analysis by immunohistochemistry and immunofluorescence staining. Targeted proteomic approach was used to determine PTX3 levels in GBM and GSC. Alterations in the cell cycle regulatory gene expression in GSC and GBM tumor line in presence and absence of PTX3 was identified by transcriptome array analysis. Results: Our targeted proteomic approach using antibody array identified substantially higher levels of PTX3 in GSCs. GBM tumor lines showed higher percent of cells in G1 phase, where as GSCs showed increased number of cells in G2 and S-phase, both under normoxia and hypoxia. GSCs showed increased levels of GADD45A, known to protect GBM cells from apoptosis. Increased PTX3 expression correlated with increased cell cycle progression. Furthermore, exogenous PTX3 increased CyclinD1, a protein required for progression through the G1 phase of the cell cycle. Conclusion: GSC cells show cell cycle progression, presumably with an increased growth advantage. PTX3 expression is associated with GBM malignancy, and may contribute to GBM cell cycle progression and invasion. Overall, these results indicate that PTX3 and the cell cycle pathway are strongly associated with malignant GBM. Citation Format: Umadevi V. Wesley, Paul Clark, Jacob Jaeger, John Kuo, Robert Dempsey. Cell cycle pathway gene regulation in glioblastoma multiforme (GBM) and GBM derived stem cells: Implicating Pentraxin 3 upregulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4300.

This paper describes the effects of optical feedback on the sensitivity of VCSEL tunable-diode laser spectroscopy (TDLS). Three VCSELs, emitting at different wavelengths in the near-infrared, were used. A TDLS system, subjected to optical feedback, exhibited a common signal-to-noise ratio profile for all three lasers. A catastrophic degradation of TDLS sensitivity occurred when feedback exceeded a level which we associate with coherence collapse. The TDLS system had a CH4 minimum detection limit of 7.5 ppmm without optical feedback. Optical feedback of less than ten percent reduced this sensitivity by two orders of magnitude. This reduction of system sensitivity was accompanied by a second-harmonic absorption signal baseline shift which degraded the system accuracy.

ZnO/MgO quasi core−shell quantum dots (QDs) were grown by a metal-organic chemical vapor deposition method on silicon substrates. The core−shell structure was well-characterized by a combination of cross-sectional transmission electron microscopy and angle-resolved X-ray photoelectron spectroscopy (XPS). Valence band XPS measurements were performed to investigate the effects of MgO shell layer on the energy band of ZnO/MgO QDs. Photoluminescence (PL) emission from the QDs showed remarkable enhancement after the growth of the MgO layer. In addition, exciton binding energy of 118 ± 5 meV in the ZnO/MgO QDs was obtained from temperature-dependent PL.

a b s t r a c t A series of ZnO/Zn1 xMgxO multi-quantum wells (MQWs) were grown on Si(111) substrates by pulsed laser deposition (PLD), with different well widths and depths. Transmission electron mi- croscopy (TEM) analysis revealed that all the samples exhib- ited a good periodic structure with clear interfaces. Moreover, temperature- dependent behavior of excitonic photoluminescence (PL) was investigated in order to investigate the mechanism of the carrier dynamics. In the temperature range studied, the lumines- cence was dominated by localized exciton (LE) emission, which was significantly blueshifted with respect to the ZnO single layer, due to the well-known quantum-size effect. The blueshift values increased with elevating Mg compositions in barrier layers or de- creasing well thickness, being consistent with the calculated re- sults. The relevant activation energies were deduced, varying in a range of 6.2 to 22 meV.

