BACKGROUND & AIMS: :During maximal whole body exercise VO2 peak is limited by O2 delivery. In turn, it is though that blood flow at near-maximal exercise must be restrained by the sympathetic nervous system to maintain mean arterial pressure. To determine whether enhancing vasodilation across the leg results in higher O2 delivery and leg VO2 during near-maximal and maximal exercise in humans, seven men performed two maximal incremental exercise tests on the cycle ergometer. In random order, one test was performed with and one without (control exercise) infusion of ATP (8 mg in 1 ml of isotonic saline solution) into the right femoral artery at a rate of 80 microg.kg body mass-1.min-1. During near-maximal exercise (92% of VO2 peak), the infusion of ATP increased leg vascular conductance (+43%, P<0.05), leg blood flow (+20%, 1.7 l/min, P<0.05), and leg O2 delivery (+20%, 0.3 l/min, P<0.05). No effects were observed on leg or systemic VO2. Leg O2 fractional extraction was decreased from 85+/-3 (control) to 78+/-4% (ATP) in the infused leg (P<0.05), while it remained unchanged in the left leg (84+/-2 and 83+/-2%; control and ATP; n=3). ATP infusion at maximal exercise increased leg vascular conductance by 17% (P<0.05), while leg blood flow tended to be elevated by 0.8 l/min (P=0.08). However, neither systemic nor leg peak VO2 values where enhanced due to a reduction of O2 extraction from 84+/-4 to 76+/-4%, in the control and ATP conditions, respectively (P<0.05). In summary, the VO2 of the skeletal muscles of the lower extremities is not enhanced by limb vasodilation at near-maximal or maximal exercise in humans. The fact that ATP infusion resulted in a reduction of O2 extraction across the exercising leg suggests a vasodilating effect of ATP on less-active muscle fibers and other noncontracting tissues and that under normal conditions these regions are under high vasoconstrictor influence to ensure the most efficient flow distribution of the available cardiac output to the most active muscle fibers of the exercising limb.

背景与目标： : 在最大的全身运动期间，VO2峰值受到O2输送的限制。反过来，尽管在接近最大运动时的血流必须受到交感神经系统的限制，以维持平均动脉压。为了确定在人类接近最大和最大运动期间，增强腿部的血管舒张是否会导致较高的O2递送和腿部VO2，七名男子在自行车测功机上进行了两次最大增量运动测试。以随机顺序，进行一次测试，其中一次 (对照运动) 以80微克kg身体mass-1.min-1的速率将ATP (8 mg在1毫升的等渗盐溶液中) 输注到右股动脉中。在接近最大运动 (VO2峰的92%) 期间，ATP的输注增加了腿部血管电导 (43%，P<0.05)，腿部血流量 (20%，1.7 l/min，P<0.05) 和腿部O2的输送 (20%，0.3 l/min，P<0.05)。未观察到对腿部或全身vo2的影响。腿部O2分数提取在输注的腿部从85 +/-3 (对照) 降低到78 +/-4% (ATP) (P & lt; 0.05)，而在左腿保持不变 (84 +/-2和83 +/-2%; 对照和ATP; n = 3)。最大运动时ATP输注可增加17% (P<0.05)，而腿部血流量可增加0.8 l/min (P = 0.08)。然而，在对照和ATP条件下，由于O2提取从84 +/-4降低到76 +/-4% 而增强的体循环或腿部峰值VO2值都没有增强 (P<0.05)。总而言之，在人类几乎最大或最大的运动中，肢体血管舒张不会增强下肢骨骼肌的VO2。ATP输注导致运动腿部O2提取减少的事实表明，ATP对活动较少的肌纤维和其他非收缩组织具有血管舒张作用，并且在正常条件下，这些区域处于较高的血管收缩作用下，以确保最有效的血流分布。锻炼肢体的肌肉纤维。

