To elucidate the mechanisms underlying this phenomenon, the transport of carbohydrates into tomato fruits and the regulation of starch synthesis during fruit development in tomato plants cv. ‘Micro-Tom’ exposed to high levels of salinity stress were examined. Growth with 160 A1155463 mM NaCl doubled starch accumulation in tomato fruits compared to control plants during the early stages of development, and soluble sugars increased as the fruit matured. Tracer analysis with (13)C confirmed that elevated carbohydrate accumulation in fruits exposed to salinity stress was confined to the early development

stages and did not occur after ripening. Salinity stress also up-regulated sucrose transporter expression in source leaves and increased activity of ADP-glucose pyrophosphorylase (AGPase) in fruits during the early development stages. The results indicate that salinity stress enhanced carbohydrate accumulation as starch during the early development stages and it is responsible for the

increase in soluble sugars in ripe fruit. Quantitative RT-PCR analyses of salinity-stressed plants Bcl-2 apoptosis showed that the AGPase-encoding genes, AgpL1 and AgpS1 were up-regulated in developing fruits, and AgpL1 was obviously up-regulated by sugar at the transcriptional level but not by abscisic acid and osmotic stress. These results indicate AgpL1 and AgpS1 are involved in the promotion of starch biosynthesis under the salinity stress in ABA- and osmotic stress-independent manners. These two genes are differentially regulated at the transcriptional level, and AgpL1 is

suggested to play a regulatory role in this event.”
“We present a new way of forming phononic crystal waveguides by coupling a series of line-defect resonators. The dispersion proprieties of these coupled resonator acoustic waveguides (CRAW) can be engineered by using their geometrical parameters. We show that single-mode guiding over a large bandwidth is possible in CRAW formed in a honeycomb-lattice phononic crystal ALK inhibitor review slab of holes in zinc oxide. In addition, a finite length of CRAW structure acts as an efficient selective acoustic filter for Lamb waves. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3500226]“
“The arboreal species Spondias mombin L. (Anacardiaceae) is widely distributed in Brazil, where the fruits, known by the common name of caja, are an important commercial commodity. We evaluated genetic variability among 32 caja accessions of the Germplasm Collection of Embrapa Meio-Norte using RAPD technique. Reaction conditions for efficient RAPD amplifications were optimized in preliminary tests, and primers were selected from a set designed by the University of British Columbia on the basis of high levels of polymorphism and adequate band resolution. The 21 primers employed in the final analysis produced 145 fragments, 79% of which were polymorphic.

We examined the reliability, validity and responsiveness of scores among a prospective cohort of 947 HIV-1-infected adults initiating antiretroviral therapy between May 2003 and May 2004 in rural Uganda.

Methods Physical (PHS) and mental health (MHS) summary scores were developed from baseline MOS-HIV sub-domains using exploratory factor analysis. Construct and discriminant validity were established by ALK inhibitor comparing mean summary scores across known groups of sociodemographic, clinical and health status characteristics. Effect sizes were calculated to assess responsiveness to therapy.

Results Reliability of the PHS and MHS scores was 0.79 and 0.85, respectively. Mean baseline PHS and MHS

scores varied significantly by CD4 cell count, HIV viral load, WHO stage of disease and Karnofsky performance status scores. By 12 months on antiretroviral therapy, PHS and MHS scores improved by 14.6 points (P < 0.001) and 13.9 points (P < 0.001), respectively.

Conclusions PHS and MHS scores can be derived from the MOS-HIV and used to assess health status among cohorts of patients taking antiretroviral therapy in rural Uganda.”
“In the present study, the mechanisms underlying plastic deformation of a Ni-based bulk metallic glass (BMG) are explored. Based on the microstructural investigations, a model is proposed how fracture

emerges in BMGs. After deformation, the glass is macroscopically more fragile indicating a selleck chemicals llc decrease in the viscosity within the shear bands due to shear softening. These fluctuations of viscosity and therefore Poisson ratio between the deformed and undeformed regions appear to be the initiation sites for nano meter-scale cracks, which are aligned parallel to the applied force. Coalescence of voids is believed to form these small cracks, which eventually interconnect along the interface between the sheared and unsheared regions BMS-345541 cost to form a detrimental defect resulting in fracture. (C)

