Neurologic injuries in pelvic ring fractures

Unstable fractures of the pelvic ring are an increasingly frequent outcome of motor vehicle trauma. Neurologic injury after such injuries can be a cause of significant morbidity. The available literature on neurologic injuries was reviewed and compared with a clinical review of 90 unstable pelvic injuries treated during a 3-year period. Eighty-three patients were available for followup examination. Neurologic injuries were seen in 21 % of the patients. Thirty-seven percent of patients had sensory deficits alone whereas the remaining 63% had motor and sensory findings. All patients showed some evidence of neurologic recovery at an average or 24-months followup. At least 1 grade of muscle function improvement was consistently seen and 53% of patients had complete neurologic recovery. Improvement in function was seen as many as 24 months postinjury, but L5 function was least likely to progress to full recovery. The incidence of neurologic injuries and their distribution was similar to that reported in the literature, whereas the prognosis for neurologic recovery was significantly better. This may be related to techniques of early anatomic reduction and stabilization of unstable pelvic ring injuries.     

Ventricular electrical instability in the conscious dog: effects of psychologic stress and beta adrenergic blockade

The effect of psychologic stress on cardiac vulnerability was examined in 10 conscious dogs. The repetitive extrasystole threshold was employed as a measure of susceptibility to ventricular fibrillation. Instrumental aversive conditioning constituted a stressful environment. The repetitive extrasystole threshold decreased by nearly 50 percent during 3 days in which the animals were exposed to the stressful environment. When Tolamolol hydrochloride, a cardioselective beta adrenoceptor blocking agent, was administered before a stress session, the repetitive extrasystole threshold was unaltered from the control value. Thus, stress-evoked changes in cardiac vulnerability are mediated through the sympathetic nervous system.     

Distributed Strain Measurement in Steel Bridge with Fiber Optic Sensors: Validation through Diagnostic Load Test

Fiber optic sensing technologies are emerging as valid alternatives for the health monitoring of civil structures. Distributed sensors based on Brillouin scattering add the unique capability of measuring strain and temperature profiles along optical fibers. Measurement is performed by establishing the correlation between fiber strain and temperature, and the frequency shift of the Brillouin backscattered light induced by a monochromatic light pulse. The technology holds potential for use on large structures and integrated transportation infrastructure. Its effectiveness has been assessed through scaled laboratory experiments, whereas field validation is limited to very few demonstration projects conducted to date. This paper presents a pilot application of Brillouin optical time domain reflectometry to measure strain profiles along the steel girders of a continuous slab-on-girder bridge subjected to diagnostic load testing. One of the exterior continuous girders required heat-straightening after falling during construction due to wind. The significance of applying a distributed measurement technique lies in the potential to assess the global girder response, which would be impractical and uneconomical using discrete measurement techniques. A 1.16?km long sensing circuit was installed onto the web of four girders. The circuit comprises bare optical fiber sensors, and a novel adhesively bonded fiberglass tape with embedded sensing fibers for strain measurement and thermal compensation. The strain profiles were first converted into deflection profiles and validated against discrete deflection measurements performed with a high-precision total station system. Structural assessment based on comparison of the strain profiles with the results of three-dimensional finite-element analysis of the bridge superstructure, and with specification mandated criteria, indicated that the response of the girder under investigation was within the design limits, and did not pose serviceability concerns. Factors that may affect measurement accuracy are finally discussed on the basis of the experimental and numerical results.     

Tool management in flexible manufacturing systems with network part program

Recent technological developments have allowed a new concept of a part program to execute the machining operations that remove the software constraints introduced by the numerical control of machining centres. This change allows machines executing a part program to be structured as a net of operations and not linearly as normally happens in shop floors. The main advantage of using the network part program in numerically controlled machines is that it gives the system more flexibility by increasing the number of alternatives that machines can follow during work. In such a way, machines select their path in the network part program taking into account the dynamic state of resources (e.g. spindles, tools, carriers, pallets, etc.). The paper contains a study on the flexibility related to network part program exploitation in numerically controlled machines. Easy-to-calculate indicators are also defined. They estimate the potential flexibility of a network part program related to a particular product. The study has allowed the definition of a new tool management rule to be used in a flexible manufacturing system where the tools are shared dynamically among machines. The numerical results carried out on two different real cases demonstrate the validity of the new concept by quantifying the advantages in terms of throughput increment and machine idle-time reduction.     

Poly(lactic acid) biocomposites with mango waste and organo-montmorillonite for packaging

Poly(lactic acid) (PLA) is a biodegradable polymer used in packaging, but its properties can be improved by manufacturing composite matrixes. The combination of PLA, starch, and nano-montmorillonite leads to materials with superior mechanical properties. Mango lump is rich in cellulose and starch. The goal of this study is to develop and characterize biocomposites based on PLA, mango waste, and nano-organo-montmorillonite for packaging. The samples were microstructurally, morphologically, and mechanically characterized. Physical interaction between the phases was observed. The mango components displaced the PLA X-ray diffraction peaks and the clays altered their intensity, by interfering with chain packing. The addition of single components to PLA increased the samples’ transition temperatures, but the addition of multiple components diminished them. PLA showed adhesiveness to cellulose fibers and nonadhesiveness to starch granules. Thicker samples presented better mechanical properties. PLA–mango–“chocolate clay” samples are relatively stable materials, while PLA–mango–“bofe clay” samples could represent promising highly biodegradable materials. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47512.     

