2,937 research outputs found
Appendix tumors in the era of laparoscopic appendectomy
Background: The safety of laparoscopic appendectomy for the management of incidentally discovered appendiceal tumors has not yet been established. Methods: Appendiceal tumor cases managed by laparoscopy or laparotomy over a 10-year period were reviewed. Results: The pathological diagnoses were 23 carcinoid and 20 cancerous lesions. The median patient ages were 36 and 69years, respectively, for carcinoid and other tumors (p < 0.05). Acute appendicitis was present in 70% of carcinoid cases and 35% of other tumors (p < 0.05). Eight patients with carcinoid tumors were operated on by laparoscopy, whereas 15 underwent laparotomy. Laparoscopic and open procedures were performed in three and 17 patients with cancerous lesions, respectively. Invaded surgical margins were seen after laparoscopy in 20% of patients and open surgery in 6%. Synchronous colon carcinoma was detected in 14% of the patients with an appendix neoplasm. The 5-year survival rates were similar after both laparoscopic and open appendectomy for either carcinoid or other tumors. Conclusion: Laparoscopic appendectomy for appendiceal tumors seems to have a slightly higher rate of inadequate resection. However, it is not associated with a significantly worse patient prognosis than open appendectom
Optimization of protein extraction and ELISA immunodetection from protein-based paint models with mesoporous silica nanoparticles and MCM41
Protein-based biological materials such as albumin, casein and collagen are found in various cultural heritage (CH) artefacts. This study focuses on the study of protein binders from easel paintings media. Proteins have complex structures which are difficult to identify with non-invasive spectroscopic methods (FT-IR, Raman, UV). Immunoassays such as ELISA determine the protein’s source of origin which is necessary for art objects. To increase the detection and identification of proteins by immunoassays, the efficiency of micro-extraction of proteins from heritage materials is a crucial step. Extractions mediated by cycles of orbital agitation and ultrasonic radiation give the possibility to extract proteins from easel painting sample. In this work, protein-based paint models coupled with silica nanoparticles were used for micro-extraction. Nanoparticles possess high surface-to-volume ratios that can attach bioactive molecules such as proteins and increase the total protein recovered from microsamples. Protein extracts were quantified with Bradford Assay in the presence of Coomassie blue. The protein recovery results were statistically computed, and the SPSS analysis shows significant (p <0.05) increase in protein recovery, above 1.3 times for NPSiO2 and above 1.6 times for MCM-41. The statistical data shows evidence that silica nanoparticles intensify the total protein recovered from paint microsamples. Finally, ELISA was realized on the protein extracts to verify and compare the immunodetection of protein from the paint models with and without the use of silica nanoparticles
Usefulness of 99mTc(V)-dimercaptosuccinic acid scintigraphy in the assessment of response to external radiation therapy in soft tissue sarcoma in Giant Snauzer dog
A nine-year-old male black Giant Schnauzer dog was referred
for the scintigraphic evaluation with a history of malignant fibrosarcoma
with a rapidly growing non painful mass on the left shoulder
region quite near to the site of an operation performed four months
ago. We carried out oncological scintigraphy using pentavalent
99mTechnetium labelled dimercaptosuccinic acid [99mTc(V)-DMSA], a tumour localising radiopharmaceutical agent. The study
was performed to assess the margins, vascularity of the tumour
and response to the cancer therapy. Uniform intense radiopharmaceutical
uptake was observed in the lesion indicating its margins,
vascularity and malignant nature. The dog was subjected to
external radiation therapy to control the growth of the cancer and
to bring the tumour mass to an operable size. The dog was followed
up with 99mTc(V)-DMSA scintigraphy pre-irradiation and
post-irradiation. Immediately after the post-irradiation scintigraphy,
the dog was operated on. During the surgery, resection of
the tumour margins was performed carefully using
a hand held gamma probe to assure that no tumour tissue was
left inside. In conclusion, the authors would like to state that
99mTc(V)-DMSA oncoscintigraphy is valuable in the assessment
and evaluation of therapy in canine soft tissue cancer
Fast DNA translocation through a solid-state nanopore
We report translocation experiments on double-strand DNA through a silicon
oxide nanopore. Samples containing DNA fragments with seven different lengths
between 2000 to 96000 basepairs have been electrophoretically driven through a
10 nm pore. We find a power-law scaling of the translocation time versus
length, with an exponent of 1.26 0.07. This behavior is qualitatively
different from the linear behavior observed in similar experiments performed
with protein pores. We address the observed nonlinear scaling in a theoretical
model that describes experiments where hydrodynamic drag on the section of the
polymer outside the pore is the dominant force counteracting the driving. We
show that this is the case in our experiments and derive a power-law scaling
with an exponent of 1.18, in excellent agreement with our data.Comment: 5 pages, 2 figures. Submitted to PR
Calcium Valence-to-Core X-ray Emission Spectroscopy: A Sensitive Probe of Oxo Protonation in Structural Models of the Oxygen-Evolving Complex
Calcium is an abundant, nontoxic metal that finds many roles in synthetic and biological systems including the oxygen-evolving complex (OEC) of photosystem II. Characterization methods for calcium centers, however, are underdeveloped compared to those available for transition metals. Valence-to-core X-ray emission spectroscopy (VtC XES) selectively probes the electronic structure of an element’s chemical environment, providing insight that complements the geometric information available from other techniques. Here, the utility of calcium VtC XES is established using an in-house dispersive spectrometer in combination with density functional theory. Spectral trends are rationalized within a molecular orbital framework, and Kβ_(2,5) transitions, derived from molecular orbitals with primarily ligand p character, are found to be a promising probe of the calcium coordination environment. In particular, it is shown that calcium VtC XES is sensitive to the electronic structure changes that accompany oxo protonation in Mn₃CaO₄-based molecular mimics of the OEC. Through correlation to calculations, the potential of calcium VtC XES to address unresolved questions regarding the mechanism of biological water oxidation is highlighted
Interfaz JAUS para herramientas de desarrollo en el campo de la robótica
Software modularization presents important advantages when it comes to robotic development.
