An In-Depth Study of the Barkhausen Emission Signal Properties of the Plastically Deformed Fe-2%Si Alloy

This paper presents the results of the in-depth study of the Barkhausen effect signal properties for the plastically deformed Fe-2%Si samples. The investigated samples have been deformed by cold rolling up to plastic strain epsilon(p) = 8%. The first approach consisted of time-domain-resolved pulse and frequency analysis of the Barkhausen noise signals whereas the complementary study consisted of the time-resolved pulse count analysis as well as a total pulse count. The latter included determination of time distribution of pulses for different threshold voltage levels as well as the total pulse count as a function of both the amplitude and the duration time of the pulses. The obtained results suggest that the observed increase in the Barkhausen noise signal intensity as a function of deformation level is mainly due to the increase in the number of bigger pulses.

Direct drinking water treatment by spiral-wound ultrafiltration membranes

This paper presents the results of a research on direct drinking water treatment through an ultrafiltration pilot plant unit using spiral-wound membranes (3500 MWCO). The source of water is the Guarapiranga Reservoir, an eutrophicated water body located in the metropolitan region of Sao Paulo, Brazil. The data were collected during a period of almost 3400 h, from August 2005 to January 2006. The main objective of the study was to evaluate the membrane production capacity and contaminant removal efficiency. It was verified that the system was able to produce a high quality permeate with a flow close to the specified by the membrane manufacturer. The average permeate flow was 19.7 L.h(-1).m(-2), at 467 kPa and 25 degrees C, with a global water recovery of almost 85%. The removal efficiencies for TOC, UV light absorption, and turbidity were 85%, 56%, and 95%, respectively. The results provide substantial evidence of the technical feasibility of spiral-wound UF membranes for direct drinking water treatment from euthrophicated sources, as an alternative for conventional drinking water treatment systems.

Optimal irrigation depth for bean crops considering water constraints and farmer`s risk aversion level

Nowadays, the rising competition for the use of water and environmental resources with consequent restrictions for farmers should change the paradigm in terms of irrigation concepts, or rather, in order to attain economical efficiency other than to supply water requirement for the crop. Therefore, taking into account the social and economical role of bean activity in Brazil, as well as the risk inherent to crop due to its high sensibility to both deficit and excessive water, the optimization methods regarding to irrigation management have become more interesting and essential. This study intends to present a way to determine the optimal water supply, considering different combinations between desired bean yield and level of risk, bringing as a result a graph with the former associated with the latter, depending on different water depths.

On the relationship between the critical temperature and the London penetration depth in layered organic superconductors

We present an analysis of previously published measurements of the London penetration depth of layered organic superconductors. The predictions of the BCS theory of superconductivity are shown to disagree with the measured zero temperature, in plane, London penetration depth by up to two orders of magnitude. We find that fluctuations in the phase of the superconducting order parameter do not determine the superconducting critical temperature as the critical temperature predicted for a Kosterlitz–Thouless transition is more than an order of magnitude greater than is found experimentally for some materials. This places constraints on theories of superconductivity in these materials.

Factors influencing wound healing after surgery for metastatic disease of the spine

Study Design, The study group consisted of 53 patients who underwent 75 operations for spine metastases. Patient and tumor demographic factors, preoperative nutritional status, and perioperative adjunctive therapy were retrospectively reviewed. Objective, To determine the risk factors for wound breakdown and infection in patients undergoing surgery for spinal metastases. Summary of Background Data. Spinal Fusion using spine implants may be associated with an infection rate of 5% or more. Surgery for spine metastases is associated with an infection rate of more than 10%. Factors other than the type of surgery performed may account for the greater infection rate. Methods. Data were obtained by reviewing patient records. Age, sex, and neurologic status of the patient; tumor type and site; and surgical details were noted. Adjunctive treatment with corticosteroids and radiotherapy was recorded, Nutritional status was evaluated by determining serum protein and serum albumin concentrations and by total lymphocyte count. Results. Wound breakdown and Infection occurred in 75 of 75 wounds. No patient or tumor demographic factors other than intraoperative blood loss (P < 0.1) were statistically associated with infection; The correlation between preoperative protein deficiency (P < 0.01) or perioperative corticosteroid administration (P < 0.10) and wound infection was significant. There was no statistical correlation between lymphocyte count or perioperative radiotherapy and wound infection. Conclusions, The results indicate that preoperative protein depletion and perioperative administration of corticosteroids are risk factors for wound infection in patients undergoing surgery for spine metastases, Perioperative correction of nutritional depletion and cessation of steroid therapy may reduce wound complications.

