Carotid artery stenosis, an underestimated cause of stroke recurrence in patients with ischaemic monocular visual loss.

INTRODUCTION: Isolated monocular ischaemic events are thought to be low risk for stroke recurrence. In the presence of carotid stenosis however, the risks should not be treated similarly and surgical intervention should be considered at an early stage. The aim of this study was to determine the vascular risk profile and stroke recurrence in patients with ischaemic monocular visual loss. METHODS AND METHODS: Consecutive records for all patients with monocular ischaemia were reviewed from January 2014 to October 2016. Stroke, transient ischaemic attack or monocular ischaemia recurrence within 90 days were recorded. Carotid stenosis was assessed with duplex ultrasound, computed tomography or magnetic resonance angiography. RESULTS: In total, 400 patients presented with monocular ischaemia; 391 had carotid imaging (97.8%). Causality was symptomatic carotid stenosis ≥ 50% in 53 (13.6%), including carotid stenosis ≥ 70% in 31 (7.9%). Patients with permanent visual loss (n = 131) were more likely to have significant stenosis compared with patients with transient visual loss (n = 260), 19.8% compared with 10.4% (P = 0.012). Recurrent stroke, transient ischaemic attack or monocular ischaemia within 90 days after presentation occurred in three patients (5.7%) in the carotid stenosis group, compared to three (0.9%) who did not have stenosis (P = 0.035). Age, male sex and hypertension were associated with carotid stenosis but hypercholesterolaemia, diabetes and smoking were not. CONCLUSIONS: Carotid stenosis ≥ 50% is present in patients with ocular ischaemia in approximately 20% of those with persistent visual loss and in 10% with transient visual loss. Those with carotid stenosis have a higher risk of stroke recurrence and should be considered urgent surgical intervention as other forms of stroke.

Contemporary prevalence of carotid stenosis in patients presenting with ischaemic stroke.

BACKGROUND: Carotid stenosis is a common cause of ischaemic stroke and transient ischaemic attack (TIA). Despite rising recognition and centralization of stroke services there has been a decline in interventions for carotid stenosis in recent years. The aim of this study was to determine the current prevalence and management of carotid stenosis in the UK. METHODS: This was a 1-year prospective observational study of consecutive patients presenting with ischaemic stroke, TIA or ischaemic retinal artery occlusion to a central London hyperacute stroke unit. Patients with significant carotid stenosis, defined as atherosclerotic narrowing of 50 per cent or greater, underwent multidisciplinary team (MDT) discussion to determine the cause of stroke/TIA and classify carotid stenosis as symptomatic or incidental. RESULTS: In total, 2707 patients were seen; half had an ischaemic event and the majority had carotid imaging (1252 of 1444). Carotid stenosis of at least 50 per cent was seen in 238 (prevalence 19·0 (95 per cent c.i. 16·6 to 21·4) per cent). Patients with significant carotid stenosis were more likely to have hypertension, hypercholesterolaemia, diabetes and ischaemic heart disease. Carotid stenosis was deemed symptomatic in 99 patients (7·9 (6·3 to 9·5) per cent); of these, 17 had carotid occlusion, 17 were unfit for surgery and 58 patients were referred for carotid intervention. Among 139 patients with asymptomatic stenosis, 75 had carotid stenosis ipsilateral to the stroke but, after MDT discussion, the cause was deemed to be atrial fibrillation (32), small-vessel disease (15), another determined cause (5), or not determined owing to atypical imaging or clinical presentation. CONCLUSION: Carotid stenosis is common, affecting one in five patients presenting with stroke or TIA. Careful MDT discussion may avoid unnecessary intervention and should be the standard of care.

Indoor air quality in hairdressing salons in Taipei.

To improve indoor air quality and to protect public health, Taiwan has enacted the "Indoor Air Quality Act (IAQ Act)" in 2012. For the general public, the indoor air quality in hair salons is important because it is a popular location that people will often visit for hair treatments. However, only a few exposure assessments regarding air pollutants have previously been performed in hair salons. To assess the air quality of hairdressing environments in Taipei, ten hairdressing salons were included for a walk-through survey in this study. In addition, the airborne concentrations of formaldehyde, volatile organic compounds (VOCs), CO2 , and phthalate esters were also determined in 5 salons. Charcoal, XAD-2, and OVS-Tenax tubes were used for the air sampling, while the samples were analyzed with gas chromatography/mass spectrometer. It was found that the products used in hair salons contained various chemicals. In fact, from the walk-through survey, a total of 387 different ingredients were found on 129 hair product labels. The hair salons were not well ventilated, with CO2 levels of 600 to 3576 ppm. The formaldehyde concentrations determined in this study ranged from 12.40 to 1.04 × 103  µg m-3 , and the maximum level was above the permissible exposure limit (PEL) of US Occupational Safety and Health Administration (US OSHA). Additionally, 83% of the samples were with levels higher than the standard regulated by Taiwan's IAQ Act. The concentrations of VOCs and phthalate esters were below the occupational exposure limits (OELs), but higher than what was found in general residential environments. The hair products were considered as the major source of air pollutants because significantly higher concentrations were found around the working areas. The number of perming treatments, the number of workers, and the frequency of using formaldehyde releasing products, were found to be associated with the levels of formaldehyde. This study indicates that efforts are needed to improve the indoor air quality in hairdressing salons in Taipei.

