1,064 research outputs found
Optical power transfer and communication methods for wireless implantable sensing platforms
Ultrasmall scale implants have recently attracted focus as valuable tools for monitoring both acute and chronic diseases. Semiconductor optical technologies are the key to miniaturizing these devices to the long-sought sub-mm scale, which will enable long-term use of these devices for medical applications. This can also enable the use of multiple implantable devices concurrently to form a true body area network of sensors. We demonstrate optical power transfer techniques and methods to effectively harness this power for implantable devices. Furthermore, we also present methods for optical data transfer from such implants. Simultaneous use of these technologies can result in miniaturized sensing platforms that can allow for large-scale use of such systems in real world applications
Nonlinear photoacoustic microscopy via a loss modulation technique: from detection to imaging
In order to achieve high-resolution deep-tissue imaging, multi-photon fluorescence microscopy and photoacoustic tomography had been proposed in the past two decades. However, combining the advantages of these two imaging systems to achieve optical-spatial resolution with an ultrasonic-penetration depth is still a field with challenges. In this paper, we investigate the detection of the two-photon photoacoustic ultrasound, and first demonstrate background-free two-photon photoacoustic imaging in a phantom sample. To generate the background-free two-photon photoacoustic signals, we used a high-repetition rate femtosecond laser to induce narrowband excitation. Combining a loss modulation technique, we successfully created a beating on the light intensity, which not only provides pure sinusoidal modulation, but also ensures the spectrum sensitivity and frequency selectivity. By using the lock-in detection, the power dependency experiment validates our methodology to frequency-select the source of the nonlinearity. This ensures our capability of measuring the background-free two-photon photoacoustic waves by detecting the 2nd order beating signal directly. Furthermore, by mixing the nanoparticles and fluorescence dyes as contrast agents, the two-photon photoacoustic signal was found to be enhanced and detected. In the end, we demonstrate subsurface two-photon photoacoustic bio-imaging based on the optical scanning mechanism inside phantom samples
Zero-shot Domain-sensitive Speech Recognition with Prompt-conditioning Fine-tuning
In this work, we propose a method to create domain-sensitive speech
recognition models that utilize textual domain information by conditioning its
generation on a given text prompt. This is accomplished by fine-tuning a
pre-trained, end-to-end model (Whisper) to learn from demonstrations with
prompt examples. We show that this ability can be generalized to different
domains and even various prompt contexts, with our model gaining a Word Error
Rate (WER) reduction of up to 33% on unseen datasets from various domains, such
as medical conversation, air traffic control communication, and financial
meetings. Considering the limited availability of audio-transcript pair data,
we further extend our method to text-only fine-tuning to achieve domain
sensitivity as well as domain adaptation. We demonstrate that our text-only
fine-tuned model can also attend to various prompt contexts, with the model
reaching the most WER reduction of 29% on the medical conversation dataset.Comment: F-T Liao and Y-C Chan contributed equall
Optical Methods for Wireless Implantable Sensing Platforms
Ultra small scale implants have gained lots of importance for both acute and chronic applications. Optical techniques
hold the key to miniaturizing these devices to long sought sub-mm scale. This will lead towards long term use of these
devices for medically relevant applications. It can also allow using multiple of these devices at the same time and
forming a true body area network of sensors. In this paper, we present optical power transfer to such devices and the
techniques to harness this power for different applications, for example high voltage or high current applications. We
also present methods for wireless data transfer from such implants
Using Rare Earth Elements to Constrain Particulate Organic Carbon Flux in the East China Sea
Fluxes of particulate organic carbon (POC) in the East China Sea (ECS) have been reported to decrease from the inner continental shelf towards the outer continental shelf. Recent research has shown that POC fluxes in the ECS may be overestimated due to active sediment resuspension. To better characterize the effect of sediment resuspension on particle fluxes in the ECS, rare earth elements (REEs) and organic carbon (OC) were used in separate two-member mixing models to evaluate trap-collected POC fluxes. The ratio of resuspended particles from sediments to total trap-collected particles in the ECS ranged from 82-94% using the OC mixing model, and 30-80% using the REEs mixing model, respectively. These results suggest that REEs may be better proxies for sediment resuspension than OC in high turbidity marginal seas because REEs do not appear to undergo degradation during particle sinking as compared to organic carbon. Our results suggest that REEs can be used as tracers to provide quantitative estimates of POC fluxes in marginal sea
