Biomechanical Study Using the Finite Element Method of Internal Fixation in Pauwels Type III Vertical Femoral Neck Fractures

Background: Several factors are known to influence osseous union of femoral neck fractures. Numerous clinical studies have reported different results, hence with different recommendations regarding treatment of Pauwels III fractures: femoral neck fractures with a more vertically oriented fracture line. The current study aimed to analyze biomechanically whether this fracture poses a higher risk of nonunion. Objectives: To analyze the influence of one designated factor, authors believe that a computerized fracture model, using a finite element Finite Element Method (FEM), may be essential to negate the influence of other factors. The current study aimed to investigate a single factor, i.e. orientation of the fracture line toward a horizontal line, represented by Pauwels classification. It was hypothesized that a model with a vertically oriented fracture line maintaining parity of all other related factors has a higher stress at the fracture site, which would delay fracture healing. This result can be applicable to other types of pinning. Patients and Methods: The finite element models were constructed from computed tomography data of the femur. Three fracture models, treated with pinning, were constructed based on Pauwels classification: Type I, 30° between the fracture line and a horizontal line; Type II, 50°; and Type III, 70°. All other factors were matched between the models. The Von Mises stress and principal stress distribution were examined along with the fracture line in each model. Results: The peak Von Mises stresses at the medial femoral neck of the fracture site were 35, 50 and 130 MPa in Pauwels type I, II, and III fractures, respectively. Additionally, the peak Von Mises stresses along with the fracture site at the lateral femoral neck were 140, 16, and 8 MPa in Pauwels type I, II, and III fractures, respectively. The principal stress on the medial femoral neck in Pauwels type III fracture was identified as a traction stress, whereas the principal stress on the lateral femoral neck in Pauwels type I fracture was a compression stress. Conclusions: The most relevant finding was that hook pinning in Pauwels type III fracture may result in delayed union or nonunion due to significantly increased stress of a traction force at the fracture site that works to displace the fracture. However, in a Pauwels type I fracture, increased compression stress contributes to stabilize it. Surgeons are recommended not to treat Pauwels type III femoral neck fractures by pinning

Mechanism-based CYP2D6 inactivation by acridone alkaloids of Indonesian medicinal plant Lunasia amara

Fourteen acridone alkaloids isolated from Lunasia amara Blanco were tested for their mechanismbased inhibition on human liver microsomal dextromethorphan O-demethylation activity, a prototype marker for cytochrome P450 2D6 (CYP2D6). Among the 14 compounds, 5-hydroxygraveroline (1), 8-methoxyifflaiamine (2), lunamarine (3), and lunine (12) increased their inhibitory activity with increasing preincubation time. Then, we further examined the possibility of mechanismbased inhibition on 5-hydroxygraveroline (1) and lunamarine (3), which showed the potent inhibition. Further investigations on 1 and 3 showed that the characteristic time- and concentration-dependent inhibition, which required a catalytic step with NADPH, was not protected by nucleophiles, and was decreased by the presence of a competitive inhibitor. Thus, 1 and 3 were concluded as mechanism-based inactivators of CYP2D6

Nonlinear Response of an Annular Sector Plate Subjected to In-Plane Dynamic Moment

The nonlinear dynamic instability of an annular sector plate subjected to equal and opposite time-varying moments is examined. The equation of motion describing a large deflection of the annular sector plate based upon Berger\u27s approximate equation is analyzed by the Galerkin method.The resulting equations for time variables are integrated by using the Runge-Kutta-Gill method. Numerical results are presented for various boundary conditions, damping forces, and static moments.Proceedings of the 38th Japan National Congress for Applied Mechanics, 198

Reactions of excited-state benzophenone ketyl radical in a room-temperature ionic liquid

