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1.
Completeness of extraction, losses during isolation and, in particular, the formation of new constituents are challenges during the enrichment of volatiles for GC analysis. Especially the isolation of volatiles by simultaneous steam distillation/extraction has long been known to generate artifacts due to the hot water treatment. However, even a simple treatment of dry foods with cold water may already lead to the release of odour-active volatiles. After treatment of chocolate or cocoa beans with water, the concentrations of the four Strecker aldehydes 2- and 3-methylbutanal, 3-(methylthio)propanal and phenylacetaldehyde were increased by factors between 10 and 100. Also in other dry processed foods, such as malt or crackers, the concentrations of the Strecker aldehydes were substantially increased upon water addition. Although a physical release of the aldehydes weakly bound to, e.g. proteins or starch is possible, in a further experiment, it could be shown that a yet unknown precursor of 3-(methylthio)propanal and phenylacetaldehyde could be isolated by solvent extraction from caramalt and Munich malt. As a consequence, the presence or absence of water during the work-up procedure might either lead to an over- or underestimation of the relevance of the respective aroma compounds, which might also effect aroma formation and perception during the process of eating.  相似文献   
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The overall rate of complications after ileal pouch-anal anastomosis is 60%. This rate, however, includes complications such as bowel-obstruction and hernias. Pouch-related complications occur after ileal pouch-anal anastomosis with a frequency of 15-25%. In an analysis of the recent literature the main risk factors are: tension of the ileal pouch-anal anastomosis, anastomotic leakage, lack of protective ileostomy, preoperatively undiagnosed Crohn's disease and the experience of the surgeon. We classified pouch related-complications into (1) surgical complications (leakage, bleeding, pelvic sepsis, fistulas); (2) technical problems (long S-pouch spout, rectal cuff stenosis, etc.); (3) functional problems (anal sphincter insufficiency, night incontinence, hypermotility, evacuation disorders); (4) pouchitis; (5) pouch neoplasias. Pathogenesis, diagnostic features, and medical and surgical therapy are discussed in detail. In our own series of 11 pouch-redo operations we had 6 pouch fistulas (3 related to Crohn's disease, 3 postoperative fistulas), 3 wrongly constructed pouches, 1 chronic pouchitis and 1 long S-pouch spout. In 3 cases the pouch had to be excised completely. Two patients remained with a permanent ileostomy. In 6 patients the pouch could be preserved on long term. Due to the technical complexity, the need to understand pathophysiology and the need for a differentiated diagnostic procedure, this operation should be performed only in specialised centers.  相似文献   
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Three sets of experiments were conducted to explore the increase in recovery of Campylobacter from broiler carcasses after defeathering. In the first set of experiments, live broilers obtained from a commercial processor were transported to a pilot plant, and breast skin was sampled by a sponge wipe method before and after defeathering. One of 120 broiler breast skin samples was positive for Campylobacter before defeathering, and 95 of 120 were positive after defeathering. In the second set of experiments, Campylobacter-free flocks were identified, subjected to feed withdrawal, and transported to the pilot plant. Carcasses were intracloacally inoculated with Campylobacter (10(7) CFU) just prior to entering the scald tank. Breast skin sponge samples were negative for Campylobacter before carcasses entered the picker (0 of 120 samples). After defeathering, 69 of 120 samples were positive for Campylobacter, with an average of log10 2.7 CFU per sample (approximately 30 cm2). The third set of experiments was conducted using Campylobacter-positive broilers obtained at a commercial processing plant and transported live to the pilot plant. Just prior to scalding, the cloacae were plugged with tampons and sutured shut on half of the carcasses. Plugged carcasses were scalded, and breast skin samples taken before and after defeathering were compared with those collected from control broilers from the same flock. Prior to defeathering, 1 of 120 breast skin sponge samples were positive for the control carcasses, and 0 of 120 were positive for the plugged carcasses. After passing through the picker, 120 of 120 control carcasses had positive breast skin sponge samples, with an average of log10 4.2 CFU per sample (approximately 30 cm2). Only 13 of 120 plugged carcasses had detectable numbers of Campylobacter on the breast skin sponge, with an average of log10 2.5 CFU per sample. These data indicate that an increase in the recovery of Campylobacter after defeathering can be related to the escape of contaminated feces from the cloaca during defeathering.  相似文献   
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Dekker's algorithm was thought to be safe in an environment without atomic reads or writes where bits flicker or scramble during simultaneous operations. A counter‐example is presented showing Dekker's algorithm is unsafe without atomic read. A modification to the original algorithm is presented making it RW‐safe, allowing threaded systems to be built on low cost/power hardware without atomic read/write. Correctness is verified by means of invariants and UNITY logic. A performance comparison is made for several two‐thread software mutual‐exclusion algorithms to see if the RW‐safe Dekker is competitive. A subset of the two‐thread solutions are then compared in two N‐thread tournament algorithms. The performance results show that the additional checks in the RW‐safe Dekker do not disadvantage the algorithm in comparison with other two‐thread algorithms. The RW‐safe N‐thread tournament algorithms are competitive with the hardware‐assisted Mellor‐Crummey and Scott algorithm. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
