Interpenetrating polymer networks of poly(dimethylsiloxane) with polystyrene,polybutadiene and poly(glycerylpropoxytriacrylate)

The synthesis of full and semi interpenetrating networks (IPNs) based on poly(dimethy1-siloxane) (PDMS)/polystyrene, PDMS/polybutadiene and PDMS/poly(glycerylpropoxytriacry-late) 1

1 Glycerylpropoxytriacrylate (GFTA):

is described. PDMS was used as host polymer in most cases. PDMS networks were prepared with two prepolymers having different number-average molecular weights between junctions, M?_c = 15 · l0³ and M?_c = 75 · l0³. Physical properties of IPN samples such as stress-strain behaviour, swelling and glass transition temperature (T_g) were examined. IPNs of both PDMS/polystyrene and PDMS/poly(glycerylpropoxytriacrylate) exhibit superior mechanical and elastomeric properties with respect to pure PDMS network. Most of the IPN systems studied in this work display two T_gs and indicate phase separation.     

Serum kisspeptin levels in deep-infiltrating,ovarian, and superficial endometriosis: A prospective observational study

The diagnosis of endometriosis may delay for many years due to non-deterministic symptoms and avoiding surgical interventions. Kisspeptins are hormones that interact with endometrial tissue to limit invasions during placentation and various cancers and are suggested to be also associated with endometriosis. This study evaluated if serum kisspeptin levels are associated with the invasion depth in endometriosis. Forty patients between 18 and 45 years of age and admitted to a tertiary-care Obstetrics and Gynecology Department between 2020 and 2021 with a diagnosis of endometriosis, and 40 patients without endometrioma were included in the study. Demographic, obstetric, clinical, and biochemical characteristics were evaluated in patients with superficial (SE) and deep infiltrating (DIE) endometriosis and healthy controls. Twenty patients (50%) had SE, 14 (35%) had DIE, and 22 (55%) had endometrioma in the patient group. Fertility rates were higher among controls, but similar between patients with SE and DIE. CA125 levels were significantly higher in the DIE group. SE and DIE groups had similar kisspeptin values, significantly higher than controls. CA125 and kisspeptin levels were not correlated in study groups. Serum kisspeptin levels were significantly different between endometriosis patients and healthy controls. However, kisspeptin levels were unable to differentiate endometriosis severity. Our results suggest that kisspeptins might play a role in the pathogenesis of endometriosis, which needs further assessment in more comprehensive studies.     

How understandable are the patient education materials about flat foot on the Internet for parents?

Flat foot is a common reason for parents to visit orthopedic clinics. As the Internet has become an easy-search platform, parents often seek online educational materials before seeking out a professional. The aim of this study was to investigate the quality, readability, and understandability of such online materials for parents. An Internet search was performed for “flat foot” and “pes planus” using the Google search engine. The readability was evaluated using 6 different grading systems: Flesch Reading Ease Score, Flesch–Kincaid Grade Level, Simple Measure of Gobbledygook, Fry Readability score, Gunning Fog Index tests, and Automated Readability Index. The Patient Education Materials Assessment Tool test was used to assess the understandability. For quality assessment, the Journal of American Medical Association benchmark criteria and Health on the Net code were applied. One hundred nine websites were included and evaluated for readability, understandability, and quality. The mean readability grade for all websites was 10.5 ± 2.0. The mean Gunning Fog Index tests and Flesch–Kincaid Grade Level scores for all websites were 12.4 ± 2.2 and 9.7 ± 2.1 sequentially. The mean Coleman–Liau index score was 10.0 ± 1.5, and the average Fry Readability score was 9.9 ± 2.0. The automated readability index for all websites was 10.3 ± 2.5. The average Flesch Reading Ease score for all educational materials was 59.3 ± 10.1. The average Patient Education Materials Assessment Tool score for all educational materials was 81% (range, 70–87%). The mean Journal of American Medical Association benchmark criterion for all websites was 1.0, with a range from 1.0 and 2.0. Eighteen (16.5%) websites had Health on the Net certificates. Readability, understandability, and quality of patient education materials about flat feet on the Internet vary and are often worse than professional recommendations.     

Preparation of ABCBA-type block copolymers by use of macro-initiators containing peroxy and azo groups

Some new macroinitiators ( 5 ) containing azo and peroxy groups were synthesized by transformation of esters of poly(ethylene glycol) ( 1 ) (PEG) of different molecular weight with hydroxyl end groups and an azo group in the middle into the corresponding polymers with tert-butylperoxycarbonyl end groups by reaction with terephthaloyl chloride and subsequently with tert-butyl hydroporoxide. Decomposition in the presence of styrene at 60°C or with 3,6,9-triazaun-decane-1,11-diamine in presence of methyl methacrylate gave the corresponding ABA block copolymer 6 and the ABBA block copolymer 7 , respectively. Both block copolymers were used as polymeric initiators. The ABCBA block copolymer 8 was synthesized from 6 and methyl methacrylate or from 7 and styrene by thermally induced polymerization at 80°C. The resulting block copolymers were separated from the homopolymers by selective solvent extraction and characterized by spectroscopic and fractional precipitation methods.     