Content and context of monocular regions determine perceived depth in random dot, unpaired background and phantom stereograms

Perceived depth was measured for three-types of stereograms with the colour/texture of half-occluded (monocular) regions either similar to or dissimilar to that of binocular regions or background. In a two-panel random dot stereogram the monocular region was filled with texture either similar or different to the far panel or left blank. In unpaired background stereograms the monocular region either matched the background or was different in colour or texture and in phantom stereograms the monocular region matched the partially occluded object or was a different colour or texture. In all three cases depth was considerably impaired when the monocular texture did not match either the background or the more distant surface. The content and context of monocular regions as well as their position are important in determining their role as occlusion cues and thus in three-dimensional layout. We compare coincidence and accidental view accounts of these effects. (C) 2002 Elsevier Science Ltd. All rights reserved.

Wavefront Analysis, Contrast Sensitivity, and Depth of Focus After Cataract Surgery With Aspherical Intraocular Lens Implantation

PURPOSE: To determine whether implantation of an aspherical intraocular lens (IOL) results in reduced ocular aberrations and improved contrast sensitivity after cataract surgery without critical reduction of depth of focus. DESIGN: Double-blinded, randomized, prospective study. METHODS: In an intraindividual study of 25 patients with bilateral cataract, an aspherical IOL (Akreos Advanced Optic [AO]; Bausch & Lomb, Inc., Rochester, New York, USA) was implanted in one eye and a spherical IOL (Akreos Fit; Bausch & Lomb, Inc) in the fellow eye. Higher-order aberrations with a 5- and 6-mm pupil were measured with a dynamic retinoscopy aberrometer at 1 and 3 months after surgery. Uncorrected and best-corrected visual acuity and contrast sensitivity under mesopic and photopic conditions also were measured. Distance-corrected near and intermediate visual acuity were studied as a measurement of depth of focus. RESULTS: There was no statistically significant difference between eyes in uncorrected and best-corrected visual acuity at I and 3 months after surgery. There was a statistically significant between-group difference in contrast sensitivity under photopic conditions at 12 cycles per degree and under mesopic conditions at all spatial frequencies. The Akreos AO group obtained statistically significant lower values of higher-order aberrations and spherical aberration with 5- and 6-mm pupils compared with the Akreos Fit group (P < .05). There was no significant difference in distance-corrected near and intermediate visual acuity between both groups. CONCLUSIONS: Aspherical aberration-free Akreos AO IOL induced significantly less higher-order aberrations and spherical aberration than the Akreos Fit. Contrast sensitivity was better under mesopic conditions with the Akreos AO with similar results of depth of focus. (Am J Ophthalmol 2010;149:383-389. (C) 2010 by Elsevier Inc. All rights reserved.)

Short-term specialized enteral diet fails to attenuate malnutrition impairment of experimental open wound acute healing