Factors associated with outcomes of second-line treatment for EGFR-mutant non-small-cell lung cancer patients after progression on first- or second-generation EGFR-tyrosine kinase inhibitor treatment
PurposeEpidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are standard first-line treatments for advanced EGFR-mutant non-small-cell lung cancer (NSCLC) patients. However, factors associated with outcomes after progression on first-line therapy are seldom investigated.Materials and methodsFrom January 2016 to December 2020, we enrolled 242 EGFR-mutant stage IIIB–IV NSCLC patients who progressed on first- or second-generation EGFR-TKI treatments, and 206 of them receive second-line treatments after disease progression. The factors that predict the survival outcomes of different second-line treatments after disease progression were evaluated. Clinical and demographic characteristics, including metastatic sites, neutrophil-to-lymphocyte ratio (NLR) at first-line progression, and second-line treatment regimens, and whether re-biopsied after disease progression or not, were reviewed for outcome analysis.ResultsThe univariate analysis showed that the PFS was shorted in male patients (p =0.049), patients with ECOG performance state ≥ 2 (p =0.014), former smokers (p =0.003), patients with brain metastasis (p =0.04), second-line chemotherapy or EGFR-TKIs other than osimertinib (p =0.002), and NLR ≥5.0 (p=0.024). In addition, second-line osimertinib was associated with longer OS compared to chemotherapy and other EGFR-TKI treatment (p =0.001). In the multivariate analysis, only second-line osimertinib was an independent predictor of PFS (p =0.023). Re-biopsy after first-line treatment was associated with a trend of better OS. Patients with NLR ≥5.0 at disease progression had shorter OS than patients with NLR <5.0 (p = 0.008).ConclusionThe benefits of osimertinib necessitate that aggressive re-biopsy after progression on first- or second-generation EGFR-TKI treatment is merited for appropriate second-line treatments to provide better outcomes for these patients
Modularity of Escherichia coli sRNA regulation revealed by sRNA-target and protein network analysis
<p>Abstract</p> <p>Background</p> <p>sRNAs, which belong to the non-coding RNA family and range from approximately 50 to 400 nucleotides, serve various important gene regulatory roles. Most are believed to be <it>trans</it>-regulating and function by being complementary to their target mRNAs in order to inhibiting translation by ribosome occlusion. Despite this understanding of their functionality, the global properties associated with regulation by sRNAs are not yet understood. Here we use topological analysis of sRNA targets in terms of protein-protein interaction and transcription-regulatory networks in <it>Escherichia coli </it>to shed light on the global correlation between sRNA regulation and cellular control networks.</p> <p>Results</p> <p>The analysis of sRNA targets in terms of their networks showed that some specific network properties could be identified. In protein-protein interaction network, sRNA targets tend to occupy more central positions (higher closeness centrality, <it>p-val </it>= 0.022) and more cliquish (larger clustering coefficient, <it>p-val </it>= 0.037). The targets of the same sRNA tend to form a network module (shorter characteristic path length, <it>p-val </it>= 0.015; larger density, <it>p-val </it>= 0.019; higher in-degree ratio, <it>p-val </it>= 0.009). Using the transcription-regulatory network, sRNA targets tend to be under multiple regulation (higher indegree, <it>p-val </it>= 0.013) and the targets usually are important to the transfer of regulatory signals (higher betweenness, <it>p-val </it>= 0.012). As was found for the protein-protein interaction network, the targets that are regulated by the same sRNA also tend to be closely knit within the transcription-regulatory network (larger density, <it>p-val </it>= 0.036), and inward interactions between them are greater than the outward interactions (higher in-degree ratio, <it>p-val </it>= 0.023). However, after incorporating information on predicted sRNAs and down-stream targets, the results are not as clear-cut, but the overall network modularity is still evident.</p> <p>Conclusions</p> <p>Our results indicate that sRNA targeting tends to show a clustering pattern that is similar to the human microRNA regulation associated with protein-protein interaction network that was observed in a previous study. Namely, the sRNA targets show close interaction and forms a closely knit network module for both the protein-protein interaction and the transcription-regulatory networks. Thus, targets of the same sRNA work in a concerted way toward a specific goal. In addition, in the transcription-regulatory network, sRNA targets act as "multiplexor", accepting regulatory control from multiple sources and acting accordingly. Our results indicate that sRNA targeting shows different properties when compared to the proteins that form cellular networks.</p
Single nucleotide polymorphisms of one-carbon metabolism and cancers of the esophagus, stomach, and liver in a Chinese population.