2009 American Institute of Physics. [doi:10.1063/1.3259418]“
“The protective effect of an ethanol extract of Curcuma comosa against cisplatin-induced renal toxicity in mice was studied. Adult male mice were pretreated for 4 days with the ethanol extract of C. comosa [100-200 mg/kg body weight (BW), orally (p.o.)] before injection of cisplatin (12.5 mg/kg BW, intraperitoneally (i.p.)). Five days later the mice were killed, and blood samples were collected to determine blood urea nitrogen (BUN) and plasma creatinine levels. Kidneys were examined histopathologically and levels of lipid peroxidation, gluthathione (GSH) content, and superoxide dismutase (SOD), gluthathione peroxidase (GPx), and catalase (CAT) activities were determined. Histological examinations revealed degenerative changes and tubular necrosis in mice treated with cisplatin, which were improved by pretreatment with C. comosa ethanol extract.

Corresponding structural brain changes and the timing, frequency, and duration of stress exposure required to modify brain functions remain to be elucidated in future research. These studies will advance our understanding of coping as a learning process

CBL0137 datasheet and provide mechanistic insights for the development of new interventions that promote stress coping skills.”
“OBJECTIVE: To evaluate the performance of an in-house interferon-gamma (IFN-gamma) enzyme-linked immunospot (ELISpot) assay for the detection of latent tuberculosis infection (LTBI) in bacille Calmette-Guerin (BCG) vaccinated individuals with or without human immunodeficiency virus (HIV) infection.

METHODS: A total of 202 participants

(93 HIV-infected and 109 non-infected) who received BCG vaccination Nepicastat molecular weight at birth underwent tuberculin skin testing (TST) and T cell-based ELISpot assays. The performance of an in-house IFN-gamma ELISpot assay (ELISpot) was evaluated by parallel comparison with the commercial IFN-gamma release assay (IGRA) kit, T-SPOT (R).TB, in 127 subjects. The effect of BCG vaccination on the ELISpot assay was prospectively determined by comparing the responses of IGRAs before and 3 months after BCG vaccination in 27 individuals.

RESULTS: High agreement between ELISpot and T-SPOT.TB was observed in both HIV-infected (92.47%, kappa = 0.754) and non-HIV-infected subjects (97.06%, kappa = 0.653). CD4(+) T-cell count does not affect Mycobacterium tuberculosis selleck chemicals IFN-gamma response as measured by both ELISpot and T-SPOT.TB. BCG vaccination resulted in 100% conversion of TST, but did not change responses to IGRAs.

CONCLUSION: The performance of this in-house ELISpot assay is comparable to commercial T-SPOT.TB in diagnosing LTBI. Both assays are useful for diagnosing LTBI in BCG-vaccinated subjects with or without HIV infection in a setting with a high prevalence of tuberculosis.”
“Background: The Center for Epidemiologic Studies

– Depression scale (CES-D) is a validated tool commonly used to screen depressive symptoms. As with any self-administered questionnaire, missing data are frequently observed and can strongly bias any inference. The objective of this study was to investigate the best approach for handling missing data in the CES-D scale.

Methods: Among the 71,412 women from the French E3N prospective cohort (Etude Epidemiologique aupres des femmes de la Mutuelle Generale de l’Education Nationale) who returned the questionnaire comprising the CES-D scale in 2005, 45% had missing values in the scale. The reasons for failure to complete certain items were investigated by semi-directive interviews on a random sample of 204 participants.

Clinical Findings-Both dogs had low blood glucose and high serum insulin concentrations. Results of abdominal ultrasonography were unremarkable for both dogs. Exploratory laparotomy revealed a mass that extended from the body of the pancreas into the pancreaticoduodenal vein in each dog.

Treatment and Outcome-Marginal resection of pancreatic masses was

performed, and tumor thrombi were removed via venotomy in both dogs. Histologic evaluation indicated the masses were pancreatic islet cell tumors with tumor thrombi. Clinical signs resolved following surgical resection of tumors and tumor thrombi, and the dogs were euglycemic during the follow-up period (17 and 45 months after surgery).