That is based on the definition of well-known limits for each module that make the parallel development easier. Furthermore, that way of working allows the reutilization of one module in more systems.
There is a paradigm known as Components Based Software which follows the mentioned idea and needs definitions that include interfaces, responsibilities and certain communication rules between the members of the whole system. Precisely, the JAUS standard defines both a model of components with their interfaces, and an architecture, in the specific context of robotics. There are several SDKs, but they either lack a multi-platform support, or work with platforms whose features do not satisfy the needs of the developers, such as agile development of proof of concepts, robotic specific development resources (existent projects, community support, GUI, among others).
This work extends the possibilities of the implementation of a component, and allows the developer to take advantage of the benefits of the chosen platform. As a result, projects based on widely used tools used in robotics (such as MATLAB, Simulink and LabVIEW) can be easily integrated in a short period of time.Presentado en el II Workshop Innovación en Sistemas de Software (WISS)Red de Universidades con Carreras en Informática (RedUNCI
Interfaz JAUS para herramientas de desarrollo en el campo de la robótica
Software modularization presents important advantages when it comes to robotic development.
That is based on the definition of well-known limits for each module that make the parallel development easier. Furthermore, that way of working allows the reutilization of one module in more systems.
There is a paradigm known as Components Based Software which follows the mentioned idea and needs definitions that include interfaces, responsibilities and certain communication rules between the members of the whole system. Precisely, the JAUS standard defines both a model of components with their interfaces, and an architecture, in the specific context of robotics. There are several SDKs, but they either lack a multi-platform support, or work with platforms whose features do not satisfy the needs of the developers, such as agile development of proof of concepts, robotic specific development resources (existent projects, community support, GUI, among others).
This work extends the possibilities of the implementation of a component, and allows the developer to take advantage of the benefits of the chosen platform. As a result, projects based on widely used tools used in robotics (such as MATLAB, Simulink and LabVIEW) can be easily integrated in a short period of time.Presentado en el II Workshop Innovación en Sistemas de Software (WISS)Red de Universidades con Carreras en Informática (RedUNCI
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Decoupling of As and Fe release to Bangladesh groundwater under reducing conditions. Part I: Evidence from sediment profiles
This study reexamines the notion that extensive As mobilization in anoxic groundwater of Bangladesh is intimately linked to the dissolution of Fe oxyhydroxides on the basis of analyses performed on a suite of freshly collected samples of aquifer material. Detailed sediment profiles extending to 40 to 70 m depth below the surface were obtained at six sites where local groundwater As concentrations were known to span a wide range. The sediment properties that were measured include (1) the proportion of Fe(II) in the Fe fraction leached in hot 1.2 N HCl, (2) diffuse spectral reflectance, and (3) magnetic susceptibility. In parallel with local concentrations of dissolved As ranging from <5 to 600 μg/L, Fe(II)/Fe ratios in shallow (gray) Holocene sands tended to gradually increase with depth from values of 0.3 to 0.5 to up to 0.9. In deeper (orange) aquifers of presumed Pleistocene age that were separated from shallow sands by a clay layer and contained <5 μg/L dissolved As, leachable Fe(II)/Fe ratios averaged ∼0.2. There was no consistent relation between sediment Fe(II)/Fe and dissolved Fe concentrations in groundwater in nearby wells. The reflectance measurements indicate a systematic linear relation (R2 of 0.66; n = 151) between the first derivative transform of the reflectance at 520 nm and Fe(II)/Fe. The magnetic susceptibility of the shallow aquifer sands ranged from 200 to 3600 (x 10−9 m3/kg SI) and was linearly related (R2 of 0.75; n = 29) to the concentrations of minerals that could be magnetically separated (0.03 to 0.79% dry weight). No systematic depth trends in magnetic susceptibility were observed within the shallow sands, although the susceptibility of deeper low-As aquifers was low (up to ∼200 × 10−9 m3/kg SI). This set of observations, complemented by incubation results described in a companion paper by van Geen et al. (this volume), suggests that the release of As is linked to the transformation of predominantly Fe (III) oxyhydroxide coatings on sand particles to Fe(II) or mixed Fe(II/III) solid phases with a flatter reflectance spectrum such as siderite, vivianite, or magnetite, without necessarily resulting in the release of Fe to groundwater. The very low As/Fe ratio of magnetically separated minerals compared to the As/Fe of bulk acid leachate (2 vs. 40 10−6, respectively) suggests that such a transformation could be accompanied by a significant redistribution of As to a mobilizable phase on the surface of aquifer particles
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