BACKGROUND & AIMS: :There are numerous analytic and methodological limitations to current measures of drug market activity. This paper explores the structure of markets and individual user behavior to provide an integrated understanding of behavioral and economic (and market) aspects of illegal drug use with an aim toward developing improved procedures for measurement. This involves understanding the social processes that structure illegal distribution networks and drug users' interactions with them. These networks are where and how social behaviors, prices, and markets for illegal drugs intersect. Our focus is upon getting an up close measurement of these activities. Building better measures of consumption behaviors necessitates building better rapport with subjects than typically achieved with one-time surveys in order to overcome withholding and underreporting and to get a comprehensive understanding of the processes involved. This can be achieved through repeated interviews and observations of behaviors. This paper also describes analytic advances that could be adopted to direct this inquiry including behavioral templates, and insights into the economic valuation of labor inputs and cash expenditures for various illegal drugs. Additionally, the paper makes recommendations to funding organizations for developing the mechanisms that would support behavioral scientists to weigh specimens and to collect small samples for laboratory analysis-by providing protection from the potential for arrest. The primary focus is upon U.S. markets. The implications for other countries are discussed.

背景与目标： : 目前对药品市场活动的衡量有许多分析和方法上的限制。本文探讨了市场结构和个人用户行为，以提供对非法药物使用的行为和经济 (和市场) 方面的综合理解，旨在开发改进的测量程序。这涉及了解构成非法分销网络的社会过程以及吸毒者与他们的互动。这些网络是非法药物的社会行为，价格和市场相交的地方和方式。我们的重点是对这些活动进行近距离测量。与一次性调查相比，建立更好的消费行为衡量标准需要与受试者建立更好的融洽关系，以克服预扣和漏报并全面了解所涉及的过程。这可以通过反复采访和观察行为来实现。本文还介绍了可以用来指导此查询的分析进展，包括行为模板，以及对各种非法药物的劳动力投入和现金支出的经济评估的见解。此外，本文还向资助组织提出了建议，以开发支持行为科学家称重标本并收集小样本进行实验室分析的机制-通过提供保护免受逮捕的可能性。主要重点是美国市场。讨论了对其他国家的影响。

BACKGROUND & AIMS: BACKGROUND:Central venous oxygen saturation (ScvO2) remains the gold standard surrogate for tissue oxygen extraction in paediatric cardiac surgery. Near-infrared spectroscopy (NIRS) has been developed as a non-invasive diagnostic tool for regional oxygen saturation. The aim was to compare regional oxygen saturation measured by NIRS with ScvO2 in postoperative paediatric cardiac patients. METHODS:In this prospective study, we included newborns and infants younger than 45 days undergoing heart surgery. We recorded continuous ScvO2 and NIRS regional saturation placed on the forehead (B) and right flank (S) for 48 h postoperatively. A Bland-Altman's analysis was used to assess the agreement between these measurements. RESULTS:A total of 23 patients were included with a median age of 12 days (2-46) and median weight of 3.1 kg (2.3-4.47). The mean difference (MD) ScvO2- B NIRS was 10.45% with limits of agreement (LOA) -17.23 to 38.13% and ScvO2- S NIRS MD 7.16% with LOA: -25.51 to 39.84%. The single ventricle ScvO2- S NIRS subgroup had MD within ± 5%; however, wide LOA was observed. The remaining subgroups showed MD nearly above ± 5%, with wide LOA. CONCLUSIONS:The regional oxygen saturation of brain and kidney did not match ScvO2 as estimation of global tissue perfusion. Nevertheless, NIRS may still provide information regarding regional circulation that may help in the management of neonatal cardiac surgery patients.

背景与目标：

BACKGROUND & AIMS: :The intracellular α-synuclein (α-syn) protein, whose conformational change and aggregation have been closely linked to the pathology of Parkingson's disease (PD), is highly populated at the presynaptic termini and remains there in the α-helical conformation. In this study, circular dichroism confirmed that natively unstructured α-syn in aqueous solution was transformed to its α-helical conformation upon addition of trifluoroethanol (TFE). Electrochemical and UV-visible spectroscopic experiments reveal that both Cu (I) and Cu (II) are stabilized, with the former being stabilized by about two orders of magnitude. Compared to unstructured α-syn (Binolfi et al., J. Am. Chem. Soc. 133 (2011) 194-196), α-helical α-syn stabilizes Cu (I) by more than three orders of magnitude. Through the measurements of H(2)O(2) and hydroxyl radicals (OH) in solutions containing different forms of Cu (II) (free and complexed by unstructured or α-helical α-syn), we demonstrate that the significantly enhanced Cu (I) binding affinity helps inhibit the production of highly toxic reactive oxygen species, especially the hydroxyl radicals. Our study provides strong evidence that, as a possible means to prevent neuronal cell damage, conversion of the natively unstructured α-syn to its α-helical conformation in vivo could significantly attenuate the copper-modulated ROS production.

