Biaxial flexural strength and phase transformation of Ce-TZP/Al2O3 and Y-TZP core materials after thermocycling and mechanical loading

PURPOSE

The purpose of the present study was to evaluate the effect of thermocycling and mechanical loading on the biaxial flexural strength and the phase transformation of one Ce-TZP/Al₂O₃ and two Y-TZP core materials.

MATERIALS AND METHODS

Thirty disc-shaped specimens were obtained from each material. The specimens were randomly divided into three groups (control, thermocycled, and mechanically loaded). Thermocycling was subjected in distilled water for 10000 cycles. Mechanical loading was subjected with 200 N loads at a frequency of 2 Hz for 100000 times. The mean biaxial flexural strength and phase transformation of the specimens were tested. The Weibull modulus, characteristic strength, 10%, 5% and 1% probabilities of failure were calculated using the biaxial flexural strength data.

RESULTS

The characteristic strengths of Ce-TZP/Al₂O₃ specimens were significantly higher in all groups compared with the other tested materials (P<.001). Statistical results of X-ray diffraction showed that thermocycling and mechanical loading did not affect the monoclinic phase content of the materials. According to Raman spectroscopy results, at the same point and the same material, mechanical loading significantly affected the phase fraction of all materials (P<.05).

CONCLUSION

It was concluded that thermocycling and mechanical loading did not show negative effect on the mean biaxial strength of the tested materials.     

Hybrid polymers bearing oligo-l-lysine(carboxybenzyl)s: synthesis and investigations of secondary structure

Hybrid polymers of peptides resembling (partially) folded protein structures are promising materials in biomedicine, especially in view of folding-interactions between different segments. In this study polymers bearing repetitive peptidic folding elements, composed of N-terminus functionalized bis-ω-ene-functional oligo-l-lysine(carboxybenzyl(Z))s (Lys_n) with repeating units (n) of 3, 6, 12, 24 and 30 were successfully synthesized to study their secondary structure introduced by conformational interactions between their chains. The pre-polymers of ADMET, narrowly dispersed Lys_ns, were obtained by ring opening polymerization (ROP) of N-carboxyanhydride (NCA) initiated with 11-amino-undecene, following N-terminus functionalization with 10-undecenoyl chloride. The resulting Lys_ns were subsequently polymerized via ADMET polymerization by using Grubbs’ first generation (G1) catalyst in 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) generating the ADMET polymers (A-[Lys_n]_m) (m = 2–12) with molecular weights ranging from 3 to 28 kDa, displaying polydispersity (Đ) values in the range of 1.5–3.2. After chemical analyses of Lys_ns and A-[Lys_n]_ms by ¹H-NMR, GPC and MALDI-ToF MS, secondary structural investigations were probed by CD spectroscopy and IR spectroscopy in 2,2,2-trifluoroethanol (TFE). In order to study A-[Lys_n]_ms with defined molecular weights and low polydispersity values (Đ = 1.03–1.48), the ADMET polymers A-[Lys_n=3]_m=3 and A-[Lys_n=24]_m=4 were fractionated by preparative GPC, and subsequently analysed by ¹H-NMR, analytical GPC, MALDI-ToF MS and CD spectroscopy. We can demonstrate the influence of chain length of the generated polymers on the formation of secondary structures by comparing Lys_ns with varying n values to the ADMET-polymers with the help of spectroscopic techniques such as CD and FTIR-spectroscopy in a helicogenic solvent.

We demonstrate the influence of chain length of segmented polymers bearing dynamic folding elements onto the formation of secondary structures with the help of spectroscopic techniques such as CD and FTIR-spectroscopy in a helicogenic solvent.     

Recommendations for Hepatitis B Immunoglobulin and Antiviral Prophylaxis Against Hepatitis B Recurrence After Liver Transplantation

The combination of hepatitis B immunoglobulin and potent nucleos(t)ide analogs after liver transplantation is considered as the standard of care for prophylaxis against hepatitis B virus recurrence. However, the recommended doses, route of administration, and duration of HBIG administration remain unclear. Moreover, hepatitis B immunoglobulin-free prophylaxis with potent nucleos(t)ide analogs has shown promising disease outcomes in preventing hepatitis B virus recurrence. The current recommendations, produced by the Turkish Association for the Study of the Liver, Acute Liver Failure and Liver Transplantation Special Interest Group, suggest a reduced need for hepatitis B immunoglobulin administration with effective long-term suppression of hepatitis B virus replication using potent nucleos(t)ide analogs after liver transplantation.     

What do we Know about Bullying in Syrian Adolescent Refugees? A Cross Sectional Study from Turkey

Psychiatric Quarterly - The aim of this study was to assess the bullying status of Syrian adolescent refugees in Turkey and identify factors that contribute to bullying. The adolescents aged...     

Cardiac magnetic resonance imaging in dilated cardiomyopathy in adults��towards identification of myocardial inflammation

Objective

To assess active myocardial inflammation by cardiovascular magnetic resonance (CMR) and endomyocardial biopsy (EMB) amongst adult patients with dilated cardiomyopathy (DCM).

