Arterial spin labeling MR image denoising and reconstruction using unsupervised deep learning

Arterial spin labeling (ASL) imaging is a powerful magnetic resonance imaging technique that allows to quantitatively measure blood perfusion non-invasively, which has great potential for assessing tissue viability in various clinical settings. However, the clinical applications of ASL are currently limited by its low signal-to-noise ratio (SNR), limited spatial resolution, and long imaging time. In this work, we propose an unsupervised deep learning-based image denoising and reconstruction framework to improve the SNR and accelerate the imaging speed of high resolution ASL imaging. The unique feature of the proposed framework is that it does not require any prior training pairs but only the subject's own anatomical prior, such as T1-weighted images, as network input. The neural network was trained from scratch in the denoising or reconstruction process, with noisy images or sparely sampled k-space data as training labels. Performance of the proposed method was evaluated using in vivo experiment data obtained from 3 healthy subjects on a 3T MR scanner, using ASL images acquired with 44-min acquisition time as the ground truth. Both qualitative and quantitative analyses demonstrate the superior performance of the proposed txtc framework over the reference methods. In summary, our proposed unsupervised deep learning-based denoising and reconstruction framework can improve the image quality and accelerate the imaging speed of ASL imaging.     

The impact of different step rate threshold methods on physical activity intensity in older adults

BackgroundOlder adults benefit most from engaging in higher-intensity physical activity, which is often determined using step rate thresholds. Fixed step rate thresholds that correspond to moderate (MPA) and vigorous-intensity physical activity (VPA) have been developed for heuristic activity promotion. The activPAL monitor uses step rate thresholds to determine activity intensity. Stepping thresholds may also vary based on body mass index (BMI) or aerobic fitness level in older adults. Despite the various thresholds used in the literature, it is unclear whether they produce similar outcomes.Research QuestionHow does time spent in physical activity intensities compare between different step rate thresholds in older adults?MethodsThirty-eight participants (24♀; 67 ± 4 years; BMI: 26.6 ± 4.4 kg/m²) wore an activPAL monitor 24-hr/day for up to 7-d (total: 205-d). Aerobic fitness (V̇O₂max: 23 ± 8 ml/kg/min) was determined via indirect calorimetry during a maximal, graded cycling test. Time spent in each intensity category (light-physical-activity [LPA], MPA, VPA) was determined using the fixed (MPA/VPA) 100/130, 110/130, and activPAL step rate thresholds (74/212), as well as BMI-adjusted absolute (108.5 ± 2.5/134.0 ± 4.8) and BMI-adjusted relative (40%/60% V̇O₂max; 111.4 ± 14.7/132.0 ± 19.0) cut-offs. Times spent in each intensity category were compared between methods.ResultsThe activPAL and 100/130 thresholds yielded less LPA and more MPA than all other methods. The activPAL had no time spent in VPA at all. The BMI-adjusted absolute and relative thresholds produced statistically equivalent time in LPA and MPA (via equivalence testing), but not VPA. No two methods yielded similar time spent in LPA, MPA, or VPA.SignificanceThe choice of step rate threshold has a major impact on physical activity intensity outcomes in older adults. Inherently, strategies that adjust for older adults’ body size and/or aerobic fitness level provide a more individualized data processing strategy than fixed thresholds that assume the same threshold for all older adults     

制何首乌的炮制方法探索

目的:考察黑豆汁炖制时间对制何首乌外观性状及各类有效成分含量变化规律的影响。方法:采用HPLC同时测定不同炮制时间制何首乌样品中二苯乙烯苷、大黄素、大黄素甲醚、大黄素-8-O-β-D-葡萄糖苷、大黄素甲醚-8-O-葡萄糖苷的含量,选择Agilent ZORBAX Extend-C_(18)色谱柱(4. 6 mm×250 mm,5μm),甲醇(A)-水(B)为流动相梯度洗脱(0～30 min,5%～100%A; 30～40 min,100%A),流速1. 0 mL·min~(-1),柱温35℃,检测波长280 nm。结果:随炖制时间的增加,二苯乙烯苷含量逐渐降低,与8 h时相比,至64 h时含量降低76%;大黄素-8-O-β-D-葡萄糖苷和大黄素甲醚-8-O-葡萄糖苷2种蒽醌苷含量先上升后下降,至24 h时达最高值,炖制40 h时降至与8 h近似的水平,之后略有波动;大黄素、大黄素甲醚2种蒽醌苷元含量先上升后下降,炖制32 h时达最大值,之后缓慢降低并趋于稳定。结论:炖制时间对制何首乌中各类成分含量的影响显著,且变化趋势不尽相同,应规范制何首乌饮片的炮制时间;同时,仅以二苯乙烯苷及蒽醌类成分作为制何首乌的指标性成分依据不够充分,应考虑增加多糖类等质量控制指标。     