背景与目标： : 细胞内 α-突触核蛋白 (α-syn) 蛋白的构象变化和聚集与Parkingson病 (PD) 的病理密切相关，在突触前末端高度聚集，并保留在 α-螺旋构象中。在这项研究中，圆二色性证实，加入三氟乙醇 (TFE) 后，水溶液中的原生非结构化 α-syn转化为其 α-螺旋构象。电化学和紫外可见光谱实验表明，Cu (I) 和Cu (II) 都是稳定的，前者稳定了大约两个数量级。与非结构化 α-syn (Binolfi等人，J. Am. Chem. Soc. 133 (2011) 194-196) 相比，α-螺旋 α-syn使Cu (I) 稳定超过三个数量级。通过测量含有不同形式的Cu (II) (游离并通过非结构化或 α-螺旋 α-syn络合) 的溶液中的H(2)O(2) 和羟基自由基 (OH)，我们证明了显着增强的Cu (I) 结合亲和力有助于抑制高毒性活性氧的产生，尤其是羟基自由基。我们的研究提供了有力的证据，表明作为防止神经元细胞损伤的一种可能手段，在体内将非结构化的 α-syn转化为其 α-螺旋构象可以显着减弱铜调节的ROS的产生。

BACKGROUND & AIMS: :Eight patients with chronic obstructive lung disease (COLD) and pulmonary hypertension were given an infusion of a calcium antagonist, felodipine, during ongoing, long-term oxygen treatment (LTOT). The effects on central haemodynamics and ventilation-perfusion matching were studied. At rest pulmonary and systemic vascular resistances (PVR and SVR) were reduced by 18% (NS) and 26% (p less than 0.05), respectively. Cardiac output increased by 23%. There was a tendency to increased perfusion of low alveolar ventilation-perfusion ratio (VA/Q) areas (VA/Q less than 0.1) and to increased shunt compared to pretreatment values. Arterial oxygen tension (PaO2) fell by 0.7 kPa (p less than 0.001) but total oxygen transport increased by 23% (p less than 0.001). After treatment with oral felodipine (7.5-15 mg.day-1) for a mean time of 14 wks, PVR and SVR were reduced by 16% (p less than 0.05) and 7% (NS), respectively, as compared to pretreatment values at rest. Cardiac output rose by 13%. The VA/Q ratios and the PaO2 returned towards pretreatment values. The total oxygen transport increased by 11% (p less than 0.05) at rest and increased by 19% (p less than 0.05) during exercise as compared to the pretreatment value. The positive effect on central haemodynamics indicates that felodipine may be a valuable adjunct to ongoing LTOT.

背景与目标： : 在正在进行的长期氧气治疗 (LTOT) 期间，对8名患有慢性阻塞性肺疾病 (COLD) 和肺动脉高压的患者进行了钙拮抗剂非洛地平的输注。研究了对中心血流动力学和通气-灌注匹配的影响。静止时，肺和全身血管阻力 (PVR和SVR) 分别降低了18% (NS) 和26% (p小于0.05)。心输出量增加23%。与预处理值相比，低肺泡通气-灌注比 (VA/Q) 区域的灌注增加 (VA/Q小于0.1) 和分流增加的趋势。动脉血氧张力 (PaO2) 下降了0.7 kPa (p小于0.001)，但总输氧增加了23% (p小于0.001)。在用口服非洛地平 (7.5-15 mg.day-1) 治疗14 wks的平均时间后，与休息时的预处理值相比，PVR和SVR分别降低了16% (p小于0.05) 和7% (NS)。心输出量上升了13%。VA/Q比和PaO2返回预处理值。与预处理值相比，总氧传输在静止时增加11% (p小于0.05)，在运动期间增加19% (p小于0.05)。对中枢血流动力学的积极影响表明，非洛地平可能是正在进行的LTOT的有价值的辅助手段。