金沢大学理工研究域自然システム学系The photochemistry of the benzophenone ketyl radical in D1 excited state, BPH(D1), was studied by means of two-color dual-pulse laser flash photolysis (355 and 532 nm) in a room-temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide (Bmim-TFSA), and in methanol. Upon excitation with the 532 nm pulse, BPH(D1) emitted strong fluorescence. The transient absorption and fluorescence spectra of BPH(D1) were measured with nanosecond and sub-nanosecond time resolution, respectively. The observed Stokes shift was 1700 cm-1 in Bmim-TFSA, and this shift was close to that in acetonitrile. The fluorescence lifetime of BPH(D1) was determined to be 5 ns in Bmim-TFSA, and again the value was close to that in acetonitrile. The rate constant of the reaction of BPH(D1) with CCl4 in Bmim-TFSA was determined to be (2.1 ± 0.4) × 109 M-1 s-1, which was 10 times the rate constant calculated on the basis of the bulk viscosity of Bmim-TFSA. The results are discussed in terms of the effective microscopic viscosity of the ionic liquid that was recently reported for the cage effect. © 2010 the Owner Societies

Double Smiley Face Rod Method

We report a case of double-level lumbar spondylolysis at L4 and L5 that was successfully treated with the double “smiley face” rod method. A healthy 29-year-old man who presented with a 6-year history of chronic low back pain was referred to us for surgical treatment. Plain radiographs and computed tomography of the lumbar spine revealed bilateral pars defects at L4 and L5 without slip or scoliosis. The patient underwent direct repair of the pars defects using the double smiley face rod method at L4 and L5. There were no intraoperative or postoperative complications, and the patient had improved clinically by 1 year after surgery. The low back pain was completely disappeared and visual analog scale was 0. He restarted tennis again as the recreational level. While several techniques for direct repair of lumbar spondylolysis have been described, this is the first report of the double smiley face rod method being used to repair the consecutive double-level lumbar spondylolysis

Fermionic trimers in spin-dependent optical lattices

We investigate the formation of three-body bound states (trimers) in two-component Fermi gases confined in one dimensional optical lattice with spin-dependent tunneling rates. The binding energy and the effective mass of the trimer are obtained from the solution of the Mattis integral equation generalized to the case of unequal Bloch masses. We show that this equation admits multiple solutions corresponding to excited bound states, which are only stable for large mass asymmetry.Comment: 8 pages, 5 figures, special few-body issue of the Journal of the French Academy of Sciences (CRAS

コハツセイ スイシンケイ ナイブンピツシュヨウ ノ ゲカテキチリョウ

　Recently, new treatment guidelines and classifications were proposed for the management of pancreatic neuroendocrine tumors（P-NETs）, and are now being used in clinical practice. The World Health Organization classification published in 2010 emphasized the importance of a grading system for P-NETs based on parameters of proliferative activity, such as mitotic count and Ki-67 labeling index, proposed by the European Neuroendocrine Tumor Society. For surgical treatment of P-NETs, it is important to select a strategy based on the degree of tumor malignancy. However, there are still no clear indications for organ-preserving pancreatic resection or lymph node dissection. This article outlines the surgical management and clinicopathological features of P-NETs. There are various surgical options, such as tumor enucleation, spleen-preserving distal pancreatectomy（SpDP），distal pancreatectomy with splenectomy, pancreatoduodenectomy, and duodenumpreserving pancreatic head resection. Hepatectomy is the first choice for liver metastasis from welldifferentiated neuroendocrine carcinoma without extrahepatic metastasis. Other treatment options are radiofrequency ablation, transarterial chemoembolization/ embolization, and liver transplantation. Systematic chemotherapy, biotherapy such as somatostatin analogue and interferon-α, and targeted therapy are used for recurrence after surgery and unresectable tumors. This article also gives details of the surgical techniques available for tumor enucleation and SpDP

Molecular cloning of human cathepsin O, a novel endoproteinase and homologue of rabbit OC2

AbstractA 1670-bp cDNA coding for a novel human cysteine protease has been isolated from a monocyte-derived macrophage cDNA library. This cDNA predicts a 329-amino acid preprocathepsin with more than 50% identity to both human cathepsin S and cathepsin L and 94% identity to a rabbit cDNA, termed OC2, recently isolated from osteoclasts. Based on its high homology to OC2, we have named the human enzyme cathepsin O. Cathepsin O mRNA was identified as a single ∼1.7 kb transcript in cultures of 15-day-old monocyte-derived macrophages, but was not expressed in human monocytes or alveolar macrophages. When transfected into COS-7 cells, cathepsin O displayed potent endoprotease activity against fibrinogen at acid pH. This novel endoprotease may play an important role in extracellular matrix degradation