A well‐defined random copolymer of styrene (S) and chloromethylstyrene (CMS) featuring lateral chlorine moieties with an alkyne terminal group is prepared (P(S‐co‐CMS), $\overline{M}_{\rm n}$ = 5500 ...Da, PDI = 1.13). The chloromethyl groups are converted into Hamilton wedge (HW) entities (P(S‐co‐HWS), $\overline{M}_{\rm n}$ = 6200 Da, PDI = 1.13). The P(S‐co‐HWS) polymer is subsequently ligated with tetrakis(4‐azidophenyl)methane to give HW‐functional star‐shaped macromolecules (P(S‐co‐HWS))4, $\overline{M}_{\rm n}$ = 25 100 Da, PDI = 1.08). Supramolecular star‐shaped copolymers are then prepared via self‐assembly between the HW‐functionalized four‐arm star‐shaped macromolecules (P(S‐co‐HW))4 and cyanuric acid (CA) end‐functionalized PS (PS–CA, $\overline{M}_{\rm n}$ = 3700 Da, PDI = 1.04), CA end‐functionalized poly(methyl methacrylate) (PMMA–CA, $\overline{M}_{\rm n}$ = 8500 Da, PDI = 1.13) and CA end‐functionalized polyethylene glycol (PEG–CA, $\overline{M}_{\rm n}$ = 1700 Da, PDI = 1.05). The self‐assembly is monitored by 1H NMR spectroscopy and light scattering analyses.
A Hamilton wedge (HW)‐functionalized well‐defined star‐shaped macromolecule is prepared. Subsequently, hydrogen‐bond‐driven self‐assembly between HW and cyanuric acid recognition motifs generates – for the first time – (PS‐g‐PS)4, (PS‐g‐PMMA)4, and (PS‐g‐PEG)4 supramolecular star‐shaped polymers in CH2Cl2 or CD2Cl2 at ambient temperature.
To determine a way to prevent the formation of adhesions and delay the time of suture adjustment in the course of adjustable strabismus surgery, an animal study was performed to assess and compare ...the effects of mitomycin C (Mit-C) and viscoelastic material Viscoat (sodium hyaluronate 3% and chondroitin sulphate 4%, Alcon, Fort Worth, TX).
Right eyes of 47 rabbits were divided into three groups. After recession of the superior rectus muscle (SRM), Mit-C was administered beneath and over the SRM in Group M (16 eyes), Viscoat was administered beneath and over SRM in Group V (16 eyes), and ringer lactate was administered in Group C (15 eyes). SRM then recessed 5 mm with adjustable strabismus surgery technique. Animals in each group were subdivided into 1 and 2, where 1 = adjustment 1 week postoperatively and 2 = adjustment 3 weeks postoperatively. Delayed adjustment was performed in M1 group (6 eyes), V1 group (6 eyes), and C1 group (7 eyes) after 1 week; in M2 group (6 eyes), V2 group (6 eyes), and C2 group (6 eyes) after 3 weeks. Histopathologic examinations were performed for the remaining 10 eyes without suture adjustment at the end of first and third weeks after adjustable strabismus surgery. The possible length and the necessary force to adjust and the degree of adhesions were recorded.
When length and strength of the adjustment, adhesions between muscle and sclera, and adhesions between muscle and conjunctiva were taken into consideration, there was no statistically significant difference among M, V, and C groups at postoperative weeks 1 and 3. The force needed for adjustment in M1 group was statistically lower than M2 group. CONCLUSIONS. The intraoperative use of Mit-C (0.4 mg/mL) may decrease adhesion formation in the early postoperative period, especially in the first week. The intraoperative use of Viscoat was not effective in reducing postoperative adhesions and delaying adjustment.
To compare the thickness of the retinal nerve fiber layer (RNFL), the macular volume, and the macular thickness of the amblyopic eye with those of the non-amblyopic eye in patients with unilateral ...strabismic amblyopia using optical coherence tomography (OCT).
