Bioactivities and Synergistic Effect of Elsholtzia ciliata Essential Oil and Its Main Components against Lasioderma serricorne.

Investigations have shown that storage bugs seriously harm grains during storage. In the interim, essential oils (EOs) have been proven to be a good botanical pesticide. The anti-Lasioderma serricorne properties of Elsholtzia ciliata essential oil, which was obtained by steam distillation, were evaluated using DL-limonene, carvone, and their two optical isomer components using contact, repelling, and fumigation techniques. Simultaneously, the fumigation, contact, and repellent activities of carvone and its two optical isomers mixed with DL-limonene against L. serruricorne were evaluated. The results showed that E. ciliata, its main components (R-carvone, DL-limonene), and S-carvone exhibited both fumigations (LC50 = 14.47, 4.42, 20.9 and 3.78 mg/L) and contact (LD50 = 7.31, 4.03, 28.62 and 5.63 µg/adult) activity against L.serricorne. A binary mixture (1:1) of R-carvone and DL-limonene displayed an obvious synergistic effect. A binary mixture (1:1) of carvone and its two optical isomers exhibited an obvious synergistic effect, too. Furthermore, the repellent activity of the EO, carvone, and its two optical isomers, DL-limonene, and a combination of them varied. To stop insect damage during storage, E. ciliata and its components can be utilized as bio-insecticides.

The engineering of defect-modified boron nitride ribbons: an effective adsorbent to rapid capture for tetracycline.

Antibiotics, the persistent organic pollutants, have brought serious pollution to the aquatic environment. Therefore, it is necessary to select rapid adsorbents to remove them from their long-term threat. Herein, the introduction of defects in BN was employed to enhance its surface chemical activity for rapid capture of tetracycline via hydrothermal and calcination methods. The defect content in BN can be controlled by adjusting the volume ratio of ethanol to water. Among them, when the volume ratio of H2O/ethanol is 4/1 (BN-3), BN-3 has the most N defects at 33%, which increases the adsorption rate of h-BN for TC and promotes the adsorption capacity to 302.15 mg g-1, which is due to the introduction of nitrogen defects significantly regulates the electronic structure of BN. The corresponding theoretical calculations confirm that BN with N defects decreases the absorption energy of BN for TC. Additionally, the adsorption removal rate of tetracycline still reached 95.5% after 5 cycles of TC adsorption by BN-3, indicating that the defect-modified BN has good reusability and is beneficial for its use in pollutant adsorption.

Hierarchical antibiotic delivery system based on calcium phosphate cement/montmorillonite-gentamicin sulfate with drug release pathways.

Antibiotic-loaded calcium phosphate cement (CPC) has emerged as a promising biomaterial for drug delivery in orthopedics. However, there are problems such as the burst release of antibiotics, low cumulative release ratio, inappropriate release cycle, inferior mechanical strength, and poor anti-collapse properties. In this research, montmorillonite-gentamicin (MMT-GS) was fabricated by solution intercalation method and served as the drug release pathways in CPC to avoid burst release of GS, achieving promoted cumulative release ratios and a release cycle matched the time of inflammatory response. The results indicated that the highest cumulative release ratio and release concentration of GS in CPC/MMT-GS was 94.1 ± 2.8 % and 1183.05 µg/mL, and the release cycle was up to 504 h. In addition, the hierarchical GS delivery system was divided into three stages, and the kinetics followed the Korsmeyer-Peppas model, the zero-order model, and the diffusion-dissolution model, respectively. Meanwhile, the compressive strength of CPC/MMT-GS was up to 51.33 ± 3.62 MPa. Antibacterial results demonstrated that CPC/MMT-GS exhibited excellent in vitro long-lasting antibacterial properties to E. coli and S. aureus. Furthermore, CPC/MMT-GS promoted osteoblast proliferation and exhibited excellent in vivo histocompatibility. Therefore, CPC/MMT-GS has favorable application prospects in the treatment of bone defects with bacterial infections and inflammatory reactions.

Quma Tongluo Prescription in the Treatment of Chronic Oxaliplatin Related Peripheral Neuropathy: A Single-Center, Open, Randomized Controlled Study.