BACKGROUND & AIMS: :The effects of bread consumption change over time on anthropometric measures have been scarcely studied. We analysed 2213 participants at high risk for CVD from the PREvención con DIeta MEDiterránea (PREDIMED) trial to assess the association between changes in the consumption of bread and weight and waist circumference gain over time. Dietary habits were assessed with validated FFQ at baseline and repeatedly every year during 4 years of follow-up. Using multivariate models to adjust for covariates, long-term weight and waist circumference changes according to quartiles of change in energy-adjusted white and whole-grain bread consumption were calculated. The present results showed that over 4 years, participants in the highest quartile of change in white bread intake gained 0·76 kg more than those in the lowest quartile (P for trend = 0·003) and 1·28 cm more than those in the lowest quartile (P for trend < 0·001). No significant dose-response relationships were observed for change in whole-bread consumption and anthropometric measures. Gaining weight (>2 kg) and gaining waist circumference (>2 cm) during follow-up was not associated with increase in bread consumption, but participants in the highest quartile of changes in white bread intake had a reduction of 33 % in the odds of losing weight (>2 kg) and a reduction of 36 % in the odds of losing waist circumference (>2 cm). The present results suggest that reducing white bread, but not whole-grain bread consumption, within a Mediterranean-style food pattern setting is associated with lower gains in weight and abdominal fat.

背景与目标： : 面包消费随时间变化对人体测量的影响很少被研究。我们分析了来自prevenci ó n con DIeta meditr á nea (PREDIMED) 试验的2213名CVD高危参与者，以评估随时间推移面包和体重变化与腰围增加之间的关联。在基线时使用经过验证的FFQ评估饮食习惯，并在随访的4年中每年重复进行。使用多变量模型对协变量进行调整，根据能量调整后的白色和全麦面包消费量变化的四分位数，计算了长期体重和腰围的变化。目前的结果表明，在过去的4年里，白面包摄入量变化最高四分位数的参与者比最低四分位数的参与者增加了0·76千克 (趋势P = 0·003)，比最低四分位数的参与者增加了1·28厘米 (趋势P <0·001)。对于全面包消费和人体测量的变化，未观察到明显的剂量反应关系。随访期间体重增加 (> 2千克) 和腰围增加 (> 2厘米) 与面包消耗量增加无关，但是，白面包摄入量变化最高四分位数的参与者的减肥几率降低了33% (> 2千克)，而腰围下降的几率降低了36% (> 2厘米)。目前的结果表明，在地中海风格的食物模式环境中，减少白面包而不是全麦面包的消费与体重和腹部脂肪的减少有关。

BACKGROUND & AIMS: BACKGROUND:Research has shown a strong link between alcohol use and a variety of problems, including violence. Parker and colleagues have presented a selective disinhibition theory for the link between alcohol use and homicide (and other violence) that posits a causal relationship that is also influenced by other situational and contextual factors. This model is particularly well suited for aggregate-level investigations. In this study, we examine the impact of alcohol factors, including consumption measures and Alcoholics Anonymous (AA) membership rates, on homicide mortality rates in Ontario, and test predictions derived from the selective disinhibition model. METHODS:Time series analyses with ARIMA modeling were applied to total, male, and female homicide rates in Ontario between 1968 and 1991. The analyses performed included total alcohol consumption, spirits consumption, beer consumption, and wine consumption. Missing AA membership data were interpolated with cubic splines. RESULTS:For the total population and males, homicide rates were significantly and positively related to total alcohol consumption and to the consumption of beer and spirits. They were also negatively related to AA membership rates in the analyses involving spirits and wine and positively related to unemployment rates in the analyses involving beer, wine, and total alcohol. Among females, none of the measures were significant predictors of homicide mortality rates. CONCLUSIONS:These data provide important support for the selective disinhibition model and confirm important relationships between per capita consumption measures and homicide mortality rates, especially among males, seen in other studies. Additionally, the results for AA membership rates are consistent with the hypothesis that AA membership and treatment for misuse of alcohol can exert beneficial effects observable at the population level.