Clinical Relevance-Although gross tumor thrombus formation has been identified www.selleckchem.com/products/gsk2879552-2hcl.html in humans with insulinomas, tumor thrombi have

Prexasertib not been previously reported for dogs with insulinomas. Surgical removal of tumor thrombi via venotomy seemed to be well tolerated by the dogs. Tumor thrombus formation did not seem to adversely affect prognosis for the 2 dogs of this report. (J Am Vet Med Assoc 2012;241:1065-1069)”
“The structural effects of polydimethylsiloxane (PDMS) or polyhedral oligosilsesquioxanes (POSSs) on the thermomechanical properties of polyurethane (PU) networks were studied. An ester-amine-functionalized silsesquioxane and a PDMS macromer were synthesized, and the macromer (10 wt %) was crosslinked with the PU prepolymer to obtain PU networks. The synthesized macromers and hybrids were characterized with Fourier transform infrared, (1)H-NMR, (13)C-NMR, and (29)Si-NMR spectroscopy techniques. The influence of POSS cubes on the thermal and mechanical properties of the polymer

network films was studied comparatively with the similarly functionalized PDMS linear chain via thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA) measurements. The degradation pattern of the POSS-incorporated PU nanocomposites was almost the same as that of the PU network synthesized from the linear PDMS macromer. The differences Tariquidar price in the char yields and activation energies of the hybrids reflected the enhancement of the thermal properties of the nanohybrids. The TGA and DSC curves of the macromers suggested that the thermal properties of the macromers not only depended on either the PDMS or POSS inorganic core but also depended on the organic peripheral attached to the inorganic core. The glass-transition temperatures of the nanohybrids were higher than those of the linear-PDMS-incorporated hybrids. The storage modulus values increased 3-fold upon the incorporation of POSS rigid groups into the PU hybrids in comparison with the flexible PDMS-chain-incorporated PU hybrids. The DMA measurements showed a long-range rubbery plateau region for all the PU hybrids, with high storage modulus and tan 8 values showing the structural homogeneity of the crosslinked networks.

AE had no association with weight loss at 6 months. At 12, 24, and 36 months following LAGB, patients who reported 150 min or more per week of exercise had an EWL of 35.5, 47.3, and 54.1 %, respectively, while those reporting 0-59 min per week of AE had an EWL of 25.3, 32.1, and 33.0 % (p = 0.03, 0.03, and 0.02, respectively). BMI and age was not statistically different among groups. Diabetes

and Selleckchem DMXAA obstructive sleep apnea were significantly improved in patients exercising at least 60 min per week as compared to those exercising 0-59 min.

AE is significantly associated with weight loss and comorbidity resolution after LAGB. We propose that patients who perform more AE will have higher levels of EWL.”
“Purpose: 4SC-202 mouse To isolate and identify chemical constituents with yeast alpha-glucosidase inhibitory activity from the methanol extract of V. myrtillus (blueberry) flowers.

Methods: The active fraction (ethyl acetate extract) were chromatographed on C18 MPLC column, Sephadex LH-20 column and semi-preparative HPLC column.

The isolated compounds were identified by the extensive H-1-nuclear magnetic resonance spectroscopy (NMR), C-13-NMR, 2D-NMR and high resolution mass spectral (HR-MS) analyses.

Results: Two phenolic compounds, an acylated flavonoid and a coumaric acid derivative, were isolated and identified as isorhamnetin-3-O-(6 ”-O-coumaroyl)-beta-D-glucoside (1) and cis-cinnamic acid methyl (2). Compound 1 showed powerful alpha-glucosidase inhibitory activity and in this regard, was superior to the positive drug, acarbose.

Conclusion: Compounds 1 and 2 were isolated for the VX-689 concentration first time from this species and the genus of Vaccinium. This is the first report on characterization of these phenolic compounds and the possible utilization of blueberry flowers for nutraceutical and functional food applications.”
“Each year, tens of thousands of children undergo cardiopulmonary bypass (CPB) to correct congenital heart defects. Although necessary for surgery, CPB involves stopping the heart and exposing it to ischemic conditions.

On reoxygenation, the heart can experience effects similar to that of acute myocardial infarction. Although much is known about adult injury, little is known about the effects of global ischemia on newborn ventricles. We studied newborn (2 to 4 days old) and adult (> 8 weeks old) rabbit hearts subjected to ischemia-reperfusion (30 min of ischemia and 60 min of reperfusion). Our data demonstrated chamber- and age-specific changes in oxidative stress. During ischemia, hydrogen peroxide (H2O2) increased in both right-ventricular (RV) and left-ventricular (LV) myocytes of the newborn, although only the RV change was significant. In contrast, there was no significant increase in H2O2 in either RV or LV myocytes of adults. There was a fivefold increase in H2O2 formation in newborn RV myocytes compared with adults (P = 0.006).

