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High-precision mass measurements of exotic ^{95-97}Ag isotopes close to the N=Z line have been conducted with the JYFLTRAP double Penning trap mass spectrometer, with the silver ions produced using the recently commissioned inductively heated hot cavity catcher laser ion source at the Ion Guide Isotope Separator On-Line facility. The atomic mass of ^{95}Ag was directly determined for the first time. In addition, the atomic masses of β-decaying 2^{+} and 8^{+} states in ^{96}Ag have been identified and measured for the first time, and the precision of the ^{97}Ag mass has been improved. The newly measured masses, with a precision of ≈1  keV/c^{2}, have been used to investigate the N=50 neutron shell closure, confirming it to be robust. Empirical shell-gap and pairing energies determined with the new ground-state mass data are compared with the state-of-the-art ab initio calculations with various chiral effective field theory Hamiltonians. The precise determination of the excitation energy of the ^{96m}Ag isomer in particular serves as a benchmark for ab initio predictions of nuclear properties beyond the ground state, specifically for odd-odd nuclei situated in proximity to the proton dripline below ^{100}Sn. In addition, density functional theory calculations and configuration-interaction shell-model calculations are compared with the experimental results. All theoretical approaches face challenges to reproduce the trend of nuclear ground-state properties in the silver isotopic chain across the N=50 neutron shell and toward the proton dripline.

Unlabelled: The progress in computer technology and the increased use of finite element analysis in the medical field by nonengineers and medical researchers lead us to believe that there is a need to develop a systematic approach to validate a finite element model (FEM), of a human orbit, that simulates part of the maxillofacial skeleton and to investigate the effects and the clinical significance of changing the geometry, boundary conditions, that is, muscle forces, and orthotropic material properties on the predictive outcome of an FEM of a human orbit., Methods: Forty-seven variables affecting the material properties, boundary conditions, and the geometry of an FEM of a human orbit including the globe were systematically changed, creating a number of FEMs of the orbit. The effects of the variations were quantified as differences in the principal strain magnitudes modeled by the original FEM (criterion standard), before the sensitivity analyses, and those generated by the changed FEMs., Results: The material properties that had the biggest impact on the predicted principal strains were the shear moduli (up to 21%) and the absence of fatty tissue (up to 75%). The boundary condition properties that had the biggest impact on the predicted principal strains were the superior rectus muscle and canthal ligaments (up to 18% and 23%, respectively). Alterations to the geometry of the orbit, such as an increase in its volume, had the greatest effect on principal strain magnitudes (up to 52%)., Conclusions: Changes in geometry, boundary conditions, and orthotropic material properties can induce significant changes in strain patterns. These values must therefore be chosen with care when using finite element modeling techniques. This study also highlights the importance of restoring the orbital fat and volume when reconstructing the orbital floor following a blunt injury. The possibility that the unrestored increase in the orbital volume and the resulting stresses may be a source of globe injuries, causing diplopia, cannot be excluded.

Purpose: The purpose of the study was to compare the preemptive analgesic effect of celecoxib, a cyclooxygenase 2 inhibitor, with a traditional nonsteroidal anti-inflammatory drug, ibuprofen, in patients after minor oral surgery procedures., Patients and Methods: This randomized, double-blind, placebo-controlled, prospective clinical trial was conducted over an 8-month period. Participants were randomly allocated to receive a standard oral dose of 200 mg celecoxib, 400 mg ibuprofen, or a placebo containing lactose, preemptively 1 h before surgery. Using a patient diary, patients recorded pain intensity, pain relief, and global evaluations throughout the 24-hour period after dosing. The overall analgesic effect, onset of action, peak effect, and duration of effect were evaluated, with the primary end point being total pain relief over 8 hours. The safety profile was assessed on the basis of physical findings and spontaneous reports of adverse experiences., Results: The results showed that compared with ibuprofen, celecoxib had superior analgesic effects on all measures of analgesic efficacy, including overall analgesic effect (total pain relief over 8 hours: 18.1 vs 12.2, P < 0.001), time to onset of effect (30 vs 60 minutes, P = 0.003), peak pain relief (score, 2.7 vs 2.4, P < 0.05), and duration of effect (>24 vs 7.0 hours, P < 0.001). The safety profile was similar across all treatment groups., Conclusions: This is the first reported study that demonstrates the superior analgesic effect of celecoxib, for the release of acute postoperative pain following surgery, when compared with the traditional nonsteroidal anti-inflammatory drug, ibuprofen. There was no safety compromise when celecoxib was used in lower doses to provide analgesia for patients who need minor surgery.

