Survey of ochratoxin A and deoxynivalenol in stored grains from the 1999 harvest in the UK

Three hundred and twenty samples from the 1999 UK harvest comprising wheat (201 samples), barley (106) and oats (13) were analysed for ochratoxin A and deoxynivalenol. A small number of organic samples was also obtained. Samples were collected from farms, central stores, mills, maltings and ports from across the UK from February to April 2000. Ochratoxin A and deoxynivalenol analysis was by affinity column clean up and high-performance liquid chromatography with fluorescence and ultraviolet light detection, respectively, with limits of detection of 0.2 and 20 μg kg^-1. The survey found ochratoxin A at below 5 μg kg^-1 in 97% of the samples indicating satisfactory storage conditions. The remaining 3% of the samples contained ochratoxin A at levels between 5.2 and 231 μg kg^-1, but none of these samples was intended for human consumption. Deoxynivalenol was detected in 88% of all samples, with 83% below 100 μg kg^-1; the maximum level was 600 μg kg^-1. Twenty samples containing deoxynivalenol at or above 150 μg kg^-1 by high-performance liquid chromatography were all confirmed by gas chromatography/mass spectrometry. Nivalenol was also detected by gas chromatography/mass spectrometry at levels of 50 μg kg^-1 or higher in 18 of 20 samples where deoxynivalenol was confirmed.     

Spirometry as a motivational tool to improve smoking cessation rates: a systematic review of the literature.

Obtaining spirometric testing and providing those results to individuals who smoke has been advocated as a motivational tool to improve smoking cessation. However, its effectiveness is not known. We conducted a systematic review to determine if this approach improves rates of smoking cessation. Data sources included MEDLINE (1966 to October 2005), the Cochrane Library, and experts in the field. Eligible randomized controlled trials (RCTs) enrolled at least 25 smokers per arm, evaluated spirometry with associated counseling or in combination with other treatments, followed subjects at least 6 months, and provided smoking abstinence rates. Results from nonrandomized studies also were summarized. The primary outcome was patient-reported long-term (at least 6 months) sustained abstinence with biological validation. Additional outcomes included self-reported abstinence and point-prevalence abstinence. Seven RCTs (N = 6,052 subjects) met eligibility criteria. Follow-up duration ranged from 9 to 36 months. In six trials, the intervention group received concomitant treatments previously demonstrated to increase cessation independently. The range of abstinence was 3%-14% for control subjects and 7%-39% among intervention groups, statistically significantly in favor of intervention in four studies. The only RCT that assessed the independent contribution of spirometry in combination with counseling demonstrated a nonsignificant 1% improvement in patient-reported point-prevalence abstinence at 12 months in the group that received spirometry plus counseling versus counseling alone (6.5% versus 5.5%). Findings from observational studies were mixed, and the lack of controls makes interpretation problematic. Available evidence is insufficient to determine whether obtaining spirometric values and providing that information to patients improves smoking cessation compared with other smoking cessation methods. Spirometric values are of limited benefit as a predictor of smoking cessation or as a tool to "customize" smoking cessation strategies.     

新建联合循环发电锅炉的化学清洗

联合循环机组日益广泛应用于发电厂。与传统的燃煤机组相比 ,联合发电厂的设备及安装成本、发电效率高 ,而且对环境影响小。余热锅炉 ( HRSG)是联合循环机组的一个组成部分。虽然 HRSG的热负荷比传统锅炉低 [1] ,但锅炉水化学却很重要。因此 ,新建 HRSG的化学清洗一直受到关注。传统的新建锅炉中存在油脂 ,氧化皮及焊渣等 ,其化学清洗是为了除去这类杂质以保障机组的正常启动及运行。HRSG系统中存在类似的杂质 ,但 HRSG由两到三个压力不同的蒸汽发生回路所组成 (见图 1 ) ,化学清洗较为复杂。这种锅炉结构一般需要多步或扩大性化学…     

Tuft-to-capsule adhesions and their precursors: differences between the vascular and tubular poles of the human glomerulus

The hypothalamo-pituitary-adrenal (HPA) axis is modulated by sex hormones. Few data exist on the relation between acute estrogen deficit and HPA axis response to corticotropin-releasing hormone (CRH). The effects of a sudden drop in estradiol levels on basal and CRH-stimulated levels of ACTH, cortisol, testosterone, androstenedione and 17-hydroxyprogesterone (17-OHP) were assessed in nine premenopausal women (44-48 years of age), before and after ovariectomy. The CRH test was performed before and 8 days after ovariectomy. A significant reduction in ACTH and adrenal steroids but not in cortisol response to CRH was observed after ovariectomy. The ratio of deltamax androstenedione/17-OHP after CRH stimulation was substantially the same before and after ovariectomy, whereas deltamax 17-OHP/cortisol was significantly lower in ovariectomized women showing increased 21- and 11beta-hydroxylase activity. The results show that the acute estrogen deficit induces changes in the HPA axis characterized by reduced stimulated secretion of ACTH and steroids but normal stimulated cortisol production.     