Objective: To observe the effect of oral Quma Tongluo decoction on oxaliplatin-related chronic peripheral neuropathy. Methods: A total of 64 patients who met the inclusion criteria were randomly divided into an experimental group and a control group, with 32 cases in each group. The experimental group took Quma Tongluo decoction granules orally (2 times a day, 1 package each time, morning and evening after meals), and the control group took mecobalamin tablets orally (1 tablet each time, 3 times a day, after meals). After 4 weeks of treatment, the quantitative score of chronic peripheral neuropathy severity, a quantitative score of numbness, a quantitative score of pain, a chemotherapeutic peripheral neurotoxicity score, comprehensive neuropathy score, peripheral neurotoxicity grade, KPS score, and neuropathy area range score were compared between the two groups before and after treatment. Results: Before treatment, there were no significant differences between the two groups in the quantitative score of chronic peripheral neuropathy severity, quantitative score of numbness, chemotherapeutic peripheral neurotoxicity score, total neuropathy score, peripheral neurotoxicity grade, and chronic OIPN symptom range score (P > .05). After 4 weeks of treatment, there were significant differences in the quantitative score of chronic peripheral neuropathy severity, quantitative score of numbness, chemotherapeutic peripheral neurotoxicity score, total neuropathy score, peripheral neurotoxicity grade, and chronic OIPN symptom range score between the two groups (P < .05). There was no significant difference in pain quantification score and KPS score between the two groups before and after treatment (P > .05). The total effective rate of Quma Tongluo decoction in the treatment of oxaliplatin-related chronic peripheral neuropathy was higher than that of mecobalamin (87.1% > 20.6%), and no obvious adverse reactions such as Gastrointestinal reactions and allergic reactions were observed.One patient in the experimental group had diarrhea, the incidence of adverse reactions was about 3.2%, and the control group had no adverse reactions. Conclusions: Quma Tongluo decoction can effectively treat oxaliplatin-related chronic peripheral neuropathy, reduce the symptoms while reducing the scope of symptoms, and has no obvious adverse reactions in clinical practice, with good safety.

Ion-incorporated titanium implants for staged regulation of antibacterial activity and immunoregulation-mediated osteogenesis.

Antibacterial properties and osteogenic activity are considered as two crucial factors for the initial healing and long-term survivability of orthopedic implants. For decades, various drug-loaded implants to enhance biological activities have been investigated extensively. More importantly, to control the drug release timing is equally significant due to the sequential biological processes after implantation. Hence, developing a staged regulation system on the titanium surface is practically significant. Here, we prepared TiO2 nanotubes (TiO2 NTs) on the titanium surface by anodization, followed by the incorporation of zinc (Zn) and strontium (Sr) sequentially through a hydrothermal process. Surface characterization confirmed the successful fabrication of Zn and Sr-incorporated TiO2 NTs (Zn-Sr/TiO2) on the titanium surface. The ion release results exhibited the differential release characteristic of Zn and Sr, which meant the early-stage release of Zn and the long-term release of Sr. It was exactly in accord with  the biological process after implantation, laying the basis of staged regulation after implantation. Zn-Sr/TiO2 showed favorable anti-early infection properties both in vitro and in vivo. Its inhibition effect on bacterial biofilm formation was attributed to the resistance against bacteria's initial adhesion and the killing effect on planktonic bacteria. Additionally, the release of Sr could alleviate infection-induced damage via immunoregulation. The biocompatibility and osteogenic activity mediated by M2 macrophage activation were confirmed with in vitro and in vivo studies. Therefore, it exhibited great potential in staged regulation for antibacterial activity in the early stage and the M2 activation-mediated osteogenic activity in the late stage. The staged regulation process was based on the differential release of Zn and Sr to achieve the early antibacterial effect and the long-term immune-induced osteogenic activity, to prevent implant-related infection and achieve better osseointegration. These two kinds of ions played their roles synergistically and complement mutually. This work is expected to provide an innovative idea for realizing sequential regulation after implantation.

Regulation of the upconversion effect to promote the removal of biofilms on a titanium surface via photoelectrons.

