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关键词： Pressure-sensitive paint   Differential luminescent imaging   Acoustic field   Pressure measurement  

摘要： A differential luminescent imaging method is applied to a pressure-sensitive paint (PSP) measurement to capture a quasi-steady acoustic pressure field. Conventionally, PSP measurements capture an absolute luminescent intensity and convert it to pressure. When the mean component of the absolute luminescent intensity occupies a substantial portion of the dynamic range of the image acquisition device, it leads to a coarse signal resolution. Differential luminescent imaging, utilizing two-color luminescent intensities and a differential amplifier, extracts the fluctuation component from the absolute luminescent intensity. The developed differential luminescent imaging system gives a point-wise pressure measurement. These measurements are combined to produce a spatially resolved image. It is capable of resolving the periodic pressure wave over the acoustic field where the resolution of a conventional PSP measurement falls into one digital count. This comparison to a conventional PSP measurement is given as a reference by which to evaluate the spatiotemporal resolution of the differential luminescent imaging method.

关键词： Tomato(Solanum lycopersicum L   )   Extreme temperature   Acclimation   Fruit quality   Ascorbate   Tocochromanols  

摘要： The upcoming climate change presents a great challenge for plant growth and development being extremes temperatures among the major environmental limitations to crop productivity. Understanding the repercussions of these extreme temperatures is of high importance to elaborate future strategies to confront crop damages. Tomato plants (Solanum lycopersicum L.) are one of the most cultivated crops and their fruits are consumed worldwide standing out for their organoleptic characteristics and nutritional value. Tomato plants are sensitive to temperatures below 12 degrees C and above 32 degrees C. In this study, Micro-Tom cultivar was used to evaluate the effects of extreme temperatures on the plant of tomato and the fruit productivity and quality from the stressed plants, either exposed to cold (4 degrees C for three nights per week) or heat (32 degrees C during the day, seven days per week) treatments. Total productivity and the percentage of ripe fruits per plant were evaluated together with foliar stress markers and the contents of photosynthetic pigments and tocochromanols. Fruit quality was also assessed determining lycopene contents, total soluble solids, total acidity and ascorbate contents. High temperatures altered multiple physiological parameters indicating a moderate stress, particularly decreasing fruit yield. As a response to this stress, plants enhanced their antioxidant contents both at leaf and fruit level. Low temperatures did not negatively affect the physiology of plants with similar yields as compared to controls, suggesting chilling acclimation. Both high and low temperatures, but most particularly the former, increased total soluble solids contents indicating that temperature control may be used as a strategy to modulate fruit quality.

关键词： Obesity   Bariatric surgery   Body composition   Fat mass   Fat-free mass   Total body water   Biliary pancreatic diversion   Revised biliary pancreatic diversion   Gastric bypass   Sleeve gastrectomy  

摘要： Aims Bariatric surgeries induce profound weight loss (decrease in body mass index, BMI), through a decrease in fat mass (FM) and to a much lesser degree of fat-free mass (FFM). Some reports indicate that the weight which is lost after gastric bypass (RYGB) and sleeve gastrectomy (SG) is at least partially regained 2 years after surgery. Here we compare changes in BMI and body composition induced by four bariatric procedures in a 5 years follow-up study. Methods We analyzed retrospectively modifications in BMI, FM and FFM obtained through Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), biliopancreatic diversion (BPD) and a long common limb revisional biliopancreatic diversion (reduction of the gastric pouch and long common limb;BPD + LCL-R). Patients were evaluated at baseline and yearly for 5 years. Of the whole cohort of 565 patients, a subset of 180 patients had all yearly evaluations, while the remaining had incomplete evaluations. Setting University Hospital. Results In a total of 180 patients evaluated yearly for 5 years, decrease in BMI and FM up to 2 years was more rapid with RYGB and SG than BPD and BPD + LCL-R;with RYGB and SG both BMI and FM slightly increased in the years 3-5. At 5 years, the differences were not significant. When analysing the differences between 2 and 5 years, BPD + LCL-R showed a somewhat greater effect on BMI and FM than RYGB, BPD and SG. Superimposable results were obtained when the whole cohort of 565 patients with incomplete evaluation was considered. Conclusions All surgeries were highly effective in reducing BMI and fat mass at around 2 years;with RYGB and SG both BMI and FM slightly increased in the years 3-5, while BPD and BPD + LCL-R showed a slight further decreases in the same time interval.

