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51.
The appearance of a surface can be controlled by creating periodic microstructures designed to diffract light and produce structural colors. Nevertheless, since structural coloration is based on diffraction, the produced colors have a strong dependence on the viewing angle and absence of coloration takes place while tilting the samples. In this work direct laser interference patterning is used to firstly provide transparent polymer sheets a structural coloration with a high‐range observation angle, and secondly to demonstrate the combination of structural colors, producing a white coloring effect. The employed approaches are based on the fabrication of micro‐gratings with multiple periods in the same structured area and on the engineering of the diffraction orders of the diffraction spectrum. The patterned surfaces are characterized by confocal microscopy and angular spectrometry in reflection mode. The morphological characterization shows homogeneous surface patterns, while the spectral results demonstrate that combining four spatial periods on a single patterned surface, a white appearance is obtained over an angular observation range higher than 30°. The experimental results are supported by theoretical predictions by means of generalized formulas based on the diffraction of light.  相似文献   
52.
53.
Aims. To examine the utility and validate the use of the Cardiac Depression Scale in patients who had first‐time coronary artery bypass graft surgery. Background. The Beck Depression Inventory, though frequently used, may not be sufficiently sensitive for use in cardiac patients. The Cardiac Depression Scale has been shown to identify the range of depression in medical cardiac patients. Design. Survey. Methods. The Beck Depression Inventory and Cardiac Depression Scale were administered to 120 men at hospital discharge, as well as six, 12 and 36 weeks postoperatively. Cronbach’s α scores were calculated for the measures at each point. Changes in scores over time were analysed using repeated measures analysis of variance. Associations between the measures scores were calculated using Pearson product–moment correlations. Agreement between the measures’ dichotomised scores (depression/no depression) was examined using Cohen’s Kappa statistic. Results. Internal consistency was similar for the Beck Depression Inventory (0·793–0·904) and Cardiac Depression Scale (0·859–0·910). Depression scores decreased over time with the Beck Depression Inventory [F(2·50, 175·29) = 22·27, p < 0·001] and Cardiac Depression Scale [F(2·68, 190·37) = 13·18, p < 0·001]. The measures had similar power [Cohen’s f = 0·65 (Beck Depression Inventory) and 0·43 (Cardiac Depression Scale)] to reveal changes over time. The continuous scores were highly correlated at each point [0·737 (p < 0·001)–0·819 (p < 0·001)]. However, when dichotomised scores were compared, the chance corrected level of agreement was less impressive [0·198 (p = 0·014)–0·381 (p < 0·001)]. Conclusions. The Cardiac Depression Scale may have utility for use with surgical cardiac patients. However, continued examination of this measure of depression is warranted. Relevance to clinical practice. Given the prevalence of depression and its negative impact on coronary artery disease, it is important to identify even mild depression in cardiac patients. Using a measure of depression specifically for cardiac patients, rather than a generic measure, may best accomplish this goal.  相似文献   
54.
Zusammenfassung Trotz zahlreicher Fortschritte in der Intensivmedizin stellt die Behandlung von Patienten mit schwerer Sepsis und septischem Schock eine medizinische Herausforderung dar. In der Pathogenese der systemischen Inflammation (SIRS) kommt es zur exzessiven Freisetzung von multiplen endogenen und exogenen inflammatorischen Mediatoren [z. B. Lipopolysaccharid (LPS), Tumor-Nekrose-Faktor (TNF)-α, Interleukin (IL)-1, IL-6] und zur Entwicklung eines Multi- Organ-Versagen (MOV). Dies führt bekannterma?en zu schlechten überlebenszahlen septischer Patienten. Ein komplexes dynamisches Kontrollsystem führt in der Abfolge meist zur zeitnahen gegen-regulatorischen antiinflammatorischen Antwort mittels Induktion anti-inflammatorischer Mediatoren (IL-10, transforming growth factor-beta [TGF-β]). In einer gro?en Anzahl septischer Patienten kommt es durch eine Persistenz des inflammatorischen Reizes zu einer Deaktivierung von antigenpr?sentierenden Zellen bzw. zu einem Versagen des zellvermittelten Immunsystems („Immunparalyse“). Unselektive und selektive intermittierende und kontinuierliche extrakorporale Therapieverfahren wurden evaluiert, ob diese in der Lage sind, in inflammatorische durch den klinischen Verlauf günstig zu beeinflussen. Technologische Fortschritte im Hinblick auf die Entwicklung von extrakorporalen Plasmapherese- bzw. Adsorptionsverfahren bieten heute neue, effektive M?glichkeiten, Mediatoren aus der Blutbahn septischer Patienten zu entfernen. In der vorliegenden übersichtsarbeit werden aktuell verfügbare und zukünftige adjunktive extrakorporale Therapiestrategien vorgestellt und vor dem Hintergrund aktueller Studien diskutiert.   相似文献   
55.
56.
The transient nature of the internal pore structure of particulate wall flow filters, caused by the continuous deposition of particulate matter, makes studying their flow and filtration characteristics challenging. In this article we present a new methodology and first experimental demonstration of time resolved in-situ synchrotron micro X-ray computed tomography (micro-CT) to study aerosol filtration. We directly imaged in 4D (3D plus time) pore scale deposits of TiO2 nanoparticles (nominal mean primary diameter of 25 nm) with a pixel resolution of 1.6 μm. We obtained 3D tomograms at a rate of ∼1 per minute. The combined spatial and temporal resolution allows us to observe pore blocking and filling phenomena as they occur in the filter’s pore space. We quantified the reduction in filter porosity over time, from an initial porosity of 0.60 to a final porosity of 0.56 after 20 min. Furthermore, the penetration depth of particulate deposits and filtration rate was quantified. This novel image-based method offers valuable and statistically relevant insights into how the pore structure and function evolves during particulate filtration. Our data set will allow validation of simulations of automotive wall flow filters. Evolutions of this experimental design have potential for the study of a wide range of dry aerosol filters and could be directly applied to catalysed automotive wall flow filters.  相似文献   
57.