The PAPA/Ag nanocomposites with 1 : 10 silver nitrate

(AgNO3) : PAPA ratio revealed the presence of well-dispersed Ag nanoparticles in the polymer matrix. All of these Ag nanoparticles formed are spherical and more than 80% of them are in the range of 1525 nm. (c) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011″
“Study Design. Retrospective cohort study.

Objective. To describe long-term clinical and imaging results focusing on the uninstrumented lumbar spine after posterior spinal fusion for adolescent idiopathic scoliosis.

Summary of Background Data. Although previous studies found rates of low back pain after long fusion for adolescent idiopathic scoliosis which are comparable to rates found in the general population, many surgeons believe that the long lever arm associated with the fusion mass will result in increased see more stress at uninstrumented caudal intervertebral discs and accelerated degenerative changes.

Methods. This is a retrospective chart and imaging review of adolescent idiopathic scoliosis patients treated with posterior fusion and segmental instrumentation. Patients completed follow-up examination, BLZ945 Protein Tyrosine Kinase inhibitor outcome questionnaires, radiographs, and magnetic resonance

(MR) imaging. MR images were scored for evidence of degeneration of lumbar discs below the level of the fusion.

Results. Twenty patients participated in the study, providing 90 discs below fusions for evaluation. The average follow-up was 11.8 years. The distal level of fixation was at L1 on average. The major curve averaged 55 degrees +/- 11 degrees before surgery and was corrected to 25 degrees +/- 10 degrees at follow-up. Follow-up MR imaging demonstrated new disc pathology in 85% of patients enrolled. Only one patient demonstrated significant degenerative disc disease at the junctional level, whereas most pathology was seen at the L5-S1 disc. The average Pfirrmann grade at uninstrumented levels deteriorated from 1.1 before surgery to 1.8 at follow-up. The greatest degree of degeneration was seen at the L5-S1 click here disc

space where average degenerative scores increased from 1.2 before surgery to 2.3 after surgery. Three patients with severe disc disease were taking nonsteroidal anti-inflammatory drugs for pain, but no narcotics. Only mild scoliosis research society (SRS) and Oswestry changes were noted in this severe degeneration group.

Conclusion. Despite demonstrating an accelerated rate of L5-S1 disc degeneration, our study group has good functional scores and maintenance of correction over 10 years postfusion. In this long-term MR imaging follow-up study, disc degeneration was found remote to the lowest instrumented vertebra.”
“Purpose: To evaluate the value of computed tomographic (CT) myelography in the detection of root damage and differentiation of root avulsions from neurotmesis in a large cohort of patients with an obstetric brachial plexus lesion (OBPL).

Materials and Methods: Institutional review board approval was obtained.

Carbon Capture and Storage (CCS) reflects a number of new technologies designed to reduce CO2 emissions, but which may have much broader environmental implications than greenhouse gas emissions. This paper considers a wider range of pollutants from a full life-cycle perspective, illustrating a methodology for assessing environmental impacts

using source-apportioned effects based impact factors calculated by the national scale UK Integrated Assessment Model,(UKIAM). Contrasting illustrative scenarios for the deployment of CCS towards 2050 are presented AZD0530 mouse which compare the life-cycle effects of air pollutant emissions upon human health and ecosystems of business-as-usual, deployment of CCS and widespread uptake of IGCC for power generation. Together with estimation of the transboundary impacts we discuss the benefits of an effects based approach to such assessments in relation to emissions based techniques. (C) 2013 Elsevier Ltd. All rights reserved.”
“BACKGROUND The treatment of periungual warts is a therapeutic challenge. Various treatment modalities can be ineffective and may cause scarring

and permanent nail changes.

OBJECTIVES A prospective C59 wnt pilot study to investigate the efficacy and safety of a low concentration (0.1 U/mL) of bleomycin in the treatment of periungual warts.