基于主客观嗅觉评价结合挥发性成分分析优选美洲大蠊去腥矫臭炮制方法

目的通过主客观评价结合分析挥发性成分变化,筛选美洲大蠊去腥矫臭的炮制方法,研究去腥矫臭作用机制。方法分别制备美洲大蠊生品、醋炙品、酒炙品与麸炒品,采用志愿者感官评价法结合电子鼻系统评价美洲大蠊生品与炮制品的腥臭气味差异,筛选较优炮制品种类。采用顶空-固相微萃取-气相-质谱联用(HS-SPME-GC-MS)结合相对气味活度值(ROAV)分析关键性腥臭气味成分,并采用面积归一化法结合多元统计分析方法分析生品与炮制品挥发性成分差异,探究炮制去腥矫臭的作用机制。结果志愿者评分结果显示生品、醋炙品、酒炙品与麸炒品的平均评分分别为3.38、1.25、2.88与3.04。电子鼻结果显示,醋炙品、酒炙品、麸炒品与生品间的欧式距离分别为7.34、3.77、1.60,但醋炙品的散点分布方向与酒炙品、麸炒品方向相反,提示可能作用机制有异。整合分析主客观评价数据,确定醋炙为最优去腥矫臭炮制方法。ROAV法确认美洲大蠊关键性腥臭气味成分为3-甲基丁醛、己醛、壬醛、庚醛、癸醛、苯乙醛、(E,E)-2,4-壬二烯醛、2-戊基呋喃、(+)-柠檬烯、肉豆蔻醛。挥发性成分的PCA结果显示,4种炮制品可被明显区分开,挥发性成分及含量存在差异。正交偏最小二乘判别分析(OPLS-DA)结果表明,生品与醋炙品中存在7个差异性成分,分别为己醛、棕榈酸、油酸、油酸乙酯、醋酸、棕榈酸乙酯、亚油酸乙酯,醋炙品含量较生品均有减少,其中关键性腥臭味成分己醛减少最为明显。结论醋炙为改善美洲大蠊腥臭气味的较优方法,其炮制机制是通过降低己醛等挥发性腥臭气味成分实现的。     

杜仲炮制工艺对其质量的影响及化学成分与药理研究进展

杜仲是一种传统中药材,中医常以生品和盐制品入药,入肝、肾经,起到补肝肾,强筋骨的作用。笔者在文献考证的基础上,论述了杜仲的炮制方法、工艺对质量的影响,以及所含的化学成分与药理作用的最新研究进展,为杜仲饮片的规范化、标准化研究奠定基础。     

不同制法下瘀血汤对CCl4诱导大鼠肝纤维化的影响

目的:探讨蜜丸酒煎下瘀血汤与饮片酒煎下瘀血汤抗肝纤维化作用是否存在异同。方法:40只Wistar大鼠随机分为正常组、模型组、蜜丸酒煎下瘀血汤组、饮片酒煎下瘀血汤组、扶正化瘀方组。以50%CCl_4皮下注射9周制备肝纤维化模型。第7周首日开始,正常组与模型组给予0.3%羧甲基纤维素钠灌胃,其余3组分别给予蜜丸酒煎下瘀血汤(0.58 g·kg~(-1)),饮片酒煎下瘀血汤(0.43 g·kg~(-1)),扶正化瘀方(2 g·kg~(-1))灌胃,第9周结束后收集肝组织和血清样本。分别采用苏木素-伊红(HE)染色观察各组大鼠肝组织病理学,天狼猩红染色观察纤维化程度,碱水解法测定肝组织羟脯氨酸含量情况,全自动分析法检测大鼠血清肝功能,实时荧光定量聚合酶链式反应(Real-time PCR)检测肝组织α-平滑肌肌动蛋白(α-SMA)和Ⅰ型胶原(COL-I)mRNA的表达情况,蛋白免疫印迹法(Western blot)和免疫组化测定肝组织α-SMA蛋白的表达,酶联免疫吸附测定(ELISA)测定炎症因子与氧化指标。结果:与正常组比较,模型组大鼠肝肝纤维化程度较严重,肝组织天狼猩红阳性染色面积比、羟脯氨酸含量,α-SMA和COL-I蛋白及mRNA表达显著增加(P0.01),大鼠血清丙氨酸氨基转移酶(AST),天门冬氨酸氨基转移酶(ALT),总胆红素(TBil),肿瘤坏死因子-α(TNF-α),白细胞介素(IL)-1β,IL-17A及丙二醛(MDA)的水平显著增加(P0.01),超氧化物歧化酶(SOD)及谷胱甘肽过氧化物酶(GSH-Px)的水平显著降低(P0.01);与模型组比较,蜜丸酒煎下瘀血汤与饮片酒煎下瘀血汤可明显减轻肝纤维化程度,肝组织天狼猩红阳性染色面积比、羟脯氨酸含量,α-SMA和COL-I蛋白及mRNA表达,大鼠血清AST,ALT,TBil,TNF-α,IL-1β,IL-17A,MDA的水平明显降低(P0.05,P0.01),SOD及GSH-Px水平明显增加(P0.05,P0.01)。其中蜜丸酒煎下瘀血汤组肝组织病理变化的改善显著优于饮片酒煎下瘀血汤,且肝组织在天狼猩红阳性染色面积比、羟脯氨酸含量、肝组织COL-I mRNA以及α-SMA mRNA和蛋白的表达降低也较饮片酒煎下瘀血汤明显(P0.05,P0.01)。血清肝功能、炎症因子及氧化相关指标2种制法下瘀血汤组间差异无统计学意义,但蜜丸酒煎下瘀血汤改善趋势更为明显。结论:蜜丸酒煎下瘀血汤与饮片酒煎下瘀血汤均具有较好的抗肝纤维化作用,其中以蜜丸酒煎下瘀血汤作用更为显著,提示制蜜丸一定程度上能够增加下瘀血汤抗肝纤维化作用。     

