3,660 research outputs found
A modified porous titanium sheet prepared by plasma activated sintering for biomedical applications
This study aimed to develop a contamination free porous titanium scaffold by
a plasma activated sintering within an originally developed TiN coated graphite
mold. The surface of porous titanium sheet with or without a coated graphite
mold was characterized. The cell adhesion property of porous titanium sheet was
also evaluated in this study. The peak of TiC was detected on the titanium
sheet processed with the graphite mold without a TiN coating. Since the
titanium fiber elements were directly in contact with the carbon graphite mold
during processing, surface contamination was unavoidable event in this
condition. The TiC peak was not detectable on the titanium sheet processed
within the TiN coated carbon graphite mold. This modified plasma activated
sintering with the TiN coated graphite mold would be useful to fabricate a
contamination free titanium sheet. The number of adherent cells on the modified
titanium sheet was greater than that of the bare titanium plate. Stress fiber
formation and the extension of the cells were observed on the titanium sheets.
This modified titanium sheet is expected to be a new tissue engineering
material in orthopedic bone repair.Comment: 5 pages, 4 figure
Hip Function Was Not Associated with the Incidence of Preoperative Deep Vein Thrombosis in Patients Undergoing Primary Total Hip Arthroplasty
The prevalence of preoperative deep vein thrombosis (DVT) has been reported to be relatively high in patients undergoing total hip arthroplasty. We investigated the prevalence of DVT, the association between hip function and preoperative DVT, and the effect of a history of surgery in patients who underwent primary total hip arthroplasty. We retrospectively analyzed the cases of the patients who underwent primary total hip arthroplasty between April 2013 and February 2020 at our institution. We evaluated the prevalence of preoperative DVT based on the results of the patients’ ultrasound screening. We performed univariate and multivariate analyses to investigate the association between the incidence of DVT and patient factors including age, sex, hip function, medical histories, and American Society of Anesthesiologists Physical Status classification. We analyzed 451 patients (494 hips). The prevalence of DVT was 14.2% (64 patients). The multivariate analysis demonstrated that increased age was an independent significant risk factor for DVT. The prevalence of preoperative DVT was relatively high among patients who underwent primary total hip arthroplasty. Preoperative DVT tended to be more prevalent in older patients. Hip function was not associated with the incidence of DVT
β-tricalcium Phosphate/Collagen Composites Improve Bone Regeneration in Rat Calvarial Bone Defects
Autogenous bone grafting is the most widely accepted approach for repairing bone defects, yet limitations in the donor site and subsequent morbidity associated with harvesting bone from other sites remain as major concerns. Consequently, synthetic bone-like biocomposites have drawn much attention as a novel regenerative strategy. This study evaluated the regenerative properties of our prototype β-TCP/collagen composite in an animal model. We prepared the original β-TCP/collagen composite by mixing an acidic atelocollagen gel and alkaline colloidal β-TCP, and Raman microspectroscopy of the composite revealed the typical spectral features attributable to bone after manual mixing. We then transplanted either the composite or collagen alone into a full-thickness trephine defect made in the calvarial bone of rats. At 8 weeks after implantation, the elastic modulus of regenerated bone that developed alongside the composite was comparable to that of native cortical bone. Decalcification and processing of the calvarial bones for histological observation revealed that the β-TCP/collagen enabled better bone regenerative properties compared to collagen alone. Our newly developed β-TCP/collagen composite imitates the structural properties of bone, and thus provides a potentially useful scaffold material to support the mechanical integrity of regenerated bone
CLINICAL PREDICTORS FOR ATHEROMA PROGRESSION DESPITE OPTIMAL GLYCEMIC CONTROL IN EARLY-STAGE DIABETIC PATIENTS: SUB-ANALYSIS FROM DIANA STUDY
Data de realització de les fotografies del Mercat aproximada (1994
Inter-Intra Molecular Dynamics as an Iterated Function System
The dynamics of units (molecules) with slowly relaxing internal states is
studied as an iterated function system (IFS) for the situation common in e.g.
biological systems where these units are subjected to frequent collisional
interactions. It is found that an increase in the collision frequency leads to
successive discrete states that can be analyzed as partial steps to form a
Cantor set. By considering the interactions among the units, a self-consistent
IFS is derived, which leads to the formation and stabilization of multiple such
discrete states. The relevance of the results to dynamical multiple states in
biomolecules in crowded conditions is discussed.Comment: 7 pages, 7 figures. submitted to Europhysics Letter
Antimicrobial Property of Titanium Plates Treated with Silica-Bound Protamine
Antimicrobial activity is necessary for dental prosthetic devices to maintain oral and systemic health in elderly people wearing prostheses. In particular, dental prosthetic devices with antifungal properties are urgently needed to prevent aspiration pneumonia. However, practical application methods to deliver antimicrobial properties to dental prosthetic devices have not yet been established. Therefore, in this study we aimed to fix protamine on titanium plates treated with silica coating using a Silano-Pen, and to evaluate the antimicrobial properties of the titanium plates against Candida albicans. Strong antifungal properties were obtained by soaking titanium plates in an aqueous protamine solution after silica coating treatment. Since this brand-new method is simple, its practical application is expected in the near future
Post-load hyperglycemia as an important predictor of long-term adverse cardiac events after acute myocardial infarction: a scientific study
<p>Abstract</p> <p>Background</p> <p>Diabetes mellitus (DM) and impaired glucose tolerance (IGT) are risk factors for acute myocardial infarction (AMI). However, it is unknown whether hyperglycemic state is associated with increased major adverse cardiovascular events (MACE) after AMI. In this study, we evaluated the relationship between glucometabolic status and MACE in patients after AMI, and determined the critical level of 2 h post-load plasma glucose that may be used to predict MACE.</p> <p>Methods</p> <p>AMI patients (n = 422) were divided into 4 groups as follows: normal glucose tolerance (NGT) group, IGT group, newly diagnosed DM (NDM) group, and previously known DM (PDM) group. MACE of the 4 groups were compared for 2 years from AMI onset.</p> <p>Results</p> <p>The NDM group had a significantly higher event rate than the IGT and NGT groups and had a similar event rate curve to PDM group. The logistic models analyses revealed that 2 h post-load plasma glucose values of ≥160 mg/dL was the only independent predictor of long-term MACE after AMI (p = 0.028, OR: 1.85, 95% CI: 1.07-3.21). The 2-year cardiac event rate of patients with a 2 h post-load hyperglycemia of ≥160 mg/dL was significantly higher than that of patients with 2 h post-load glucose of <160 mg/dL (32.2% vs. 19.8%, p < 0.05) and was similar to that of PDM group (37.4%, p = 0.513).</p> <p>Conclusions</p> <p>NDM increases the risk of MACE after AMI as does PDM. Particularly, post-AMI patients with a 2 h post-load hyperglycemia ≥160 mg/dL may need adjunctive therapy after AMI.</p
Kondo effect in nanostructures
Kondo effect arises whenever a coupling to the Fermi gas induces transitions
within the otherwise degenerate ground state multiplet of an interacting
system. Both coupling to the Fermi gas and interactions are naturally present
in any nanoscale transport experiment. At the same time, many nanostructures
can easily be tuned to the vicinity of a degeneracy point. This is why the
Kondo effect in its various forms often influences the low temperature
transport in meso- and nanoscale systems.
In this short review we discuss the basic physics of the Kondo effect and its
manifestations in the low-temperature electronic transport through a single
electron transistor
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