Methods

We evaluated 23 adults with chronic DCM, who had successfully undergone both CMR and EMB within 3.5?±?2.6?days. EMB was considered the gold standard. CMR assessment of myocardial inflammation used the following parameters as recommended by the recently published ??Lake Louise Criteria??: global myocardial oedema, global relative enhancement (RE), and late gadolinium enhancement (LGE). According to ??Lake Louise Criteria??, myocardial inflammation was diagnosed if two or more of the three above-mentioned parameters were positive.

Results

Myocardial inflammation was confirmed by immunohistology in 12 patients (52.2%). Sensitivity, specificity, and diagnostic accuracy of CMR to detect immunohistologically confirmed myocardial inflammation were 75.0%, 72.7%, and 73.9%, respectively. Sensitivity, specificity, and diagnostic accuracy of the individual CMR parameters to detect myocardial inflammation were as follows: global myocardial oedema, 91.7%, 81.8%, and 87.0%, respectively; global RE, 58.3%, 63.6%, and 60.9%, respectively; LGE, 58.3%, 45.4%, and 52.2%, respectively.

Conclusion

Global myocardial oedema was identified as a promising CMR parameter for assessment of myocardial inflammation in patients with DCM. In these patients, global myocardial oedema yielded superior diagnostic performance compared to ??Lake Louise Criteria??.     

Shall We Inject Superficial or Deep to the Plantar Fascia? An Ultrasound Study of the Treatment of Chronic Plantar Fasciitis

We compared the effectiveness of ultrasound (US)-guided corticosteroid, injected superficial or deep to the fascia, in patients with plantar fasciitis. Thirty patients (24 females [75%] and 6 males [25%]) with unilateral chronic plantar fasciitis were divided into 2 groups according to the corticosteroid injection site: superficial (n = 15) or deep (n = 15) to the plantar fascia. Patient heel pain was measured using a Likert pain scale and the Foot Ankle Outcome Scale (FAOS) for foot disability, evaluated at baseline and repeated in the first and sixth weeks. The plantar fascia and heel pad thicknesses were assessed on US scans at baseline and the sixth week. The groups were similar in age, gender, and body mass index (p > .05 for all). Compared with the baseline values, the Likert pain scale (p < .001 for all) and FAOS subscale (p < .01 for all) scores had improved at the first and sixth week follow-up visits in both groups. Although the plantar fascia thickness had decreased significantly in both groups at the sixth week (p < .001 for both), the heel pad thickness remained unchanged (p > .05 for both). The difference in the FAOS subscales (pain, p = .002; activities of daily living, p = .003; sports/recreational activities, p = .008; quality of life, p = .009) and plantar fascia thickness (p = .049) showed better improvement in the deep than in the superficial injection group. US-guided corticosteroid injections are safe and effective in the short-term therapeutic outcome of chronic plantar fasciitis. Additionally, injection of corticosteroid deep to the fascia might result in greater reduction in plantar fascia thickness, pain, and disability and improved foot-related quality of life.     

Early and late diagnoses of 17β-Hydroxysteroid dehydrogenase type-3 deficiency in two unrelated patients

17β-hydroxysteroid dehydrogenase type 3 deficiency is a rare cause of 46 XY disorders of sexual development. Mutations in the HSD17B3 gene result in reduced activity of the 17β-HSD3 enzyme, decreasing the conversion of androstenedione to testosterone. In this report, two cases, admitted with different clinical findings in the neonatal and adolescent periods and were decided to be raised in different genders are presented. The first case who had complete female external genitalia presented on the third postnatal day with the complaint of swelling in the groin. He was decided to be raised as a male and was treated successfully with parenteral testosterone in order to increase phallus size before surgical correction of the external genitalia. The second case was an adolescent girl who presented due to pubertal virilisation and primary amenorrhoea and chose female gender. Molecular genetic analyses of the HSD17B3 gene revealed two different previously reported homozygous variants. We emphasise that patients with 17β-hydroxysteroid dehydrogenase type 3 deficiency can present with heterogeneous clinical findings in different age groups. Early diagnosis is important to prevent future gender confusion and related problems.     

Prognostic value of cutaneous reinnervation with GAP-43 in oxaliplatin-induced neuropathy

Journal of Neurology - Oxaliplatin-induced neuropathy (OIN) implies axonal damage of both small and large sensory nerve fibers. We aimed at comparing the neurophysiological changes occurred after...     

Multiple sulfatase deficiency: A case series of four children

Multiple sulfatase deficiency is biochemically characterized by the accumulation of sulfated lipids and acid mucopolysaccharides. The gene sulfatase-modifying factor 1 (SUMF1), recently identified, encodes the enzyme responsible for post-translational modification of a cysteine residue, which is essential for the activity of sulfatases. We describe clinical findings and mutation analysis of four patients. The patients presented with hypotonia, developmental delay, coarse face, ichthyosis, and hepatosplenomegaly. The diagnosis was made through clinical findings, enzymatic assays, and mutation analysis. We were detected to be homozygous for a novel missense mutation c. 739G > C causing a p.G247R amino acid substitution in the SUMF1 protein.Key Words: Child, multiple sulfatase deficiency, sulfatase-modifying factor 1 gene