567 research outputs found
Imaging findings of right colon diverticulitis that mimics colon cancer: a case report
We present a case report of a patient with imaging findings of right colon diverticulitis that mimics colon cancer. The computed tomography showed a segment of narrowing with shoulder formation at ascending colon suggesting cancer. The colonoscopy and the follow-up imaging clarify the diagnosis of diverticulitis. We assess the value of computed tomography findings of acute diverticulitis in excluding cancer
Advancing Brain Research through Surface-Enhanced Raman Spectroscopy (SERS):Current Applications and Future Prospects
Surface-enhanced Raman spectroscopy (SERS) has recently emerged as a potent analytical technique with significant potential in the field of brain research. This review explores the applications and innovations of SERS in understanding the pathophysiological basis and diagnosis of brain disorders. SERS holds significant advantages over conventional Raman spectroscopy, particularly in terms of sensitivity and stability. The integration of label-free SERS presents promising opportunities for the rapid, reliable, and non-invasive diagnosis of brain-associated diseases, particularly when combined with advanced computational methods such as machine learning. SERS has potential to deepen our understanding of brain diseases, enhancing diagnosis, monitoring, and therapeutic interventions. Such advancements could significantly enhance the accuracy of clinical diagnosis and further our understanding of brain-related processes and diseases. This review assesses the utility of SERS in diagnosing and understanding the pathophysiological basis of brain disorders such as Alzheimer’s and Parkinson’s diseases, stroke, and brain cancer. Recent technological advances in SERS instrumentation and techniques are discussed, including innovations in nanoparticle design, substrate materials, and imaging technologies. We also explore prospects and emerging trends, offering insights into new technologies, while also addressing various challenges and limitations associated with SERS in brain research
16S and 18S rRNA Gene Metabarcoding Provide Congruent Information on the Responses of Sediment Communities to Eutrophication
Metabarcoding analyses of bacterial and eukaryotic communities have been proposed as efficient tools for environmental impact assessment. It has been unclear, however, to which extent these analyses can provide similar or differing information on the ecological status of the environment. Here, we used 16S and 18S rRNA gene metabarcoding to compare eutrophication-induced shifts in sediment bacterial and eukaryotic community structure in relation to a range of porewater, sediment and bottom-water geochemical variables, using data obtained from six stations near a former rainbow trout farm in the Archipelago Sea (Baltic Sea). Shifts in the structure of both community types were correlated with a shared set of variables, including porewater ammonium concentrations and the sediment depth-integrated oxygen consumption rate. Distance-based redundancy analyses showed that variables typically employed in impact assessments, such as bottom water nutrient concentrations, explained less of the variance in community structure than alternative variables (e.g., porewater NH4+ inventories and sediment depth-integrated O2 consumption rates) selected due to their low collinearity (up to 40 vs. 58% of the variance explained, respectively). In monitoring surveys where analyses of both bacterial and eukaryotic communities may be impossible, either 16S or 18S rRNA gene metabarcoding can serve as reliable indicators of wider ecological impacts of eutrophication.Peer reviewe
Symmetries and alignment of biaxial nematic liquid crystals
The possible symmetries of the biaxial nematic phase are examined against the
implications of the presently available experimental results. Contrary to the
widespread notion that biaxial nematics have orthorhombic symmetry, our study
shows that a monoclinic () symmetry is more likely to be the case for
the recently observed phase biaxiality in thermotropic bent-core and calamitc
tetrapode nematic systems. The methodology for differentiating between the
possible symmetries of the biaxial nematic phase by NMR and by IR spectroscopy
measurements is presented in detail. The manifestations of the different
symmetries on the alignment of the biaxial phase are identified and their
implications on the measurement and quantification of biaxiality as well as on
the potential use of biaxial nematic liquid crystals in electro-optic
applications are discussed.Comment: 24 pages, 4 figure
Bioprocess development for scalable production of cultivated meat
Traditional farm-based products based on livestock are one of the main contributors to greenhouse gas emissions. Cultivated meat is an alternative that mimics animal meat, being produced in a bioreactor under controlled conditions rather than through the slaughtering of animals. The first step in the production of cultivated meat is the generation of sufficient reserves of starting cells. In this study, bovine adipose-derived stem cells (bASCs) were used as starting cells due to their ability to differentiate towards both fat and muscle, two cell types found in meat. A bioprocess for the expansion of these cells on microcarriers in spinner flasks was developed. Different cell seeding densities (1,500, 3,000, and 6,000 cells/cm 2) and feeding strategies (80%, 65%, 50%, and combined 80%/50% medium exchanges) were investigated. Cell characterization was assessed pre- and postbioprocessing to ensure that bioprocessing did not negatively affect bASC quality. The best growth was obtained with the lowest cell seeding density (1,500 cells/cm 2) with an 80% medium exchange performed (p '.0001) which yielded a 28-fold expansion. The ability to differentiate towards adipogenic, osteogenic, and chondrogenic lineages was retained postbioprocessing and no significant difference (p '.5) was found in clonogenicity pre- or postbioprocessing in any of the feeding regimes tested
Single-Brane Cosmological Solutions with a Stable Compact Extra Dimension
We consider 5-dimensional cosmological solutions of a single brane. The
correct cosmology on the brane, i.e., governed by the standard 4-dimensional
Friedmann equation, and stable compactification of the extra dimension is
guaranteed by the existence of a non-vanishing \hat{T}^5_5 which is
proportional to the 4-dimensional trace of the energy-momentum tensor. We show
that this component of the energy-momentum tensor arises from the backreaction
of the dilaton coupling to the brane. The same positive features are exhibited
in solutions found in the presence of non-vanishing cosmological constants both
on the brane (\Lambda_{br}) and in the bulk (\Lambda_B). Moreover, the
restoration of the Friedmann equation, with the correct sign, takes place for
both signs of so long as the sign of is opposite
in order to cancel the energy densities of the two cosmological
constants. We further extend our single-brane thin-wall solution to allow a
brane with finite thickness.Comment: 25 pages, Latex file, no figures, comments added, references updated,
final version to appear in Physical Review
Braneworld stars and black holes
We look for spherically symmetric star or black hole solutions on a
Randall-Sundrum brane from the perspective of the bulk. We take a known bulk
solution, and analyse possible braneworld trajectories within it that
correspond, from the braneworld point of view, to solutions of the brane
Tolman-Oppenheimer-Volkoff equations. Our solutions are therefore embedded
consistently into a full bulk solution. We find the full set of static
gravitating matter sources on a brane in a range of bulk spacetimes, analyzing
which can correspond to physically sensible sources. Finally, we look at
time-dependent trajectories in a Schwarzschild--anti de Sitter spacetime as
possible descriptions of time-dependent braneworld black holes, highlighting
some of the general features one might expect, as well as some of the
difficulties involved in getting a full solution to the question.Comment: 39 pages, 15 figure
Bianchi type I space and the stability of inflationary Friedmann-Robertson-Walker space
Stability analysis of the Bianchi type I universe in pure gravity theory is
studied in details. We first derive the non-redundant field equation of the
system by introducing the generalized Bianchi type I metric. This non-redundant
equation reduces to the Friedmann equation in the isotropic limit. It is shown
further that any unstable mode of the isotropic perturbation with respect to a
de Sitter background is also unstable with respect to anisotropic
perturbations. Implications to the choice of physical theories are discussed in
details in this paper.Comment: 5 pages, some comment adde
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