Biofilms on public devices and medical instruments are harmful. Hence, it is of great importance to fabricate antibacterial surfaces. In this work, we target the preparation of an antibacterial surface excited by near-infrared light via the coating of rare earth nanoparticles (RE NPs) on a titanium surface. The upconverted luminescence is absorbed by gold nanoparticles (Au NPs, absorber) to produce hot electrons and reactive oxygen species to eliminate the biofilms. The key parameters in tuning the upconversion effect to eliminate the biofilms are systematically investigated, which include the ratios of the sensitizer, activator, and matrix in the RE NPs, or the absorber Au NPs. The regulated RE NPs exhibit an upconversion quantum yield of 3.5%. Under illumination, photogenerated electrons flow through the surface to bacteria, such as E. coli, which disrupt the breath chain and eventually lead to the death of bacteria. The mild increase of the local temperature has an impact on the elimination of biofilms on the surface to a certain degree as well. Such a configuration on the surface of titanium exhibits a high reproducibility on the removal of biofilms and is functional after the penetration of light using soft tissue. This work thus provides a novel direction in the application of upconversion materials to be used in the fabrication of antibacterial surfaces.

Photoelectrons Sequentially Regulate Antibacterial Activity and Osseointegration of Titanium Implants.

Titanium implants are widely used ; however, implantation occasionally fails due to infections during the surgery or poor osseointegration after the surgery. To solve the problem, an intelligent functional surface on titanium implant that can sequentially eradicate bacteria biofilm at the initial period and promote osseointegration at the late period of post-surgery time is designed. Such surfaces can be excited by near infrared light (NIR), with rare earth nanoparticles to upconvert the NIR light to visible range and adsorb by Au nanoparticles, supported by titanium oxide porous film on titanium implants. Under NIR irradiation, the implant converts the energy of phonon to hot electrons and lattice vibrations, while the former flows directly to the contact substance or partially reacts with the surrounding to generate reactive oxygen species, and the latter leads to the local temperature increase. The biofilm or microbes on the implant surface can be eradicated by NIR treatment in vitro and in vivo. Additionally, the surface exhibits superior biocompatibility for cell survival, adhesion, proliferation, and osteogenic differentiation, which provides the foundation for osseointegration. In vivo implantation experiments demonstrate osseointegration is also promoted. This work thus demonstrates NIR-generated electrons can sequentially eradicate biofilms and regulate the osteogenic process, providing new solutions to fabricate efficient implant surfaces.

Microbial corrosion behavior of pipeline steels in simulation environment of natural gas transportation pipeline.

Bacteria are introduced into natural gas transmission pipelines through water-driven gas extraction, which can exacerbate the occurrence of pipeline corrosion. This study utilized a micro-reactor to design a simulated corrosion environment that mimics natural gas gathering and transportation pipelines. The objective was to investigate the corrosion behavior of X80 pipeline steel under the combined effects of CO2, Cl-, sulfate reducing bacteria (SRB), and iron bacteria (IOB). Additionally, it aimed to elucidate the influence mechanisms of these two microorganisms on corrosion. Under a humid environment with a total pressure of 8.5 MPa and a partial pressure of CO2 at 0.85 MPa, the corrosion rate of X80 pipeline steel was observed to follow the sequence: IOB > control (asepsis) > SRB + IOB > SRB. During the initial stages of corrosion, highly active IOB becomes the primary factor contributing to corrosion. As corrosion progresses, the concentration of dissolved oxygen in the SRB system gradually decreases while SRB activity intensifies, leading to the formation of FeS through the process of corrosion. The corrosion current density (icorr) exhibited a significant decrease, thereby intensifying localized corrosion of the corrosion products beneath the film. This resulted in a maximum pitting depth of 113.5 µm. Research on the behavior of microbial-enhanced corrosion provides significant guidance in the development and implementation of protective coatings.

Study on the poly(methyl methacrylate-acrylic acid)/calcium phosphate cement composite bound by chelation with enhanced water absorption and biomechanical properties.

