Comparative structural and optical properties of different ceria nanoparticles.

Herein a comparative study of five nanocrystalline cerium oxides (CeO(2-delta)) synthesised by different methods and calcined at 500 degrees C is reported. XRPD analysis showed that stoichiometry parameter delta, crystallite size/strain and lattice constant were only slightly affected by the method utilized. All ceria nanoparticles are nearly spherical in shape with faceted morphology, free of defects and with a relatively uniform size distribution. The average microstrain was found to be approximately 10 times higher than that of bulk counterpart. The absorption edge of nanocrystalline materials was shifted towards a higher wavelengths (red shift) in comparison with bulk counterpart, and band gap values were in the range 2.7-3.24 eV (3.33 eV for bulk counterpart).

Effects of Eu3+ concentration on structural, optical and vibrational properties of multifunctional Ce(1-x)Eu(x)O2-delta) nanoparticles synthesized by thermolysis of 2,4-pentanedione complexes.

The 5-10 nm Ce(1-x)Eu(x)O(2-delta) (0 < or = x < or = 0.30) nanoparticles with fluorite structure were synthesized by thermal decomposition of Eu- and Ce-2,4-pentanedione complexes mixtures. X-ray line broadening analysis of mixed samples Ce(1-x)Eu(x)O(2-delta) (0.05 < or = x < or = 0.30) showed that the crystallite size was lower and root mean square strain higher than in pure ceria. However, within mixed samples Ce(1-x)Eu(x)O(2-delta) (0.05 < or = x < or = 0.30) crystallite size and root mean square strain were independent of Eu3+ concentration. Raman spectroscopy results indicated that europium ions yield disorder by breaking the phonon propagation and therefore making the non-centre Brillouin zone modes Raman active. The absorption bands in the spectra of mixed oxides were blue-shifted in comparison to pure CeO(2-delta) nanopowder. The samples show red emission typical for Eu ions. The biggest photoluminescent intensity was observed for the highest Eu3+ concentration (x = 0.30) and further enhanced with the increase in crystallinity.

Growth performance, carcass characteristics, and selected meat quality traits of two strains of Pekin duck reared in intensive vs semi-intensive housing systems.

Selection of optimal hybrid of Pekin duck and housing system could improve yield and quality of duck meat. The aim of this study was to investigate the effects of two rearing systems (intensive vs semi-intensive housing) on growth performance, carcass quality, and selected physical meat quality traits of two commercial strains of Pekin ducks. The study was performed on 240 one-day-old Pekin ducklings of two different strains (120 ducklings of STAR 53 medium hybrid and 120 ducklings of SM3 heavy hybrid) during a 49-day period. Half the birds (120) were reared in a complete confinement system on a floor (intensive system), while the remaining 120 ducks had access to land outside (semi-intensive system). Growth performance of ducks was determined by BW, weight gain, feed intake, and feed conversion ratio (FCR), carcass quality by dressing percentage, percentage of basic cuts in carcasses, and content of various tissues in basic cuts, while meat quality was determined by pH, drip loss, cooking loss, Warner-Bratzler shear force, and color (L*, a*, and b*) values. At the end of the study, SM3 heavy hybrid and STAR 53 hybrid Pekin ducks achieved similar BWs. Higher final BW and lower overall FCR were found in ducks reared in the intensive system than in ducks kept in the semi-intensive system. Higher dressing percentage, weight and percentage of breast, but also a lower percentage of back with pelvis in the carcasses were determined in SM3 hybrid ducks than in STAR 53 hybrid ducks. The strain of duck did not affect meat pH, drip loss, or L* color value. Moreover, housing system affected the physical meat quality of the ducks, since breasts from ducks reared in the semi-intensive system had higher initial meat pH, higher percentage of EZ-drip loss and cooking loss, and higher L*, a*, and b* values than did breasts from intensively-reared ducks. In conclusion, SM3 ducks were more suited for broiler production due to their better carcass quality than STAR 53 ducks. Furthermore, ducks reared in the intensive system had better growth performance results and better physical meat quality traits than did ducks from the semi-intensive system.

Cardioprotective effects of fullerenol C(60)(Oh)(24) on a single dose doxorubicin-induced cardiotoxicity in rats with malignant neoplasm.

