180 research outputs found

    High brightness inductively coupled plasma source for high current focused ion beam applications

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    A high brightnessplasmaion source has been developed to address focused ion beam(FIB) applications not satisfied by the liquid metal ion source (LMIS) based FIB. The plasmaFIB described here is capable of satisfying applications requiring high mill rates (>100μm³/s) with non-gallium ions and has demonstrated imaging capabilities with sub- 100-nm resolution. The virtual source size, angular intensity, mass spectra, and energy spread of the source have been determined with argon and xenon. This magnetically enhanced, inductively coupled plasmasource has exhibited a reduced brightness(βr) of 5.4×10³Am⁻²sr⁻¹V⁻¹, with a full width half maximum axial energy spread (ΔE) of 10eV when operated with argon. With xenon, βr=9.1×10³Am⁻²sr⁻¹V⁻¹ and ΔE=7eV. With these source parameters, an optical column with sufficient demagnification is capable of forming a sub-25-nm spot size at 30keV and 1pA. The angular intensity of this source is nominally three orders of magnitude greater than a LMIS making the source more amenable to creating high current focused beams, in the regime where spherical aberration dominates the LMIS-FIB. The source has been operated on a two lens ion column and has demonstrated a current density that exceeds that of the LMIS-FIB for current greater than 50nA. Source lifetime and current stability are excellent with inert and reactive gases. Additionally, it should be possible to improve both the brightness and energy spread of this source, such that the (βr/ΔE₂) figure-of-merit could be within an order of magnitude of a LMIS

    The presence and clinical implications of α-2,6-galactose-linked sialic acids in non-small-cell lung cancer brain metastases — preliminary study

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    Brain metastases (BM) in non-small-cell lung cancer (NSCLC) patients present an increasing clinical challenge. Identifying biomarkers which specifically identify patients at high risk of BM may improve their early diagnosis, which is crucial for surgical and radiotherapeutic treatment outcome. Alpha-2,6-sialyltransferase (α-2,6-ST) and the primary product of its activity, alpha-2,6-galactose-linked sialic acids (α-2,6-GalSA) have been found responsible for the adhesion of tumor cells to the brain vessels’ endothelium and enabling their transmigration through the blood-brain barrier in brain metastatic tumors. The aim of the study was to investigate by histochemical method the presence and possible role of α-2,6-GalSA in the formation of brain metastasis in NSCLC. In the screening phase 76 metastatic brain tumors were stained for α-2,6-GalSA and the second phase involved an identical staining of 20 primary tumors of patients who had their primary tumors treated with surgery or definite radiochemotherapy yet who later developed BM. The results were compared to a control group of 22 patients treated with surgery for NSCLC and who survived 5 years without the recurrence of disease. Alpha-2,6-GalSA presence was found to be down-regulated in poorly differentiated tumor types, whereas majority of differentiated tumors overexpressed it. This was statistically significant for both BM and the primary tumors. The expression of α-2,6-GalSA remained stable in primary and metastatic tumor pairs, however, no statistically significant differences were observed between study and control groups. Within the study group, a higher α-2,6-GalSA expression was associated with better overall survival, but not all statistical models found this result significant. Further studies are recommended to validate these findings

    63 Napromienianie przedoperacyjne u chorych na raka dolnej części odbytnicy

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    Od marca 1996 do czerwca 1998, u 47 chorych na raka dolnej części odbytnicy (dolna granica guza do 6 cm od brzegu odbytu) zastosowano napromienianie przedoperacyjne dawką 25 Gy we frakcjach po 5 Gy podaną w czasie tygodnia. Operację wykonano 1–7 dni po zakończeniu radioterapii. Odsetek ostrych powikłań popromiennych i ich nasilanie było umiarkowane. Niską resekcję przednią wykonano u 24 (51%) chorych, amputację odbytnicy sposobem brzuszno-kroczowym u 19 (40%), operację Hartmannu u 2 (4%) i (74%) chorych w podgrupie, w której nowotwór nie naciekał zwieraczy. Usuwano całe mezorektum. Margines pomiędzy dolnym brzegiem makroskopowo widocznego guza, a cięciem chirurgicznym jelita wynosił od 0,1 cm do 3 cm, mediana 0,8 cm (nie uwzględniono krążków ze staplera).Wszyscy chorzy przeżyli operację 30-dniowy okres pooperacyjny. Odsetek powikłań pooperacyjnych nie odbiegał znacząco od obserwowanych po porównywalnych operacjach u chorych nienapromienianych. Uzupełniającą chemioterapię otrzymało 20 chorych (43%). Okres obserwacji wynosi od 7 miesięcy do 30 miesięcy, mediana 15 miesięcy. Wznowę miejscową obserwowano w dwóch przypadkach (8%); późne powikłania popromienne pod postacią bólów w okolicy krzyżowej u dwóch chorych (8%).Wczesne wyniki sugerują wysoką miejscową skuteczność leczenia przy stosunkowo niewielkim odsetku powikłań i znacznym odsetku chorych z zachowanymi zwieraczami