背景与目标：

BACKGROUND & AIMS: Our aim was to determine the effects of 12 h of hypoxaemia on cerebral blood flow (CBF) and cerebral O2 delivery in ovine fetuses at 0.6 gestation. During fetal hypoxaemia, induced by reduced uterine blood flow, fetal SaO2 and PaO2 were reduced (p < 0.01) from control values of 77.0 +/- 1.6% and 27.3 +/- 1.0 mm Hg, respectively, to 28.4 +/- 3.4% and 15.6 +/- 0.6 mm Hg; fetal pHa decreased from control values of 7.37 +/- 0.01 to 7.20 +/- 0.02 at 3 h, but returned to control values before 12 h. CBF (ml/min/100 g) was 2.0- to 2.6-fold higher (p < 0.01) than control values during hypoxaemia, but only 1.7-fold higher (p < 0.01) at 3 h when pHa was lowest. Cerebral O2 delivery (ml/min/100 g) was lower (p < 0.01) than control values of 3.15 +/- 0.29 at 1.5h (2.09 +/- 0.36) and 3h (1.84 +/- 0.22) of hypoxaemia and higher 1 h after hypoxaemia had ceased (3.81 +/- 0.22, p < 0.01). We conclude that the ovine fetus at 0.6 gestation is unable to sustain increased CBF and hence maintain cerebral O2 delivery during the first 6 h of hypoxaemia, a time which coincides with acidaemia; in contrast, at 6 and 12 h of hypoxaemia, when pHa was normal, cerebral O2 delivery was similar to control values. Reduced cerebral O2 delivery during the early, acidaemic, stages of hypoxaemia may lead to impaired neural development.

背景与目标： 我们的目的是确定12小时低氧血症对0.6妊娠的绵羊胎儿脑血流量 (CBF) 和脑O2输送的影响。在胎儿低氧血症期间，由子宫血流量减少引起的胎儿SaO2和PaO2从77.0 +/- 1.6% 和27.3 +/-1.0毫米Hg的对照值分别降低到28.4 +/- 3.4% 和15.6 +/-0.6毫米Hg (p <0.01); 胎儿pHa在3小时从7.37 +/- 0.01的对照值降至7.20 +/- 0.02，但在12小时前恢复到对照值。在低氧血症期间，CBF (ml/min/100g) 比对照值高2.0至2.6倍 (p <0.01)，但在3小时pHa最低时仅高1.7倍 (p <0.01)。低氧血症1.5小时 (2.09 +/- 0.36) 和3小时 (1.84 +/- 0.22) 时，脑O2递送 (ml/min/100g) 低于3.15 +/- 0.29的对照值 (p <0.01)，低氧血症停止后1小时更高 (3.81 +/- 0.22，p <0.01)。我们得出的结论是，0.6妊娠的绵羊胎儿无法维持CBF的增加，因此在低氧血症的前6小时 (与酸血症相吻合) 中维持脑O2的输送; 相反，在低氧血症的6和12小时，当pHa正常时，脑O2输送与对照值相似。低氧血症的早期，酸血症阶段的脑O2输送减少可能导致神经发育受损。

BACKGROUND & AIMS: :Purpose of this study was to assess the additional value of first pass myocardial perfusion imaging during peak dose of dobutamine stress Cardiac-MR (CMR). Dobutamine Stress CMR was performed in 115 patients with an inconclusive diagnosis of myocardial ischemia on a 1.5 T system (Magnetom Avanto, Siemens Medical Systems). Three short-axis cine and grid series were acquired during rest and at increasing doses of dobutamine (maximum 40 microg/kg/min). On peak dose dobutamine followed immediately by a first pass myocardial perfusion imaging sequence. Images were graded according to the sixteen-segment model, on a four point scale. Ninety-seven patients showed no New (Induced) Wall Motion Abnormalities (NWMA). Perfusion imaging showed absence of perfusion deficits in 67 of these patients (69%). Perfusion deficits attributable to known previous myocardial infarction were found in 30 patients (31%). Eighteen patients had NWMA, indicative for myocardial ischemia, of which 14 (78%) could be confirmed by a corresponding perfusion deficit. Four patients (22%) with NWMA did not have perfusion deficits. In these four patients NWMA were caused by a Left Bundle Branch Block (LBBB). They were free from cardiac events during the follow-up period (median 13.5 months; range 6-20). Addition of first-pass myocardial perfusion imaging during peak-dose dobutamine stress CMR can help to decide whether a NWMA is caused by myocardial ischemia or is due to an (inducible) LBBB, hereby preventing a false positive wall motion interpretation.

