An analog front end for full-duplex digital transceivers working ontwisted pairs

An analog front-end chip fabricated in a 4-μm CMOS process has been described. The chip, together with a digital signal processor, implements a full-duplex transceiver for twisted pairs. A fully differential architecture has been used in all the analog signal-processing blocks to get high dynamic range and common-mode noise rejection. The front-end output is a 12-b word generated by a 6-μs A/D (analog-to-digital) converter with autocalibration, with a linearity better than 1 LSB     

Growth hormone secretion, puberty and adult height after cranial irradiation with 18 Gy for leukaemia

The dose of prophylactic cranial irradiation given to patients for acute lymphoblastic leukaemia has been decreased from 24 to 18 Gy, but the beneficial effect of this decrease on growth is controversial. This study compares the growth hormone (GH) secretion and growth of 35 patients (20 boys) given 18 Gy at 3.7+/-0.3 (SE) years, and routinely evaluated 5.4+/-0.4 years after irradiation to define the indications for GH treatment in these patients. Of these, 63% had a low GH peak (< 10 microg/l) after one (22 cases) or two (17 cases) stimulation tests. The plasma concentrations of insulin-like growth factor I and its GH-dependent binding protein were normal for age in all but two cases. The height changes between irradiation and evaluation were correlated with the GH peaks (P < 0.03) and were concordant, except in patients with early puberty. This occurred in 16 patients including all 12 girls irradiated before 4 years of age. A significant (P < 0.03) reduction in height (SD) between irradiation and adult height occurred in untreated GH-deficient patients (-1+/-0.3, n=6), but not in GH-deficient patients given GH (-0.6+/-0.3, n=8) or in those with normal GH peak (-0.4+/-0.3, n=7). CONCLUSION: In children irradiated for acute lymphoblastic leukaemia, GH deficiency is frequent after 18 Gy but its impact on adult height is smaller than after higher doses. We suggest that the indications for gonadotropin releasing hormone analogue therapy should be broad in patients with early or rapidly progressing puberty and those for GH therapy in those patients with a below average constitutional height before irradiation.     

Adult height in girls with idiopathic true precocious puberty

GnRH analogs are used to suppress pituitary-gonadal activity in children with true precocious puberty. The indications for therapy in this situation are not established, as some girls have a slow evolutive form, and the capacity of GnRH analogs to preserve the adult height has not been evaluated. This study analyzes the growth and adult heights of 2 groups of girls with idiopathic true precocious puberty, 1 with a predicted height of 155 cm or less (group 1, 19 cases) and the other with a predicted height of more than 155 cm (group 2, 15 cases). Group 1 patients were treated with a long-acting GnRH analog (D-Trp6-GnRH), and group 2 patients were followed without therapy. Group 1 showed greater clinical signs of estrogenization, vaginal maturation index (P < 0.03), plasma estradiol (P < 0.0004), and ratio of LH/FSH peaks (P < 0.01) at the initial evaluation than did group 2. The mean target heights were similar (difference, 0.9 cm). In group 1, the adult height (159 +/- 1.1 cm) was greater than the predicted height before therapy (152 +/- 1.4 cm; P < 0.0001). The difference between the adult height and the predicted height before therapy (mean, 6.5 cm) correlated positively with the bone age advance (P < 0.01), negatively with the predicted height (P < 0.05), and positively with the difference between the target and predicted heights (P < 0.001) before therapy. In group 2, the adult height (162 +/- 1.4 cm) was similar to the predicted height at the initial evaluation (162.5 +/- 1.4 cm). Adult heights correlated with target height in group 1 and with predicted height at the initial evaluation in group 2. In conclusion, some girls with true precocious puberty and poor adult height prediction who are treated with GnRH analog achieve an adult height more comparable to their target height. However, the lack of effect on height in girls with predicted height at the onset of therapy similar to their target height and preservation of the growth potential in the slow evolutive forms suggest that these forms might not require immediate therapy. Careful follow-up before therapy may be a better way of evaluating their natural course.     

Combining make to order and make to stock

In inventory control and production planning one is tempted to use one of two strategies: produce all demand to stock or produce all demand to order. The disadvantages are well-known. In the make everything to order case (MTO) the response times may become quite long if the load is high, in the make everything to stock case (MTS) one gets an enormous inventory if the number of different products is large.In this paper we study two simple models which combine MTO and MTS, and investigate the effect of combining MTO and MTS on the production lead times.     

