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1.
A significant reversible decrease in testosterone (T) has been associated with microgravity in male rodents and humans. Urinary T excretion increases in primates under hypergravity. Hypogonadism is somehow related to abnormally high levels of leptin (L), a hormone produced by the adipose tissue which has been found to increase under microgravity simulation conditions like head down bed rest (HDBR). The aim of this study was to assess hemodynamic and pituitary-adrenal and -gonadal adaptation to an acute HDBR test to be eventually used on a routine basis to get better prepared to next space flights. The Authors performed a 1 hour ?12° HDBR in 6 male and 6 female volunteers who underwent heart rate and blood pressure measurement together with a blood draw three times at 30 min intervals from the start to the end of the test for L, T, estradiol (E2), LH, androstenedione (A), cortisol (F), ACTH. 12 age- and sexmatched control subjects followed the same protocol except for keeping the sitting position all the time. According to the ANOVA for repeated measures, no changes occurred in L, T, E2 or LH whereas A, F and ACTH significantly decreased independently of gender. During HDBR systolic blood pressure decreased in both genders, diastolic blood pressure decreased significantly only in men and HR showed a more clear-cut decrease in women than in men. As a conclusion, such an acute steep-slope HDBR protocol may be efficiently used to testing immediate individual haemodynamic or adrenal response to microgravity but is not suitable for studies concerning gonadal adaptation.  相似文献   
2.
Part modelling in a CAD environment requires a bi-manual 3D input interface to fully exploit its potentialities. In this research we provide extensive user tests on bi-manual modelling using different devices to control 3D model’s rotation. Our results suggest that a simple trackball device is effective when the user task is mostly limited to rotation control (i.e. when modelling parts in a CAD environment). In our tests, performances are even better than those achieved with a specifically designed device. Since the task of rotating a CAD part often shows the need of flipping the controlled object, we introduce a non linear transfer function which combines the precision of a zero order control mode with the ability to recognise fast movements. This new modality shows a significant improvement in the user’s performances and candidates itself for integration in next generation CAD interfaces.  相似文献   
3.
Two cases of neonatal aortic arch thrombosis are reported. One patient, who had ascending aortic thrombosis, died preoperatively. The other had reoperation and is alive and well at 6 months' follow-up. No obvious cause was found.  相似文献   
4.
Colorectal cancer (CRC) is a leading cause of cancer death worldwide, and about 20% is metastatic at diagnosis and untreatable. Increasing evidence suggests that the heterogeneous nature of CRC is related to colorectal cancer stem cells (CCSCs), a small cells population with stemness behaviors and responsible for tumor progression, recurrence, and therapy resistance. Growing knowledge of stem cells (SCs) biology has rapidly improved uncovering the molecular mechanisms and possible crosstalk/feedback loops between signaling pathways that directly influence intestinal homeostasis and tumorigenesis. The generation of CCSCs is probably connected to genetic changes in members of signaling pathways, which control self-renewal and pluripotency in SCs and then establish function and phenotype of CCSCs. Particularly, various deregulated CCSC-related miRNAs have been reported to modulate stemness features, controlling CCSCs functions such as regulation of cell cycle genes expression, epithelial-mesenchymal transition, metastasization, and drug-resistance mechanisms. Primarily, CCSC-related miRNAs work by regulating mainly signal pathways known to be involved in CCSCs biology. This review intends to summarize the epigenetic findings linked to miRNAome in the maintenance and regulation of CCSCs, including their relationships with different signaling pathways, which should help to identify specific diagnostic, prognostic, and predictive biomarkers for CRC, but also develop innovative CCSCs-targeted therapies.  相似文献   
5.
Recurrent urinary tract infections (RUTI) are a significant health problem for many women, and host characteristics that increase susceptibility are not completely defined. This study evaluated data from 99 patients to examine further the question of a possible association between major histocompatibility complex (MHC) or red blood cell (RBC) antigen phenotype and predisposition to RUTIs. MHC class I and II, ABO, and Lewis RBC phenotypes were determined serologically. The MHC class II phenotypes of 55 subjects were also determined by DNA polymerase chain reaction techniques. There were no significant differences in the proportions of HLA-A or -B antigen types between patients and controls, nor in the frequencies of serologically or DNA-defined HLA-DR or -DQ phenotypes. Patient ABO and Lewis RBC phenotypes were not statistically different than those for controls. Thus, the overall risk for women to develop RUTIs does not appear to be associated with any single HLA, ABO, or Lewis phenotype.  相似文献   
6.