Purpose: The purpose of this study was to develop a finite element model (FEM) of a human orbit, of 1 patient, who had an orbital blow-out fracture, to study the effect of using a "stiffness-graded" (SG) biodegradable implant on the biomechanics of bone-fracture repair., Methods: An FEM of the orbit and the globe, of 1 patient who had an orbital blow-out fracture and was treated with biodegradable poly-L/DL-lactide [P(L/DL)LA 70/30], was generated based on computed tomography scan images. Simulations were performed with a computer using a commercially available finite element software. The FEM was then used to study the effect of using an SG biodegradable implant on the stress distribution in the fractured bone. This was compared with the stress distribution at the fracture interface and at the bone-implant interface, when using P(L/DL)LA implant with a uniform stiffness., Results: The use of SG implants caused less stress shielding to the fractured bone. At 50% of the bone healing stage, stress at the fracture interface was compressive in nature, that is, 0.2 MPa for the uniform implant, whereas SG implants resulted in tensile stress of 0.2 MPa. The result was that SG implants allowed the 50% healed bone to participate in loadings. Stiffness-graded implants are more flexible and hence permit more bending of the fractured bone. This results in higher compressive stresses, induced at the fractured faces, to accelerate bone healing. However, away from the fracture interface, the reduced stiffness and elastic modulus of the implant cause the neutral axis of the composite structure to be lowered into the bone, resulting in the higher tensile stress in the bone layer underneath the implant., Conclusions: The use of SG implants induced significant changes in the stress patterns at the fracture interface and at the bone-implant interface. Stiffness-graded biodegradable implants offered less stress shielding to the bone, providing higher compressive stress at the fractured surface, to induce accelerated bone healing, as well as higher tensile stress in the intact portion of the bone. It seems that this is the first reported study, in the literature, on the use of SG biodegradable implants to repair and promote bone healing at the fracture site of the inferior orbital wall bone defect.

Purpose of the Study: The purpose was to study the biomechanics of bone fracture repair, of the orbital floor, using osteosynthetic bioresorbable implant and how to improve the implant design., Materials and Methods: A finite element model of the orbit and the globe of 1 patient who experienced orbital blowout fracture and treated with bioresorbable poly-L/DL-lactide (P[L/DL]LA 70:30) implant (PolyMax; Synthes, Oberdorf, Switzerland) was generated based on computed tomographic scans. Simulations were performed with a computer using a commercially available finite element software. The effects of changing the geometry, bony support, and method of fixation of the implant on the finite element model predictions were investigated., Results: The factor that had the biggest impact on the predicted principal strain magnitudes was absence of bony support of the implant (up to 65%). Applying elastic fixation reduced stresses (up to 40%) posteriorly. The principal stresses inside the bone and the implant were evenly distributed when elastic fixation was applied to the implant. Applying rigid fixation increased stresses (up to 50% and 80% anteriorly and posteriorly, respectively). The resulting stress values indicated a likely rapid failure of the osteosynthetic implant when rigid fixation was applied., Conclusions: Applying rigid fixation induced a significant increase in stress patterns. Principal stresses were reduced remarkably when elastic fixation was applied to the implant. The role of fixation becomes more prominent when there is no bony support posteriorly and/or medially. It is recommended to avoid rigid fixation and to apply elastic fixation when using bioresorbable P(L/DL)LA 70:30 implants to reconstruct inferior orbital wall bony defects.