Polymethylmethacrylate (PMMA) bone cement has been widely used as a critical material for fixing prostheses and filling bone defects. The shrinkage of PMMA bone cement was addressed by the additives, however, the uneven integral water absorption and expansion performance as well as the deteriorated mechanical properties of the modified bone cement after immersion in phosphate buffered saline (PBS) and simulation body fluid (SBF) affected the long-term stability after implantation. Calcium phosphate cement (CPC) is a biomaterial with promising applications in orthopedics, whose hydration reaction provides an important driving force for the transfer of water. Besides, the mechanical properties of CPC can be enhanced with the curing process. In this study, CPC was utilized to modify the poly(methyl methacrylate-acrylic acid) [P(MMA-AA)] bone cement. The results demonstrated the successful construction of interconnected CPC water delivery networks in the P(MMA-AA)/CPC composite, the water absorption ratio and expansion ratio of the composite were up to 131.18 ± 9.14% and 168.19 ± 5.44%, respectively. Meanwhile, the transformation of CPC water delivery networks into rigid mechanical support networks as well as the chelation interaction between organic-inorganic enhanced the mechanical properties of the composite after immersion, the compressive strength after immersion reached 62.97 ± 0.97 MPa, which was 27.65% higher than that before immersion. The degradation ratio of the composite was up to 13.76 ± 0.23% after 9 days of immersion, which was 16.4% higher than that of CPC. Furthermore, composites exhibited superior biocompatibility as the release of Ca2+. Therefore, P(MMA-AA)/CPC composite serves as a promising medical filling material for clinical use.

KCNAB2 overexpression inhibits human non-small-cell lung cancer cell growth in vitro and in vivo.

Non-small-cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancer cases. NSCLC patients often have poor prognosis demanding urgent identification of novel biomarkers and potential therapeutic targets. KCNAB2 (regulatory beta subunit2 of voltage-gated potassium channel), encoding aldosterone reductase, plays a pivotal role in regulating potassium channel activity. In this research, we tested the expression of KCNAB2 as well as its potential functions in human NSCLC. Bioinformatics analysis shows that expression of KCNAB2 mRNA is significantly downregulated in human NSCLC, correlating with poor overall survival. In addition, decreased KCNAB2 expression was detected in different NSCLC cell lines and local human NSCLC tissues. Exogenous overexpression of KCNAB2 potently suppressed growth, proliferation and motility of established human NSCLC cells and promoted NSCLC cells apoptosis. In contrast, CRISPR/Cas9-induced KCNAB2 knockout further promoted the malignant biological behaviors of NSCLC cells. Protein chip analysis in the KCNAB2-overexpressed NSCLC cells revealed that KCNAB2 plays a possible role in AKT-mTOR cascade activation. Indeed, AKT-mTOR signaling activation was potently inhibited following KCNAB2 overexpression in NSCLC cells. It was however augmented by KCNAB2 knockout. In vivo, the growth of subcutaneous KCNAB2-overexpressed A549 xenografts was significantly inhibited. Collectively, KCNAB2 could be a novel effective gene for prognosis prediction of NSCLC. Targeting KCNAB2 may lead to the development of advanced therapies.

Sensitivity of Pharmacokinetics to Differences in the Particle Size Distribution for Formulations of Locally Acting Mometasone Furoate Suspension-Based Nasal Sprays.

To assess bioequivalence of locally acting suspension-based nasal sprays, the U.S. FDA currently recommends a weight-of-evidence approach. In addition to in vitro and human pharmacokinetic (PK) studies, this includes a comparative clinical endpoint study to ensure equivalent bioavailability of the active pharmaceutical ingredient (API) at the site of action. The present study aimed to assess, within an in vitro/in vivo correlation paradigm, whether PK studies and dissolution kinetics are sensitive to differences in drug particle size for a locally acting suspension-based nasal spray product. Two investigational suspension-based nasal formulations of mometasone furoate (MF-I and MF-II; delivered dose: 180 µg) differed in API particle size and were compared in a single-center, double-blind, single-dose, randomized, two-way crossover PK study in 44 healthy subjects with oral charcoal block. Morphology-directed Raman spectroscopy yielded volume median diameters of 3.17 µm for MF-I and 5.50 µm for MF-II, and dissolution studies showed that MF-II had a slower dissolution profile than MF-I. The formulation with larger API particles (MF-II) showed a 45% smaller Cmax and 45% smaller AUC0-inf compared to those of MF-I. Systemic bioavailability of MF-I (2.20%) and MF-II (1.18%) correlated well with the dissolution kinetics, with the faster dissolving formulation yielding the higher bioavailability. This agreement between pharmacokinetics and dissolution kinetics cross-validated both methods and supported their use in assessing potential differences in slowly dissolving suspension-based nasal spray products.

