Acute endocarditis of the native aortic valve caused by Propionibacterium acnes

Propionibacterium acnes is often considered to be a contaminant but it has also been found to be the principal pathogen in serious infections. P. acnes is a rare cause of infective endocarditis. It has been suggested that aortic root abscesses are caused by bacteria that are particularly virulent. The strongest risk factor for serious infections by this bacteria is the presence of foreign bodies. A case is presented in which endocarditis of a native aortic valve caused by P. acnes was associated with an aortic root abscess. Transesophageal echocardiography is particularly helpful in the diagnosis of this severe complication of infective endocarditis. The literature for P. acnes endocarditis is reviewed.     

Forming processes control by means of artificial intelligence techniques

Forming processes are manufacturing processes that use force and pressure in order to modify the shape of a material part until obtaining the final product. The wide range of non-linear factors that drive this sort of processes make them very complex and extremely difficult to be controlled. Traditional control techniques, like PID controllers, have not offered a reliable solution when global control has been pursued and the figure of the operator still remains present in most of the forming facilities. On the other hand, although operators have demonstrated to be a very successful strategy when controlling this type of processes, the actual market evolution towards the fabrication of more complex parts, made of lower formability materials at higher production rates, is decreasing their capacity of reaction when solving the daily problems. Thus, the development of new global control systems based not on traditional control techniques and mathematical models but on the control strategy that has been used successfully for many years, the control through the experience and knowledge is now even more necessary. In the present work, an intelligent control system based on one of the main techniques within the artificial intelligence, expert systems, has been developed. The main purpose of this intelligent control system is to emulate the decisions that expert operators take but in a quicker and more reliable way. The developed intelligent control system has been installed in a blanking facility and very good results have been achieved.     

Ultrastructural and immunohistochemical study of the effect of sodium alendronate in the progression of experimental periodontitis in rats

The aim of the present research was to investigate the ultrastructural aspects and the immunoexpression of receptor activator of NFκB ligand (RANKL) and osteoprotegerin (OPG) on experimental periodontal disease of alendronate (ALN)‐treated rats. Male Wistar rats received daily injections of 2.5 mg/kg body weight of ALN during 7 days previously and 7, 14, and 21 days after the insertion of a 4.0 silk suture into the gingival sulcus around the right upper second molar. Specimens were fixed in 0.1% glutaraldehyde + 4% formaldehyde under microwave irradiation, decalcified in 4.13% EDTA and paraffin embedded for TRAP histochemistry and immunohistochemistry for RANKL and OPG, or embedded in Spurr epoxy resin for TEM analysis. ALN reduced the activity of osteoclasts and significantly decreased the resorption of the alveolar crest. In the control group the alveolar crest appeared resorbed by TRAP‐positive osteoclasts, which presented ultrastructural features of activated cells. The immunoexpression of RANKL was not inhibited by the drug; however, the expression of OPG was increased in the treated animals. The alveolar crest of ALN‐treated specimens at 21 days showed signs of osteonecrosis, like empty osteocyte lacunae, the exposed bone regions and bacterial infection. The results showed that ALN treatment in individuals with periodontal disease represents a risk of osteonecrosis because of the reduced activity of osteoclasts resultant of the increased immunoexpression of OPG. Microsc. Res. Tech. 77:902–909, 2014. © 2014 Wiley Periodicals, Inc.     

Microbiological, physicochemical, and sensory characteristics of kefir during storage

Changes in certain microbiological, physicochemical, and sensory parameters of kefir were studied during refrigerated storage. Kefir batches were prepared using 1% and 5% added kefir grains, and samples for analysis were taken 24 h after inoculation and then after 2, 7, 14, 21, and 28 days of storage at 5 ± 1 °C. After fermentation for 24 h after inoculation, lactobacilli and lactococci were present at levels of 10⁸ cfu/ml, and yeasts and acetic acid bacteria were present at levels of 10⁵ and 10⁶ cfu/ml, respectively. The lactic acid flora decreased by about 1.5 log units between days 7 and 14 and then stabilized at that level. Yeast and acetic acid bacterial counts, lactose, and pH all remained constant over the storage period, while the total fat content and dry matter decreased. The percentage inoculate did exert an influence, and the sample batches made using 1% added kefir grains had higher lactic acid bacterial counts, lactose, and pH, while the sample batches made using 5% added kefir grains had higher yeast and acetic acid bacterial counts and viscosity. The total fat and dry matter contents were similar in both sample batches. Sensory analysis of the kefir samples revealed maximum acceptability levels in the first 2 days of storage.     

