Development and verification of design methods for ducts in a space nuclear shield

A practical method for computing the effectiveness of a space nuclear shield perforated by small tubing and cavities is reported. Performed calculations use solutions for a two dimensional transport code and evaluate perturbations of that solution using last flight estimates and other kernel integration techniques. In general, perturbations are viewed as a change in source strength of scattered radiation and a change in attenuation properties of the region

Preventing postsurgical venous thromboembolism: pharmacological approaches

The use of antithrombotic drugs for the prevention of venous thromboembolism (VTE) in patients undergoing surgery is presently based on solid principles and high-level scientific evidence. This article reviews current strategies of pharmacological thromboprophylaxis. The level of VTE risk following surgery depends on a variety of factors that the surgeon should take into account, including the type of surgery and the presence of additional risk factors, such as elderly age and cancer. In patients undergoing minor general surgery, early mobilization is sufficient as prophylaxis, whereas in those undergoing major general surgery, thromboprophylaxis with low molecular weight heparin (LMWH), low-dose unfractionated heparin, or the pentasaccharide fondaparinux is recommended. Patients undergoing major orthopedic surgery have a particularly high risk of VTE, and routine thromboprophylaxis with LMWH, fondaparinux, or a vitamin K antagonist (international normalized ratio target: 2.0 to 3.0) is the standard of care in this group of patients. Recently, two new oral anticoagulants, rivaroxaban (a factor Xa inhibitor) and dabigatran etexilate (a direct thrombin inhibitor) have been licensed to be used for thromboprophylaxis after orthopedic surgery in Europe. Mechanical methods of thromboprophylaxis (compression stockings, intermittent pneumatic compression, vena cava filters), not discussed in detail in this review, should always be considered in patients at high thrombotic risk, in association with the pharmacolocical strategies, or in cases of contraindications to antocoagulants, as in patients or procedures at high risk of bleeding

Endocrine morbidity in midline brain defects: Differences between septo-optic dysplasia and related disorders

Background Septo-optic dysplasia (SOD) is a heterogeneous congenital condition. The aim of this study was to investigate the clinical phenotypes of a large cohort of children with SOD, Multiple Pituitary Hormone Deficiency (MPHD) and Optic Nerve Hypoplasia (ONH), with a focus on endocrine testing. Methods Retrospective single-centre longitudinal study of children with SOD (n:171), MPHD (n:53) and ONH (n:35). SOD+ and SOD- indicate patients with or without hypopituitarism, respectively. Findings All deficits were more frequent and occurred earlier in MPHD than SOD+ [Hazard Ratios (HR): 0·63(0·45,0·89) for GH, 0·48(0·34,0·69) for TSH, 0·55(0·38,0·80) for ACTH, 0·28(0·11,0·68) for gonadotropins], except Diabetes Insipidus (DI) [HR: 2·27(0·88,5·9)]. Severe hypothalamo-pituitary (H-P) abnormalities were more frequent in MPHD [80·0% vs 41·6%, p<0·0001 for Ectopic Posterior Pituitary (EPP)]. Stalk and PP abnormalities were associated with more severe endocrine phenotypes and placed a subgroup of SOD+ at risk of developing deficits earlier. SOD and ONH shared heterogeneous phenotypes ranging from pubertal delay to precocity and from leanness to extreme obesity, whilst MPHD had GnD and obesity only. Mortality was recorded in 4·2% (6/144) SOD and 3·2% (1/31) ONH, and only in patients with multisystem phenotypes. Interpretation More than a single disease, SOD represents a spectrum of malformative conditions involving different brain structures and characterised by a dynamic and sequential nature of endocrine. In contrast, MPHD displays a more homogeneous phenotype of (mainly) anterior pituitary early-onset failure. Stalk and PP abnormalities place a subgroup of SOD+ at a higher risk of early-onset deficits. Additionally, there are striking differences between the SOD and MPHD cohorts in terms of pubertal progression. The shared phenotypes between ONH and SOD could be partly explained by common hypothalamic dysfunction. The differences between the cohorts are important as they may aid in planning management and preventing morbidity by dictating earlier interventions

Analysis and Geographical Representation of Cilento’s Monastic Architecture

This paper is part of a wider research on the Cilento monastic architec-tures of Italo-Greek origin located in southern Campania (Italy). The investigationconcentrates on the study, updating and analysis of the existing constructions forthe enrichment of the geographical information databases of the Cilento. On thisopportunity, the analysis focuses specifically on two monuments of Basilian foun-dation: the Abbey of Santa Maria di Pattano, in Vallo della Lucania, and the churchof San Nicola di Myra in Sacco Vecchia. The first case study presents superfe-tations that make it difficult to read the architectural languages and to interpretits conformation. On the other hand, the church of San Nicola in Myra, despitebeing located in one of the most famous ghost towns of the Cilento countrysideand showing important deterioration, still preserves its original morphology, char-acterized by a splendid hieratic character that is completely Basilian. The study ofthese constructions was carried out with digital models and geographic informa-tion systems, in order to obtain the original conformation of the Badia of Pattano.The comparative analysis of the information gathered on the other monument wasused to obtain the necessary data to clarify and identify the main constructionpatterns of the Byzantine and Basilian architectures of the area. These data willserve to enrich the current information and, furthermore, to develop more specificmultidisciplinary analyses in the future

Smoking Habit in Severe Obese after bariatric procedures.