Study on the Constitutive Relationship between Ordinary Concrete and Nano-Titanium Dioxide-Modified Concrete at High Temperature.

After high-temperature treatment, both nano-titanium dioxide-modified concrete and ordinary concrete exhibit typical splitting failure. High-temperature heating reduces the mechanical properties and brittleness of concrete and improves the ductility of concrete. The stress-strain relationship of the specimens was obtained through the uniaxial compression test of ordinary concrete and nano-titanium dioxide-modified concrete cube specimens under normal temperature and high-temperature conditions. In addition, the relationship between temperature and damage variables was established, and the unified constitutive model containing damage variables after room temperature and high-temperature treatment of ordinary concrete and nano-titanium dioxide-modified concrete were established. It provides a reference for future research on the mechanical properties of high-performance concrete structures after high temperatures (fire).

A self-supervised guided knowledge distillation framework for unpaired low-dose CT image denoising.

Low-dose computed tomography (LDCT) can significantly reduce the damage of X-ray to the human body, but the reduction of CT dose will produce images with severe noise and artifacts, which will affect the diagnosis of doctors. Recently, deep learning has attracted more and more attention from researchers. However, most of the denoising networks applied to deep learning-based LDCT imaging are supervised methods, which require paired data for network training. In a realistic imaging scenario, obtaining well-aligned image pairs is challenging due to the error in the table re-positioning and the patient's physiological movement during data acquisition. In contrast, the unpaired learning method can overcome the drawbacks of supervised learning, making it more feasible to collect unpaired training data in most real-world imaging applications. In this study, we develop a novel unpaired learning framework, Self-Supervised Guided Knowledge Distillation (SGKD), which enables the guidance of supervised learning using the results generated by self-supervised learning. The proposed SGKD scheme contains two stages of network training. First, we can achieve the LDCT image quality improvement by the designed self-supervised cycle network. Meanwhile, it can also produce two complementary training datasets from the unpaired LDCT and NDCT images. Second, a knowledge distillation strategy with the above two datasets is exploited to further improve the LDCT image denoising performance. To evaluate the effectiveness and feasibility of the proposed method, extensive experiments were performed on the simulated AAPM challenging and real-world clinical LDCT datasets. The qualitative and quantitative results show that the proposed SGKD achieves better performance in terms of noise suppression and detail preservation compared with some state-of-the-art network models.

Low-Dose CT Image Synthesis for Domain Adaptation Imaging Using a Generative Adversarial Network With Noise Encoding Transfer Learning.

Deep learning (DL) based image processing methods have been successfully applied to low-dose x-ray images based on the assumption that the feature distribution of the training data is consistent with that of the test data. However, low-dose computed tomography (LDCT) images from different commercial scanners may contain different amounts and types of image noise, violating this assumption. Moreover, in the application of DL based image processing methods to LDCT, the feature distributions of LDCT images from simulation and clinical CT examination can be quite different. Therefore, the network models trained with simulated image data or LDCT images from one specific scanner may not work well for another CT scanner and image processing task. To solve such domain adaptation problem, in this study, a novel generative adversarial network (GAN) with noise encoding transfer learning (NETL), or GAN-NETL, is proposed to generate a paired dataset with a different noise style. Specifically, we proposed a method to perform noise encoding operator and incorporate it into the generator to extract a noise style. Meanwhile, with a transfer learning (TL) approach, the image noise encoding operator transformed the noise type of the source domain to that of the target domain for realistic noise generation. One public and two private datasets are used to evaluate the proposed method. Experiment results demonstrated the feasibility and effectiveness of our proposed GAN-NETL model in LDCT image synthesis. In addition, we conduct additional image denoising study using the synthesized clinical LDCT data, which verified the merit of the proposed synthesis in improving the performance of the DL based LDCT processing method.

