Strontium modification is known to alter the amount, characteristics, and distribution of porosity in Al-Si castings. Although many theories have been proposed to account for these effects, most can ...be considered inadequate because of their failure to resolve contradictions and discrepancies in the literature. In an attempt to critically appraise some of these theories, the amount, distribution, and morphology of porosity were examined in sand-cast plates of Sr-free and Sr-containing pure Al, Al-1 wt pct Si, and Al-9 wt pct Si alloys. Statistical significance testing was used to verify apparent trends in the porosity data. No apparent differences in the amount, distribution, and morphology of porosity were observed between Sr-free and Sr-containing alloys with no or very small eutectic volume fractions. However, Sr modification significantly changed the amount, distribution, and morphology of porosity in alloys with a significant volume fraction of eutectic. The addition of Sr reduced porosity in the hot spot region of the casting, and the pores became well dispersed and rounded. This result can be explained by considering the combined effect of the casting design and the differences in the pattern of eutectic solidification between unmodified and Sr-modified alloys. PUBLICATION ABSTRACT
Electromagnetic calorimeter (ECAL) is being developed to complement dilepton spectrometer HADES. ECAL will enable the HADES FAIR experiment to measure data on neutral meson production in heavy ion ...collisions at the energy range of 2-10 AGeV on the beam of future accelerator SIS100 FAIR. We will report results of the last beam test with quasi-monoenergetic photons carried out in MAMI facility at Johannes Gutenberg Universitat Mainz.
Two cell wall proteins from chickpea, known to be rapidly insolubilised by an elicitor-stimulated oxidative burst in-vivo, were purified from suspension cells. N-terminal protein sequencing revealed ...them as a proline-rich protein and an extensin-like protein. Oxidative cross-linking could be modelled in an in vitro system utilising horseradish peroxidase, H2O2 and the substrate proteins.
Elicitation of cultured chickpea cells caused rapid insolubilization of two cell wall structural proteins, p190, a putative hydroxyproline-rich glycoprotein and p80, a putative proline-rich protein. ...This process appeared to result from an H2O2-mediated oxidative cross-linking mechanism and was initiated within 5 min and complete within 20 min. Further, elicitation of cells induced a rapid, transient generation of H2O2 (oxidative burst), with an onset after 5 min and a maximum H2O2-release after 20 min, as measured by a luminol-dependent chemiluminescence assay. Both chemiluminescence and protein insolubilization were suppressed by exogenous application of catalase or diphenylene iodonium, an inhibitor of plasma-membrane NADPH oxidase, respectively. In contrast, exogenous H2O2 mimicked the effect of the elicitor, suggesting that the putative oxidative cross-linking of the proteins depends directly on H2O2 from the oxidative burst. The peroxidase inhibitor salicylhydroxamic acid blocked both the elicitor- and the exogenous-H2O2-stimulated insolubilization, indicating that a peroxidase activity downstream of H2O2-supply is required. The protein kinase inhibitor staurosporine blocked the elicitation of the oxidative burst and protein insolubilization. In contrast, the protein phosphatase 2A inhibitor cantharidin accelerated, potentiated and extended the elicited oxidative burst. Cantharidin even stimulated the responses in the absence of the elicitor. The competitive effect of both inhibitors confirms that a coordinated activation of (i) protein kinase(s) and (ii) counteracting protein phosphates(s) is a poised signal transduction step for the induction of an NADPH-oxidase-dependent oxidative burst, which drives the putative peroxidase-catalyzed cross-linking of the cell wall proteins.
Elicitation of cultured chickpea (Cicer arietinum L.) cells stimulates a signal transduction pathway leading to several rapid responses: (1) oxidative burst, (2) extracellular alkalinisation, (3) ...extracellular acidification, (4) transient K
efflux, and (5) activation of defence related genes all within 2 hours. Induced genes are encoding acidic and basic chitinases, a thaumatin-like protein and isoflavone reductase. All these elicitor-induced responses are in hibited by the Ser/Thr protein kinase inhibitor staurosporine and the anion channel blocker anthracene-9-carboxylic acid but stimulated by the Ser/Thr protein phosphatase 2A inhibitor cantharidin. The oxidative burst leads to a transient extracellular H
accumulation which seems to be preceded by O
production, indicating dismutation of O
to H
. The oxidative burst is accompanied by transient alkalinisation of the culture medium which is followed by long-lasting extracellular acidification. An 80 percent inhibition of the alkalinisation after complete inhibition of the H
burst with diphenylene iodonium indicates that the elicitor induced increase of extracellular pH is mainly based on a proton consumption for O
dismutation. A simultaneous deactivation of the plasma membrane H
-ATPase during oxidative burst and extracellular alkalinisation is also suggested. The elicitor-stimulated extracellular acidification is inhibited by the plasma membrane H
-ATPase inhibitor N, N'-dicyclohex-ylcarbodiimide assuming a reactivation of the H
-ATPase 25 min after elicitation. Extracellular acidification seems not to be necessary for elicitor-induced activation of defence related genes. Opposite modulation of K
and proton fluxes after elicitation and/or treatment with the H
-ATPase effectors fusicoccin or N, N'-dicyclohexylcarbodiimide indicate that the elicitor induced transient K
efflux is regulated by a K
/H
exchange reaction.