Single-stage endovascular treatment in patients with severe extracranial large vessel stenosis and concomitant ipsilateral unruptured intracranial aneurysm

PURPOSE

We aimed to evaluate the safety and effectiveness of single-stage endovascular treatment in patients with severe extracranial large vessel stenosis and concomitant ipsilateral unruptured intracranial aneurysm.

METHODS

Hospital database was screened for patients who underwent single-stage endovascular treatment between February 2008 and June 2013 and seven patients were identified. The procedures included unilateral carotid artery stenting (CAS) (n=4), bilateral CAS (n=2), and proximal left subclavian artery stenting (n=1) along with ipsilateral intracranial aneurysm treatment (n=7). The mean internal carotid artery stenosis was 81.6% (range, 70%–95%), and the subclavian artery stenosis was 90%. All aneurysms were unruptured. The mean aneurysm diameter was 7.7 mm (range, 5–13 mm). The aneurysms were ipsilateral to the internal carotid artery stenosis (internal carotid artery aneurysm) in five patients, and in the anterior communicating artery in one patient. The patient with subclavian artery stenosis had a fenestration aneurysm in the proximal basilar artery. Stenting of the extracranial large vessel stenosis was performed before aneurysm treatment in all patients. In two patients who underwent bilateral CAS, the contralateral carotid artery stenosis, which had no aneurysm distally, was treated initially.

RESULTS

There were no procedure-related complications or technical failure. The mean clinical follow-up period was 18 months (range, 9–34 months). One patient who underwent unilateral CAS experienced contralateral transient ischemic attack during the clinical follow-up. There was no restenosis on six-month follow-up angiograms, and all aneurysms were adequately occluded.

CONCLUSION

A single-stage procedure appears to be feasible for treatment of patients with severe extracranial large vessel stenosis and concomitant ipsilateral intracranial aneurysm.The concomitance of severe extracranial large vessel stenosis and unruptured ipsilateral distal intracranial aneurysm is often detected incidentally and their management is not clear (1). Although there are many studies in the literature that report different treatment approaches, there is no definite consensus on the management of the concomitant lesions (2–14). Various treatment options have been suggested, such as initial treatment of the aneurysm before revascularization of the stenosis, treating both lesions in the same surgical session and correcting the stenosis without treating the aneurysm (1, 5, 6, 9–11, 14–16). Few studies have reported single-stage endovascular treatment of both lesions as an effective method (17–19). On the other hand, the treatment of each lesion by this technique may lead to procedure-related undesired events such as cerebral ischemia/stroke or aneurysm rupture.In this study, we aimed to present the radiologic and clinical results of seven consecutive patients who underwent single-stage endovascular treatment of severe extracranial large vessel stenosis and concomitant unruptured ipsilateral intracranial aneurysm and discuss the safety and feasibility of this approach. In addition, distinct from the limited number of similar studies in the literature, we present our experience with bilateral carotid artery stenting (CAS) and proximal subclavian artery stenting during single-stage endovascular treatment.     

Higher Incidence of Cholelithiasis in Chronic Renal Failure Patients with Secondary Hyperparathyroidism Undergoing Peritoneal Dialysis

Background. In this study, we endeavored to determine whether the incidence of cholelithiasis (CL) was increased in chronic renal failure (CRF) patients with secondary hyperparathyroidism on a peritoneal dialysis (PD) program. We also evaluated the factors that might have some influence on the development of CL. Methods. A total of 59 CRF patients undergoing PD were included in the study. We studied the following groups to determine whether parathyroid hormone (PTH) levels were increased in CRF-PD patients: twenty patients with secondary hyperparathyroidism (group 1) and 39 patients with normal PTH levels (group 2). PTH levels were maintained at three times the upper limit of normal. Biochemical parameters were obtained for each CRF-PD patient. All patients underwent abdominal ultrasonography to screen for the presence of cholelithiasis. For statistical analysis, χ², t test, and logistic regression analysis were used; p < 0.05 was considered as significant. Results. We found an almost ten times higher incidence (25% vs. 2.6%) of CL in group 1 patients with statistical significance (p = 0.007). When the incidence of CL according to sex, creatinine, and PTH levels were considered, female gender, creatinine, and PTH levels were higher in group 1, which was also significant statistically. No significant relationship was detected between gallbladder stone formation and the other analyzed biochemical parameters. Conclusions. We found that the incidence of CL in CRF-PD patients with secondary hyperparathyroidism was higher than CRF-PD patients with normal PTH levels. It was also detected that female gender, high creatinine levels, and elevated PTH levels might influence the development of CL in CRF-PD patients.