X-ray CT image denoising with MINF: A modularized iterative network framework for data from multiple dose levels.

In clinical applications, multi-dose scan protocols will cause the noise levels of computed tomography (CT) images to fluctuate widely. The popular low-dose CT (LDCT) denoising network outputs denoised images through an end-to-end mapping between an LDCT image and its corresponding ground truth. The limitation of this method is that the reduced noise level of the image may not meet the diagnostic needs of doctors. To establish a denoising model adapted to the multi-noise levels robustness, we proposed a novel and efficient modularized iterative network framework (MINF) to learn the feature of the original LDCT and the outputs of the previous modules, which can be reused in each following module. The proposed network can achieve the goal of gradual denoising, outputting clinical images with different denoising levels, and providing the reviewing physicians with increased confidence in their diagnosis. Moreover, a multi-scale convolutional neural network (MCNN) module is designed to extract as much feature information as possible during the network's training. Extensive experiments on public and private clinical datasets were carried out, and comparisons with several state-of-the-art methods show that the proposed method can achieve satisfactory results for noise suppression of LDCT images. In further comparisons with modularized adaptive processing neural network (MAP-NN), the proposed network shows superior step-by-step or gradual denoising performance. Considering the high quality of gradual denoising results, the proposed method can obtain satisfactory performance in terms of image contrast and detail protection as the level of denoising increases, which shows its potential to be suitable for a multi-dose levels denoising task.

Bioactive graphene oxide-functionalized self-expandable hydrophilic and osteogenic nanocomposite for orthopaedic applications.

Polymethyl methacrylate (PMMA) bone cement (PBC) is commonly used in orthopaedic surgery. However, polymerization volumetric shrinkage, exothermic injury, and low bioactivity prevent PBC from being an ideal material. The developed expandable P(MMA-AA-St) well overcomes the volumetric shrinkage of PBC. However, its biomechanical properties are unsatisfactory. Herein, graphene oxide (GO), a hydrophilic material with favourable biomechanics and osteogenic capability, was added to P(MMA-AA-St) to optimize its biomechanics and bioactivity. The GO-modified self-expandable P(MMA-AA-St)-GO nanocomposite (PGBCs) exhibited outstanding compressive strength (>70 â€‹MPa), water absorption, and volume expansion, as well as a longer handling time and a reduced setting temperature. The cytocompatibility of PGBCs was superior to that of PBC, as demonstrated by CCK-8 assay, live-dead cell staining, and flow cytometry. In addition, better osteoblast attachment was observed, which could be attributed to the effects of GO. The improved level of osteogenic gene and protein expression further illustrated the improved cell-material interactions between osteoblasts and PGBCs. The results of an in vivo study performed by filling bone defects in the femoral condyles of rabbits with PGBCs demonstrated promising intraoperative handling properties and convenient implantation. Blood testing and histological staining demonstrated satisfactory in vivo biosafety. Furthermore, bone morphological and microarchitecture analyses using bone tissue staining and micro-CT scanning revealed better bone-PGBCs contact and osteogenic capability. The results of this study indicate that GO modification improved the physiochemical properties, cytocompatibility, and osteogenic capability of P(MMA-AA-St) and overcame the drawbacks of PBC, allowing its material derivatives to serve as effective implantable biomaterials.

Collision of Commonality and Personalization: Better Understanding of the Periosteum.

The periosteum is quite essential for bone repair. The excellent osteogenic properties of periosteal tissue make it a popular choice for accelerated osteogenesis in tissue engineering. With advances in research and technology, renewed attention has been paid to the periosteum. Recent studies have shown that the complexity of the periosteum is not only limited to histological features but also includes genetic and phenotypic features. In addition, the periosteum is proved to be quite site-specific in many ways. This brings challenges to the selection of periosteal donor sites. Limited understanding of the periosteum sets up barriers to developing optimal tissue regeneration strategies. A better understanding of periosteum could lead to better applications. Therefore, we reviewed the histological structure, gene expression, and function of the periosteum from both the commonality and personalization. It aims to discuss some obscure issues and untapped potential of periosteum and artificial periosteum in the application, where further theoretical research is needed. Overall, the site-specificity of the periosteum needs to be fully considered in future applications. However, significant further work is needed in relevant clinical trials to promote the further development of artificial periosteum.

