Aneurysms of the intracranial segment of the ophthalmic artery trunk. case report and systematic literature review

Aneurysms arising from the ophthalmic artery trunk (OAT) are very rare, particularly in the artery's intracranial course. The onset of a subarachnoid hemorrhage (SAH) from a ruptured OAT aneurysm in this segment is extremely rare. We present a case and discuss the anatomy, clinical significance, and therapeutic options for an aneurysm at this site. We also retrospectively analyzed the record of a patient with a ruptured aneurysm of the intracranial segment of the OAT and conducted a comprehensive and systematic review of the PubMed and Scopus databases for literature on this pathology. Only one case report of SAH from an aneurysm of the intracranial segment of the OAT was published in the literature. Only in our case was the intracranial OAT segment aneurysm discovered in the acute phase of SAH. Conventional angiography with three-dimensional acquisition may help detect aneurysms at this level. Detailed knowledge of the anatomy of the OAT is of paramount importance for both surgical and endovascular approaches. Surgical treatment is complex because of difficulties in accessing the orbital region and the risk of optic nerve and vascular injuries. Endovascular treatment, when feasible, could be a good alternative to reduce the risk of loss of vision related to surgical manipulation

A model-based approach for the rational design of the freeze-thawing of a protein-based formulation

Proteins are unstable molecules that may be severely injured by stresses encountered during freeze-thawing. Despite this, the selection of freeze-thaw conditions is currently empirical, and this results in reduced process control. Here we propose a mathematical model that takes into account the leading causes of protein instability during freeze-thawing, i.e. cold denaturation and surface-induced unfolding, and may guide the selection of optimal operating conditions. It is observed that a high cooling rate is beneficial for molecules that are extremely sensitive to cold denaturation, while the opposite is true when ice-induced unfolding is dominant. In all cases, a fast thawing rate is observed to be beneficial. The simulation outputs are confirmed by experimental data for myoglobin and lactate dehydrogenase, suggesting that the proposed modeling approach can reproduce the main features of protein behavior during freeze-thawing. This approach can therefore guide the selection of optimal conditions for protein-based formulations that are stored in a frozen or freeze-dried state

Neuronavigation and intraoperative imaging system in orbital tumor surgery: a review of recent literature

Orbit is a small complex anatomic space that contains important structures, ocular globe, extrinsic muscles, cranial nerves, blood vessels, fat, lacrimal gland. In presence of orbital tumors it is mandatory to use a surgical approach that allows to achieve an adequate surgical field while preserving neurological function. Neuronavigation is the set of computer-assisted technologies used to guide or "navigate” the edges of the tumor to allow the surgeon during resection or biopsy. This technology started with use of CT data to get some landmarks of human anatomy defined “targets” that could be readily used in surgery. Finally, the evolution of modern neuroimaging technologies such intraoperative CT and MRI boosted the surgery accuracy. In order to identify advantages and practical use of these technologies we performed a nonsystematic review of the current literature using the keywords “orbital tumor or orbital neoplasia or orbital mass or orbital lesion” and “neuronavigation or navigation” published in last 10 years. We evaluated 29 papers and we can conclude that navigation in orbital surgery helps to reduce surgical damage while at the same time, allowing a more radical tumor resection. CT and MRI scans are complementary in diagnosing and in intraoperative navigation allow the surgeon to avoid and preserve vital structures, particularly in a complex surgical procedure without real anatomical landmarks for intraoperative orientation. Future is going towards rapid changes and the integration with intraoperative procedures is carrying on to new technologies further our contemporary bounds

Autophagy-lysosome pathway alteration in ocular surface manifestations in Fabry disease patients