背景与目标： : 这项研究的目的是评估多巴酚丁胺应激心脏MR (CMR) 峰值剂量期间首过心肌灌注成像的附加价值。多巴酚丁胺应激CMR在1.5 T系统 (Magnetom Avanto，Siemens Medical Systems) 上对115例未明确诊断为心肌缺血的患者进行。在休息期间和增加多巴酚丁胺的剂量 (最大40微克/千克/分钟) 获得了三个短轴电影和网格系列。在峰值剂量多巴酚丁胺之后立即进行首过心肌灌注成像序列。根据十六段模型对图像进行了四分制的分级。97名患者未显示新的 (诱发的) 壁运动异常 (NWMA)。灌注成像显示这些患者中有67例 (69%) 不存在灌注缺陷。在30例患者 (31%) 中发现了可归因于已知先前心肌梗塞的灌注缺陷。18例患者患有NWMA，指示心肌缺血，其中14例 (78% 例) 可以通过相应的灌注不足来确认。四名NWMA患者 (22%) 没有灌注缺陷。在这四名患者中，NWMA是由左束支传导阻滞 (LBBB) 引起的。在随访期间 (中位13.5个月; 范围6-20)，他们没有心脏事件。在峰值剂量多巴酚丁胺应激CMR期间增加首过心肌灌注成像可以帮助确定NWMA是由心肌缺血引起还是由 (可诱导的) LBBB引起，从而防止假阳性壁运动解释。

BACKGROUND & AIMS: :The effects of ionisation density on the structure of the glow curve of LiF:Mg,Ti (TLD-100) are briefly reviewed and discussed within the framework of the spatially correlated TC/LC model and localised recombination. The effects of 'slow-cooling' on the structure of composite peak 5 following low-ionisation density beta/gamma irradiation are described and analysed in both 'slow-cooled' and 'normally cooled' samples. It is demonstrated that 'slow-cooling' using a cooling rate of 30 degrees C h(-1) increases the relative intensity of glow peak 5a to composite glow peak 5 from approximately 0.1 to approximately 2, thereby greatly improving the precision of measurement of the ratio 5a/5. The improved precision removes a hurdle impeding the development of the ionisation density discrimination properties of the peak 5a/5 nanodosimeter.

背景与目标： : 在空间相关的TC/LC模型和局部重组的框架内，简要回顾和讨论了电离密度对LiF:Mg，Ti (TLD-100) 辉光曲线结构的影响。在 “慢冷” 和 “正常冷却” 样品中描述并分析了低电离密度 β/γ 辐照后 “慢冷” 对复合峰5结构的影响。证明了使用30 °c h(-1) 的冷却速率的 “缓慢冷却” 将辉光峰5a与复合辉光峰5的相对强度从大约0.1增加到大约2，从而大大提高了比率5a/5的测量精度。提高的精度消除了阻碍峰5a/5纳米剂量计电离密度判别特性发展的障碍。

BACKGROUND & AIMS: :The evolution of oxygen transport hemoglobins occurred on at least two independent occasions. The earliest event led to myoglobin and red blood cell hemoglobin in animals. In plants, oxygen transport "leghemoglobins" evolved much more recently. In both events, pentacoordinate heme sites capable of inert oxygen transfer evolved from hexacoordinate hemoglobins that have unrelated functions. High sequence homology between hexacoordinate and pentacoordinate hemoglobins in plants has poised them for potential structural analysis leading to a molecular understanding of this important evolutionary event. However, the lack of a plant hexacoordinate hemoglobin structure in the exogenously ligand-bound form has prevented such comparison. Here we report the crystal structure of the cyanide-bound hexacoordinate hemoglobin from barley. This presents the first opportunity to examine conformational changes in plant hexacoordinate hemoglobins upon exogenous ligand binding, and reveals structural mechanisms for stabilizing the high-energy pentacoordinate heme conformation critical to the evolution of reversible oxygen binding hemoglobins.