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To determine how the individual components of extenders affected boar sperm function and membrane structure and to test a new surfactant's cryoprotective ability, boar sperm were cryopreserved in straws in BF5 extender plus or minus egg yolk plus or minus glycerol plus or minus a surfactant (Orvus ES Paste [OEP] or various concentrations of Pluronic F-127). After thawing, sperm function and fluidity of the isolated head plasma membrane (HPM) were determined. Total motility and adenosine triphosphate content (a measure of viability) were superior postthaw in sperm extended in egg yolk plus glycerol (P < 0.05); neither surfactant improved function. Egg yolk plus any other ingredients improved normal acrosome morphology, whereas a combined measure of motility and normal acrosome morphology was better in the presence of 0.33% OEP or 0.1% Pluronic F-127 (P < 0.05 vs. controls). Head plasma membrane was isolated from freshly collected spermatozoa and spermatozoa cryopreserved in the various extenders. Membrane fluidity was monitored with the probes cis-parinaric acid (cPNA), transparinaric acid (tPNA), and 1,6-diphenyl-1 ,3,5-hexatriene (DPH). The cPNA and the DPH monitor the fluidity of gel and liquid-crystalline areas of the membrane, whereas the tPNA preferentially monitors the gel-phase domains of the membrane. Additionally, DPH monitors the hydrophobic core of the bilayer. In the HPM from fresh sperm, the fluidity of each domain changed over time in a manner unique to that domain, and the behavior of the DPH domain varied among boars. The fluidity dynamics of each domain responded uniquely to cryopreservation. The cPNA domain was unaffected, the tPNA domain was altered by four of the eight extenders, and all extenders affected the fluidity of the DPH domain. Membrane structure was significantly correlated with cell function for sperm cryopreserved in extenders that preserved viability and motility. Sperm cryopreserved in egg yolk plus glycerol plus either OEP or 0.1% Pluronic F-127 functioned best when the bulk domains were less fluid initially and the gel domain solidified more slowly. Therefore, the behavior of domains in the HPM of boar spermatozoa is affected by cryopreservation and is related to the postthaw function of boar sperm cryopreserved in different extenders.  相似文献   
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BACKGROUND: Emergency surgery for colorectal cancer has become more aggressive and radical over the past decade. This retrospective review analyses the impact on outcome. METHODS: The results of emergency surgery within 24 h of admission were compared between 1982 and 1987 (77 patients) and 1988 and 1993 (75 patients). Patient and tumour characteristics were similar in both groups. RESULTS: Right colonic obstruction or perforation was treated by primary resection and anastomosis in 11 of 12 patients before 1988 and in all 19 patients thereafter. Primary resection was also the treatment of choice for perforated cancer of the left colon and rectum before 18 of 20) and after (20 of 21) 1988. The rate of primary resection for obstructing cancer of the left colon and rectum increased from 17 of 45 to 30 of 35. One-stage resections for obstructing cancer were performed in ten of 45 and 22 of 35 patients before and after 1988 respectively. The overall mortality rate declined from 14 of 77 to three of 75 after 1988 (P< 0.01). The rate of radical lymphadenectomy rose from six of 46 patients to 42 of 69 after 1988. The 3-year survival rate increased from 50 to 74 per cent (P < 0.05). CONCLUSION: The data support further efforts towards improving the immediate and late outcome of emergency surgery in complicated colorectal cancer.  相似文献   
10.
The development of the majority of colorectal carcinomas is associated with a diminished expression of the intestinal mucin MUC2 in the tumor cells. The significance and the mechanism of this alteration are not yet known. We sought to determine the molecular basis of this tumor-associated change and to investigate the extent to which it might also relate to metastases. MUC2 gene expression was compared in normal (N), carcinomatous (T), and metastatic tissues (M) from nine patients by immunohistochemistry, in situ hybridization, and Northern blotting. Immunohistochemistry and in situ hybridization showed consistently lower amounts of the expressed protein and mRNA in T and in M than in N; quantitative analysis by Northern blotting confirmed that the differences between MUC2 mRNA expression between N, T, and M were significant, the expression in metastases being less than 5% of that in the normal colonic tissue. The influence of DNA methylation as a possible regulatory mechanism of MUC2 gene expression was tested after the 5' and 3'-regions flanking the first exon of MUC2 were recovered from a genomic DNA library and used as probes in Southern blot. The DNA was isolated from colon carcinoma cell lines expressing MUC2 strongly (LS174T) or moderately (T84) and from that which was nonexpressing (Colo 205), and it was digested with the methylation-sensitive enzyme HpaII. The Southern blot patterns indicated that the increased methylation in the promoter region was concomitant with the decrease of MUC2 mRNA expression. Methylation of the promoter region ligated into a reporter vector suppressed the expression of the luciferase reporter gene in the three investigated cell lines. Furthermore, the expression of MUC2 gene was enhanced by treating the MUC2-expressing colon carcinoma cells with 5-aza-2'-deoxycytidine, a methylation-inhibiting agent. To our knowledge this is the first report to show that: (a) MUC2 gene is strongly suppressed in liver and lymph node metastases of colorectal carcinomas, and (b) suppression of MUC2 gene in colon carcinoma cells in vitro is associated with methylation of the promoter region.  相似文献   
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