Underlayer Effect on Perpendicular Magnetic Anisotropy in Co20Fe60B20\MgO Films.

Perpendicular Magnetic Tunneling Junctions (pMTJs) with Ta\CoFeB\MgO have been extensively studied in recent years. However, the effects of the underlayer on the formation of the CoFeB perpendicular magnetic anisotropy (PMA) are still not well understood. Here we report the results of our systematic use of a wide range of elements (Ti, V, Cr, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Hf, Ta, W, Re, Os, Ir, Pt and Au) encompassed by columns IVA, VA, VIA, VIIA and VIIIA of the periodic table as the underlayer in a underlayer\Co20Fe60B20\MgO stack. Our goals were to survey more elements which could conceivably create a PMA in CoFeB and thereby to explore the mechanisms enabling these underlayers to enhance or create the PMA. We found underlayer elements having both an outer shell of 4d electrons (Zr, Nb Mo, and Pd) and 5d electrons (Hf, Ta, W, Re, Ir, and Pt) resulted in the development of a PMA in the MgO-capped Co20Fe60B20. Hybridization between the 3d electrons of the Fe or Co (in the Co20Fe60B20) at the interface with the 4d or 5d electrons of the underlayer is thought to be the cause of the PMA development.

Transcranial Doppler Ultrasound Detection of Microemboli as a Predictor of Cerebral Events in Patients with Symptomatic and Asymptomatic Carotid Disease: A Systematic Review and Meta-Analysis.

OBJECTIVE: Identification of patients who will benefit from carotid endarterectomy is not entirely effective, primarily utilising degree of carotid stenosis. This study aimed at determining if microembolic signals (MES) detected by transcranial Doppler ultrasound (TCD) can provide clinically useful information regarding stroke risk in patients with carotid atherosclerosis. METHODS: A meta-analysis of prospective studies was performed. Three analyses were proposed investigating MES detection as a predictor of: stroke or TIA, stroke alone, and stroke or TIA but with an increased positivity threshold. Subgroup analysis was used to compare pre-operative (symptomatic or asymptomatic) patients and peri- or post-operative patients. RESULTS: Twenty-eight studies reported data regarding both MES status and neurological outcome. Of these, 22 papers reported data on stroke and TIA as an outcome, 19 on stroke alone, and eight on stroke and TIA with increased positivity threshold. At the median pre-test probability of 3.0%, the post-test probabilities of a stroke after a positive and negative TCD were 7.1% (95% CI 5-10.1) and 1.2% (95% CI 0.6-2.5), respectively. In addition, the sensitivities and specificities of each outcome showed that increasing the threshold for positivity to 10 MES per hour would make TCD a more clinically useful tool in peri- and post-operative patients. CONCLUSION: TCD provides clinically useful information about stroke risk for patients with carotid disease and is technically feasible in most patients. However, the generally weak level of evidence constituting this review means definitive recommendations cannot be made.

miR-155 and miR-146b negatively regulates IL6 in Helicobacter pylori (cagA+) infected gastroduodenal ulcer.

OBJECTIVE: Helicobacter pylori (H. pylori) infection is the main cause of gastroduodenal ulcer. The molecular mechanisms that underlying this progress are still not very clear. MicroRNAs (miRNAs) are small noncoding RNAs that function as negative regulator of numerous target genes at posttranscriptional level. miRNAs plays important roles in the development of many infection related diseases. The roles of miRNAs in the development of H. pylori-infected gastroduodenal ulcer haven't been well studied yet. MATERIALS AND METHODS: The miRNA and mRNA profiles in normal gastroduodenal biopsy, H. pylori-infected gastroduodenal biopsy and H. pylori-infected gastroduodenal ulcer biopsy samples were compared and analyzed to identify potential related miRNAs and their target genes. The differential expression of the identified miRNAs and their target gene were validated in an independent set of H. pylori positive gastroduodenal ulcer biopsy samples by immunohistochemistry staining and RT-PCR. Then microRNA mimics were transfected to gastric epithelial cells infected with H. pylori 26695 (cagA+). RT-PCR and Western blotting were performed to confirm the target gene of the identified microRNAs. RESULTS: The integrative analysis and immunohistochemistry staining validation indicated that miR-155 and miR-146b, as well as their predicted target gene IL6, are up-regulated in H. pylori positive gastroduodenal ulcer. Further experiments in gastric epithelial cells revealed that H. pylori 26695 (cagA+) infection induces IL6 overexpression. But the overexpression of IL6 is weaken due to negative regulation by miR-155 and miR-146b. CONCLUSIONS: This study indicated that the up-regulation of miR-155 and miR-146b decreases H. pylori (cagA+)-introduced IL6 overexpression, which might weaken the cleanup of H. pylori (cagA+) and contributes to ulcer.