Consumer Liking of Fruit Juices with Different Açaí (Euterpe oleracea Mart.) Concentrations

ABSTRACT:  Overall liking, flavor, and perceived healthiness of one newly developed fruit juice with high açaí content (40% açaí) and 5 commercially available fruit juices with lower (4% to 20%) açaí concentrations were evaluated by consumers in Belgium. General trends for the overall sample were examined by means of analysis of variance, whereas individual consumer preferences were evaluated using internal preference mapping and hierarchical cluster analysis. The relative contribution of flavor and perceived health benefits as predictors of consumers' overall liking of the 6 açaí-based fruit juices was estimated through linear regression analysis. The results showed a negative relationship between the juices' overall liking and their açaí concentrations. Although the vast majority of consumers preferred the juices having a low açaí content (4% to 5% açaí), a small consumer segment liked the juice with 40% açaí. Flavor or taste experience superseded consumers' perceived health benefits as the primary determinant of the fruit juices' overall liking. The impact of perceived health benefits on the overall liking of the açaí juices decreased with higher taste dissatisfaction.     

Sepsis-induced vasoparalysis does not involve the cerebral vasculature: indirect evidence from autoregulation and carbon dioxide reactivity studies

We have studied cerebral autoregulation and vasoreactivity to carbon dioxide in 10 patients with the sepsis syndrome receiving intensive therapy. All patients were sedated with infusions of midazolam and fentanyl, and their lungs were ventilated mechanically with oxygen-air to maintain normoxia and normocapnia. Inotropic support and antibiotics were administered as necessary. During a period of constant level of sedation and stable haemodynamics, cerebral autoregulation was tested by increasing mean arterial pressure (MAP) by 23 (SD 2) mm Hg from baseline with an infusion of phenylephrine and simultaneously recording middle cerebral artery blood flow velocity (vmca) using transcranial Doppler ultrasonography. Carbon dioxide reactivity was tested by varying PaCO2 between 3.0 and 7.0 kPa and simultaneously recording vmca. There was no significant change in vmca (57 (22) and 59 (23) cm s-1) during the increase in MAP (75 (11) to 98 (10) mm Hg). The mean index of autoregulation (IOR) was 0.92 (SEM 0.03), which was not significantly different from 1, indicating near perfect autoregulation. Although absolute carbon dioxide reactivity was lower than reported previously in awake subjects, relative carbon dioxide reactivity was within normal limits for all patients (11.6 (SEM 0.8) cm s-1 and 20.3 (3) % kPa-1, respectively). We conclude that cerebral carbon dioxide reactivity and pressure autoregulation remained intact in patients with the sepsis syndrome, providing indirect evidence that at least in the early stages of the syndrome, the widespread sepsis-induced vasoparalysis does not involve the cerebral vasculature.     

Catalytic combustion of model carbon particles (CPs) over Pt/β-SiC catalyst

Topics in Catalysis - Platinum catalyst supported on a medium surface area β-SiC was successfully used for the catalytic combustion of model carbon particles and compared to a catalyst...     

Hip fusion through an anterior approach with the use of a ventral plate

A new technique to achieve a reliable fusion of the hip joint through an anterior approach with use of a ventral low contact dynamic compression plate and a lateral 6.5 mm lag screw is presented in detail. The advantages of this technique are that the approach does not jeopardize the vascularity of the femoral head, that the fixation on the pelvic side uses the strong bone stock of the sciatic buttress, and that the hip abductor muscles and greater trochanter are preserved. The authors also present the indications and the results of their experience with 12 patients. The followup period averaged 24.8 months (range, 10-42 months). Ten patients (83%) achieved a solid fusion by radiologic and clinical criteria. Although a moderately symptomatic nonunion developed in 1 patient, another patient went on to a painful nonunion to whom another attempt for fusion has been recommended. According to the hip score of Merle d'Aubigné and Postel, the average figures for pain and ambulation increased from 3.2 points to 5.0 points and from 2.7 points to 4.5 points, respectively, after surgery. Six of the 12 patients regained the ability to work in their former jobs or in new occupations. Eight patients felt no or minor restrictions in doing their former sports activities. Patient satisfaction was high with a majority reporting minor discomfort mainly around the fused hip.     

Microstructure and thermomechanical pretreatment effects on creep behaviour of helium-implanted DIN 1·4970 austenitic stainless steel

Microstructure investigations were carried out on unimplanted and 150 at.ppm helium implanted foil specimens of DIN 1·4970 austenitic stainless steel after various thermomechanical pretreatments. Creep tests were also carried out for both helium-implanted and unimplanted specimens at 700°C and 800°C. The strength, ductility and rupture time are correlated with the dislocation and precipitate distributions. Helium embrittlement can be reduced in these experiments when dispersive TiC precipitate distributions are produced by proper pretreatments or allowed to form during creep test.