Aim of the present study was to investigate on the possible alterations induced by on ground modeled microgravity on ion-water transport proteins at cellular level. For the purpose we used astrocytes, C6 line, neurons (NT2 line from human teratocarcinoma) and testicular cells (germ cells, Sertoli cells, and Leydig cells; primary cultures from trypsinised prepuberal pig testes). Modeled microgravity was achieved by a desktop 3D Random Positioning Machine, cultures were kept rotating for 30′, 1h and 24h. After 30′, immunopositivity for the antibodies to Na+/K+ATPase and Na+/K+/Cl? co-transporters was greatly diminished, the plasma membrane appeared to be altered, and the mitochondria inner cristae were disrupted. Immunostaining to the antibody to the water channel aquaporin 4 was very bright. After 1h at random rotation immunostaining for the heat shock protein Hsp27 was visible, After 24h, immunostaining for the ion transport proteins was again like that of the controls, plasma membrane and the mitochondria were again normal. Immunostaining for aquaporin 4 become again similar to that of the controls. We conclude that low gravity induces only transient alterations in the cell’s transmembrane ion-water transport: the cells are able to adapt to the gravity vector changes in few hours.  相似文献   
7.
8.
BACKGROUND: The purpose of this study was to determine whether, with appropriate techniques, diabetic patients could benefit from the advantages of double internal thoracic artery (ITA) coronary bypass without an increased hospital risk. METHODS: Between January 1990 and December 1996, 207 consecutive diabetic patients underwent coronary artery bypass graft operations. In 74 patients both arteries (bilateral ITA group) were used, whereas 133 patients received one ITA and vein grafts or vein grafts alone (nonbilateral group). Patients in the bilateral ITA group were younger (p<0.0001), predominantly male (p<0.0001), and were operated on more electively. The internal thoracic arteries were harvested by skeletonization without electrocautery, and strict glycemic control was pursued. RESULTS: No death was observed in the bilateral ITA group, whereas 7 patients died in the nonbilateral ITA group (p<0.05). Deep sternal wound infection was observed in 2 patients in the nonbilateral ITA group (1.5%) and in none of the bilateral ITA group (p = NS). There was no significant difference in the morbidity rate between the two groups except for greater blood losses in the bilateral ITA group. CONCLUSION: Double ITA coronary revascularization in young diabetic patients was performed without increased morbidity and mortality. The low rate of sternal wound infections may be related to ITA harvesting by a skeletonization technique, but larger studies are required to confirm these data.  相似文献   
9.
Sixteen terpene compounds were isolated from the soldier defensive secretions of seven European termite taxa of the genus Reticulitermes (Isoptera, Rhinotermitidae). We describe species-specific mixtures of monoterpenes (-pinene, -pinene, limonene), sesquiterpenes (germacrene C, germacrene A, germacrene B, -selinene, -selinene, -selinene, (E)--farnesene, -cadinene, nerolidol), diterpenes (geranyl linalool, geranyl geraniol, geranyl geranial), and one sesterterpene (geranyl farnesol). Compounds were purified by HPLC and their structures determined by means of MS spectrometry, or 1D and 2D NMR spectroscopy. Comparison of two different analytical approaches, GC-MS and HPLC with subsequent NMR spectroscopy, revealed Cope rearrangement of germacrene A, germacrene B, and germacrene C to the respective -elemene, -elemene, and -elemene under GC conditions, thus demonstrating the limits for this analytical approach. The species-specific compound composition provides insight into taxonomy and species origin of European Reticulitermes. The biological significance of the species-specific composition of Reticulitermes defensive secretions is briefly discussed.  相似文献   
10.
The failures that bugs in software lead to can sometimes be bypassed by the so-called workarounds: when a (faulty) routine fails, alternative routines that the system offers can be used in place of the failing one, to circumvent the failure. Existing approaches to workaround-based system recovery consider workarounds that are produced from equivalent method sequences, automatically computed from user-provided abstract models, or directly produced from user-provided equivalent sequences of operations. In this paper, we present two techniques for computing workarounds from Java code equipped with formal specifications, that improve previous approaches in two respects. First, the particular state where the failure originated is actively involved in computing workarounds, thus leading to repairs that are more state specific. Second, our techniques automatically compute workarounds on concrete program state characterizations, avoiding abstract software models and user-provided equivalences. The first technique uses SAT solving to compute a sequence of methods that is equivalent to a failing method on a specific failing state, but which can also be generalized to schemas for workaround reuse. The second technique directly exploits SAT to circumvent a failing method, building a state that mimics the (correct) behaviour of a failing routine, from a specific program state too. We perform an experimental evaluation based on case studies involving implementations of collections and a library for date arithmetic, showing that the techniques can effectively compute workarounds from complex contracts in an important number of cases, in time that makes them feasible to be used for run-time repairs. Our results also show that our state-specific workarounds enable us to produce repairs in many cases where previous workaround-based approaches are inapplicable.  相似文献   
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