Biological properties of sodium alkyl methyl ester sulfonate/alkyltrimethylammonium bromide surfactant mixtures.

Quaternary ammonium compounds (QACs) are commonly used as disinfectant in medical care, food industry, detergents and glue industries. This is due to a small concentration of QACs is sufficient to inhibit the growth of various bacteria strains. In this work, the inhibitive power of cationic surfactants, alkyltrimethylammonium bromide (C(n)TAB) in the presence of anionic surfactants, sodium alkyl methyl ester α-sulfonate (C(n)MES) was studied. The growth inhibition test with gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria were used to determine the toxicity of single and mixed surfactants. Results from this work showed that certain mixed surfactants have lower minimum inhibition concentration (MIC) as compared to the single C(n)TAB surfactants. Besides that, it was also found that alkyl chain length and the mixing ratios of the surfactants play a significant role in determining the mixture inhibitive power.

Size dependence in tunneling spectra of PbSe quantum-dot arrays.

Interdot Coulomb interactions and collective Coulomb blockade were theoretically argued to be a newly important topic, and experimentally identified in semiconductor quantum dots, formed in the gate confined two-dimensional electron gas system. Developments of cluster science and colloidal synthesis accelerated the studies of electron transport in colloidal nanocrystal or quantum-dot solids. To study the interdot coupling, various sizes of two-dimensional arrays of colloidal PbSe quantum dots are self-assembled on flat gold surfaces for scanning tunneling microscopy and scanning tunneling spectroscopy measurements at both room and liquid-nitrogen temperatures. The tip-to-array, array-to-substrate, and interdot capacitances are evaluated and the tunneling spectra of quantum-dot arrays are analyzed by the theory of collective Coulomb blockade. The current-voltage of PbSe quantum-dot arrays conforms properly to a scaling power law function. In this study, the dependence of tunneling spectra on the sizes (numbers of quantum dots) of arrays is reported and the capacitive coupling between quantum dots in the arrays is explored.

Anatomical and functional outcome of surgery of primary rhegmatogenous retinal detachment in high myopic eyes.

PURPOSE: To analyse the anatomical and functional outcome of surgery for primary rhegmatogenous retinal detachment (RRD) in highly myopic eyes. METHODS: We retrospectively reviewed the medical records of 111 high myopic patients (111 eyes) with primary RRD treated by scleral buckling or pars plana vitrectomy in a tertiary referral university hospital. The postoperative retinal status and best-corrected visual acuity were recorded. Risk factors including age, refractive error, duration of retinal detachment, preoperative visual acuity, extent of detachment, and intraoperative and postoperative complications were evaluated. Multiple logistic regression analysis was used to determine the independent correlation of each variable on anatomical and functional outcome. RESULTS: Primary surgery resulting in retinal reattachment was achieved in 96 (86.5%) eyes with more than 6 months follow-up (range, 6-60 months). Sixty-eight (61.3%) eyes had postoperative corrected visual acuity 20/50 or more. Postoperative complications in high myopic eyes were variable, and the most common was cataract progression (19.8%). Upon multiple logistic regression analysis, young patients had significantly better anatomical outcome, although the variables including less refraction error, better preoperative visual acuity, scleral buckling procedure, and less surgical intervention showed better functional outcome in our series. CONCLUSIONS: The anatomical outcome of surgery for primary RRD in highly myopic eyes was favourable, and young patients tended to have a higher success rate. Functional outcome was significantly correlated with refractive error, preoperative visual acuity, surgical procedure, and number of vitreoretinal surgery.

Particle separation to enhance the efficiency of soil acid washing--case study on the removal of cadmium from contaminated soil in southwestern Taiwan.