背景与目标： : 氧转运血红蛋白的演变至少发生在两个独立的场合。最早的事件导致动物出现肌红蛋白和红细胞血红蛋白。在植物中，氧气运输 “leghe血红蛋白” 是最近进化的。在这两种情况下，能够惰性氧转移的五配位的血红素位点都是由具有无关功能的六配位的血红蛋白进化而来的。植物中六配位和五配位血红蛋白之间的高序列同源性使它们可以进行潜在的结构分析，从而对这一重要的进化事件有了分子理解。然而，由于缺乏外源配体结合形式的植物六配位血红蛋白结构，因此无法进行这种比较。在这里，我们报告了大麦中氰化物结合的六配位血红蛋白的晶体结构。这为研究外源配体结合后植物六配位血红蛋白的构象变化提供了第一个机会，并揭示了稳定对可逆氧结合血红蛋白的进化至关重要的高能五配位血红素构象的结构机制。

BACKGROUND & AIMS: BACKGROUND:The reasons for low adherence to cereal dietary guidelines are not well understood but may be related to knowledge, attitudes, beliefs and perceived barriers. This study aims to assess trends in cereal foods consumption, intention to change and factors associated with intake among Western Australian (WA) adults 18 to 64 years. METHOD:Cross-sectional data from the 1995, 1998, 2001, 2004, 2009, and 2012 Nutrition Monitoring Survey Series involving 7044 adults were pooled. OUTCOME VARIABLES:types and amount of cereals (bread, rice, pasta, and breakfast cereal) eaten the day prior. Attitudes, knowledge, intentions, weight status and sociodemographic characteristics were measured. Descriptive statistics, multiple binary logistic and multinomial logistic regressions assess factors associated with consumption. RESULTS:Bread (78%) was the most commonly consumed cereal food. The proportion eating bread decreased across survey years (Odds Ratio OR = 0.31; 95% Confidence Interval; 0.24-0.40 in 2012 versus 1995), as did the amount (4.1 slices of bread in 1995 to 2.4 in 2012). The odds of consuming whole-grain cereal foods increased since 2009 (OR = 1.27; 1.02-1.58 versus 1995 p < 0.05). The likelihood of trying to eat less cereal food in the past year was greater in 2012 compared to 1995 (Relative Risk Ratio RRR 10.88; 6.81-17.4). Knowledge of cereal recommendations decreased over time (OR = 0.20; 0.15-0.27 in 2012 versus 1995 p < 0.001). Overweight and obese respondents were more likely than healthy weight respondents to have tried to eat less cereals (RRR 1.65; 1.22-2.24 and 1.88; 1.35-2.63 respectively). 'I already eat enough' was the main barrier (75% in 1995 to 84% in 2012 (p < 0.001)). CONCLUSIONS:WA adults are actively reducing the amount of cereal foods they eat and intake is associated with a misperception of adequacy of intake. Nutrition intervention is needed to increase awareness of the health benefits of cereal foods, particularly whole-grains, and to address barriers to incorporating them daily. TRIAL REGISTRATION:Not applicable.

背景与目标：

BACKGROUND & AIMS: :Oxygen therapy can be life-saving for patients with chronic obstructive pulmonary disease (COPD) and is the backbone of any acute COPD treatment strategy. Although largely considered to be a benign drug, many publications have highlighted the need to accurately adjust oxygen delivery to avoid both hypoxemia and the problem of hyperoxia-induced hypercapnia. Recent clinical data have shown that the deleterious effects of excess oxygen treatment can not only alter carbon dioxide levels (which has been known for more than 60 years) but can also lead to an increase in mortality. Nevertheless, despite the extensive literature, the risks associated with hyperoxia are often overlooked and published clinical recommendations are largely ignored. This failure in knowledge translation has become increasingly important not only because of the desire to reduce medical error, but in a society with limited health care resources, the economic burden of COPD is such that it cannot afford to make preventable medical mistakes. Recently, novel devices have been developed to automatically adjust oxygen flow rates to maintain stable oxygen saturations. These closed-loop oxygen delivery systems have the potential to reduce medical error, improve morbidity and mortality, and reduce health care costs. Preliminary data in this field are promising and will require a significant amount of research in the coming years to determine the precise indications for these systems. The importance of appropriate oxygen dosing and the current literature regarding novel oxygen delivery systems are reviewed.