To study the role of radiotherapy and tamoxifen after breast-conserving surgery (BCS) in patients with a favourable prognosis, a clinical trial was initiated by the German Breast Cancer Study Group. Between 1991 and 1998, 361 patients (pT1pN0M0, aged 45–75 years, receptor positive, grade I–II) were randomised to radiotherapy (yes/no) and tamoxifen for 2 years (yes/no) in a 2×2 factorial design; the exclusion of seven centres (14 patients) left 347 patients in the analysis. After a median follow-up of 5.9 years, 77 events concerning event-free survival have been observed. Since a strong interactive effect between radiotherapy and tamoxifen has been established, the results are presented in terms of the treatment effects for all four treatment groups separately. Mainly due to the presence of local recurrences, the event rate was about three times higher in the group with BCS only than in the other three groups. No difference could be established between the four treatment groups for distant disease-free survival rates. It is concluded that even in patients with a favourable prognosis, the avoidance of radiotherapy and tamoxifen after BCS increases the rate of local recurrences substantially.

We have developed novel antibacterial coatings from innocuous polyammonium compounds which are chemically coupled to a polymer surface. For immobilization we used two strategies: In the first strategy, the polymer surface is plasma activated to generate radicals. Then antibacterial monomers, such as diallyldimethylammonium chloride (DADMAC) are grafted to the surface by a radical polymerization. In the second strategy, the polymer surface is plasma treated to create oxygen functionalities. Antibacterial copolymers, such as DADMAC copolymers, are coupled to the activated surface. Microbiological data prove that the DADMAC copolymers reduce the settlement of bacteria such as Micrococcus luteus (gram positive) and Escherichia coli (gram negative) by a factor of 10 5 –10 6 . The layers were characterized by X-ray photoelectron spectroscopy (XPS) and contact angle measurements. The extremely thin coatings of only 2–3 nanometers thickness do not change the material properties of the substrate.

Background Ambulatory care sensitive (ACS) conditions are health problems that could be prevented or ameliorated with adequate access to primary care services. Objectives To determine the extent to which ACS conditions account for care received by children in U.S. emergency departments (EDs) and the patient charges for this care. Methods A retrospective, cross-sectional analysis of the 2010 Nationwide Emergency Department Sample was performed. Patients 0–19 years of age were included and visits for ACS conditions were identified. Main outcome measures were the percentage of visits for ACS conditions, regression models predicting presentation for ACS conditions based on patient demographic characteristics, and ED charges for ACS ED visits. Results Of almost 30 million pediatric ED visits in the United States in 2010, 13.2% were for exclusively ACS conditions. Patients with public or no insurance were 1.2 times more likely than privately insured patients to present for an ACS condition. Lower household income (adjusted odds ratio [aOR] 1.49; 95% confidence interval [CI] 1.33–1.66) and younger patient age (aOR = 2.55; 95% CI 2.41–2.69) were also predictive of an ACS ED visit. The total of charges for ACS visits was almost $3 billion, of which publicly insured patients accounted for $1.5 billion. Conclusions Almost one in seven U.S. pediatric ED visits may be preventable by quality primary care. Patients with public insurance and lower income are more likely than other groups to present with ACS conditions. Better access to and use of primary care services could reduce health care costs and relieve ED overcrowding.

Ingestion of plastic toys is common in children and usually does not result in harm. We report a case of coma in a 20-month-old child after an ingestion of a toy containing 1,4-butanediol, an industrial solvent used to manufacture plastics. When ingested, 1,4-butanediol is metabolized to gamma-hydroxybutyrate, which can have significant systemic effects including death. Health care providers should suspect the possibility of a toxic component when a presumed nontoxic object causes unusual symptoms.

Large angle convergent beam electron diffraction (LACBED) has been used to examine thin buried layers (single quantum wells) of Ge in Si which contain self-organized islands 80–200 nm across. Using plan view samples of epitaxially grown Si/GeSi/Si tricrystals, rocking curves for reflections from planes inclined to the growth (001) direction are found to be asymmetric. This asymmetry is the result of a normal displacement of atomic planes across the GeSi layer induced by the lattice mismatch between Si and GeSi. A simple measurement of the asymmetry, using only small values of the deviation parameter, has been related to the integrated Ge content of the layer by comparison with two-beam dynamical calculations. Finite element analysis is used to correct for bulk strain relaxation in the Si cladding layers around island edges. For comparison electron energy loss spectroscopy (EELS) has been applied in cross-section to measure the composition profile within the layers. These results have been found t...