Primary mesenchymal stem cells (MSCs) are fraught with aging-related shortfalls. Human-induced pluripotent stem cell (iPSC)-derived MSCs (iMSCs) have been shown to be a useful clinically relevant ...source of MSCs that circumvent these aging-associated drawbacks. To date, the extent of the retention of aging-hallmarks in iMSCs differentiated from iPSCs derived from elderly donors remains unclear.
Fetal femur-derived MSCs (fMSCs) and adult bone marrow MSCs (aMSCs) were isolated, corresponding iPSCs were generated, and iMSCs were differentiated from fMSC-iPSCs, from aMSC-iPSCs, and from human embryonic stem cells (ESCs) H1. In addition, typical MSC characterization such as cell surface marker expression, differentiation capacity, secretome profile, and trancriptome analysis were conducted for the three distinct iMSC preparations-fMSC-iMSCs, aMSC-iMSCs, and ESC-iMSCs. To verify these results, previously published data sets were used, and also, additional aMSCs and iMSCs were analyzed.
fMSCs and aMSCs both express the typical MSC cell surface markers and can be differentiated into osteogenic, adipogenic, and chondrogenic lineages in vitro. However, the transcriptome analysis revealed overlapping and distinct gene expression patterns and showed that fMSCs express more genes in common with ESCs than with aMSCs. fMSC-iMSCs, aMSC-iMSCs, and ESC-iMSCs met the criteria set out for MSCs. Dendrogram analyses confirmed that the transcriptomes of all iMSCs clustered together with the parental MSCs and separated from the MSC-iPSCs and ESCs. iMSCs irrespective of donor age and cell type acquired a rejuvenation-associated gene signature, specifically, the expression of INHBE, DNMT3B, POU5F1P1, CDKN1C, and GCNT2 which are also expressed in pluripotent stem cells (iPSCs and ESC) but not in the parental aMSCs. iMSCs expressed more genes in common with fMSCs than with aMSCs. Independent real-time PCR comparing aMSCs, fMSCs, and iMSCs confirmed the differential expression of the rejuvenation (COX7A, EZA2, and TMEM119) and aging (CXADR and IGSF3) signatures. Importantly, in terms of regenerative medicine, iMSCs acquired a secretome (e.g., angiogenin, DKK-1, IL-8, PDGF-AA, osteopontin, SERPINE1, and VEGF) similar to that of fMSCs and aMSCs, thus highlighting their ability to act via paracrine signaling.
iMSCs irrespective of donor age and cell source acquire a rejuvenation gene signature. The iMSC concept could allow circumventing the drawbacks associated with the use of adult MSCs und thus provide a promising tool for use in various clinical settings in the future.
In recent years Industrial Product Service Systems (IPSS), characterized by an integrated supply of products and services, have emerged as new business models. The aim of this paper is to compare the ...traditional business model for simple transactions and the full-service business model. The question of whether the full service business model can contribute to the degree of vertical integration is supposed to be answered.
Total knee arthroplasty (TKA) is associated with severe pain and inflammation despite an extensive multimodal analgesic approach, but the effect of high-dose glucocorticoid administration has not ...been studied.
Forty-eight patients undergoing unilateral TKA were included in a randomized, double-blind, placebo-controlled trial receiving preoperative methylprednisolone (MP) 125 mg i.v. or saline. All surgery was performed under lumbar spinal anaesthesia and patients received a standardized, multimodal analgesic regime. The primary endpoint was pain during walking 24 h after surgery, and secondary endpoints were pain at rest, pain upon hip flexion, and pain upon knee flexion. Pain assessments were performed repeatedly for the first 48 h after surgery, in a questionnaire from days 2 to 10, and at follow-up on days 21 and 30. Tertiary endpoints were postoperative nausea and vomiting (PONV), plasma C-reactive protein (CRP) concentrations, fatigue, sleep quality, and rescue analgesic and antiemetic requirements.
Pain during walking was significantly lower in the MP group up to 32 h after operation. Overall pain and cumulative pain scores (2–48 h) were lower for all pain assessments (P<0.04). Consumption of rescue oxycodone was lower from 0 to 24 h (P=0.02) and PONV, consumption of ondansetron reduced (P<0.05), and CRP concentrations were lower at 24 h (P<0.000001). Fatigue throughout the day of surgery was lower (P=0.02), but sleep quality was worse on the first night (P=0.002). No side-effects or complications were observed in other respects.
MP 125 mg before surgery improves analgesia and immediate recovery after TKA, even when combined with a multimodal analgesic regime. These findings call for further studies on safety aspects.
Registered with ClinicalTrails.gov under the US National Library of Medicine (registration number: NCT00968578).
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