Purpose of the Study: The purpose of this study was to develop a finite element model (FEM) of a human orbit, who experienced a pure orbital blowout fracture, to study the effect of the geometrical mismatch-induced stresses on the orbital floor/graft interface and how to improve the graft design when restoring the orbital floor., Materials and Methods: A FEM of the orbit and the globe of 1 patient who experienced pure orbital blowout fracture and treated with autogenous bone graft was generated based on computed tomographic scans. Simulations were performed with a computer using a commercially available finite element software NISA (EMRC, Troy, MI). The FEM was then used to study the effects of changing the geometry, position, material properties, and method of fixation of the autogenous bone graft on its predictions., Results: The factors that had the biggest impact on the predicted principal strain magnitudes were absence of cancellous bone (up to 60%) and bony support of the graft (up to 50%). Applying rigid fixation reduced stresses by 30% posteriorly and by almost 100% anteriorly. Alterations to the geometry of the bone graft, such as an increase in its thickness, increased principal strain magnitudes (up to 42%)., Conclusions: Applying rigid fixation reduced principal stresses significantly. The role of rigid fixation becomes more prominent when there is no bony support posteriorly and/or medially. This study also highlights the importance of preserving cancellous bone, when harvesting and preparing the autogenous bone graft to reconstruct the orbital floor. The possibility that absence of cancellous bone and the resulting stresses may be a source of graft resorption and/or failure cannot be excluded.

Purpose: To develop a finite element model (FEM) to study the effect of the vascular wall compliance on blood flow at the graft/recipient vessel junction., Materials and Methods: Finite element models of the end-to-end and end-to-side anastomoses were constructed. Simulations were performed with a computer using the finite element software NISA. The FEMs were then used to study the effects of changing the elasticity of the vascular wall on its predictions., Results: Deformations were relatively large; the maximum displacement for the compliant model, end-to-end anastomosis, was 55 and 88 mm for the 90-degree end-to-side anastomosis. The maximum displacement for the rigid model, end-to-end anastomosis, was 155 and 188 mm for the 90-degree end-to-side anastomosis. When the angle of inset was set at 45 degrees, there was no remarkable difference in deformation between the compliant and rigid models., Conclusions: The principal stresses were remarkably less at the graft/vessel junction in models of compliant grafts and compliant vessels than for rigid wall models. The 45-degree end-to-side anastomosis seems to be the best technique when planning microvascular anastomosis for elderly patients and/or patients with systemic disease, which reduces vascular wall elasticity.

Purpose of the Study: The purpose of this study was to report our clinical experience, in a pilot study, of the use of the selective cyclooxygenase-2 (COX-2) inhibitor celecoxib, pre-emptively, to control pain in patients after surgical extraction of a mandibular molar tooth., Patient and Methods: This randomised, double-blind, placebo-controlled, prospective clinical trial was conducted over an eight-month period. Participants were randomly allocated to receive a standard oral dose of 200 mg celecoxib, 400 mg ibuprofen, or a placebo containing lactose, pre-emptively, one hour before surgery. Each patient was prescribed amoxycillin 500 mg three times per day postoperatively for seven days. The participants were given standardised participant information sheets, and written informed consent was subsequently obtained from the participants prior to the commencement of the study., Results: The results showed that 13% of the patients who had ibuprofen had severe pain two to three days postoperatively. This was diagnosed as alveolar osteitis, which is in line with the universally accepted outcome for the surgical extraction of mandibular molar teeth. Statistical analysis (Chi-square test) confirmed that the ibuprufen group had a significantly higher alveolar osteitis incidence than the celecoxib group (p < or = 0.05) and the placebo group (p < or = 0.05)., Conclusion: This is the first reported study to demonstrate that the use of celecoxib resulted in a significant decrease in the occurrence of alveolar osteitis.

In retrospective radon measurements, the 22-y half life of (210)Pb is used as an advantage. (210)Pb is often considered to be relatively immobile in glass after alpha recoil implanted by (222)Rn progenies. The diffusion of (210)Pb could, however, lead to uncertain wrong retrospective radon exposure estimations if (210)Pb is mobile and can escape from glass, or lost as a result of cleaning-induced surface modification. This diffusion was studied by a radiotracer technique, where (209)Pb was used as a tracer in a glass matrix for which the elemental composition is known. Using the ion guide isotope separator on-line technique, the (209)Pb atoms were implanted into the glass with an energy of 39 keV. The diffusion profiles and the diffusion coefficients were determined after annealing at 470-620 degrees C and serial sectioning by ion sputtering. In addition, the effect of surface cleaning on diffusion was tested. From the Arrhenius fit, the activation enthalpy (H) was determined, which is equal to 3.2 +/- 0.2 eV, and also the pre-exponential factor D(0), in the order of 20 m(2)s(-1). This result confirms the assumption that over a time period of 50 y (209)Pb (and (210)Pb) is effectively immobile in the glass. The boundary condition obtained from the measurements had the characteristic of a sink, implying loss of (209)Pb in the topmost surface at high temperatures.