METHODS Periungual warts were injected with bleomycin (0.1 U/mL) every 4 weeks until elimination of the lesions or until the injections were discontinued because of Napabucasin price adverse effects. Bleomycin was administered using

the translesional multipuncture technique.

RESULTS We recruited 15 patients with periungual warts from March 2007 to March 2008. Thirteen patients were male (86.6%); median age was 30. Seven patients (46.6%) demonstrated complete clearance 1 month after the first injection; two required two treatment sessions. Thirteen (86.6%) patients had complete clearance of the treated wart at the 6-month follow-up with only one injection. Wart recurrence was observed in two patients. All patients were followed for 6 months after the initial treatment. No significant long-term adverse effects were noted. Only one patient demonstrated mild postinflammatory hyperpigmentation, which resolved after 1 month, and nine (60%) had localized moderate pain for 2 to 3 days after the injection.

CONCLUSION Translesional multipuncture treatment with a low concentration (0.1 U/mL) of bleomycin is an effective modality for periungual warts that results in minimal side effects. Larger controlled studies are needed.”
“High density of crystal defects is formed in Si layers during their growth on the nanostructured surface composed of dense arrays of Ge islands grown on oxidized Si substrates.

At the beginning of leaf dehydration, moderate light accelerated the leaf water-loss rate and then lowered www.selleckchem.com/products/tpx-0005.html the maximal light-trapping efficiency of P-680. Upon further dehydration under moderate light or dehydration under high light, light accelerated the water-loss rate and also

directly decreased the maximal light-trapping efficiency of P-680. The more significant decrease in the exchange capacity of plastoquinones at the Q(B) site was mainly attributed to the faster water-loss rate under moderate light than in the dark. Under high light, irradiation also directly lowered the capacity. The reoxidation of PQH(2) in the dehydrated leaves was enhanced by the light irradiation. The rapidly decreased contents of P-700 + plastocyanin were mainly attributed to the faster water-loss rate under light conditions in contrast with Selleck HSP inhibitor that in the dark. The different effects of light irradiations on the photosynthetic electron transport chain might be involved in the acclimation of apple tree leaves to dehydration. (C) 2012 Elsevier Masson SAS. All rights reserved.”
“Ten Aureobasidium isolates were collected from bathroom surfaces in Thailand. They were identified as Aureobasidium pullulans. Cell extracts from all isolates were tested for antifungal activities against four selected Aspergillus species using a paper disc diffusion and conidial germination

inhibition assay. BM1, KT1, HKW1 and HKW2 extracts inhibited Aspergillus terreus, whereas KT1 and BM1 extracts also inhibited Aspergillus fumigatus. BM1 extract alone HSP990 inhibited Aspergillus flavus. From TLC analysis, an antifungal compound with an identical Rf to that of aureobasidin A was found in all extracts. Antifungal tests of TLC-separated compounds supported the paper disc diffusion and conidial germination inhibition assays.”
“The functional relevance of NOS3 and ACE genetic variations to endothelial cell function is largely unstudied. Here we tested the functional relevance of the NOS3 (Glu298Asp)

polymorphism and ACE (I/D) polymorphism in endothelial cells in vitro. Our hypothesis was that these genetic polymorphisms alter endothelial cell sensitivity to glucose and 3-nitrotyrosine (3NT). Genotyped HUVECs were incubated with glucose, free 3NT or a combination of these two toxicants. Significant differences in glucose-induced cell death and free 3NT-induced cell death were observed among the NOS3 genotypes. Combined glucose/3NT caused increased toxicity among the NOS3 genotypes. No differences were observed among the ACE genotypes in their responses to glucose/3NT. These data demonstrate that the NOS3 genotype may be an important predictor of, or be mechanistically involved in, endothelial vulnerability, whereas the ACE I/D genotype is apparently less important. Thus this NOS3 genetic variation may play a role in vulnerability to endothelium-dependent diabetic vascular complications.