Objective: We assessed the effect of enteral refeeding on the morphology, gene expression, and contraction of acute open wounds in previously malnourished rats using two different enteral diets. Methods: Adult male isogenic Lewis rats divided into two groups (eutrophic, n = 30; and previously malnourished, 12-15% body weight loss, n = 27) were subjected to cutaneous dorsal wounds and gastrostomy. Control rats received a standard oral diet (AIN-93M chow) plus enteral saline solution. Subject rats received chow plus a standard enteral diet or an enteral diet enriched with arginine and antioxidants. On post-trauma days 7 and 14, wound granulation tissue samples were collected for morphologic analysis using hematoxylin and eosin and picrosirius stain or immunohistochemistry slides and real-time polymerase chain reaction for collagen I and III gene expression. Wound contraction was also evaluated by comparing wound images from days 0,7, and 14. Results: Malnourished control rats had increased intensity and duration of wound inflammation, impaired increase of fibroblast cells contingent on post-trauma days 7 to 14, decreased expression of collagen III, and less wound contraction compared with eutrophic control rats. A specialized enteral diet did not improve wound healing of malnourished rats but did promote wound contraction at post-trauma day 7 in eutrophic rats. Conclusion: Short-term enteral refeeding, even with a specialized diet, failed to protect previously wounded malnourished rats from a prolonged inflammatory phase and impaired healing. (C) 2010 Elsevier Inc. All rights reserved.

Involvement of Astroglial Fibroblast Growth Factor-2 and Microglia in the Nigral 6-OHDA Parkinsonism and a Possible Role of Glucocorticoid Hormone on the Glial Mediated Local Trophism and Wound Repair

We have observed in previous studies that 6-hydroxydopamine (6-OHDA)-induced lesions in the nigrostriatal dopamine (DA) system promote increases of the astroglial basic fibroblast growth factor (FGF-2, bFGF) synthesis in the ascending DA pathways, event that could be modified by adrenosteroid hormones. Here, we first evaluated the changes of microglial reactivity in relation to the FGF-2-mediated trophic responses in the lesioned nigrostriatal DA system. 6-OHDA was injected into the left side of the rat substantia nigra. The OX42 immunohistochemistry combined with stereology showed the time course of the microglial activation. The OX42 immunoreactivity (IR) was already increased in the pars compacta of the substantia nigra (SNc) and ventral tegmental area (VTA) 2 h after the 6-OHDA injection, peaked on day 7, and remained increased on the 14th day time-interval. In the neostriatum, OX42 immunoreactive (ir) microglial profiles increased at 24 h, peaked at 72 h, was still increased at 7 days but not 14 days after the 6-OHDA injection. Two-colour immunofluorescence analysis of the tyrosine hydroxylase (TH) and OX42 IRs revealed the presence of small patches of TH IR within the activated microglia. A decreased FGF-2 IR was seen in the cytoplasm of DA neurons of the SNc and VTA as soon as 2 h after 6-OHDA injection. The majority of the DA FGF-2 ir cells of these regions had disappeared 72 h after neurotoxin. The astroglial FGF-2 IR increased in the SNc and VTA, which peaked on day 7. Two-colour immunofluorescence and immunoperoxidase analyses of the FGF-2 and OX42 IRs revealed no FGF-2 IR within the reactive or resting microglia. Second, we have evaluated in a series of biochemical experiments whether adrenocortical manipulation can interfere with the nigral lesion and the state of local astroglial reaction, looking at the TH and GFAP levels respectively. Rats were adrenalectomized (ADX) and received a nigral 6-OHDA stereotaxical injection 2 days later and sacrificed up to 3 weeks after the DA lesion. Western blot analysis showed time-dependent decrease and elevation of TH and GFAP levels, respectively, in the lesioned versus contralateral midbrain sides, events potentiated by ADX and worsened by corticosterone replacement. ADX decreased the levels of FGF-2 protein (23 kDa isoform) in the lesioned side of the ventral midbrain compared contralaterally. The results indicate that reactive astroglia, but not reactive microglia, showed an increased FGF-2 IR in the process of DA cell degeneration induced by 6-OHDA. However, interactions between these glial cells may be relevant to the mechanisms which trigger the increased astroglial FGF-2 synthesis and thus may be related to the trophic state of DA neurons and the repair processes following DA lesion. The findings also gave further evidence that adrenocortical hormones may regulate astroglial-mediated trophic mechanisms and wound repair events in the lesioned DA system that may be relevant to the progression of Parkinson`s disease.