Dichotic listening and corpus callosum magnetic resonance imaging in relapsing-remitting multiple sclerosis with emphasis on sex differences.

Twenty-five early-onset relapsing-remitting multiple sclerosis patients (12 women and 13 men) with mild disability were compared with 25 matched controls in a dichotic listening (DL) test under nonforced and forced attentional-shift conditions. Patients showed left ear impairment and no left ear advantage in the forced-left condition. Four corpus callosum (CC) regions were measured in patients on a rnidsaggital magnetic resonance imaging scan. The right ear score was negatively correlated whereas the left ear score was positively correlated with CC regions (significant only for the nonforced condition). Moreover, in men, the correlations with DL scores were linked mainly to the splenium and posterior isthmus, and in women, they were stronger for anterior isthmus and posterior body. An inverse correlation between months of disease evolution and CC area was found only in women. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A microfabricated suspended-tube chemical reactor for thermally efficient fuel processing

We present a suspended-tube chemical reactor/heat exchanger for high-temperature fuel processing in micro energy conversion systems, primarily for hydrogen production in portable fuel cell systems. This reactor, designed to thermally isolate a high-temperature reaction zone, consists of four free-standing silicon nitride tubes comprising two independent U-shaped fluidic channels. Portions of the tubes are encased in silicon to enable heat exchange between the fluids in these channels. A thin-film platinum resistor is embedded for localized heating and temperature sensing. This paper describes the design and fabrication process for the MEMS fuel processor. Fluidic testing, thermal characterization up to 825/spl deg/C, and preparation of catalyst washcoats in the reactor microchannels are discussed. In addition, results from catalytic autothermal butane combustion and ammonia cracking in the reactor are presented.     

Ultrastructural and immunohistochemical study of early repair of alveolar sockets after the extraction of molars from alendronate‐treated rats

The aim of the present research was to analyze ultrastructural and immunohistochemical aspects of the alveolar repair after the extraction of molars of alendronate (ALN)‐treated rats. Wistar rats received 2.5mg/kg body wt/day of ALN during 14 days previously and 7, 14 and 21 days after the extraction of the second mandibular molar. Specimens were fixed in 2% glutaraldehyde + 2.5% formaldehyde under microwave irradiation, decalcified in 4.13% EDTA and paraffin embedded for TRAP histochemistry and immunohistochemistry for OPN, BSP and endoglin, or embedded in Spurr epoxy resin for TEM analysis. Additional specimens had their soft tissues removed and were processed for scanning electron microscopy. The ALN group presented latent TRAP‐positive osteoclasts and nonresorbed alveolar crests with bacterial infection. Mild bone necrosis signs were observed at all time points studied. Ultrastructurally, empty osteocyte lacunae were observed and bone trabeculae surface presented hyalinized aspect. A significant delay in alveolar repair occurred, as well as decreased angiogenesis. ALN treatment provoked mild signs of bone necrosis, despite the high dose employed. The present findings add new information about the ultrastructural aspect of the early repair of rats under ALN treatment and highlight for giving attention when oral surgeries are performed in patients using this drug. Microsc. Res. Tech. 76:633–640, 2013. © 2013 Wiley Periodicals, Inc.     