The therapeutic utility of the anthracycline antibiotic doxorubicin is limited due to its cardiotoxicity. Our aim was to investigate the efficacy of fullerenol C(60)(OH)(24) in preventing single, high-dose doxorubicin-induced cardiotoxicity in rats with malignant neoplasm. Experiment was performed on adult female Sprague Dawley rats with chemically induced mammary carcinomas. The animals were sacrificed two days after the application of doxorubicin and/or fullerenol, and the serum activities of CK, LDH and alpha-HBDH, as well as the levels of MDA, GSH, GSSG, GSH-Px, SOD, CAT, GR, and TAS in the heart, were determined. The results obtained from the enzymatic activity in the serum show that the administration of a single dose of 8 mg/kg in all treated groups induces statistically significant damage. There are significant changes in the enzymes of LDH and CK (p < 0.05), after an i.p. administration of doxorubicin/fullerenol and fullerenol. Comparing all groups with untreated control group, point to the conclusion that in the case of a lower alpha-HBDH/LDH ratio, results in more serious the liver parenchymal damage. The results revealed that doxorubicin induced oxidative damage and that the fullerenol antioxidative influence caused significant changes in MDA, GSH, GSSG, GSH-Px, SOD, CAT, GR, and TAS level in the heart (p < 0.05). Therefore, it is suggested that fullerenol might be a potential cardioprotector in doxorubicin-treated individuals.

Experimental peri-implant tissue breakdown around hydroxyapatite-coated implants.

This study monitored experimental peri-implant tissue breakdown around hydroxyapatite (HA)-coated titanium dental implants. Thirty-two HA-coated cylindrical implants, in groups of two, were bilaterally inserted in the posterior maxilla and mandible in 4 Macaca mulatta monkeys. Two months after healing-abutment connection, a 2-month plaque control program was initiated. Clinical and radiographic recordings and peri-implant submucosal microbial samples were then obtained (baseline). Cotton ligatures were next placed around the healing-abutments and plaque control measures were abandoned. Clinical and radiographic recordings were repeated at 5 and 10 months post-baseline. Microbial samples were repeated at 10 months post-baseline, and ligatures were removed. Clinical, radiographic, and microbial examinations were again repeated at 11 months post-baseline. Mean modified plaque index (mPI; P < 0.01), gingival index (G]; P < 0.01), and bleeding on probing (BOP; P < 0.05) scores increased over the plaque accumulation period. The mPI, and GI scores decreased after ligature removal (P < 0.001). Mean probing depth (PD) and clinical attachment level (AL) increased between baseline and the 5- and 10-month examinations (delta PD 3.0 mm; delta AL 2.7 mm; P < 0.05). PD values were reduced following ligature removal (P < 0.05). AL values and BP scores remained unchanged. A significant negative correlation was found between induced defect depth and width of keratinized mucosa at baseline (P = 0.03). At baseline, the submucosal microbiota was dominated by coccoid cells. Following ligature placement, the microbiota included a large proportion of Gram-negative anaerobic rods, predominantly Porphyromonas gingivalis, Bacteroides forsythus, and Fusobacterium species as well as beta-hemolytic streptococci. Ligature removal had a limited effect on the composition of the submucosal microbiota. This non-human primate study indicates that ligature-enhanced plaque accumulation is a precursor of progressive peri-implant tissue breakdown around HA-coated implants. The associated microbiota resembles that of peri-implantitis and destructive periodontal disease in humans. This preclinical model may be useful to study modalities aimed at arresting peri-implant tissue breakdown and at regeneration of bone in peri-implantitis defects.

Bone formation and reosseointegration in peri-implantitis defects following surgical implantation of rhBMP-2.

This study was designed to evaluate bone formation and reosseointegration following surgical implantation of recombinant human bone morphogenetic protein-2 (rhBMP-2) in peri-implantitis defects. Hydroxyapatite-coated dental implants were placed bilaterally in the mandibular and maxillary premolar area in four rhesus monkeys and were allowed to osseointegrate for 1 year. Cotton ligatures were then placed around the healing abutments, and plaque was allowed to accumulate for 11 months. Resulting circumferential peri-implantitis defects exhibited a large intrabony and horizontal component. At reconstructive surgery, peri-implantitis defects in contralateral jaw quadrants were randomly assigned to receive rhBMP-2 (0.43 mg/mL implant volume) in an absorbable collagen sponge carrier or a carrier control. The animals were sacrificed 4 months postsurgery, and block sections were prepared for histometric analysis. Summary statistics included means calculated per animal. Paired t tests were used to evaluate differences between experimental conditions (n = 4). Defect depth amounted to 3.4 +/- 0.9 mm and 3.2 +/- 0.9 mm for rhBMP-2 and control defects, respectively. Vertical bone gain in rhBMP-2 defects (2.6 +/- 1.2 mm) was significantly greater than in controls (0.8 +/- 0.8 mm; P < .01). Reosseointegration within the confines of the defect for rhBMP-2 defects (29.0 +/- 10.5%) differed significantly from that in the control (3.5 +/- 2.5%; P < .01). Reosseointegration within the extent of newly formed bone averaged 40.0 +/- 11.0% in rhBMP-2 defects as compared to 8.9 +/- 7.8% in the control (P < .01). Osseointegration in resident bone amounted to 69.5 +/- 6.9% and 72.6 +/- 8.0% for rhBMP-2 and control defects, respectively. There is significant evidence that rhBMP-2 has potential to promote bone formation and reosseointegration in advanced peri-implantitis defects in a demanding nonhuman primate model.