We have a previously reported that interleukin-10 (IL-10) is a potent but IL-6-unrelated growth factor for freshly explanted myeloma cells (Lu et al, Blood 85:2521, 1995). We have also shown that exogenous IL- 10 supported the growth of XG-1 and XG-2 human myeloma cell lines (HMCL) through an IL-6-independent mechanism. (Lu et al, Blood 85:2521, 1995). Because the IL-10 receptor does not involve the gp 130 IL-6 transducer, we have attempted to elucidate the mechanisms of IL-10 action on myeloma cells. Our results indicate that the myeloma cell growth factor activity of IL-10 was abrogated by an antibody to the gp 130 IL-6 transducer, indicating that it was mediated through one of the gp 130-activating cytokines. We found that myeloma cells from XG-1 and XG-2 HMCL and from 5 of 6 patients' tumoral samples produced oncostatin M (OM) constitutively but failed to produce IL-6, IL-11 and leukemia- inhibitory factor (LIF). The autocrine OM was inactive in the absence of IL-10 due to lack of a functional OM receptor on myeloma cells. IL- 10, by inducing the receptor for LIF (LIFR), produced a functional autocrine OM loop in XG-1 and XG-2 cells and in primary myeloma cells from 2 patients. We also found that some myeloma cell lines (XG-4, XG- 6, and XG-7) an fresh myeloma cells from 3 of 6 patients produced an autocrine IL-10 and that these cells constitutively expressed LIFR. One HMCL (XG-7) produced IL-10, OM, and IL-6 an expressed LIFR. The XG-7 cells used OM and IL-6 as autocrine growth factors. We have previously shown that IL-10 could induce IL-11 receptor in myeloma cells and confer on them sensitivity to IL-11 (Lu et al, FEBS Lett 377:515, 1995). Taken together, these results show that IL-10 is a key cytokine for inducing the expression of LIFR and IL-11R and possibly another uncharacterized OM coreceptor on myeloma cells and that OM and IL-10 might be produced by myeloma cells. They also emphasize that all myeloma cell growth factors reported to data involve an activation of the gp130 IL-6 transducer.  相似文献   
58.
Human cytomegalovirus (CMV) infection is often associated with myelosuppression and acute inflammatory reaction in immunocompromised patients. We have previously documented that CMV exposure of bone marrow (BM) stromal cells reduces the capacity of these cells to support hematopoiesis because of a decreased production of colony- stimulating factors. This study examines the potential role of CMV on constitutive and lipopolysaccharide (LPS)-stimulated production of cytokines involved in inflammatory reaction, interleukin-6 (IL-6) and leukemia inhibitory factor (LIF) by BM stromal cells. The release of IL- 6 was already detectable 2 hours post CMV-infection (2.5-fold increase in production) and the cumulative production of IL-6 after 5 days of infection was 23 +/- 1.2 ng/mL (ninefold increase in production). CMV was also able to induce a time-dependent production of LIF that was maximal 8 hours after CMV infection (2.5-fold increase in production). Concomitantly, there was no detectable release of granulocyte colony- stimulating factor (G-CSF) and granulocyte-macrophage CSF (GM-CSF) by CMV-infected stromal cells. The similar IL-6 and LIF production in the presence of polymyxin B ruled out the possibility that this increase could be caused by contamination of the viral stock by endotoxin. In addition, ultraviolet-inactivated virus behaved similarly to live virus and caused the release of IL-6 and LIF. However, heat-inactivated CMV was unable to induce IL-6 and LIF secretion by BM stromal cells. The production of IL-6 and LIF was also evaluated after stimulation by LPS. After 5 days of CMV exposure, the LPS-stimulated production of IL-6 and LIF was significantly lower than uninfected controls. This LPS-induced release of cytokine production was found to be dependent of viral replication. The experiments have shown that CMV is a potent inducer of IL-6 and LIF with differential effect on constitutive and LPS- stimulated cytokine production by stromal cells; we suggest that CMV induction of IL-6 and LIF during the first hours of infection could play a role in CMV-induced inflammatory reaction. Moreover, our results show that human CMV can disturb the balanced cytokine network involved in the regulation of hematopoiesis.  相似文献   
59.
Modulation of megakaryocytopoiesis by thrombopoietin: the c-Mpl ligand   总被引:2,自引:1,他引:2  
Banu  N; Wang  JF; Deng  B; Groopman  JE; Avraham  H 《Blood》1995,86(4):1331-1338
We have further characterized the biological activities, mechanism of action, and target cell populations of recombinant human and murine thrombopoietin (rhTPO and rmTPO) in in vitro human and murine model systems. Alone, hTPO or mTPO stimulated the maturation of immature murine megakaryoblasts as measured in a single cell assay. The combination of hTPO or mTPO and interleukin-6 (IL-6) resulted in a further increase in megakaryocyte differentiation in this system. Murine TPO stimulated mouse megakaryocyte progenitor development. Human megakaryocyte progenitor development was potentiated by hTPO alone and further augmented in the presence of the early-acting cytokines (IL-3) or kit ligand/stem cell factor (KL/SCF). To further define the mechanism of action of TPO, neutralization studies were performed with antisera to IL-3, granulocyte-macrophage colony-stimulating factor (GM- CSF), IL-1 beta, and IL-11. No diminution in TPO activity was observed in the presence of these antisera. Moreover, because adhesive interactions are known to modulate hematopoiesis, we studied whether hTPO might alter such interactions between human bone marrow (BM) megakaryocytes and human BM stromal fibroblasts. No changes were observed in either megakaryocyte expression of the surface molecules lymphocyte function-associated antigen-1, very late activation antigen- 4, or intercellular adhesion molecule-1 or the adhesion of megakaryocytes to stromal fibroblasts after treatment with the growth factor. Furthermore, no induction of secretion of the cytokines IL-1 alpha, IL-1 beta, GM-CSF, IL-6, granulocyte-CSF, tumor necrosis factor- alpha, transforming growth factor-beta 1, or transforming growth factor- beta 2 by primary human BM megakaryocytes was noted after treatment of the cells with hTPO. To address whether TPO affects very primitive hematopoietic progenitors, we studied the residual cells from the BMs of mice treated with high doses of 5-fluorouracil. Although no effect of mTPO alone was noted on the viability or replication of such primitive murine progenitor populations, the triple combination of IL-3 + KL/SCF + TPO stimulated growth of megakaryocyte progenitors. These results indicate that TPO is a highly lineage-specific growth factor whose primary biological effects are likely to be direct modulation of the growth and maturation of committed megakaryocyte precursors and immature megakaryoblasts.  相似文献   
60.