An established biochemical index for monitoring therapy in patients with metastatic breast cancer was tested prospectively in a multicentre study. The index uses two serum tumour markers—carcinoembryonic antigen (CEA) and carbohydrate antigen 15-3 (CA15-3) along with erythrocyte sedimentation rate (ESR). 67 patients treated by either endocrine or chemotherapy had CA15-3, CEA and ESR measured at diagnosis of metastases and sequentially during therapy. Two markers, CA15-3 and CEA, were measured on a further 16 patients giving a total of 83 patients who were assessable for CA15-3 and CEA. Of the patients with CA15-3, CEA and ESR measured at diagnosis of metastases 84% (56/67) had elevation of 1 or more markers. During therapy the number with elevated marker(s) rose to 96% (64/67). Changes in the markers were in line with and often pre-dated therapeutic outcome as assessed by the International Union Against Cancer (UICC) criteria both for remission and progression. Patients without elevation of markers on diagnosis subsequently showed a rise in the marker(s) at or before documented disease progression by UICC. The 3 women in whom markers were at no time significantly elevated remain in remission. The results using CA15-3 and CEA were similar but 12% less patients were assessable. CA15-3 and CEA (with and without ESR) provide an objective method to guide therapy in patients with metastatic breast cancer.

The stabilization and flocculation behavior of colloidal silica-particles with cationic polyelectrolytes (PE) is investigated. The zetapotentials, diffusion coefficients and flocculation rate constants of silica particles have been measured as a function of the adsorbed amount of cationic polyelectrolytes poly(diallyl-dimethyl-ammoniumchloride) (PDADMAC) of different molar masses and of statistic copolymers of DADMAC and N-methyl-N-vinyl-acetamide (NMVA) of various compositions at different salt concentrations and pH-values. Very fast flocculation due to van der Waals attraction occurs if the zetapotential is small. At low ionic strength this condition occurs just below the plateau of the adsorption isotherms where the surface charges are screened by adsorbed polycations. Additionally with high molecular polycations slow mosaic flocculation is observed at lower PE concentrations. At high ionic strength fast flocculation takes place at low macroion concentration due to the screening of the surface charges by adsorbed polycations and salt ions. At medium concentrations of polycations below plateau adorption slow bridging flocculation is observed. At plateau adsorption the suspensions become stabilized up to high ionic strength. At low salt concentration charge reversal at full coverage with polycations results in electrostatic repulsion. At high ionic strength the particles are stabilized sterically due to the osmotic repulsion of the long adsorbed PE tails. Therefore macroions of high molar mass are necessary to stabilize the suspension at high ionic strength.

Increased incidence of cardiovascular disease in postmenopausal women (PMW) is accompanied by ovarian dysfunction; hormone replacement therapy (HRT) can have cardioprotective effects. Because hypertension and atherosclerosis are associated with impaired release of endothelium-derived nitric oxide (NO) and increased levels of low-density lipoproteins (LDL), we investigated whether HRT augments NO release, and whether these increases are accompanied by a decrease in LDL levels in PMW. We determined serum nitrite/nitrate (NO2-/NO3-) and LDL levels at baseline (before initiation of HRT) and during the 6th and 12th months of the study. The PMW (n = 26) received continuous oral administration of estradiol valerate (Progynova, 2 mg daily) for 21 days supplemented with either oral cyproterone acetate (CPA; 1 mg; n = 11) or medroxyprogesterone acetate (MPA; 5 mg; n = 15) on days 12–21 of each treatment cycle. Blood samples in the PMW receiving HRT were collected at times while the subjects were taking estradiol va...