关键词： Brain tumours   Magnetic resonance imaging   Neuroimaging   Pineal gland   Sellar   Suprasellar  

摘要： Introduction Pineal, sellar and suprasellar tumours in children comprise a wide range of diseases with different biological behaviours and clinical management. Neuroimaging plays a critical role in the diagnosis, treatment planning and follow up of these patients, but imaging interpretation can prove challenging due to the significant overlap in radiological features. Materials and method A review of the literature was performed by undertaking a search of the MEDLINE and EMBASE databases for appropriate MeSH terminology. Identified abstracts were screened for inclusion and articles meeting the objectives of the review were included. Results and Conclusion In this article, we review radiological appearances of common and uncommon pineal, sellar and suprasellar tumours occurring in the paediatric population. We discuss the importance of anatomical localization, clinical information and cerebrospinal fluid tumour markers, and propose a practical approach to differential diagnosis. Lastly, we discuss future directions and prospective new imaging strategies to support state-of-the-art patient care.

关键词： hypocalcemia   EGTA   PTHLH   serotonin  

摘要： The peripartal cow experiences a rapid change in calcium metabolism at the onset of lactation. Research has focused on understanding how mammary-derived factors, such as serotonin (5HT) and parathyroid hormone like hormone (PTHLH), aid in coordinating these calcemic adaptations to lactation. Therefore, the aim of our study was to determine how induced subclinical hypocalcemia influences physiological responses, specifically the 5HT-PTHLH-Ca axis, in lactating and nonlactating dairy cows to elucidate the potential contribution of the mammary gland. Twelve nonlactating, nonpregnant (NL) multiparous Holstein cows and 12 early-lactation (EL) multiparous Holstein cows received either (1) a continuous 24-h intravenous solution of 0.9% NaCl or (2) 5% ethylene glycol tetraacetic acid (EGTA) solution in 0.9% NaCl (n = 6 EL, n = 6 NL per treatment) with the aim of maintaining blood ionized calcium (iCa) less than 1.0 mM. Mammary gland biopsies were taken immediately after and 48 h after termination of infusion. Blood was sampled hourly during infusion and 4, 8, 12, 24, 48, and 72 h after termination of infusion. Infusion of EGTA successfully decreased blood iCa concentrations. However, EL EGTA-infused cows required increased rates of EGTA infusion to maintain iCa below 1.0 mM. Circulating and mammary serotonin concentrations were increased in EL relative to NL cows, with no difference as a result of EGTA infusion. Mammary PTHLH expression was increased in EL cows, with highest expression observed in EL EGTA-infused cows. Collectively, these data demonstrate the robust adaptations EL cows have to maintain Ca homeostasis and the supporting roles 5HT and PTHLH may play.

关键词： Traditional Chinese medicine   Ephedra sinica   Endophytes   Plant-microbe interaction   Cultivation years  

摘要： Ephedra sinica is widely used in the treatment of diseases due to its rich and diverse pharmacological effects. The quality of E. sinica is various in different years. However, the effect of endophytes on the accumulation of metabolites of E. sinica in different years is still obscure. In this study, the relationship between the ecological succession of bacterial endophytes and metabolite accumulation of E. sinica grown in different years were generally investigated based on 1H NMR and 16 s rDNA sequencing. The results showed that 38 differential marker metabolites existed in E. sinica grown in different years. The distribution and abundance of bacterial endophytes changed during the growth of cultivated E. sinica, and there was remarkable correlation between the dominant endophytes and differential metabolites. This study provides a critical reference in evaluating and monitoring the quality of E. sinica in the process of cultivation, and establish a solid foundation for the use of species interactions to improve the quality of E. sinica in different years.

关键词： 偏微分方程-数值计算-高等学校-教材  

ISBN: (纸本)9787030701619

摘要： 本书内容包括常微分方程两点边值问题的差分方法、椭圆型方程的差分方法、抛物型方程的差分方法、双曲型方程的差分方法、高维发展方程的交替方向法、分数阶微分方程的有限差分方法、Schrodinger方程的差分方法、Burgers方程的差分方法、Korteweg-deVries方程的差分方法。力求做到：（a）精选内容；（b）难点分散；（c）循序渐进。先举例示范，再要求学生模仿，最后到熟练掌握；先介绍基础篇，再引入提高篇。本书可作为信息与计算科学及数学与应用数学专业高年级本科生的基础课教材，亦可作为高等学校数学及其他专业研究生的教学参考书。

