GPU acceleration of a model-based iterative method for Digital Breast Tomosynthesis

Digital Breast Tomosynthesis (DBT) is a modern 3D Computed Tomography X-ray technique for the early detection of breast tumors, which is receiving growing interest in the medical and scientific community. Since DBT performs incomplete sampling of data, the image reconstruction approaches based on iterative methods are preferable to the classical analytic techniques, such as the Filtered Back Projection algorithm, providing fewer artifacts. In this work, we consider a Model-Based Iterative Reconstruction (MBIR) method well suited to describe the DBT data acquisition process and to include prior information on the reconstructed image. We propose a gradient-based solver named Scaled Gradient Projection (SGP) for the solution of the constrained optimization problem arising in the considered MBIR method. Even if the SGP algorithm exhibits fast convergence, the time required on a serial computer for the reconstruction of a real DBT data set is too long for the clinical needs. In this paper we propose a parallel SGP version designed to perform the most expensive computations of each iteration on Graphics Processing Unit (GPU). We apply the proposed parallel approach on three different GPU boards, with computational performance comparable with that of the boards usually installed in commercial DBT systems. The numerical results show that the proposed GPU-based MBIR method provides accurate reconstructions in a time suitable for clinical trials

Gastric Mucosa Mucous Layer Thickness in Liver Cirrhosis with Portal Hypertensive Gastropathy Compare to Functional Dyspepsia

Background: This study aimed to investigate gastric mucosa mucous layer thickness in portal hypertensive gastropathy (PHG) compare to normal mucosa in functional dyspepsia and its correlation with several variables such as child class, severity of esophageal varices and gastropathy. Methods: Biopsy specimens were taken from the antrum and corpus from both group of patients with PHG and functional dyspepsia. The specimen was given cryometric for frozen section. Tissue were sliced by sagital section 11 µm, placed in object glass, fixed and stained to evaluate mucous thickness and giemsa stained to observe Helicobacter pylori. Measurement of mucous thickness was done upward muscularis mucosa started from upper epithelial layer from foveale tip until outer mucous layer on 15 points which were marked randomly and calculate the mean value by micrometer (µm). Results: Mean value of antral mucous thickness in PHG was 13.30 ± 6.5 µm, while in the functional dyspepsia it was 25.59 ± 5.66 µm. Statistical analysis for both kinds of mucous thickness was p<0.001. Mean corpus mucous thickness in PHG was 10.6 ± 6.81 µm, while mucous thickness in dyspepsia was 32.54 ± 6.51 µm. Statistical analysis revealed p<0.001. This result showed significant difference of mucous thickness of antrum and corpus statistically between PHG and dyspepsia as control group. Conclusion: The study had proven the presence of decreased gastric mucosa mucous layer thickness in corpus and antrum in PHG. Thus, therapeutic approach to increase mucous thickness must be considered in patients with PHG

Esophageal Varices Bleeding in Portal Hypertension Due to Portal Vein and Splenic Vein Obstruction

Based on its relation to the liver sinusoid, increased pressure of portal vein can occur at three levels: presinusoid, sinusoid ,and postsinusoid. Obstruction of the presinusoid veins can be caused by extra- hepatic condition such as venous thrombosis. We reported a case of portal hypertension with esophageal varices bleeding was a result of obstruction due to thrombosis of the splenic vein and portal vein under hypercoagulant conditions due to thrombocytosis. The management of esophageal varices was sclerotherapy while for overcome the thrombosis the patient was given hydroxy urea

Supercapacitor Parameter Estimation and Hybridyzation with PEMFC for Purge Compensation

This paper focuses on the hybridization of a Proton Exchange Membrane Fuel Cell (PEMFC) and a Supercapacitor to smoothen the voltage disturbance caused by purging in the Fuel Cell. Firstly, a two-branch supercapacitor (SC) model is implemented in Simulink. The parameters of the SC are estimated using Genetic Algorithm Optimization and compared with the classical Faranda method. There is good agreement with the results generated using the Genetic Algorithm Optimization approach. Additionally, experiments were carried out on a 1.2kW PEMFC to acquire the voltage data. Voltage drops during purge were measured and used with the PEMFC model to simulate purge behaviour in the fuel cell. The SC was then connected in parallel to the PEMFC to smoothen the voltage output. The work is still in progress, and so far, positive results have been achieved where the SC has been effective in negating the effects of purge phenomena in PEMFC