Histologic Study of Acute Vocal Fold Wound Healing After Corticosteroid Injection in a Rabbit Model

Objectives: Injectable corticosteroids have been used in phonosurgery to prevent scarring of the vocal fold because of their effects of wound healing, and to ensure better voice quality. We histologically evaluated the effects of dexamethasone sodium phosphate infiltration on acute vocal fold wound healing in rabbits 3 and 7 days after surgically induced injury by quantification of the inflammatory reaction and collagen deposition. Methods: A standardized surgical incision was made in the vocal folds of 12 rabbits, and 0.1 mL dexamethasone sodium phosphate (4 mg/mL) was injected into the left vocal fold. The right vocal fold was not injected and served as the control. The larynges were collected 3 and 7 days after surgery. For histologic analysis, the vocal folds were stained with hematoxylin-eosin for quantification of the inflammatory response and with picrosirius red for qunatification of collagen depostion. Results: There was no quantitative difference in the inflammatory response between vocal folds injected with the corticosteroid and control vocal folds. However, the rate of collage deposition was significantly lower in the corticosteroid-treated group at 3 and 7 days after injury (p = 0.002). Conclusions: The present results suggest that dexamethasone reduces collagen depostion during acute vocal fold wound healing.

Increased Vascular Permeability, Angiogenesis and Wound Healing Induced by the Serum of Natural Latex of the Rubber Tree Hevea brasiliensis

Increases in vascular permeability and angiogenesis are crucial events to wound repair, tumoral growth and revascularization of tissues submitted to ischemia. An increased vascular permeability allows a variety of cytokines and growth factors to reach the damaged tissue. Nevertheless, the angiogenesis supply tissues with a wide variety of nutrients and is also important to metabolites clearance. It has been suggested that the natural latex from Hevea brasiliensis showed wound healing properties and angiogenic activity. Thus, the purpose of this work was to characterize its angiogenic activity and its effects on vascular permeability and wound healing. The serum fraction of the latex was separated from the rubber with reduction of the pH. The activity of the dialyzed serum fraction on the vascular permeability injected in subcutaneous tissue was assayed according Mile`s method. The angiogenic activity was determined using a chick embryo chorioallantoic membrane assay and its effects on the wound-healing process was determined by the rabbit ear dermal ulcer model. The serum fraction showed evident angiogenic effect and it was effective in enhancing vascular permeability. In dermal ulcers, this material significantly accelerated wound healing. Moreover, the serum fraction boiled and treated with proteases lost these activities. These results are in accordance with the enhancement of wound healing observed in clinical trials carried out with a biomembrane prepared with the same natural latex. Copyright (C) 2009 John Wiley & Sons, Ltd.

Quantitative three-dimensional power Doppler angiography: a flow-free phantom experiment to evaluate the relationship between color gain, depth and signal artifact

Objectives To evaluate the presence of false flow three-dimensional (3D) power Doppler signals in `flow-free` models. Methods 3D power Doppler datasets were acquired from three different flow-free phantoms (muscle, air and water) with two different transducers and Virtual Organ Computer-aided AnaLysis was used to generate a sphere that was serially applied through the 3D dataset. The vascularization flow index was used to compare artifactual signals at different depths (from 0 to 6 cm) within the different phantoms and at different gain and pulse repetition frequency (PR F) settings. Results Artifactual Doppler signals were seen in all phantoms despite these being flow-free. The pattern was very similar and the degree of artifact appeared to be dependent on the gain and distance from the transducer. False signals were more evident in the far field and increased as the gain was increased, with false signals first appearing with a gain of 1 dB in the air and muscle phantoms. False signals were seen at a lower gain with the water phantom (-15 dB) and these were associated with vertical lines of Doppler artifact that were related to PRF, and disappeared when reflections were attenuated. Conclusions Artifactual Doppler signals are seen in flow-free phantoms and are related to the gain settings and the distance from the transducer. In the in-vivo situation, the lowest gain settings that allow the detection of blood flow and adequate definition of vessel architecture should be used, which invariably means using a setting near or below the middle of the range available. Additionally, observers should be aware of vertical lines when evaluating cystic or liquid-containing structures. Copyright (C) 2010 ISUOC. Published by John Wiley & Sons, Ltd.