维吾尔医“库西提”法炮制技术规范化研究及巴豆脂肪油含量测定

目的:评价维吾尔医“各立衣克买提”泥法炮制技术和在这种炮制方法前提下改进的新“库西提”法炮制技术对巴豆中脂肪油的含量测定的影响。方法:利用两种炮制方法炮制生巴豆,按《中国药典》2015年版一部巴豆项下的脂肪油含量测定方法进行测定。结果:采用这两种方法炮制的巴豆根据炮制时间不同脂肪油含量依次递减。结论:采用新“库西提”法炮制技术炮制的巴豆的脂肪油含量明显降低。     

Delays in the reading and spelling of children with cerebral palsy: Associations with phonological and visual processes

BackgroundThis investigation addresses the question of whether there exists a significant discrepancy in the cognitive abilities of children with cerebral palsy (CP) who, despite the presence of age appropriate communication and language, have reading and spelling delays.AimsWe wanted to discover whether there was a relationship between the phonological and visual perceptual abilities of children with CP and their progress in reading and spelling.Methods and proceduresFifteen children with CP (aged between 6:9 years and 11:6 years) were assessed on reading and spelling; communication and language; non-verbal reasoning; phonological processing; and visual perception.Outcomes and resultsTen of the children had very weak reading and spelling skills. Five children had (mostly) age appropriate scores of reading and spelling. No differences were found between these two groups in non-verbal reasoning or communication and language. However, phonological abilities, visual sequential memory and perception of visuospatial relationships were found to be related to reading and spelling.Conclusions and implicationsThe findings suggest that children with CP are at risk for reading and spelling delays when they have poor phonological processing, visual sequential memory and perception of visuospatial relationships. The implications of the findings for classroom practice are discussed.     

Spectrum-Toxicity Correlation Study Revealed the Influence of the Nine-Time Steaming and Sun Drying Method on Hepatotoxic Components of Polygoni Multiflori Radix

Objective: Polygoni Multiflori Radix (PM) is a traditional herbal medicine with repeated reports of liver injury events in recent years. We wondered whether the classical processing method, namely, nine-time steaming and sun drying (NSSD), had toxicity-attenuating effects on PM and the relationships between toxicity and times of processing, as well as with the alteration trends of its compounds. Materials and Methods: The chemical fingerprints of different PM extracts were developed using ultra-high-performance liquid chromatography. The spectrum-toxicity correlation between the chemical fingerprints and hepatocellular toxicity was analyzed with multiple correlation analysis. Results: The results suggested that the hepatotoxicity of NSSD processing products markedly decreased with the repeated steaming and sun drying, which was obviously superior to the product processed by the modern method. Comprehensive analysis revealed that the contents of cis-stilbene glycoside and emodin-8-O-β-D-glucoside related to liver injury susceptibility were reduced with the times of NSSD processing, which was consistent with the decreased trend of hepatocellular toxicity. After the five times of NSSD, the contents of them as well as the hepatotoxicity of PM were steady. Moreover, we found that the contents of catechin and physcion declined rapidly after the one time of NSSD and then remained stable until the nine times of NSSD. Based on the fact, they could be utilized to indicate whether PM products were processed by steaming and sun drying. Conclusions: This paper confirmed that the NSSD had a good influence on the toxicity attenuating to PM and found four compounds which could apply for the quality control of PM.