Biomedical Testing Research Articles

Preparation of high-efficiency anti-reflective oxide electrodes and their application in biomedical testing and thin-film lithium batteries

Nanomaterials hold great potential in the development of lithium-ion microbatteries and could assist in developing ever smaller and more reliable power sources to facilitate 21st Century life. Professor Kuan-Jiuh Lin is based in the Department of Chemistry, National Chung Hsing University, Taiwan, and runs the Interfacial Optical-Electronic (IOE) Lab. He and his team leader Dr Wen-Yin Ko are working to address gaps in nanotechnology, including how to conquer the strong interfacial coupling between the porous semiconductor membrane and the electro-plasmon metal-surface film. Their research is expected to have broad applications across electronics and optoelectronics. In a recent project, the researchers are working to develop more efficient lithium-ion microbatteries (micro-LIBs) using active nanostructured anode materials such as carbon nanomaterials composed of porous carbon, graphene and carbon nanotubes (CNTs). The researchers have developed a lightweight and high-rate CNT-based anode system that holds great potential for fast-charging batteries. The team has also created metal-doped MnO2 nanowalls with inter-networked vertically-oriented three-dimensional (3D) porous frameworks directly onto a AgCNT modified current collector, resulting in a superior performance anode material for LIBs. The researchers also created a novel 3D porous scaffold anode material of silicon–porphyrin pearl-chain-like nanowires which was placed onto the surface of a bundled titanium dioxide (TiO2) nanowire. In a world first, Lin and the team were able to achieve dial functionalities of antireflective and electrochemical properties-based anatase TiO2 nanowire devices with a high-porosity cross-linked geometry directly grown onto transparent conductive glass.

A hybrid method for heart disease diagnosis utilizing feature selection based ensemble classifier model generation

Heart disease is one of the most complicated diseases, and it affects a large number of individuals throughout the world. In healthcare, particularly cardiology, early and accurate detection of cardiac disease is critical. The Heart Disease Data Set-UCI repository collects data on heart disease. The search space and complexity of the classification models are increased by this raw dataset, which contains redundant and inconsistent data. We need to eliminate the redundant and unnecessary elements from the data to improve classification accuracy. As a consequence, feature selection approaches might be useful for reducing the cost of diagnosis by identifying the most important qualities. This research developed an ensemble classification model based on a feature selection approach in which selected features play a role in classification. Accordingly, a classification approach was introduced using ensemble learning with a genetic algorithm, feature selection, and biomedical test values to diagnose heart disease. Based on the results, it is deduced that the benefits of using the feature selection method vary depending on the utilized machine learning technique. However, the best-proposed model based on the combination of genetic algorithm and the ensemble learning model has achieved an accuracy of 97.57% on the considered datasets. The suggested diagnosis system achieved better accuracy than previously proposed methods and can easily be implemented in healthcare to identify heart disease.Graphical abstract

3D Natural Mesoporous Biosilica-Embedded Polysulfone Made Ultrafiltration Membranes for Application in Separation Technology.

Diatoms are the most abundant photosynthetic microalgae found in all aquatic habitats. In the extant study, the spent biomass (after lipid extraction) of the centric marine diatom Thalassiosira lundiana CSIRCSMCRI 001 was subjected to acid digestion for the extraction of micro composite inorganic biosilica. Then, the resulting three-dimensional mesoporous biosilica material (diatomite) was used as a filler in polysulfone (PSF) membrane preparation by phase inversion. The fabricated PSF/diatomite composite membranes were characterized by SEM-EDX, TGA, and ATR-IR, and their performances were evaluated. The number of pores and pore size were increased on the membrane surface with increased diatomite in the composite membranes as compared to the control. The diatomite composite membranes had high hydrophilicity and thermal stability, lower surface roughness, and excellent water permeability. Membranes with high % diatomite, i.e., PSF/Dia0.5, had a maximum water flux of 806.8 LMH (Liter/m2/h) at 20 psi operating pressure. High-diatomite content membranes also exhibited the highest rejection of BSA protein (98.5%) and rhodamine 6G (94.8%). Similarly, in biomedical rejection tests, the PSF/Dia0.5 membrane exhibited a maximum rejection of ampicillin (75.84%) and neomycin (85.88%) at 20 Psi pressure. In conclusion, the mesoporous inorganic biosilica material was extracted from spent biomass of diatom and successfully used in filtration techniques. The results of this study could enhance the application of natural biogenic porous silica materials in wastewater treatment for water recycling.