The current trend in remediating contaminated soil by acid washing is to separate the soil mass by their particles sizes prior to washing. However, there is little information about the cost-effectiveness of this practice in literature. In this research, a cadmium-contaminated agricultural field has been selected for conducting a comparative study on cadmium removal by applying the acid washing method to soil samples with and without prior particle separation. The study provides valuable information for the advancement of this method to remediate contaminated soil. The results indicate that sand particles constitute about 70% of the total soil mass but only 24% of the total cadmium. After acid washing once, less than 2% of cadmium remains; multiple washing of the sand portion is thus not cost-effective. Furthermore, after particle separation, the soil mass that needs to be washed is greatly reduced to 35%; the total cost is reduced by about one third due to the savings in the acid solution utilization and the treatment of used acid solution.

Field protection effectiveness of chemical protective suits and gloves evaluated by biomonitoring.

OBJECTIVES: To determine the effectiveness of protective suits and gloves by biomonitoring. METHODS: Fifteen male spray painters at a ship coating factory were studied for two weeks. Workers wore no protective clothing during the first week and wore protective suits and gloves during the second week. Sampling was conducted on four consecutive working days each week. Ethyl benzene and xylene in the air were collected by using 3M 3500 organic vapour monitors. Urine was collected before and after each work shift. RESULTS: Urinary mandelic acid (MA) and methyl hippuric acid (MHA) levels were divided by the personal exposure concentrations of ethyl benzene and xylene, respectively. Mean (SE) corrected MA and MHA concentrations in the first week were 1.07 (0.18) and 2.66 (0.68) (mg/g creatinine)/(mg/m3), and concentrations in the second week were 0.50 (0.12) and 1.76 (0.35) (mg/g creatinine)/(mg/m3) in the second week, respectively. Both MA and MHA concentrations in the second week (when spray painters wore protective suits and gloves) were lower than in the first week, respectively (p<0.001, p = 0.011). Mean decrease in MA and MHA biomarkers were 69% and 49%, respectively. CONCLUSION: This study successfully evaluated the effectiveness of chemical protective suits and gloves by using biomarkers as urinary MA and MHA. This method is feasible for determining the performance of workers wearing personal protective equipment. Moreover, the experimental results suggest that dermal exposure may be the major contributor to total body burden of solvents in spray painters without protective suits and gloves.

Study of different methods for enhancing the nitrate removal efficiency of a zero-valent metal process.

This study explores the effect of several enhancing methods, namely acid wash pretreatment, ultrasound treatment and addition of nickel catalyst on the nitrate removal efficiency of three zero-valent metals--iron, aluminium and zinc. It is hoped that by learning about the major reaction pathways of nitrate removal with zero-valent metals and the main factors influencing the reactivity of those zero-valent metals, optimum process conditions may be identified. The study results show that direct transfer of electrons is the major reaction pathway. Thus increasing a clean, fresh metal surface and decreasing the thickness of the diffusion layer to accelerate mass transfer are the main determinants of reaction rate. In the absence of a clean, fresh metal surface, the catalytic reaction of nickel becomes the primary removal pathway.

Rational pharmacotherapy in the diabetic hypertension: analysis-prescribing patterns in a general hospital in Taiwan.

OBJECTIVES: To examine prescribing at a 2800-bed hospital, also providing ambulatory services for 9000 visits per day, with a view to assessing the extent to which it followed international guidelines for treating diabetic hypertension. METHOD: Patients receiving antidiabetic and antihypertensive drugs concomitantly during the 4-week study period were included. RESULT: Of the 5015 eligible patients, most received combination antidiabetic therapy. Oral antidiabetic agents used alone or in combination included (in descending order) metformin, glibenclamide, gliclazide, glipizide, glimepiride and alpha-glucosidase inhibitors. Gliclazide accounted for most of the oral antidiabetic drug expenditure. Sulfonylurea plus metformin was the most popular regimen. Prescriptions for long-acting sulfonylureas did not differ between elderly and younger patients. For blood pressure control, calcium-channel blockers were most commonly used alone and overall, although current guidelines suggest that they should be second-line treatments. Inappropriate use of immediate-release nifedipine was noted. The combination, atenolol >100 mg/day and hydrochlorothiazide 50 mg/day (or an equivalent) were extensively used. Among 54.7% patients treated with combination antihypertensives, calcium-channel blockers and an angiotensin-converting enzyme inhibitor were most commonly used. CONCLUSION: Most diabetic hypertensive patients were treated with combination therapy for glucose and blood pressure control. Prescriptions for antihypertensive drugs often differed from current guidelines, especially in the choice of agents and their combinations.

Conformation and interaction with the membrane models of the amino-terminal peptide of influenza virus hemagglutinin HA2 at fusion pH.

