Single-cell classification, analysis, and its application using deep learning techniques.

Single-cell analysis (SCA) improves the detection of cancer, the immune system, and chronic diseases from complicated biological processes. SCA techniques generate high-dimensional, innovative, and complex data, making traditional analysis difficult and impractical. In the different cell types, conventional cell sequencing methods have signal transformation and disease detection limitations. To overcome these challenges, various deep learning techniques (DL) have outperformed standard state-of-the-art computer algorithms in SCA techniques. This review discusses DL application in SCA and presents a detailed study on improving SCA data processing and analysis. Firstly, we introduced fundamental concepts and critical points of cell analysis techniques, which illustrate the application of SCA. Secondly, various effective DL strategies apply to SCA to analyze data and provide significant results from complex data sources. Finally, we explored DL as a future direction in SCA and highlighted new challenges and opportunities for the rapidly evolving field of single-cell omics.

Aptamer-functionalized MOFs and AI-driven strategies for early cancer diagnosis and therapeutics.

Metal-Organic Frameworks (MOFs) have exceptional inherent properties that make them highly suitable for diverse applications, such as catalysis, storage, optics, chemo sensing, and biomedical science and technology. Over the past decades, researchers have utilized various techniques, including solvothermal, hydrothermal, mechanochemical, electrochemical, and ultrasonic, to synthesize MOFs with tailored properties. Post-synthetic modification of linkers, nodal components, and crystallite domain size and morphology can functionalize MOFs to improve their aptamer applications. Advancements in AI and machine learning led to the development of nonporous MOFs and nanoscale MOFs for medical purposes. MOFs have exhibited promise in cancer therapy, with the successful accumulation of a photosensitizer in cancer cells representing a significant breakthrough. This perspective is focused on MOFs' use as advanced materials and systems for cancer therapy, exploring the challenging aspects and promising features of MOF-based cancer diagnosis and treatment. The paper concludes by emphasizing the potential of MOFs as a transformative technology for cancer treatment and diagnosis.

Sweat analysis for urea sensing: trends and challenges.

With increasing population there is a rise in pathological diseases that the healthcare facilities are grappling with. Sweat-based wearable technologies for continuous monitoring have overcome the demerits associated with sweat sampling and sensing. Hence, sweat as an alternative biofluid holds great promise for the quantification of a host of biomarkers and understanding the functioning of the body, thereby deducing ailments quickly and economically. This comprehensive review accounts for recent advances in sweat-based LOCs (Lab-On-Chips), which are a likely alternative to the existing blood-urea sample testing that is invasive and time-consuming. The present review is focused on the advancements in sweat-based Lab-On-Chips (LOCs) as an alternative to invasive and time-consuming blood-urea sample testing. In addition, different sweat collection methods (direct skin, near skin and microfluidic) and their mechanism for urea sensing are explained in detail. The mechanism of urea in biofluids in protein metabolism, balancing nitrogen levels and a crucial factor of kidney function is described. In the end, research and technological advancements are explained to address current challenges and enable its widespread implementation.

Aptamer-based rapid diagnosis for point-of-care application.

Aptasensors have attracted considerable interest and widespread application in point-of-care testing worldwide. One of the biggest challenges of a point-of-care (POC) is the reduction of treatment time compared to central facilities that diagnose and monitor the applications. Over the past decades, biosensors have been introduced that offer more reliable, cost-effective, and accurate detection methods. Aptamer-based biosensors have unprecedented advantages over biosensors that use natural receptors such as antibodies and enzymes. In the current epidemic, point-of-care testing (POCT) is advantageous because it is easy to use, more accessible, faster to detect, and has high accuracy and sensitivity, reducing the burden of testing on healthcare systems. POCT is beneficial for daily epidemic control as well as early detection and treatment. This review provides detailed information on the various design strategies and virus detection methods using aptamer-based sensors. In addition, we discussed the importance of different aptamers and their detection principles. Aptasensors with higher sensitivity, specificity, and flexibility are critically discussed to establish simple, cost-effective, and rapid detection methods. POC-based aptasensors' diagnostic applications are classified and summarised based on infectious and infectious diseases. Finally, the design factors to be considered are outlined to meet the future of rapid POC-based sensors.

Improving speech perception in noise with current focusing in cochlear implant users.

Cochlear implant (CI) users typically have excellent speech recognition in quiet but struggle with understanding speech in noise. It is thought that broad current spread from stimulating electrodes causes adjacent electrodes to activate overlapping populations of neurons which results in interactions across adjacent channels. Current focusing has been studied as a way to reduce spread of excitation, and therefore, reduce channel interactions. In particular, partial tripolar stimulation has been shown to reduce spread of excitation relative to monopolar stimulation. However, the crucial question is whether this benefit translates to improvements in speech perception. In this study, we compared speech perception in noise with experimental monopolar and partial tripolar speech processing strategies. The two strategies were matched in terms of number of active electrodes, microphone, filterbanks, stimulation rate and loudness (although both strategies used a lower stimulation rate than typical clinical strategies). The results of this study showed a significant improvement in speech perception in noise with partial tripolar stimulation. All subjects benefited from the current focused speech processing strategy. There was a mean improvement in speech recognition threshold of 2.7 dB in a digits in noise task and a mean improvement of 3 dB in a sentences in noise task with partial tripolar stimulation relative to monopolar stimulation. Although the experimental monopolar strategy was worse than the clinical, presumably due to different microphones, frequency allocations and stimulation rates, the experimental partial-tripolar strategy, which had the same changes, showed no acute deficit relative to the clinical.