OCT was performed for 14 patients with unilateral strabismic amblyopia who had no neurologic disease. Nine male and 5 female patients, whose ages ranged from 5 to 18 years, were enrolled in the study. The RNFL thickness average analysis program was used to evaluate mean superior, inferior, temporal, and nasal thickness. The data for all clock quadrants (12 values averaged) were identified as the overall RNFL. The retinal thickness and volume analysis program was used to evaluate macular scans. Data were compared using the Mann-Whitney U test.
The mean age (+/- standard deviation) was 10.43 years (+/- 4.09 years). There were 6 right eyes and 8 left eyes with amblyopia; this group had a mean visual acuity (+/- standard error) of 0.3 (+/- 5.70). OCT parameters including the RNFL thickness in all quadrants, overall RNFL thickness, macular thickness, and macular volume showed no significant differences between the two groups (P > .05).
Assessment of RNFL thickness, macular thickness, and macular volume with OCT revealed no difference between the two eyes of patients with unilateral strabismic amblyopia.
To evaluate orbital blood flow velocities in patients with pseudoexfoliation glaucoma (PXG) or primary open-angle glaucoma (POAG).
Blood flow velocities in the ophthalmic, central retinal, and ...posterior ciliary arteries were evaluated by color Doppler imaging in 26 patients with PXG, 28 patients with POAG and 30 age-matched normal control subjects. The results were compared.
Compared to the control subjects, patients with PXG showed statistically significant decreases in the mean peak systolic and end-diastolic velocities and increased mean resistive indices in all vessels except for the ophthalmic artery mean peak systolic velocity (p < 0.05). Patients with POAG, when compared to the control subjects, showed statistically significant decreases in the mean end-diastolic velocities and increased mean resistive indices in all vessels measured (p < 0.05). No statistically significant differences were found in the mean blood flow parameters between POAG and PXG.
Blood flow velocities of the retrobulbar vessels are decreased in patients with PXG. Reduced blood flow velocities may be secondary as well as contributory to exfoliative glaucomatous damage. Although there was no significant difference in the mean blood flow parameters between POAG and PXG, alterations of retrobulbar vessels might be associated with different pathogenic mechanisms of PXG.
To evaluate plasma total homocysteine (tHcy) and nitric oxide (NO) marker levels in patients with pseudoexfoliation syndrome (PXS), pseudoexfoliation glaucoma (PXG), primary open-angle glaucoma ...(POAG), and normal controls.
This cross-sectional, prospective study involved 19 patients with POAG, 18 with PXS, 22 with PXG, and 20 control subjects. Fasting tHcy levels of all study participants were determined using a fluorescence polarization immunoassay method. Quantitation of total nitrate was based on the Griess reaction, in which a chromophore with a strong absorbance at 545 nm is formed by reaction of nitrite with a mixture of naphthylethylenediamine and sulphanilamide.
The mean plasma homocysteine level was statistically significantly elevated in the PXS (p=0.033) and the PXG (p=0.023) groups but not in the POAG group (p=0.996) when compared with the control group. Multiple logistic regression analyses comparing the various patient groups with the single control group indicated that elevation in plasma homocysteine concentration was a significant risk factor for PXS (odds ratio per 1 micromol/l increase in homocysteine concentration=2.05, 95% CI=1.19-3.52) and PXG (odds ratio per 1 micromol/l increase in homocysteine concentration=1.36, 95% CI=1.00-1.85) but was not a significant risk factor for POAG (odds ratio per 1 micromol/l increase in homocysteine concentration=0.99, 95% CI=0.78-1.26). NO markers levels were found to be slightly higher in PXS and PXG patients than control and POAG patients but the differences were not statistically significant (p=0.151). Multiple logistic regression analyses comparing the various patient groups with the single control group indicated that elevation in NO marker concentration was not a significant risk factor for PXS (odds ratio per 1 micromol/l increase in NO concentration=1.00, 95% CI=0.99-1.01), PXG (odds ratio per 1 micromol/l increase in NO concentration=1.00, 95% CI=0.99-1.00) and POAG (odds ratio per 1 micromol/l increase in NO concentration=0.99, 95% CI=0.99-1.00). No statistically significant correlations were observed between plasma tHcy and NO markers in study groups (p>0.05).
Elevated levels of homocysteine in pseudoexfoliation patients with and without glaucoma may partly explain the increased risk of vascular disease among patients with pseudoexfoliation. No significant difference was found in plasma NO markers among the POAG, PXS, PXG, and the control subjects.