Purpose of the Study: To develop a finite element model (FEM) to study the effect of the stress and strain, in microvascular anastomoses that result from the geometrical mismatch of anastomosed vessels., Material and Methods: FEMs of end-to-end and end-to-side anastomoses were constructed. Simulations were made using finite element software (NISA). We investigated the angle of inset in the end-to-side anastomosis and the discrepancy in the size of the opening in the vessel between the host and recipient vessels. The FEMs were used to predict principal and shear stress and strain at the position of each node., Results: Two types of vascular deformation were predicted during different simulations: longitudinal distortion, and rotational distortion. Stress values ranged from 151.1 to 282.4MPa for the maximum principal stress, from -122.9 to -432.2MPa for the minimum principal stress, and from 122.1 to 333.1MPa for the maximum shear stress. The highest values were recorded when there was a 50% mismatch in the diameter of the vessels at the site of the end-to-end anastomosis., Conclusion: The effect of the vessel's size discrepancy on the blood flow and deformation was remarkable in the end-to-end anastomosis. End-to-side anastomosis was superior to end-to-end anastomosis. FEM is a powerful tool to study vascular deformation, as it predicts deformation and biomechanical processes at sites where physical measurements are likely to remain impossible in living humans.

Central intraosseous adenoid cystic carcinoma (ACC) of the mandible, formerly known as cylindroma, is a rare neoplasm with only 16 cases reported in the literature. We describe the diagnosis, etiology, and treatment of a central ACC located in the mandibular premolar region. We also review the literature. This case illustrates 2 key facts regarding the diagnosis and etiology of ACC. First, central salivary gland tumors should be considered in the differential diagnosis of cystic lytic lesions in the mandible. Second, even though the origin of this type of tumor is still unknown, the presence of ectopic tissue anterior to the submandibular gland in the submandibular area indicates that this tumor might be made up of ectopic embryogenic inclusions.

To investigate the changes in noradrenaline concentrations in transplanted arterial grafts in rats, 31 female rats 4 to 6 weeks old of the AO/Ks:OC strain were operated on. Femoral arterial grafts were anastomosed to carotid arteries and compared with control femoral segments. Six rats were included in each follow-up group at 0, 1, 4, and 12 weeks, and there were seven rats in the 20-week follow-up group. High-performance liquid chromatography was used to determine the concentrations of noradrenaline. The operation itself decreased noradrenaline concentrations in the grafts to 76 percent of that in the control segments. One week after the operation, the noradrenaline concentration had fallen to 1.7 percent of the control values and started to recover thereafter. One month after the operation, it was 23 percent; at 3 months, it was 31 percent; and at 5 months, it was 43 percent of control values. The decrease from time 0 to 1 week was significant (p = 0.001), as was the increase from 1 week to 20 weeks (p = 0.004). Noradrenaline concentrations had fallen significantly 1 week after the operation and thereafter they increased to levels comparable to those seen in the immediate postoperative period.

The aim of this study was to investigate the rate of disappearance of noradrenaline in arterial grafts after their transplanation. Arterial grafts were harvested from AO/Ks:OC strain rats. In each rat, a graft was harvested from the femoral artery and transplanted into the common carotid artery. A contralateral unoperated femoral artery served as control. High-performance liquid chromatography (HPLC) with electrochemical detection was used to determine the noradrenaline content in grafts and controls. Immediately after grafting, the noradrenaline content was 76% of control value, at 6 h 130% of control value, and at 48 h 4% of control value. The drop in graft noradrenaline content (from 0-48 h) was statistically significant (P = 0.005). The difference between 0-h, 12-h, and 24-h groups was statistically insignificant. Compared to control specimens, grafts contained less noradrenaline after 12 h, and it disappeared almost completely from femoral arterial grafts in rats within 48 h., (Copyright 2004 Wiley-Liss, Inc.)