Gamma-Knife Radiosurgery in Acromegaly: A 4-Year Follow-Up Study

Stereotactic radiosurgery by gamma-knife (GK) is an attractive therapeutic option after failure of microsurgical removal in patients with pituitary adenoma. In these tumors or remnants of them, it aims to obtain the arrest of cell proliferation and hormone hypersecretion using a single precise high dose of ionizing radiation, sparing surrounding structures. The long-term efficacy and toxicity of GK in acromegaly are only partially known. Thirty acromegalic patients (14 women and 16 men) entered a prospective study of GK treatment. Most were surgical failures, whereas in 3 GK was the primary treatment. Imaging of the adenoma and target coordinates identification were obtained by high resolution magnetic resonance imaging. All patients were treated with multiple isocenters (mean, 8; range, 3\u201311). The 50% isodose was used in 27 patients (90%). The mean margin dose was 20 Gy (range, 15\u201335), and the dose to the visual pathways was always less than 8 Gy. After a median follow-up of 46 months (range, 9\u201396), IGF-I fell from 805 \u3bcg/liter (median; interquartile range, 640\u2013994) to 460 \u3bcg/liter (interquartile range, 217\u2013654; P = 0.0002), and normal age-matched IGF-I levels were reached in 7 patients (23%). Mean GH levels decreased from 10 \u3bcg/liter (interquartile range, 6.4\u201315) to 2.9 \u3bcg/liter (interquartile range, 2\u20135.3; P < 0.0001), reaching levels below 2.5 \u3bcg/liter in 11 (37%). The rate of persistently pathological hormonal levels was still 70% at 5 yr by Kaplan-Meier analysis. The median volume was 1.43 ml (range, 0.20\u20133.7). Tumor shrinkage (at least 25% of basal volume) occurred after 24 months (range, 12\u201336) in 11 of 19 patients (58% of assessable patients). The rate of shrinkage was 79% at 4 yr. In no case was further growth observed. Only 1 patient complained of side-effects (severe headache and nausea immediately after the procedure, with full recovery in a few days with steroid therapy). Anterior pituitary failures were observed in 2 patients, who already had partial hypopituitarism, after 2 and 6 yr, respectively. No patient developed visual deficits. GK is a valid adjunctive tool in the management of acromegaly that controls GH/IGF-I hypersecretion and tumor growth, with shrinkage of adenoma and no recurrence of the disease in the considered observation period and with low acute and chronic toxicit

Desenlaces neonatales adversos en gestantes con preeclampsia severa y sus factores asociados

Objetivo: Analizar cuáles son los desenlaces neonatales adversos que con mayor frecuencia afectan a los recién nacidos de gestantes diagnosticadas con preeclampsia severa y determinar cuáles son sus factores asociados. Material y métodos: Siguiendo un diseño de cohortes se analizaron retrospectivamente todos los casos de preeclampsia severa diagnosticados en el Instituto Nacional Materno Perinatal durante el periodo 2016-2017. Resultados: Se analizaron un total de 942 casos de preeclampsia severa (28,5 ± 7,6 años de edad). El 100% de los gestantes dio a luz a producto vivo con 36,2 ± 3,2 semanas de gestación (rango: 24-41). Los desenlaces neonatales adversos más frecuentes fueron parto pretérmino (incidencia [I]=48,7%; intervalo de confianza al 95% [IC 95%]: 45,4% a 51,9%), talla baja para edad gestacional (I=33,7%; IC 95%: 30,6% a 36,7%), pequeño para la edad gestacional (I=25,6%; IC 95%: 22,9% a 28,5%) y Apgar 1-5´ bajo al nacer (I=12,1%; IC 95%: 10,0% a 14,2%). Las gestantes adolescentes tuvieron un menor riesgo de parto prematuro (IRR =0,70; IC 95%: 0,57 a 0,85) y un puntaje Apgar 1-5´ bajo al nacer (IRR =0,39; IC 95%: 0,21 a 0,72) que las adultas. Conclusión: La incidencia de desenlaces neonatales adversos en gestantes diagnosticadas con preeclampsia severa es alta, siendo los más frecuentes prematuridad, talla baja para edad gestacional, pequeño para la edad gestacional y APGAR 1-5´ bajo al nacer. Adicionalmente, se encontró que el riesgo de parto prematuro y Apgar bajo al nacer era menor en gestantes adolescentes que en gestantes adultas

The porin and the permeating antibiotic: A selective diffusion barrier in gram-negative bacteria

Gram-negative bacteria are responsible for a large proportion of antibiotic resistant bacterial diseases. These bacteria have a complex cell envelope that comprises an outer membrane and an inner membrane that delimit the periplasm. The outer membrane contains various protein channels, called porins, which are involved in the influx of various compounds, including several classes of antibiotics. Bacterial adaptation to reduce influx through porins is an increasing problem worldwide that contributes, together with efflux systems, to the emergence and dissemination of antibiotic resistance. An exciting challenge is to decipher the genetic and molecular basis of membrane impermeability as a bacterial resistance mechanism. This Review outlines the bacterial response towards antibiotic stress on altered membrane permeability and discusses recent advances in molecular approaches that are improving our knowledge of the physico-chemical parameters that govern the translocation of antibiotics through porin channel

What Is the Optimal Duration of Adjuvant Mitotane Therapy in Adrenocortical Carcinoma? An Unanswered Question

A relevant issue on the treatment of adrenocortical carcinoma (ACC) concerns the optimal duration of adjuvant mitotane treatment. We tried to address this question, assessing whether a correlation exists between the duration of adjuvant mitotane treatment and recurrence-free survival (RFS) of patients with ACC. We conducted a multicenter retrospective analysis on 154 ACC patients treated for ≥12 months with adjuvant mitotane after radical surgery and who were free of disease at the mitotane stop. During a median follow-up of 38 months, 19 patients (12.3%) experienced recurrence. We calculated the RFS after mitotane (RFSAM), from the landmark time-point of mitotane discontinuation, to overcome immortal time bias. We found a wide variability in the duration of adjuvant mitotane treatment among different centers and also among patients cared for at the same center, reflecting heterogeneous practice. We did not find any survival advantage in patients treated for longer than 24 months. Moreover, the relationship between treatment duration and the frequency of ACC recurrence was not linear after stratifying our patients in tertiles of length of adjuvant treatment. In conclusion, the present findings do not support the concept that extending adjuvant mitotane treatment over two years is beneficial for ACC patients with low to moderate risk of recurrence