Background: Bariatric procedures provide an effective means of short term weight loss and sustained weight control for the morbidly obese. The effect of bariatric procedures on smoking habit in obese subjects is not well known. Therefore, we examined the short term effect of bariatric surgery on smoking habit of severe obese patients up to 12 months from the intervention. Patients and Methods: Smoking habit was assessed in a cohort of 78 morbid smoking obese patients followed at our clinic for bariatric procedures. They underwent non surgical intra-gastric balloon (IB) or surgical procedures such as lap-band laparoscopic surgery (LAGB) or sleeve gastrectomy/gastric by-pass (SPG). Subjects were administered a written questionnaire about their smoking habit before and 3, 6 and 12 months after the procedures. Results: No differences were found among the three groups at 6 and 12 months after the procedures (IB 21 %, LAGB 6 %, SPG 5 %; and IB 14 %, LAGB 3 %, SPG 5 %). Only after 3 months, the rate of quitting of the IB group was higher than LAGB and SPG groups (36 %, 6 % and 5 %, respectively; p = 0.02). Conclusions: Bariatric procedures have no effects on smoking habit of moderate-to-heavy smoker severe obese patients. The use of other traditional smoking cessation methods in patients undergone to bariatric procedures should be implemented

Diabetes Mellitus and Cardiovascular Prevention: The Role and the Limitations of Currently Available Antiplatelet Drugs

Diabetes mellitus (DM) is associated with macrovascular and microvascular complications. Platelets have a “key role” in atherogenesis and its thrombotic complications in subjects with DM. Moreover, the concomitant presence of multiple “classical” cardiovascular risk factors in diabetic subjects contributes to enhanced atherothrombotic risk. Antiplatelet agents are effective in primary and secondary prevention of arterial thrombosis (cardiovascular events, ischaemic stroke, and peripheral arterial occlusive disease). The role of chronic administration of antiplatelet drugs in primary prevention of arterial vascular events is known to be less clear than in secondary prevention, and, also in diabetic patients, the decision to give primary prophylaxis should be taken on an individual-patient basis, after a careful evaluation of the balance between the expected benefits and the risk of major bleedings. Although, currently, treatment has proven useful in reducing vascular events, diabetic patients continue to have a higher risk of adverse cardiovascular events compared with those in nondiabetic patients. This paper reviews the role of currently available antiplatelet drugs in primary and secondary prevention of vascular events in diabetic patients and the limitations of these drugs, and it discusses the role of novel and more potent antiplatelets and of new agents currently under clinical development

Oxidative Stress and Platelet Activation in Homozygous Homocystinuria

Background — Severe hyperhomocysteinemia due to cystathionine β-synthase deficiency (CβSD) is associated with early atherothrombotic vascular disease. Homocysteine may exert its effects by promoting oxidative damage. In the present study, we investigated whether in vivo formation of 8-iso-prostaglandin (PG) F 2α , a platelet-active product of arachidonic acid peroxidation, is enhanced in CβSD and whether it correlates with in vivo platelet activation, as reflected by thromboxane (TX) metabolite excretion. Methods and Results — Urine and blood samples were obtained from patients with homozygous CβSD (n=13) and age-matched healthy subjects. Urinary 8-iso-PGF 2α excretion was significantly higher in CβSD patients than in control subjects (640±384 versus 213±43 pg/mg creatinine; P =0.0015) and correlated with plasma homocysteine (ρ=0.398, P =0.0076). Similarly, urinary 11-dehydro-TXB 2 excretion was enhanced in CβSD (1166±415 versus 324±72 pg/mg creatinine; P =0.0015) and correlated with urinary 8-iso-PGF 2α (ρ=0.362, P =0.0153). Vitamin E supplementation (600 mg/d for 2 weeks) was associated with a statistically significant increase in its plasma levels (from 16.6±4.6 to 40.4±8.7 μmol/L, P =0.0002) and with reductions in 8-iso-PGF 2α (from 790±159 to 559±111 pg/mg creatinine, P =0.018) and 11-dehydro-TXB 2 (from 1273±383 to 913±336 pg/mg creatinine, P =0.028). A statistically significant inverse correlation was found between urinary 8-iso-PGF 2α and plasma vitamin E levels (ρ=−0.745, P =0.0135). Conclusions — The results of the present study suggest that enhanced peroxidation of arachidonic acid to form bioactive F 2 -isoprostanes may represent an important mechanism linking hyperhomocysteinemia and platelet activation in CβSD patients. Moreover, they provide a rationale for dose-finding studies of vitamin E supplementation in this setting