Domain-adaptive denoising network for low-dose CT via noise estimation and transfer learning.

BACKGROUND: In recent years, low-dose computed tomography (LDCT) has played an important role in the diagnosis CT to reduce the potential adverse effects of X-ray radiation on patients, while maintaining the same diagnostic image quality. PURPOSE: Deep learning (DL)-based methods have played an increasingly important role in the field of LDCT imaging. However, its performance is highly dependent on the consistency of feature distributions between training data and test data. Due to patient's breathing movements during data acquisition, the paired LDCT and normal dose CT images are difficult to obtain from realistic imaging scenarios. Moreover, LDCT images from simulation or clinical CT examination often have different feature distributions due to the pollution by different amounts and types of image noises. If a network model trained with a simulated dataset is used to directly test clinical patients' LDCT data, its denoising performance may be degraded. Based on this, we propose a novel domain-adaptive denoising network (DADN) via noise estimation and transfer learning to resolve the out-of-distribution problem in LDCT imaging. METHODS: To overcome the previous adaptation issue, a novel network model consisting of a reconstruction network and a noise estimation network was designed. The noise estimation network based on a double branch structure is used for image noise extraction and adaptation. Meanwhile, the U-Net-based reconstruction network uses several spatially adaptive normalization modules to fuse multi-scale noise input. Moreover, to facilitate the adaptation of the proposed DADN network to new imaging scenarios, we set a two-stage network training plan. In the first stage, the public simulated dataset is used for training. In the second transfer training stage, we will continue to fine-tune the network model with a torso phantom dataset, while some parameters are frozen. The main reason using the two-stage training scheme is based on the fact that the feature distribution of image content from the public dataset is complex and diverse, whereas the feature distribution of noise pattern from the torso phantom dataset is closer to realistic imaging scenarios. RESULTS: In an evaluation study, the trained DADN model is applied to both the public and clinical patient LDCT datasets. Through the comparison of visual inspection and quantitative results, it is shown that the proposed DADN network model can perform well in terms of noise and artifact suppression, while effectively preserving image contrast and details. CONCLUSIONS: In this paper, we have proposed a new DL network to overcome the domain adaptation problem in LDCT image denoising. Moreover, the results demonstrate the feasibility and effectiveness of the application of our proposed DADN network model as a new DL-based LDCT image denoising method.

Electrochemical biosensors based on saliva electrolytes for rapid detection and diagnosis.

In recent years, electrochemical biosensors (ECBSs) have shown significant potential for real-time disease diagnosis and in situ physical condition monitoring. As a multi-constituent oral fluid comprising various disease signaling biomarkers, saliva has drawn much attention in the field of point-of-care (POC) testing. In particular, during the outbreak of the COVID-19 pandemic, ECBSs which hold the simplicity of a single-step assay compared with the multi-step assay of traditional testing methods are expected to relieve the human and economic burden caused by the massive and long-term sample testing process. Noteworthily, ECBSs for the detection of SARS-CoV-2 in saliva have already been developed and may replace current testing methods. Furthermore, the detection scope has expanded from routine indices such as sugar and uric acid to abnormal biomarkers for early-stage disease detection and drug level monitoring, which further facilitated the evolution of ECBSs in the last 5 years. This review is divided into several main sections. First, we discussed the latest advancements and representative research on ECBSs for saliva testing. Then, we focused on a novel kind of ECBS, organic electrochemical transistors (OECTs), which hold great advantages of high sensitivity and signal-to-noise ratio and on-site detection. Finally, application of ECBSs with integrated portable platforms in oral cavities, which lead to powerful auxiliary testing means for telemedicine, has also been discussed.