Stoichiometric Engineering of Chalcogenide Semiconductor Alloys for Nanophotonic Applications

A variety of alternative plasmonic and dielectric material platforms—among them nitrides, semiconductors, and conductive oxides—have come to prominence in recent years as means to address the shortcomings of noble metals (including Joule losses, cost, and passive character) in certain nanophotonic and optical‐frequency metamaterial applications. Here, it is shown that chalcogenide semiconductor alloys offer a uniquely broad pallet of optical properties, complementary to those of existing material platforms, which can be controlled by stoichiometric design. Using combinatorial high‐throughput techniques, the extraordinary epsilon‐near‐zero, plasmonic, and low/high‐index characteristics of Bi:Sb:Te alloys are explored. Depending upon composition they can, for example, have plasmonic figures of merit higher than conductive oxides and nitrides across the entire UV–NIR range, and higher than gold below 550 nm; present dielectric figures of merit better than conductive oxides at near‐infrared telecommunications wavelengths; and exhibit record‐breaking refractive indices as low as 0.7 and as high as 11.5.     

Luteinizing hormone response to pulsatile luteinizing hormone-releasing hormone in prepubertal heifers

The effects of 12 hourly 5-micrograms injections of luteinizing hormone-releasing hormone on luteinizing hormone release, were examined in 18 prepubertal Holstein heifers at 4, 7, or 10 mo of age. During a 6-h pretreatment period, mean serum luteinizing hormone concentrations and mean number of endogenous luteinizing hormone episodes per hour were not influenced by age. The 12-h treatment regimen induced a pulsatile release of luteinizing hormone in all heifers. The magnitude, pattern, and total amount of luteinizing hormone released were not influenced by age. However, in the 4 and 10-mo-old age groups, magnitude of luteinizing hormone response to the 3rd hourly injection of luteinizing hormone-releasing hormone was greater than the response to the second injection. Magnitudes of luteinizing hormone responses decreased with time after the 4th hourly injection through the 12th injection and patterns of decline appeared similar among the three age groups. The pituitary of the prepubertal dairy heifer is able to respond to an hourly pulsatile administration of luteinizing hormone-releasing hormone and this treatment regimen appears to produce a self-priming effect on luteinizing hormone release.     

The ultrasound appearances of neonatal renal vein thrombosis

Renal vein thrombosis (RVT) is the most frequently occurring vascular condition in the new-born kidney. The predisposing factors include dehydration, sepsis, birth asphyxia, maternal diabetes, polycythaemia and the presence of an indwelling umbilical venous catheter. (RVT) may present clinically with a flank mass, haematuria, hypertension or renal failure. Many imaging modalities have been employed, but ultrasound is the technique most commonly used in the evaluation of neonates with suspected RVT. Thrombosis commences in the small renal veins and subsequently propagates via larger interlobar veins to the main renal vein and inferior vena cava (IVC). The ultrasound appearances depend upon the stage at which the examination is performed and extent of the thrombus. Initially, the interlobular and interlobar thrombus appears as highly echogenic streaks. These streaks commence in a peripheral, focal segment of the involved kidney and only persist for a few days. In the first week the affected kidney swells and becomes echogenic with prominent echopoor medullary pyramids. Later, the swelling increases and the kidney becomes heterogenous with loss of corticomedullary differentiation. Grey scale ultrasound readily demonstrates thrombus within the renal vein and IVC. Adrenal haemorrhage is a recognized association and may be identified ultrasonically. Colour Doppler scanning provides additional information. In the early stages of RVT, colour Doppler may demonstrate absent intrarenal and renal venous flow. Ultimately, the kidney may recover, show focal scarring or become atrophic. Thus, ultrasound provides an accessible and reliable tool in the assessment of suspected neonatal RVT.