In the present investigation, by making use of the familiar concept of neighborhoods of analytic and multivalent functions, we derive coefficient bounds and distortion inequalities, associated ...inclusion relations for the
(
n
,
δ
)
-neighborhoods of subclasses of analytic and multivalent functions with negative coefficients, which are defined by means of a certain nonhomogenous differential equation. Several special cases of the main results are mentioned.
A certain subclass
T(
n,
p,
λ,
α) of starlike functions in the unit disk is introduced. The object of the present paper is to derive several interesting properties of functions belonging to the class
...T(
n,
p,
λ,
α). Various distortion inequalities for fractional calculus of functions in the class
T(
n,
p,
λ,
α) are also given.
Recent developments in the automotive and telematics industries have led to a new emerging domain known as vehicular wireless networks. Vehicular wireless networks enable several new classes of ...vehicular applications that can improve traffic safety, driver convenience, roadway efficiency, and facilitate many types of in-vehicle services. Vehicular ad hoc networks (VANETs) involve not only vehicle-to-vehicle (V2V) but also vehicle-to-infrastructure (V2I) communications.
To evaluate ischemic changes in brain magnetic resonance images in patients with pseudoexfoliation syndrome (PXS) and pseudoexfoliation glaucoma (PXG) and compare them with age- and sex-matched ...control subjects.
This case-control study involved 16 consecutive patients with PXS, 21 patients with PXG and 18 healthy age- and sex-matched control subjects. Each subject underwent a comprehensive ophthalmological examination. In all participants, an axial T(1)-, T(2)- and proton-density-weighted and coronal cerebral 1.5-tesla magnetic resonance imaging (MRI) scan was made. White matter hyperintensities (WMH) were considered present if these were hyperintense on both proton-density- and T(2)-weighted images and not hypointense on T(1)-weighted images. White matter lesions were classified into two parts as the subcortical and periventricular regions. We used a validated rating scale of subcortical WMH: 0 = absent, 1 = punctuate foci, 2 = beginning confluence of foci and 3 = large confluent areas. Periventricular white matter lesions were classified on a scale of 0 (no white matter lesions), 1 (pencil-thin periventricular lining), 2 (thick lining) or 3 (large confluent white matter lesions).
The proportions of persons with WMH were 93.7% for patients with PXS, 95.2% for patients with PXG and 55.5% for control subjects. The numbers of white matter lesions in patients with PXS and PXG were significantly greater than in the control subjects (p < 0.05). White matter lesions at subcortical locations in patients with PXG were significantly more frequent than in the control subjects (80.9 vs. 33.3%; p < 0.05). The proportion of patients with subcortical WMH was 56.2% in PXS; no significant difference was found in subcortical WMH between PXS and controls. The proportions of patients with periventricular WMH were 93% in PXS, 90.4% in PXG and 44.4% in controls. White matter lesions at periventricular locations in patients with PXG and PXS were significantly more frequent than in the control subjects (p < 0.05). The difference between the pseudoexfoliation groups and controls with regard to the size of periventricular and subcortical white matter lesions was statically significant (p < 0.05). When patients with PXS were compared with PXG patients, there was no statistically significant difference in the number, size and scale of white matter lesions.
We found a significantly higher prevalence of MRI-defined WMH in patients with a clinical diagnosis of pseudoexfoliation with or without glaucoma versus control subjects. We think that the findings in this study may shed light on a possible link between ischemic brain lesions and pseudoexfoliation, which is not related with the presence of glaucomatous optic neuropathy. Further investigations are required to resolve the underlying associations.
An approximation heuristic is proposed for solving the heterogeneous multi-server queueing problem associated with the analysis of resequencing of packets travelling over multiple physical links in a ...packet-switching network. Even though a method for obtaining the exact solution exists, its processing time and memory requirements vary exponentially in terms of the number of servers and render it infeasible even for moderately-sized systems. Precision of the proposed approximation which has linear time complexity is demonstrated. The approximation is recommendable in cases when system population and resequencing delays, rather than individual link utilizations, have to be calculated.< >
PDF