Background: Fabry disease (FD) is a rare X-linked, lysosomal storage disorder caused by mutations in the alpha-galactosidase gene and characterized by neurological, cutaneous, renal, cardiovascular, cochleo-vestibular and ocular manifestations. The aim of this study is to characterize morphological, functional and autophagy-lysosome pathway alterations of the ocular surface in FD patients.Methods: Eleven subjects with a diagnosis of FD and fifteen healthy control subjects were examined. All patients underwent ocular surface slit lamp examination, corneal aesthesiometry and in vivo confocal laser-scanning microscopy (CCM). Conjunctival impression cytology was performed in six FD patients and six controls, to assess for expression of two markers of the autophagy-lysosome pathway: the microtubule-associated protein light chain 3 (LC3) and lysosome-associated membrane protein 2 (LAMP2).Results: Cornea verticillata and increased conjunctival vessel tortuosity were detected respectively in 67% and 33% of patients with FD. Compared with healthy subjects, patients affected by FD showed a significant reduction in corneal nerve fiber length, density and nerve branching on CCM and a significantly increased expression of LC3 on conjunctival impression cytology (p < 0.001). No changes were observed in the conjunctival expression of LAMP2 between the two groups.Conclusions: This study shows that FD is associated with ocular surface alterations including corneal and conjunctival morphology, innervation and vascularization changes. Our data demonstrate an increased expression of LC3 protein in patients with FD, suggesting that alteration of the autophagy-lysosome pathway may play a role in the occurrence of ocular manifestations

Studies on mineral dust using airborne lidar, ground-based remote sensing, and in situ instrumentation

© 2018 The Author(s). Published by EDP Sciences. This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (http://creativecommons.org/licenses/by/4.0/).In August 2015, the AER-D campaign made use of the FAAM research aircraft based in Cape Verde, and targeted mineral dust. First results will be shown here. The campaign had multiple objectives: (1) lidar dust mapping for the validation of satellite and model products; (2) validation of sunphotometer remote sensing with airborne measurements; (3) coordinated measurements with the CATS lidar on the ISS; (4) radiative closure studies; and (5) the validation of a new model of dustsonde.Peer reviewe

Características foliares e trocas gasosas em arvoretas de espécies nativas da Amazônia Central

Global climate models predict changes on the length of the dry season in the Amazon which may affect tree physiology. The aims of this work were to determine the effect of the rainfall regime and fraction of sky visible (FSV) at the forest understory on leaf traits and gas exchange of ten rainforest tree species in the Central Amazon, Brazil. We also examined the relationship between specific leaf area (SLA), leaf thickness (LT), and leaf nitrogen content on photosynthetic parameters. Data were collected in January (rainy season) and August (dry season) of 2008. A diurnal pattern was observed for light saturated photosynthesis (Amax) and stomatal conductance (gs), and irrespective of species, Amax was lower in the dry season. However, no effect of the rainfall regime was observed on gs nor on the photosynthetic capacity (Apot, measured at saturating [CO2]). Apot and leaf thickness increased with FSV, the converse was true for the FSV-SLA relationship. Also, a positive relationship was observed between Apot per unit leaf area and leaf nitrogen content, and between Apot per unit mass and SLA. Although the rainfall regime only slightly affects soil moisture, photosynthetic traits seem to be responsive to rainfall-related environmental factors, which eventually lead to an effect on Amax. Finally, we report that little variation in FSV seems to affect leaf physiology (Apot) and leaf anatomy (leaf thickness)

Photosynthesis and biomass accumulation in carapa surinamensis (Meliaceae) in response to water stress at ambient and elevated CO2

Climate models predict an increase in atmospheric CO2 concentration and prolonged droughts in some parts of the Amazon, but the effect of elevated CO2 is still unknown. Two experiments (ambient CO2 ‒ 400 ppm and elevated CO2 ‒ 700 ppm) were conducted to assess the effect of drought (soil at 50% field capacity) on physiological parameters of Carapa. At ambient CO2 concentration, light-saturated net photosynthetic rate (PNsat) was reduced by 33.5% and stomatal conductance (gs) by 46.4% under drought, but the effect of drought on PNsat and gs was nullified at elevated CO2. Total plant biomass and leaf area production were also reduced (42‒47%) by drought. By changing leaf traits, Carapa is able to endure drought, as the consumptive use of water was reduced under drought (32‒40%). The improvement of PNsat under elevated CO2 and water stress and the leaf plasticity of Carapa broaden our understanding of the physiology of Amazonian trees. © The authors