Directional droplet transfer on micropillar-textured superhydrophobic surfaces fabricated using a ps laser

Directional droplet transfer is essential for water collection, microfluidic and remote material transfer. Laser-enabled 2.5-dimensional fabrication of micropillars on shape-memory-polymers transfers the surface wettability from hydrophilicity to superhydrophobicity in a simple, fast, and large-scale manner. The surface wettability exhibits a tight relationship with the topographic features of the surface microstructures. By adjusting the height, diameter, bending angle of the micropillars as well as superhydrophobic chemical treatment, the contact angles of water droplets on the micropillar-textured surfaces exceed 160° and exhibit finely-tunable sliding angles from 5.4 ± 1.9° to 71.8 ± 5.9°. A water droplet on a surface textured with bended micropillar shows anisotropic sliding behavior depending on the sliding direction and the micropillar bending angle. By properly design and assembly of straight and bended micropillars, speedy sliding tracks are constructed and directional droplet transfer is demonstrated, suggesting great potential in the fields of lossless material transportation, biomedical testing and microfluidic devices.

The challenge to produce magnetic nanoparticles from waste containing heavy metals aiming at biomedical application: New horizons of chemical recycling

Silica-coated magnetite nanoparticles (SMNPs) were prepared by a green approach based on waste pickling acid. A set of techniques (PXRD, ATR, VSM, SEM, TEM, DLS and XPS) was used for their characterization, and for monitoring the levels of heavy metal impurities. The SMNPs presented an expected profile, similar to that reported for nanoparticles produced from fresh chemicals. The crystallinity and magnetic saturation confirmed the formation of the Fe3O4 phase, silanol and siloxane absorption bands, as well as TEM images confirmed the coating SiO2. The SMNPs chosen for the biomedical tests did not present a significant level of contaminants, and the non-toxic silica coat produced by the sol-gel method ensured a preliminary study on its biocompatibility with reproductive cells in vitro. SMNPs presented a high ability to immobilize spermatozoon cells, suggesting that a fine control of their surface charge must be carried out for specific biomedical purposes. The agglomeration of the solid NPs was evidenced by SEM and by DLS measurements. Its aggregation was tuned by sonication, and a 5-min long ultrasound treatment was capable of halving the agglomerate size, allowing a one-to-one interaction (one SMNPs agglomerate to each cell). The CASA system used to monitor the semen quality showed that vigor, motility and velocity parameters were kept at levels very close to the control group. Finally, a waste-based input submitted to a meticulous purification process could be used as a source for magnetic materials synthesis and evaluated in the biomedical field as long as all precautions are taken into account.

Margetuximab conjugated-PEG-PAMAM G4 nano-complex: a smart nano-device for suppression of breast cancer.

Breast cancer due to its high incidence and mortality is the second leading cause of death among females. On the other hand, nanoparticle-based drug delivery is one of the most promising approaches in cancer therapy, nowadays. Hence, margetuximab- and polyethylene glycol-conjugated PAMAM G4 dendrimers were efficiently synthesized for targeted delivery of quercetin (therapeutic agent) to MDA-MB-231 breast cancer cells. Synthesized nano-complexes were characterized using analytical devices such as FT-IR, TGA, DLS, Zeta potential analyzer, and TEM. The size less than 40nm, - 18.8 mV surface charge, efficient drug loading capacity (21.48%), and controlled drug release (about 45% of drug release normal pH after 8h) were determined for the nano-complex. In the biomedical test, the cell viability was obtained 14.67% at 24h of post-treatment for 800 nM concentration, and IC50 was ascertained at 100 nM for the nano-complex. The expression of apoptotic Bax and Caspase9 genes was increased by more than eightfolds and more than fivefolds after treatment with an optimal concentration of nanocarrier. Also, more than threefolds of cell cycle arrest was observed at the optimal concentration synthetics, and 27.5% breast cancer cell apoptosis was detected after treatment with 100 nM nano-complex. These outputs have been indicating the potential capacity of synthesized nano-complex in inhibiting the growth of breast cancer cells.

A 65nm/0.448 mW EEG processor with parallel architecture SVM and lifting wavelet transform for high-performance and low-power epilepsy detection

In recent years, low-power and wearable biomedical testing devices have emerged as a key answer to the challenges associated with epilepsy disorders, which are prone to crises and require prolonged monitoring. The feature vector of the electroencephalographic (EEG) signal was extracted using the lifting wavelet transform algorithm, and the hardware of the lifting wavelet transform module was optimized using the canonic signed digit (CSD) coding method. A low-power EEG feature extraction circuit with a power consumption of 0.42 mW was constructed. This article employs the support vector machine (SVM) technique after feature extraction to categorize and identify epilepsy. A parallel SVM processing unit was constructed to accelerate classification and identification, and then a high-speed, low-power EEG epilepsy detection processor was implemented. The processor design was completed using TSMC 65 nm technology. The chip size is 0.98 mm2, operating voltage is 1 V, operating frequency is 1 MHz, epilepsy detection latency is 0.91 s, power consumption is 0.448 mW, and energy efficiency of a single classification is 2.23 μJ/class. The CHB-MIT database test results show that this processor has a sensitivity of 91.86% and a false detection rate of 0.17/h. Compared to other processors, this processor is more suitable for portable/wearable devices.