Conformations of a 48-mer peptide corresponding to the amino-terminal region of influenza HA2 in aqueous and membranous environments were studied. In aqueous solution the peptide was found to be oligomeric and its helicity was enhanced at higher concentrations. The conformation in phospholipid bilayer and insertion depth into the sodium dodecyl sulfate (SDS) micelle for the fusion peptide were in line with those determined for the amino-terminal 25-mer analog. The turn of residues 28-31 found in the crystal structure of hemagglutinin at neutral pH persisted in the presence of SDS at pH 5.0. Except for the turn, conformational lability of the amino portion of HA2 is suggested by comparison of the secondary structure determined herein with that obtained with the influenza fusion protein crystallized in the aqueous phase at neutral pH. The backbone amide proton exchange experiment suggested an interaction with the micellar surface for the segment carboxy-terminal to the fusion peptide domain.

Feasibility of using metals to remediate water containing TCE.

The feasibility of treating underground water contaminated by a chlorinated organic compound with bimetallics Fe/ Ni, Zn/Ni and Zn single metal was studied. Column tests to simulate a reactive permeable wall in a funnel-and-gate system were used. Research results indicated that bimetallic Fe0/Ni0 and Zn0/Ni0 all had a very strong degraded power to trichloroethylene (TCE) at concentration up to 25 mg/l under different flow rates (27 cm/day-20 m/day). Furthermore, the concentrations of TCE and various ions in the treated effluent were nearly lower than the values specified in related standards for drinking water in Taiwan. These results showed that this technique could be effectively and safely used as an underground water remediation process.

The leucine zipper motif of the envelope glycoprotein ectodomain of human immunodeficiency virus type 1 contains conformationally flexible regions as revealed by NMR and circular dichroism studies in different media.

A 43-mer peptide derived from the coiled coil domain of the transmembrane glycoprotein, gp41, of human immunodeficiency virus type 1, was synthesized. Light scattering measurements suggested that the peptide molecules likely exist in the aqueous solution in trimeric form. Circular dichroism experiments showed a moderate helix population enhancement for the peptide in 80% methanol solution relative to helicity in sodium dodecyl sulfate micellar suspension. NMR spectroscopy indicated that the N-terminal section of the peptide was conformationally more sensitive to the medium. The conformationally labile regions contain residues implicated in gp41-gp120 association. Our data support the idea that the coiled coil region is responsible for oligomerization of the gp41 ectodomain and suggest a site of conformational isomerization following receptor binding-induced gp120 dissociation from gp41.

The enhancement methods for the degradation of TCE by zero-valent metals.

Batch tests were performed to compare the degradation rates of TCE on Fe0 and Zn0. Our results indicated that the degradating capability of Zn0 to TCE was nearly 10 times higher than that of Fe0. On the other hand, the degradation rates of Fe0 or Zn0 in conjunction with other metals for reduction of TCE was investigated. The selected metals were nickel (Ni0) and palladium (Pd0) both of which have a strong enhancement effect. The reduction rates of Zn0/Pd0 and Zn0/Ni0 for TCE were the fastest. Fe0 that had lost its surface activity could be activated again by the addition of Pd0 or Ni0.

The amino-terminal region of the fusion peptide of influenza virus hemagglutinin HA2 inserts into sodium dodecyl sulfate micelle with residues 16-18 at the aqueous boundary at acidic pH. Oligomerization and the conformational flexibility.

The conformation and interactions with membrane mimics of the NH(2)-terminal fragment 1-25 of HA2, HA2-(1-25), of influenza virus were studied by spectroscopic methods. Secondary structure analysis of circular dichroism data revealed 45% helix for the peptide at pH 5.0. Tryptophan fluorescence quenching by acrylamide and NMR experiments established that the Trp(14) is inside the vesicular interior and residues 16-18 are at the micellar aqueous boundary. NBD fluorescence enhancement of the NH(2)-terminal labeled fluorophore on the vesicle-bound peptide indicated that the NH(2) terminus of the fusion peptide was located in the hydrophobic region of the lipid bilayer. No significant change in insertion depth was observed between pH 5.0 and 7.4. Collectively, these spectroscopic measurements pointed to an equilibrium between helix and non-helix conformations, with helix being the dominant form, for the segment in the micellar interior. The conformational transition may be facilitated by the high content of glycine, a conformationally flexible amino acid, within the fusion peptide sequence. Self-association of the 25-mer peptide was observed in the N-[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]glycine SDS-gel electrophoresis experiments. Incorporating the NMR signal attenuation, fluorescence, and gel electrophoresis data, a working model for the organization of the fusion peptide in membrane bilayers was proposed.