Surgical template for completely edentulous patients.

Implant angulation is of utmost importance for fabrication of esthetic, hygienic, and functional prostheses, even in the treatment of completely edentulous patients. Most mandibular surgical templates are not reliable because of a lack of stability resulting either from severe resorption of the mandible or from the interference of mucoperiosteal flaps elevated during surgery. This article describes a technique for fabrication and surgical application of a stable template for the completely edentulous mandible. By combining the mandibular template with a maxillary duplicate denture, the problem of lack of stability can be overcome. A consistently reliable reference for implant placement in the edentulous mandible, specifically in relation to implant angulation (trajectory), can be obtained.

Solving the problem of violated intermaxillary space caused by poor pre-planning and improper placement of endosseous implants: a case report.

Every dental implant patient needs thorough evaluation and pre-surgical planning. It is imperative for the practitioner to have absolute knowledge of the implant system to be used. Nevertheless, sometimes we find ourselves in very difficult, almost unrestorable, situations. Often, we cannot rely on the implant manufacturers, and we have to be ready to customize some parts in order to solve difficult clinical situations. This case report shows how customized magnet keepers were fabricated by use of plastic IME's as casting patterns in order to solve the problem of violated intermaxillary space.

Root-form implants placed in subantral grafted sites.

Life-table analysis of survival data of implants placed in subantral grafts reveals a high rate of survival, particularly in comparison with implants placed in non-grafted subantral sites. However, sample size (158 grafted, 140 non-grafted, in a total of 120 patients) and follow-up time remain insufficient to reach a definite conclusion. Results also appear improved over other reports in which the sinus was penetrated by the implants, possibly because the procedure has become more standard over the years.

HA-coated implants: warranted or not?

Despite anecdotal reports that challenge hydroxyapatite (HA)-coated implant survivability, the experience in the placement of these implants over 9 years at Loma Linda University School of Dentistry has been favorable. The results of these implant placements are presented and analyzed in this article. After 7 years, the survival rate of HA-coated custom and stock blade-form implants is 97%. At 5 years, the survival rate for all upper HA-coated root form implants is 98%, and for all HA-coated implants placed in the lower jaw it is 99%. For implants placed in maxillary type 4 bone, there was a 32.6% failure rate among uncoated implants, but a rate of 14.9% in HA-coated implants. The causes of implant failure are often related to factors other than the type of implant, such as iatrogenic factors and poor oral hygiene.

[Cervical clefts as a possible etiologic factor in sterility]. / Rascepi grlica materice kao moguci etioloski faktor steriliteta i infertiliteta.

Follow-up gynecological and colposcopic examinations performed in 81 patients after the puerperium have shown that out of 15 sutured ruptures only 9 (60%) healed. The follow-up colposcopic examination revealed 19 unstitched clefts of which 13 did not heal and 6 healed leaving a scar (31.5%). The ectopy of the cervical mucosa was found 5 times (33.3) in the group of stitched clefts and 8 times (47.3%) in the group of unstitched clefts, among which there was also leukoplakia in one case. In the group without the injury of the cervix, ectopia was observed in 11 cases (23.4%). In the course of 1979, at the Gynecology Department, cerclage was performed 474 times. Out of these cases, 20 women (4.2%) underwent cerclage owing to the cleft of the uterine cervix and previous spontaneous abortions. The authors recommend a careful surgical treatment of the cleft and consider the revision of the cervix after each delivery absolutely necessary, both these measures being meant to serve as prevention against sterility and infertility.