305 research outputs found
Hydrogenation and Hydro-Carbonation and Etching of Single-Walled Carbon Nanotubes
We present a systematic experimental investigation of the reactions between
hydrogen plasma and single-walled carbon nanotubes (SWNTs) at various
temperatures. Microscopy, infrared (IR) and Raman spectroscopy and electrical
transport measurements are carried out to investigate the properties of SWNTs
after hydrogenation. Structural deformations, drastically reduced electrical
conductance and increased semiconducting nature of SWNTs upon sidewall
hydrogenation are observed. These changes are reversible upon thermal annealing
at 500C via dehydrogenation. Harsh plasma or high temperature reactions lead to
etching of nanotube likely via hydro-carbonation. Smaller SWNTs are markedly
less stable against hydro-carbonation than larger tubes. The results are
fundamental and may have implications to basic and practical applications
including hydrogen storage, sensing, band-gap engineering for novel electronics
and new methods of manipulation, functionalization and etching of nanotubes.Comment: 3 pages, 4 figure
Reducing Cycle Time in Frozen Gel-Bag Production
PurFoods, estimates they will use two million gel-bags in the fiscal year to place in their meal packages. Currently the cycle time to freeze gel-bags in a -10℉ freezer is about 24 hours, causing issues with time needed for production
I-MedSAM: Implicit Medical Image Segmentation with Segment Anything
With the development of Deep Neural Networks (DNNs), many efforts have been
made to handle medical image segmentation. Traditional methods such as nnUNet
train specific segmentation models on the individual datasets. Plenty of recent
methods have been proposed to adapt the foundational Segment Anything Model
(SAM) to medical image segmentation. However, they still focus on discrete
representations to generate pixel-wise predictions, which are spatially
inflexible and scale poorly to higher resolution. In contrast, implicit methods
learn continuous representations for segmentation, which is crucial for medical
image segmentation. In this paper, we propose I-MedSAM, which leverages the
benefits of both continuous representations and SAM, to obtain better
cross-domain ability and accurate boundary delineation. Since medical image
segmentation needs to predict detailed segmentation boundaries, we designed a
novel adapter to enhance the SAM features with high-frequency information
during Parameter Efficient Fine Tuning (PEFT). To convert the SAM features and
coordinates into continuous segmentation output, we utilize Implicit Neural
Representation (INR) to learn an implicit segmentation decoder. We also propose
an uncertainty-guided sampling strategy for efficient learning of INR.
Extensive evaluations on 2D medical image segmentation tasks have shown that
our proposed method with only 1.6M trainable parameters outperforms existing
methods including discrete and continuous methods. The code will be released
Multimodality Data Integration in Epilepsy
An important goal of software development in the medical field is the design of methods which are able to integrate information obtained from various imaging and nonimaging modalities into a cohesive framework in order to understand the results of qualitatively different measurements in a larger context. Moreover, it is essential to assess the various features of the data quantitatively so that relationships in anatomical and functional domains between complementing modalities can be expressed mathematically. This paper presents a clinically feasible software environment for the quantitative assessment of the relationship among biochemical functions as assessed by PET imaging and electrophysiological parameters derived from intracranial EEG. Based on the developed software tools, quantitative results obtained from individual modalities can be merged into a data structure allowing a consistent framework for advanced data mining techniques and 3D visualization. Moreover, an effort was made to derive quantitative variables (such as the spatial proximity index, SPI) characterizing the relationship between complementing modalities on a more generic level as a prerequisite for efficient data mining strategies. We describe the implementation of this software environment in twelve children (mean age 5.2 ± 4.3 years) with medically intractable partial epilepsy who underwent both high-resolution structural MR and functional PET imaging. Our experiments demonstrate that our approach will lead to a better understanding of the mechanisms of epileptogenesis and might ultimately have an impact on treatment. Moreover, our software environment holds promise to be useful in many other neurological disorders, where integration of multimodality data is crucial for a better understanding of the underlying disease mechanisms
Reducing Cycle Time in Frozen Gel-Bag Production
PurFoods estimates they will use two million gel-bags this year in their packaged meal delivery boxes. Currently, cycle time to freeze gel-bags is about 24 hours. PurFoods would like to reduce this time by at least 25%, opening up valuable inventory space and providing flexibility in meeting market demands
Sino-European Transcontinental Basic and Clinical High-Tech Acupuncture Studies—Part 2: Acute Stimulation Effects on Heart Rate and Its Variability in Patients with Insomnia
This second part of a series of Sino-European high-tech acupuncture studies describes the first clinical transcontinental teleacupuncture measurements in patients with insomnia. Heart rate (HR) and heart rate variability (HRV) measurements in 28 patients (mean age ± SD: 41.9 ± 14.6 years) were performed under standardized conditions in Harbin, China, and the data analysis was performed in Graz, Austria. Similar to the first part of the series, the electrocardiograms (ECGs) were recorded by an HRV Medilog AR12 system during acupuncture of the Shenmen point (HT7) on the left hand. HR decreased significantly (P < 0.001) during and after acupuncture stimulation of the HT7 acupuncture point. Total HRV increased significantly (P < 0.05) immediately after acupuncture stimulation, but there was no long-lasting effect. The values of the low-frequency (LF) and high-frequency (HF) band increased significantly after the stimulation compared to baseline values; however, the LF/HF ratio showed no significant changes. Together with the results of previous studies, the present results can serve as a solid basis for further development of acupressure or acupuncture stimulation equipment for complementary use in treating insomnia
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