One-carbon metabolism (folate metabolism) is considered important in carcinogenesis because of its involvement in DNA synthesis and biological methylation reactions. We investigated the associations of single nucleotide polymorphisms (SNPs) in folate metabolic pathway and the risk of three GI cancers in a population-based case-control study in Taixing City, China, with 218 esophageal cancer cases, 206 stomach cancer cases, 204 liver cancer cases, and 415 healthy population controls. Study participants were interviewed with a standardized questionnaire, and blood samples were collected after the interviews. We genotyped SNPs of the MTHFR, MTR, MTRR, DNMT1, and ALDH2 genes, using PCR-RFLP, SNPlex, or TaqMan assays. To account for multiple comparisons and reduce the chances of false reports, we employed semi-Bayes (SB) shrinkage analysis. After shrinkage and adjusting for potential confounding factors, we found positive associations between MTHFR rs1801133 and stomach cancer (any T versus C/C, SB odds-ratio [SBOR]: 1.79, 95% posterior limits: 1.18, 2.71) and liver cancer (SBOR: 1.51, 95% posterior limits: 0.98, 2.32). There was an inverse association between DNMT1 rs2228612 and esophageal cancer (any G versus A/A, SBOR: 0.60, 95% posterior limits: 0.39, 0.94). In addition, we detected potential heterogeneity across alcohol drinking status for ORs relating MTRR rs1801394 to esophageal (posterior homogeneity P = 0.005) and stomach cancer (posterior homogeneity P = 0.004), and ORs relating MTR rs1805087 to liver cancer (posterior homogeneity P = 0.021). Among non-alcohol drinkers, the variant allele (allele G) of these two SNPs was inversely associated with the risk of these cancers; while a positive association was observed among ever-alcohol drinkers. Our results suggest that genetic polymorphisms related to one-carbon metabolism may be associated with cancers of the esophagus, stomach, and liver. Heterogeneity across alcohol consumption status of the associations between MTR/MTRR polymorphisms and these cancers indicates potential interactions between alcohol drinking and one-carbon metabolic pathway
Bronchiolitis Obliterans Organizing Pneumonia in Swine Associated with Porcine Circovirus Type 2 Infection
Bronchiolitis obliterans organizing pneumonia (BOOP) is a chronic respiratory disease. Although the pathogenesis of BOOP is still incompletely understood, BOOP is responsive to steroids and has a good prognosis. In our five pigs with chronic postweaning multisystemic wasting syndrome (PMWS), typical BOOP lesions were revealed. All five porcine lungs showed typical intraluminal plugs, and porcine circovirus type 2 (PCV2) was identified. They also exhibited similar pathologic findings such as proliferation of type II pneumocytes and myofibroblasts (MFBs), extracellular collagen matrix (ECM) deposition, and fragmentation of elastic fibers. MFBs migration correlative molecules, for instance, gelatinase A, B and osteopontin, appeared strongly in the progressing marginal area of polypoid intraluminal plugs of fibrotic lesion. These molecules colocalized with the active MFBs. Both gelatinase activity and intercellular level of active MFBs were significantly increased (P < .05). Porcine chronic bronchopneumonia leads to BOOP and it is associated with PCV2 persistent infection. Swine BOOP demonstrates similar cellular constituents with human BOOP. Perhaps their molecular mechanisms of pathogenesis operate in a similar way. Thus we infer that the swine BOOP can be considered as a potential animal model for human BOOP associated with natural viral infection. Moreover, it is more convenient to obtain samples
Optical power transfer and communication methods for wireless implantable sensing platforms
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