Purpose

To assess the ability of quantitative pupillometry [using the Neurological Pupil index (NPi)] to predict an unfavorable neurological outcome after cardiac arrest (CA).

Methods

We performed a prospective international multicenter study (10 centers) in adult comatose CA patients. Quantitative NPi and standard manual pupillary light reflex (sPLR)—blinded to clinicians and outcome assessors—were recorded in parallel from day 1 to 3 after CA. Primary study endpoint was to compare the value of NPi versus sPLR to predict 3-month Cerebral Performance Category (CPC), dichotomized as favorable (CPC 1–2: full recovery or moderate disability) versus unfavorable outcome (CPC 3–5: severe disability, vegetative state, or death).

Results

At any time between day 1 and 3, an NPi?≤?2 (n?=?456 patients) had a 51% (95% CI 49–53) negative predictive value and a 100% positive predictive value [PPV; 0% (0–2) false-positive rate], with a 100% (98–100) specificity and 32% (27–38) sensitivity for the prediction of unfavorable outcome. Compared with NPi, sPLR had significantly lower PPV and significantly lower specificity (p? <?0.001 at day 1 and 2; p ?=?0.06 at day 3). The combination of NPi?≤?2 with bilaterally absent somatosensory evoked potentials (SSEP; n?=?188 patients) provided higher sensitivity [58% (49–67) vs. 48% (39–57) for SSEP alone], with comparable specificity [100% (94–100)].

Conclusions

Quantitative NPi had excellent ability to predict an unfavorable outcome from day 1 after CA, with no false positives, and significantly higher specificity than standard manual pupillary examination. The addition of NPi to SSEP increased sensitivity of outcome prediction, while maintaining 100% specificity.
  相似文献   
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