From August 1991 to June 2011, we performed facial reconstructive surgeries for cosmetic correction of disfigurements from both congenital and complications of previous cosmetic procedures on a total of 213

patients. These patients had undergone either 1 or more facial cosmetic surgeries in the past. In this study, our primary goal focused on revising facial asymmetries or defects from previous surgical scars, tissue contraction, under-correction, or underdevelopment. For autograft harvesting, we incised an elliptical shape along the retroauricular hairline. We then harvested sufficient amount of skin, dermal fat, fascia, or a piece of the mastoid bone if needed. After harvesting, we closed the incisional area and covered it with check details a compressive dressing. In evaluation of our results, we compared the preoperative photographs with postoperative and selleck constructed a survey on patient satisfaction. Overall, the patients in this study were greatly satisfied with their surgical results. No major complications were reported. As a result of our long-term study, we believe that the retroauricular mastoid

area has been shown to be an indispensable donor site for a variety of autograft tissues in terms of safety, convenience, and versatility of its unique structural composition consisting of skin, dermal fat, fascia, and bone.”
“A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether the of vegetations in endocarditis is an indication for surgery. Altogether, 102 papers were found using the reported search; 16 papers were identified that provided the best evidence to answer the question. The authors, journal, date, country of publication, patient group, study type, relevant outcomes

and results were tabulated. The vegetation size was classified into small (< 5 mm), medium (5-9 mm), or large (>= R406 manufacturer 10 mm) using echocardiography and a vegetation size of >= 10 mm was a predictor of embolic events and increased mortality in most of the studies with left-sided infective endocarditis. For large vegetations-that commonly resulted from the failure of antibiotics to decrease the vegetation size during 4-8 weeks’ therapy-and complications such as perivalvular abscess formation, valvular destruction and persistent pyrexia necessitated surgical intervention. In a multicentre prospective cohort study of 384 consecutive patients with infective endocarditis, it was observed that a vegetation size of > 10 mm and severe vegetation mobility were predictors of new embolic events. Equally, a meta-analysis showed that the echocardiographic detection of a vegetation size of >= 10 mm in patients with left-sided infective endocarditis posed significantly increased risk of embolic events.

“
“Purpose: This is the first report of a rare genetic tooth and nail syndrome (TNS) diagnosed in a 14-year-old Caucasian girl with a complete absence of the permanent dentition and, additionally, reduced total and lumbar spine bone mineral density (BMD). This coincidence suggests a new clinical manifestation of the disorder in

which genetic factors and/or shared mechanisms may be responsible for the deterioration of the stomatognathic system, anodontia, nail phenotype and osteopenia. Low bone mass appears to be a new component of the syndrome. There is a rationale for bone densitometry selleck chemical scans assuming that patients with TNS may have an increased risk of osteopenia. Reduced BMD and, possibly, impaired bone quality and strength may produce difficulties or even exclude such patients from future treatment with dental implants.”
“Electron beam lithography (EBL) is one of the tools of choice for writing micro- and nanostructures on a wide variety of materials. This is largely due to the fact that modern EBL machines are capable of writing nanometer-sized structures on areas up to mm(2). The aim of this contribution is to give technical and

practical backgrounds in this extremely flexible nanofabrication technique. (C) 2010 American Institute of Physics. [doi:10.1063/1.3437589]“
“Mucormycosis is a serious invasive fungal infection in immunocompromised patients. Patients undergoing treatment for hematologic malignancies are predominantly prone to the pulmonary manifestation of mucormycosis. Historically, allogeneic this website hematopoietic cell transplantation (HCT) in patients suffering from pulmonary mucormycosis (PM) was considered contraindicated owing to mortality rates up to 90%. We present 3 patients with acute PI3K inhibitor myeloid leukemia and PM who were treated with radical surgical debridement combined with high-dose liposomal amphotericin B (LAB), and subsequently underwent successful allogeneic HCT. To date, all 3 patients are in complete remission and show no signs of mucormycosis. Allogeneic HCT in patients with PM seems feasible provided that the infectious

focus is completely removed surgically and adequate antifungal pharmacotherapy, such as high-dose LAB or posaconazole, is established.”
“Normal and tangential surface ionic currents around low-permittivity nanocolloids with surface charges are shown to produce three different conductive mechanisms for ac-induced dipoles, all involving dynamic space charge accumulation at the double layer/bulk interface with a conductivity jump. However, the distinct capacitor dimensions and diffusive contributions produce three disparate crossover frequencies at which the induced dipole reverses direction relative to the bulk field. A highly conducting collapsed diffuse layer, with bulk ion mobility, renders the particle conductive and produces an ionic strength independent crossover frequency for weak electrolytes.