Improving virtual channel discrimination in a multi-channel context.

Improving spectral resolution in cochlear implants is key to improving performance in difficult listening conditions (e.g. speech in noise, music, etc.). Current focusing might reduce channel interaction, thereby increasing spectral resolution. Previous studies have shown that combining current steering and current focusing reduces spread of excitation and improves virtual channel discrimination in a single-channel context. It is unclear whether the single-channel benefits from current focusing extend to a multi-channel context, in which the physical and perceptual interference of multiple stimulated channels might overwhelm the benefits of improved spectral resolution. In this study, signal discrimination was measured with and without current focusing, in the presence of competing stimuli on nearby electrodes. Results showed that signal discrimination was consistently better with current focusing than without, regardless of the amplitude of the competing stimuli. Therefore, combining current steering and current focusing may provide more effective spectral cues than are currently available.

Reducing current spread using current focusing in cochlear implant users.

Cochlear implant performance in difficult listening situations is limited by channel interactions. It is known that partial tripolar (PTP) stimulation reduces the spread of excitation (SOE). However, the greater the degree of current focusing, the greater the absolute current required to maintain a fixed loudness. As current increases, so does SOE. In experiment 1, the SOE for equally loud stimuli with different degrees of current focusing is measured via a forward-masking procedure. Results suggest that at a fixed loudness, some but not all patients have a reduced SOE with PTP stimulation. Therefore, it seems likely that a PTP speech processing strategy could improve spectral resolution for only those patients with a reduced SOE. In experiment 2, the ability to discriminate different levels of current focusing was measured. In experiment 3, patients subjectively scaled verbal descriptors of stimuli of various levels of current focusing. Both discrimination and scaling of verbal descriptors correlated well with SOE reduction, suggesting that either technique have the potential to be used clinically to quickly predict which patients would receive benefit from a current focusing strategy.

Encoding pitch contours using current steering.

This study investigated cochlear implant (CI) users' ability to perceive pitch cues from time-varying virtual channels (VCs) to identify pitch contours. Seven CI users were tested on apical, medial, and basal electrode pairs with stimulus durations from 100 to 1000 ms. In one stimulus set, 9 pitch contours were created by steering current between the component electrodes and the VC halfway between the electrodes. Another stimulus set only contained 3 pitch contours (flat, falling, and rising). VC discrimination was also tested on the same electrodes. The total current level of dual-electrode stimuli was linearly interpolated between those of single-electrode stimuli to minimize loudness changes. The results showed that pitch contour identification (PCI) scores were similar across electrode locations, and significantly improved at longer durations. For durations longer than 300 ms, 2 subjects had nearly perfect 9-contour identification, and 5 subjects perfectly identified the 3 basic contours. Both PCI and VC discrimination varied greatly across subjects. Cumulative d(') values for VC discrimination were significantly correlated with 100-, 200-, and 500-ms PCI scores. These results verify the feasibility of encoding pitch contours using current steering, and suggest that identification of such pitch contours strongly relies on CI users' sensitivity to VCs.

Current focusing sharpens local peaks of excitation in cochlear implant stimulation.

Cochlear implant (CI) users' spectral resolution is limited by the number of implanted electrodes, interactions between the electrodes, and the underlying neural population. Current steering has been proposed to increase the number of spectral channels beyond the number of physical electrodes, however, electric field interactions may limit CI users' access to current-steered virtual channels (VCs). Current focusing (e.g tripolar stimulation) has been proposed to reduce current spread and thereby reduce interactions. In this study, current steering and current focusing were combined in a four-electrode stimulation pattern, i.e quadrupolar virtual channels (QPVCs). The spread of excitation was measured and compared between QPVC and Monopolar VC (MPVC) stimuli using a forward masking task. Results showed a sharper peak in the excitation pattern and reduced spread of masking for QPVC stimuli. Results from the forward masking study were compared with a previous study measuring VC discrimination ability and showed a weak relationship between spread of excitation and VC discriminability. The results suggest that CI signal processing strategies that utilize both current steering and current focusing might increase CI users' functional spectral resolution by transmitting more channels and reducing channel interactions.

Virtual channel discrimination is improved by current focusing in cochlear implant recipients.

Cochlear implant users' spectral resolution is limited by both the number of implanted electrodes and channel interactions between electrodes. Current steering (virtual channels) between two adjacent monopolar electrodes has been used to increase the number of spectral channels across the electrode array. However, monopolar stimulation is associated with large current spread and increased channel interaction. Current focusing across three adjacent electrodes (tripolar stimulation) has been used to reduce electrode current spread and improve channel selectivity. In the present study, current steering and current focusing were combined within a four-electrode stimulation pattern (quadrupolar virtual channels), thereby addressing the need for both increased channels and reduced current spread. Virtual channel discrimination was measured in 7 users of the Advanced Bionics Clarion II or HiRes 90K implants; virtual channel discrimination was compared between monopolar and quadrupolar virtual channels at three stimulation sites. The results showed that quadrupolar virtual channels provided better spectral resolution than monopolar virtual channels. The results suggested that quadrupolar virtual channels might provide the "best of both worlds" improving the number of spectral channels while reducing channel interactions.