Fluorescence characteristics and photoinhibition in saplings of manwood on clear days and under overcast conditions

High irradiance may reduce the productivity of tropical plants by exacerbating photoinhibition of photosynthesis, particularly in the case of shade-adapted plants. The aim of this study was to determine the effect of cloud cover on the fluorescence characteristics and photoinhibition on saplings of manwood (Minquartia guianensis Aubl.). Three-year-old saplings were exposed to full irradiance either on clear days (10, 45 and 90 min) or under overcast conditions (120, 180, and 420 min). Changes in the population of functional photosystem II (PSII), the initial (F o) and maximum fluorescences (F m), and the F v/F m ratio (maximum potential quantum yield of PSII) were monitored after plant exposure to full irradiance and during recovery (within 48 h) at low light intensity. Although photoinhibition of PSII (F v/F m) was determined by the number of photons reaching the leaf surface (photon fluence), cloudiness tended to reduce the photoinhibitory effect of irradiance. F o increased with fluence on cloudy days and was unaffected by irradiance on clear days, except for a sharp rise during the first 10 min of exposure to full sunlight. For a given photon fluence, F m was lower on clear days. Recovery from photoinhibition was similar in both light environments. Although photon fluence is the preponderant factor determining the extent of photoinhibition, cloudiness might alleviate the photoinhibitory effect of irradiance

Una licitación combinatorial aplicada a la provisión de Internet a las escuelas de Buenos Aires

Una de las clases de licitación más estudiadas en la literatura es la multi-unidades, aquella en la que se licitan varios ítems idénticos. En este trabajo, definimos una nueva subclase de las licitaciones multi-unidades, que llamamos multi-unidades logística. La característica central de una licitación multi-unidades logística es que existen fuertes asimetrías de costos entre los oferentes a causa de consideraciones logísticas. Ciertas unidades pueden ser atractivas para una firma y no para otra, de acuerdo a dichas consideraciones, y lo contrario puede suceder en otras unidades a licitar. Este tipo de licitación aparece en la provisión de Internet en las escuelas de Buenos Aires, la capital de Argentina. En 2008, la ciudad de Buenos Aires debía licitar la conexión de Internet para sus 709 escuelas públicas. En este trabajo mostramos cómo fue diseñada la licitación para realizar la adjudicación minimizando el gasto de la ciudad destinado a este fin. En nuestro diseño, cada firma debe dar un precio general por el servicio mensual a ser brindado en cada escuela, descuentos por volumen en bandas prefijadas de antemano y el listado de escuelas en las que le interesa brindar el servicio. La licitación multi-unidades logística resultante se puede interpretar como una licitación combinatorial. Se implementó un modelo de programación lineal entera para obtener el conjunto de ofertas más conveniente para el estado.De acuerdo con los análisis presentados en este trabajo, se puede estimar que la ciudad de Buenos Aires obtuvo ahorros cercanos al 20% por implementar este nuevo modelo de licitación en lugar del formato de licitación originalmente propuesto.Fil: Bonomo, Flavia. Consejo Nacional de Invest.cientif.y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Investigaciones Matematicas;Fil: Catalán, J.. Universidad de Chile. Fac. de Cs. Físicas y Matemáticas; Chile;Fil: Duran, Guillermo Alfredo. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Instituto de Calculo; Argentina;Fil: Epstein, R.. Universidad de Chile. Fac. de Cs. Físicas y Matemáticas; Chile;Fil: Jawtuschenko, Alexis Boris. Consejo Nacional de Invest.cientif.y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Investigaciones Matematicas;Fil: Marenco, Nelida Silvia. Universidad Nacional de General Sarmiento. Instituto de Ciencias; Argentina