2,079 research outputs found
Homogeneous point mutation detection by quantum dot-mediated two-color fluorescence coincidence analysis
This report describes a new genotyping method capable of detecting low-abundant point mutations in a homogeneous, separation-free format. The method is based on integration of oligonucleotide ligation with a semiconductor quantum dot (QD)-mediated two-color fluorescence coincidence detection scheme. Surface-functionalized QDs are used to capture fluorophore-labeled ligation products, forming QD-oligonucleotide nanoassemblies. The presence of such nanoassemblies and thereby the genotype of the sample is determined by detecting the simultaneous emissions of QDs and fluorophores that occurs whenever a single nanoassembly flows through the femtoliter measurement volume of a confocal fluorescence detection system. The ability of this method to detect single events enables analysis of target signals with a multiple-parameter (intensities and count rates of the digitized target signals) approach to enhance assay sensitivity and specificity. We demonstrate that this new method is capable of detecting zeptomoles of targets and achieve an allele discrimination selectivity factor >10(5)
Lab-in-a-Tube: A portable imaging spectrophotometer for cost-effective, high-throughput, and label-free analysis of centrifugation processes
Centrifuges serve as essential instruments in modern experimental sciences,
facilitating a wide range of routine sample processing tasks that necessitate
material sedimentation. However, the study for real time observation of the
dynamical process during centrifugation has remained elusive. In this study, we
developed an innovative Lab_in_a_Tube imaging spectrophotometer that
incorporates capabilities of real time image analysis and programmable
interruption. This portable LIAT device costs less than 30 US dollars. Based on
our knowledge, it is the first Wi Fi camera built_in in common lab centrifuges
with active closed_loop control. We tested our LIAT imaging spectrophotometer
with solute solvent interaction investigation obtained from lab centrifuges
with quantitative data plotting in a real time manner. Single re circulating
flow was real time observed, forming the ring shaped pattern during
centrifugation. To the best of our knowledge, this is the very first
observation of similar phenomena. We developed theoretical simulations for the
single particle in a rotating reference frame, which correlated well with
experimental results. We also demonstrated the first demonstration to visualize
the blood sedimentation process in clinical lab centrifuges. This remarkable
cost effectiveness opens up exciting opportunities for centrifugation
microbiology research and paves the way for the creation of a network of
computational imaging spectrometers at an affordable price for large scale and
continuous monitoring of centrifugal processes in general.Comment: 21 Pages, 6 Figure
Deep Learning Approach for Large-Scale, Real-Time Quantification of Green Fluorescent Protein-Labeled Biological Samples in Microreactors
Absolute quantification of biological samples entails determining expression
levels in precise numerical copies, offering enhanced accuracy and superior
performance for rare templates. However, existing methodologies suffer from
significant limitations: flow cytometers are both costly and intricate, while
fluorescence imaging relying on software tools or manual counting is
time-consuming and prone to inaccuracies. In this study, we have devised a
comprehensive deep-learning-enabled pipeline that enables the automated
segmentation and classification of GFP (green fluorescent protein)-labeled
microreactors, facilitating real-time absolute quantification. Our findings
demonstrate the efficacy of this technique in accurately predicting the sizes
and occupancy status of microreactors using standard laboratory fluorescence
microscopes, thereby providing precise measurements of template concentrations.
Notably, our approach exhibits an analysis speed of quantifying over 2,000
microreactors (across 10 images) within remarkably 2.5 seconds, and a dynamic
range spanning from 56.52 to 1569.43 copies per micron-liter. Furthermore, our
Deep-dGFP algorithm showcases remarkable generalization capabilities, as it can
be directly applied to various GFP-labeling scenarios, including droplet-based,
microwell-based, and agarose-based biological applications. To the best of our
knowledge, this represents the first successful implementation of an all-in-one
image analysis algorithm in droplet digital PCR (polymerase chain reaction),
microwell digital PCR, droplet single-cell sequencing, agarose digital PCR, and
bacterial quantification, without necessitating any transfer learning steps,
modifications, or retraining procedures. We firmly believe that our Deep-dGFP
technique will be readily embraced by biomedical laboratories and holds
potential for further development in related clinical applications.Comment: 23 pages, 6 figures, 1 tabl
Topographic Study of Extracted Molars with Advanced Furcation Involvement: Furcation Entrance Dimension and Molar Type
This study investigated the topography of the furcation entrance dimension (FED) on molars with advanced furcation involvement (FI). The sample pool consisted of 169 maxillary and mandibular molars from a group of 165 individuals with severely advanced periodontal destruction. The subjects included men and women aged 24 to 84 years (mean, 47.8 ± 7.2 years). The FEDs of the maxillary buccal, mesial, and distal surfaces as well as the mandibular buccal and lingual surfaces were measured under a stereomicroscope and clarified into grades I (FED < 0.55 mm), II (0.55-0.75 mm), and III (> 0.75 mm) using automatic grading system software designed by our research associates. The differences and relationships among molar location, furcation site, and FED grade were analyzed using the chi-square test. There was a significant difference among buccal (BFED), mesial (MFED), and distal (DFED) FEDs in both the maxillary first (χ24 = 58.915, p < 0.001) and second (χ24 = 66.839, p < 0.001) molars. The relationship between molar type and FED grade was statistically significant for both the BFED (p < 0.001) and the DFED (p < 0.001) of maxillary molars, as well as for both the BFED (p < 0.0001) and LFED (p < 0.0001). The difference in FED grade between the first and second molars was statistically significant in both maxillary (p < 0.001) and mandibular (p < 0.0001) molars. There was a significant relationship between FED grade and tooth location at molars with advanced FI
Acid-sensing ion channel 3 mediates peripheral anti-hyperalgesia effects of acupuncture in mice inflammatory pain
<p>Abstract</p> <p>Background</p> <p>Peripheral tissue inflammation initiates hyperalgesia accompanied by tissue acidosis, nociceptor activation, and inflammation mediators. Recent studies have suggested a significantly increased expression of acid-sensing ion channel 3 (ASIC3) in both carrageenan- and complete Freund's adjuvant (CFA)-induced inflammation. This study tested the hypothesis that acupuncture is curative for mechanical hyperalgesia induced by peripheral inflammation.</p> <p>Methods</p> <p>Here we used mechanical stimuli to assess behavioral responses in paw and muscle inflammation induced by carrageenan or CFA. We also used immunohistochemistry staining and western blot methodology to evaluate the expression of ASIC3 in dorsal root ganglion (DRG) neurons.</p> <p>Results</p> <p>In comparison with the control, the inflammation group showed significant mechanical hyperalgesia with both intraplantar carrageenan and CFA-induced inflammation. Interestingly, both carrageenan- and CFA-induced hyperalgesia were accompanied by ASIC3 up-regulation in DRG neurons. Furthermore, electroacupuncture (EA) at the ST36 rescued mechanical hyperalgesia through down-regulation of ASIC3 overexpression in both carrageenan- and CFA-induced inflammation.</p> <p>Conclusions</p> <p>In addition, electrical stimulation at the ST36 acupoint can relieve mechanical hyperalgesia by attenuating ASIC3 overexpression.</p
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