背景与目标： : 氧疗可以挽救慢性阻塞性肺疾病 (COPD) 患者的生命，并且是任何急性COPD治疗策略的支柱。尽管在很大程度上被认为是一种良性药物，但许多出版物都强调需要准确调整氧气输送以避免低氧血症和高氧诱导的高碳酸血症的问题。最近的临床数据表明，过量氧气治疗的有害影响不仅会改变二氧化碳水平 (已知已有60多年的历史)，还会导致死亡率增加。然而，尽管有大量文献，但与高氧相关的风险经常被忽视，发表的临床建议在很大程度上被忽视。这种知识翻译的失败变得越来越重要，这不仅是因为希望减少医疗错误，而且在医疗资源有限的社会中，COPD的经济负担使它无法承受可预防的医疗错误。最近，已经开发了新颖的设备来自动调节氧气流速以保持稳定的氧气饱和度。这些闭环氧气输送系统具有减少医疗错误，提高发病率和死亡率以及降低医疗保健成本的潜力。该领域的初步数据很有希望，并且在未来几年中将需要大量研究以确定这些系统的确切指示。回顾了适当的氧气剂量的重要性以及有关新型氧气输送系统的当前文献。

BACKGROUND & AIMS: :Catalysing the reduction of oxygen in acidic media is a standing challenge. Although activity of platinum, the most active metal, can be substantially improved by alloying, alloy stability remains a concern. Here we report that platinum nanoparticles supported on graphite-rich boron carbide show a 50-100% increase in activity in acidic media and improved cycle stability compared to commercial carbon supported platinum nanoparticles. Transmission electron microscopy and x-ray absorption fine structure analysis confirm similar platinum nanoparticle shapes, sizes, lattice parameters, and cluster packing on both supports, while x-ray photoelectron and absorption spectroscopy demonstrate a change in electronic structure. This shows that purely electronic metal-support interactions can significantly improve oxygen reduction activity without inducing shape, alloying or strain effects and without compromising stability. Optimizing the electronic interaction between the catalyst and support is, therefore, a promising approach for advanced electrocatalysts where optimizing the catalytic nanoparticles themselves is constrained by other concerns.

背景与目标： : 催化酸性介质中氧的还原是一个长期的挑战。尽管通过合金化可以大大提高铂 (最具活性的金属) 的活性，但合金的稳定性仍然令人担忧。在这里，我们报告，与商业碳负载的铂纳米颗粒相比，负载在富含石墨的碳化硼上的铂纳米颗粒在酸性介质中显示出50-100% 的活性增加和改进的循环稳定性。透射电子显微镜和x射线吸收精细结构分析证实了两种载体上相似的铂纳米颗粒形状，大小，晶格参数和团簇堆积，而x射线光电子和吸收光谱表明电子结构发生了变化。这表明，纯电子金属-载体相互作用可以显着提高氧还原活性，而不会引起形状，合金化或应变效应，并且不会损害稳定性。因此，优化催化剂和载体之间的电子相互作用是先进的电催化剂的一种有前途的方法，其中优化催化纳米颗粒本身受到其他问题的限制。

BACKGROUND & AIMS: OBJECTIVE:The present study examined whether ethanol exposure influences lactation parameters. Specifically, selected constituents in maternal blood and milk and the lactation performance of Chinese lactating mothers were evaluated after they had consumed chicken soup flavoured with sesame oil and rice wine (CSSR), a diet traditionally prescribed during the postpartum 'doing-the-month' ritual. DESIGN:Twenty-three lactating mothers were examined. Informed consent was obtained from each subject. Each subject was tested on two occasions separated by a week. The target alcohol dosage was 0.3 g/kg body weight. Milk and blood samples were collected prior to consumption of soup and at 120 and 150 min, respectively, after consumption. Levels of various constituents were measured. The time for ejection of the first milk droplet and total milk volume yielded were also measured. RESULTS:Consumption of CSSR influenced TAG, insulin and lactate levels in maternal blood. Likewise, consumption of the soup affected milk composition and its nutritional status, particularly total protein, TAG, fatty acid, beta-hydroxybutyrate and lactate levels. CSSR intake significantly affected TAG and lactate levels in milk. The time for the first milk droplet to be ejected was significantly longer in the CSSR group, indicating that the milk-ejecting reflex is inhibited. However, blood prolactin level increased slightly after ethanol intake. Milk yields were reduced after ingestion of CSSR although the difference was not statistically significant. CONCLUSION:Consumption of CSSR affects not only the composition of maternal blood and milk, but also lactation performance. These findings suggest that an alcoholic diet should be avoided during lactation.

背景与目标：