    Diagnostic value of non-enhanced computed tomography in identifying location of ruptured cerebral aneurysm in patients with aneurysmal subarachnoid haemorrhage

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    Background. In patients with SAH and multiple aneurysms, the ruptured lesion must be identified to prevent recurrent bleeding.Aim of the study. To assess the diagnostic value of non-enhanced computed tomography (NECT) in identifying the rupture site in patients with subarachnoid haemorrhage (SAH) and multiple aneurysms.Material and methods. We included patients with SAH revealed by NECT and multiple aneurysms detected on computed tomography angiography (CTA) in whom a ruptured aneurysm was identified during neurosurgery. Two radiologists predicted the location of the ruptured aneurysm based on the distribution of the SAH and location of intracerebral haematoma (ICH) by NECT.Results. Eighty-three patients with a mean age of 55.7 ± 14.4 years were included. Ruptured aneurysms were significantly larger (mean size 7.7 ± 4.7 mm) than unruptured aneurysms (mean size 5.9 ± 4.5 mm; p = 0.014). Interobserver agreement was 0.86 (p < 0.001). Overall sensitivity and specificity of radiological prediction were 78.3% (95% CI, 68.6%-87.1%) and 96.4% (95% CI, 94.3%-97.8%) respectively. Overall PPV and NPV were 78.3% (95% CI, 67.6%-86.3%) and 96.8% (95% CI, 94.8%-98.1%) respectively. The sensitivity and PPV for aneurysms in the anterior communicating, anterior, and middle cerebral arteries appeared to be significantly higher than in other locations (p = 0.015 and 0.019 respectively). Analysis of independent predictive factors of correct radiological location revealed that ICH predisposes to a correct radiological diagnosis with an odds ratio of 8.57 (95% CI, 1.07-68.99; p = 0.03).Conclusions. NECT has a high diagnostic value in identifying the source of bleeding in patients with multiple aneurysms for anterior circulation aneurysms, especially with coexisting ICH. For other locations, NECT is not reliable enough to base treatment decisions upon

    Pkd1 Regulates Lymphatic Vascular Morphogenesis during Development.

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    Lymphatic vessels arise during development through sprouting of precursor cells from veins, which is regulated by known signaling and transcriptional mechanisms. The ongoing elaboration of vessels to form a network is less well understood. This involves cell polarization, coordinated migration, adhesion, mixing, regression, and shape rearrangements. We identified a zebrafish mutant, lymphatic and cardiac defects 1 (lyc1), with reduced lymphatic vessel development. A mutation in polycystic kidney disease 1a was responsible for the phenotype. PKD1 is the most frequently mutated gene in autosomal dominant polycystic kidney disease (ADPKD). Initial lymphatic precursor sprouting is normal in lyc1 mutants, but ongoing migration fails. Loss of Pkd1 in mice has no effect on precursor sprouting but leads to failed morphogenesis of the subcutaneous lymphatic network. Individual lymphatic endothelial cells display defective polarity, elongation, and adherens junctions. This work identifies a highly selective and unexpected role for Pkd1 in lymphatic vessel morphogenesis during development

    New International Guidelines and Consensus on the Use of Lung Ultrasound

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    Following the innovations and new discoveries of the last 10 years in the field of lung ultrasound (LUS), a multidisciplinary panel of international LUS experts from six countries and from different fields (clinical and technical) reviewed and updated the original international consensus for point-of-care LUS, dated 2012. As a result, a total of 20 statements have been produced. Each statement is complemented by guidelines and future developments proposals. The statements are furthermore classified based on their nature as technical (5), clinical (11), educational (3), and safety (1) statements

    Predictors of orbital convergence in primates: A test of the snake detection hypothesis of primate evolution

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    Traditional explanations for the evolution of high orbital convergence and stereoscopic vision in primates have focused on how stereopsis might have aided early primates in foraging or locomoting in an arboreal environment. It has recently been suggested that predation risk by constricting snakes was the selective force that favored the evolution of orbital convergence in early primates, and that later exposure to venomous snakes favored further degrees of convergence in anthropoid primates. Our study tests this snake detection hypothesis (SDH) by examining whether orbital convergence among extant primates is indeed associated with the shared evolutionary history with snakes or the risk that snakes pose for a given species. We predicted that orbital convergence would be higher in species that: 1) have a longer history of sympatry with venomous snakes, 2) are likely to encounter snakes more frequently, 3) are less able to detect or deter snakes due to group size effects, and 4) are more likely to be preyed upon by snakes. Results based on phylogenetically independent contrasts do not support the SDH. Orbital convergence shows no relationship to the shared history with venomous snakes, likelihood of encountering snakes, or group size. Moreover, those species less likely to be targeted as prey by snakes show significantly higher values of orbital convergence. Although an improved ability to detect camouflaged snakes, along with other cryptic stimuli, is likely a consequence of increased orbital convergence, this was unlikely to have been the primary selective force favoring the evolution of stereoscopic vision in primates

    Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

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    Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

    Use of anticoagulants and antiplatelet agents in stable outpatients with coronary artery disease and atrial fibrillation. International CLARIFY registry

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