Semiautomatic Analysis of Phase Contrast Magnetic Resonance Imaging of Cerebrospinal Fluid Flow through the Aqueduct of Sylvius

Objective: Quantification of the cerebrospinal fluid (CSF) flow through the aqueduct of Sylvius by means of magnetic resonance imaging (MRI) is subject to interobserver variability due to the region of interest (ROI) selection. Our objective is to develop a semiautomatic measurement method to achieve reproducible quantitative analysis of CSF flow rate and stroke volume. Material and methods: MR examinations were performed using a 1.5 T scanner with a phase contrast sequence (velocity encoding [V _enc] of 20 cm/s, FOV = 160, 3 mm slice thickness, image matrix size = 256×256, TR = 53 ms, TE = 11 ms, NSA = 2, flip angle = 15° and 23 frames per cardiac cycle with peripheral retrospective pulse gating). Our method was developed using MATLAB R7. Errors introduced by background offset and possible aliased pixels were automatically detected and corrected if necessary in order to calculate the flow parameters that characterize CSF dynamics. The semiautomatic seed method reproducibility was evaluated and compared with the radius method by two observers analysing 21 healthy subjects. Results: The measurements using the semiautomatic seed method reduced the interobservers variability (intra-class correlation [ICC] = 1.0 for stroke volume and for volumetric flow rate) versus the radius method (ICC = 0.46 for stroke volume and 0.65 for flow rate). Normal stroke volume (39.19 ± 20.13 μl/cycle), flow rate (3.81 ± 2.81 ml/min), maximal mean systolic velocity (5.27 ± 1.3 cm/s) and maximal mean diastolic velocity (4.20 ± 1.4 cm/s) were calculated with the half moon and aliasing corrected seed method. Conclusions: Semiautomatic measurements (seed method with half moon background and aliasing correction) allow a generalization of the calculus of flow parameters with great consistency and independency of the operator.     

High temperature circular position sensor based on a giant magnetoresistance nanogranular Ag/sub x/Co/sub 1-x/ alloy

A new circular position sensor based on giant magnetoresistances has been developed. The sensing film is an AgCo nanogranular thin film patterned in a circular Wheatstone bridge configuration. This alloy shows a high magnetoresistance (8%) at room temperature within the field generated by an NdFeB permanent magnet that provides a sensitivity of 440 /spl mu/V/V/(/spl deg/). The operational temperature range of this sensor is -40/spl deg/C/+120/spl deg/C, although the magnetic film tolerates higher temperatures up to 200/spl deg/C. These parameters and the contactless way of sensing make this device appropriate for automotive applications. The developed sensor presents excellent characteristics for life, since it is not sensitive to pollution; it is frictionless and does not present any type of electrical noise generated by contacts.     

Erythrocyte Membrane Nanomechanical Rigidity Is Decreased in Obese Patients

This work intends to describe the physical properties of red blood cell (RBC) membranes in obese adults. The hypothesis driving this research is that obesity, in addition to increasing the amount of body fat, will also modify the lipid composition of membranes in cells other than adipocytes. Forty-nine control volunteers (16 male, 33 female, BMI 21.8 ± 5.6 and 21.5 ± 4.2 kg/m², respectively) and 52 obese subjects (16 male and 36 female, BMI 38.2± 11.0 and 40.7 ± 8.7 kg/m², respectively) were examined. The two physical techniques applied were atomic force microscopy (AFM) in the force spectroscopy mode, which allows the micromechanical measurement of penetration forces, and fluorescence anisotropy of trimethylammonium diphenylhexatriene (TMA-DPH), which provides information on lipid order at the membrane polar–nonpolar interface. These techniques, in combination with lipidomic studies, revealed a decreased rigidity in the interfacial region of the RBC membranes of obese as compared to control patients, related to parallel changes in lipid composition. Lipidomic data show an increase in the cholesterol/phospholipid mole ratio and a decrease in sphingomyelin contents in obese membranes. ω-3 fatty acids (e.g., docosahexaenoic acid) appear to be less prevalent in obese patient RBCs, and this is the case for both the global fatty acid distribution and for the individual major lipids in the membrane phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylserine (PS). Moreover, some ω-6 fatty acids (e.g., arachidonic acid) are increased in obese patient RBCs. The switch from ω-3 to ω-6 lipids in obese subjects could be a major factor explaining the higher interfacial fluidity in obese patient RBC membranes.