关键词： category contingency   product variety   profitability contingency   SKU-level analysis  

摘要： We empirically examine the effect of product variety on sales at the stock-keeping unit (SKU) level. Prior empirical operations management studies generally treat product variety as a single-dimensional measure (e.g., the number of SKUs carried by the store, distribution center, or firm) and study its impact on aggregate sales (e.g., sales at the store, distribution center, or firm). As such, SKUs from different brands are assumed to contribute equally to total sales, which is not always the case. To address this, we need to conceptualize product variety within brands and investigate its impact on sales at a more granular level. In this study, we propose and theoretically articulate two product variety dimensions (within-brand variety [WV] and average WV of other brands [AWVO]) to investigate the mechanisms that connect product variety to SKU-level sales. Using a detailed transaction dataset from a local grocery retailer, we first show that product variety conceptualized within brands (i.e., the mean of WVs [MWV]) does have an impact on aggregate subcategory sales, as the literature suggests. At the SKU level, we find WV increases same-brand SKU sales, while AWVO reduces it. Our work provides an alternative explanation to the inverted U-shaped relationship between product variety and aggregate sales observed in the literature: Increasing variety only increases sales of SKUs belonging to the brand whose variety has increased, while it decreases sales of the other SKUs. We also find that variety effects vary significantly across different profitability levels and product categories. Product variety appears to have the strongest positive effect on high-margin products. The impact of product variety on specific product category sales varies from as high as 11% to negligible. We further discuss the practical value of our findings and show the robustness of our results through multiple tests while addressing endogeneity using the control function approach.

关键词： multispectral image enhancement   remote sensing   dark channel prior   fractional differential  

摘要： Compared with single-band remote sensing images, multispectral images can obtain information on the same target in different bands. By combining the characteristics of each band, we can obtain clearer enhanced images;therefore, we propose a multispectral image enhancement method based on the improved dark channel prior (IDCP) and bilateral fractional differential (BFD) model to make full use of the multiband information. First, the original multispectral image is inverted to meet the prior conditions of dark channel theory. Second, according to the characteristics of multiple bands, the dark channel algorithm is improved. The RGB channels are extended to multiple channels, and the spatial domain fractional differential mask is used to optimize the transmittance estimation to make it more consistent with the dark channel hypothesis. Then, we propose a bilateral fractional differentiation algorithm that enhances the edge details of an image through the fractional differential in the spatial domain and intensity domain. Finally, we implement the inversion operation to obtain the final enhanced image. We apply the proposed IDCP_BFD method to a multispectral dataset and conduct sufficient experiments. The experimental results show the superiority of the proposed method over relative comparison methods.

关键词： cytokine   immunological memory   malaria   Tfh   Th1  

摘要： Plasmodium parasites that infect humans are highly polymorphic, and induce various infections ranging from an asymptomatic state to life-threatening diseases. However, how the differences between the parasites affect host immune responses during blood-stage infection remains largely unknown. We investigated the CD4+ T-cell immune responses in mice infected with P. berghei ANKA (PbA) or P. chabaudi chabaudi AS (Pcc) using PbT-II cells, which recognize a common epitope of these parasites. In the acute phase of infection, CD4(+) T-cell responses in PbA-infected mice showed a lower involvement of Th1 cells and a lower proportion of Ly6C(lo) effector CD4+ T cells than those in Pcc-infected mice. Transcriptome analysis of PbT-II cells indicated that type I interferon (IFN)-regulated genes were expressed at higher levels in both Th1- and Tfh-type PbT-II cells from PbA-infected mice than those from Pcc-infected mice. Moreover, IFN-alpha levels were considerably higher in PbA-infected mice than in Pcc-infected mice. Inhibition of type I IFN signaling increased PbT-II and partially reversed the Th1 over Tfh bias of the PbT-II cells in both PbA- and Pcc-infected mice. In the memory phase, PbT-II cells in PbA-primed mice maintained higher numbers and exhibited a better recall response to the antigen. However, recall responses were not significantly different between the infection groups after re-challenge with PbA, suggesting the effect of the inflammatory environment by the infection. These observations suggest that the differences in Plasmodium-specific CD4(+) T-cell responses between PbA- and Pcc-infected mice were associated with the difference in type I IFN production during the early phase of the infection.