Gold-enhanced biomolecular surface imaging of cells and tissue by SIMS and MALDI mass spectrometry

Surface metallization by plasma coating enhances desorption/ionization of membrane components such as lipids and sterols in imaging time-of-flight secondary ion mass spectrometry (TOF-SIMS) of tissues and cells. High-resolution images of cholesterol and other membrane components were obtained for neuroblastoma cells and revealed subcellular details (resolving power 1.5 mum). Alternatively, in matrix-enhanced SIMS, 2,5-dihydroxybenzoic acid electrosprayed on neuroblastoma cells allowed intact molecular ion imaging of phosphatidylcholine and sphingomyelin at the cellular level. Gold deposition on top of matrix-coated rat brain tissue sections strongly enhanced image quality and signal intensity in stigmatic matrix-assisted laser desorption/ionization imaging mass spectrometry. High-quality total ion count images were acquired, and the neuropeptide vasopressin was localized in the rat brain tissue section at the hypothalamic area around the third ventricle. Although the mechanism of signal enhancement by gold deposition is under debate, the results we have obtained for cells and tissue sections illustrate the potential of this sample preparation technique for biomolecular surface imaging by mass spectrometry.     

Multi-focus image fusion by local optimization over sliding windows

This article presents a technique to solve the problem of multi-focus image fusion. This technique is based on the maximization of a linear function with spatial coherence constraints. The final fused image is computed as the sum of the source images using a segmentation map. We can compute the segmentation map using the Simplex method, where the objective function includes one variable associated with each pixel. The Simplex method requires a huge amount of memory resources to produce it. We present an algorithm called CPW-S, which uses some strategies to solve the problem in a context with fewer variables; images are split into regions, thus reducing the computational effort. We present results for two pairs of synthetic images in order to quantify the results, obtaining more than \(98\%\) of pixel accuracy for the segmentation map. We also present results for several pairs of real images (widely used in the literature) and a triad of multi-focus images. The resulting fused images are qualitatively good for all the real images included in the experiments.     

区块链技术在地学数据共享中的应用可行性分析

地学数据共享是地学研究的重要内容,也是挖掘地学数据、避免地学数据重复采集的重要途径,是现代数据密集型科研范式下地学研究的重要基础,因此,如何打破地学数据“孤岛”、实现不同地学数据便捷获取、保障数据安全、提升和扩展地学数据贡献者权益保护是地学数据共享中急需解决的问题。区块链技术的兴起,为地学数据价值外化途径扩充、提升数据安全和地学数据贡献者权益保护带来了新的可能。在系统梳理地学数据共享现状、存在问题、区块链基本原理、特点、底层架构以及应用现状的基础上,探讨区块链技术在地学数据共享中的应用可行性以及应用场景,阐述区块链技术在地学数据共享中的应用挑战,以期为地学数据共享领域区块链相关研究与应用提供参考。     

TP53 in Acute Myeloid Leukemia: Molecular Aspects and Patterns of Mutation

Mutation of the tumor suppressor gene, TP53, is associated with abysmal survival outcomes in acute myeloid leukemia (AML). Although it is the most commonly mutated gene in cancer, its occurrence is observed in only 5–10% of de novo AML, and in 30% of therapy related AML (t-AML). TP53 mutation serves as a prognostic marker of poor response to standard-of-care chemotherapy, particularly in t-AML and AML with complex cytogenetics. In light of a poor response to traditional chemotherapy and only a modest improvement in outcome with hypomethylation-based interventions, allogenic stem cell transplant is routinely recommended in these cases, albeit with a response that is often short lived. Despite being frequently mutated across the cancer spectrum, progress and enthusiasm for the development of p53 targeted therapeutic interventions is lacking and to date there is no approved drug that mitigates the effects of TP53 mutation. There is a mounting body of evidence indicating that p53 mutants differ in functionality and form from typical AML cases and subsequently display inconsistent responses to therapy at the cellular level. Understanding this pathobiological activity is imperative to the development of effective therapeutic strategies. This review aims to provide a comprehensive understanding of the effects of TP53 on the hematopoietic system, to describe its varying degree of functionality in tumor suppression, and to illustrate the need for the adoption of personalized therapeutic strategies to target distinct classes of the p53 mutation in AML management.