In silico drug repositioning based on integrated drug targets and canonical correlation analysis

BackgroundBesides binding to proteins, the most recent advances in pharmacogenomics indicate drugs can regulate the expression of non-coding RNAs (ncRNAs). The polypharmacological feature in drugs enables us to find new uses for existing drugs (namely drug repositioning). However, current computational methods for drug repositioning mainly consider proteins as drug targets. Meanwhile, these methods identify only statistical relationships between drugs and diseases. They provide little information about how drug-disease associations are formed at the molecular target level.MethodsHerein, we first comprehensively collect proteins and two categories of ncRNAs as drug targets from public databases to construct drug–target interactions. Experimentally confirmed drug-disease associations are downloaded from an established database. A canonical correlation analysis (CCA) based method is then applied to the two datasets to extract correlated sets of targets and diseases. The correlated sets are regarded as canonical components, and they are used to investigate drug’s mechanism of actions. We finally develop a strategy to predict novel drug-disease associations for drug repositioning by combining all the extracted correlated sets.ResultsWe receive 400 canonical components which correlate targets with diseases in our study. We select 4 components for analysis and find some top-ranking diseases in an extracted set might be treated by drugs interfacing with the top-ranking targets in the same set. Experimental results from 10-fold cross-validations show integrating different categories of target information results in better prediction performance than only using proteins or ncRNAs as targets. When compared with 3 state-of-the-art approaches, our method receives the highest AUC value 0.8576. We use our method to predict new indications for 789 drugs and confirm 24 predictions in the top 1 predictions.ConclusionsTo the best of our knowledge, this is the first computational effort which combines both proteins and ncRNAs as drug targets for drug repositioning. Our study provides a biologically relevant interpretation regarding the forming of drug-disease associations, which is useful for guiding future biomedical tests.

Element differentiation with a Hartmann based X-ray phase imaging system

Significant efforts are currently ongoing in X-ray imaging to provide multimodal imaging systems, targeting better sensitivity and specificity for both biomedical or non-destructive testing (NDT) applications. For example, in mammography, knowing the elemental composition of breast microcalcifications would help to differentiate malign and benign tumours. Standard X-ray Phase Contrast Imaging (XPCI) techniques provide only qualitative information of elements with similar absorption. However, their chemical composition can be determined from the measurement of the phase as it is directly related to the optical index of elemental materials. We will show new experimental results obtained with a novel X-ray phase imaging system based on a Hartmann mask. The system demonstrates capacity to discriminate and quantify the elemental composition. Early data treatment succeeded to retrieve both the real and imaginary parts of the index of refraction.

Pharmacological Role of Functionalized Gold Nanoparticles in Disease Applications.

Gold has always been regarded as a symbol of nobility, and its shiny golden appearance has always attracted the attention of many people. Gold has good ductility, molecular recognition properties, and good biocompatibility. At present, gold is being used in many fields. When gold particles are as small as several nanometers, their physical and chemical properties vary with their size in nanometers. The surface area of a nano-sized gold surface has a special effect. Therefore, gold nanoparticles can, directly and indirectly, give rise to different biological activities. For example, if the surface of the gold is sulfided. Various substances have a strong chemical reactivity and are easy to combine with sulfhydryl groups; hence, nanogold is often used in biomedical testing, disease diagnosis, and gene detection. Nanogold is easy to bind to proteins, such as antibodies, enzymes, or cytokines. In fact, scientists use nanogold to bind special antibodies, as a tool for targeting cancer cells. Gold nanoparticles are also directly cytotoxic to cancer cells. For diseases caused by inflammation and oxidative damage, gold nanoparticles also have antioxidant and anti-inflammatory effects. Based on these unique properties, gold nanoparticles have become the most widely studied metal nanomaterials. Many recent studies have further demonstrated that gold nanoparticles are beneficial for humans, due to their functional pharmacological properties in a variety of diseases. The content of this review will be the application of gold nanoparticles in treating or diagnosing pressing diseases, such as cancers, retinopathy, neurological diseases, skin disorders, bowel diseases, bone cartilage disorders, cardiovascular diseases, infections, and metabolic syndrome. Gold nanoparticles have shown very obvious therapeutic and application potential.

Single-use porous polymer thin-film device: A reliable sampler for analysis of drugs in small volumes of biofluids

The response to the demand for biomedical testing on small volumes of biofluids has led to a range of new microsampling devices and related techniques. Simple cost-effective sampling devices are available, but most do not incorporate sample clean-up and necessitate extensive sample processing by the analyst. To address both cleanup and analyte stability, a porous polymeric thin film made of methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) coated (5 × 18 mm2) on a stainless steel substrate was used for the extraction of seven tricyclic antidepressants (TCAs) from plasma spots, with analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Essential factors such as sample volume, extraction time, matrix effects, and the desorption process were investigated. The optimized method is comprised of a quick 3-min extraction from 10 μL of plasma, a wash (10 s in 1 mL of 1% aqueous triethylamine (TEA) to remove plasma matrix interferences, and 2-min desorption (200 μL of ACN with 0.1% formic acid (FA)). For the purpose of sample archiving, thin film devices containing extracted TCAs were stored for 30 days at room temperature and showed a consistent analyte recovery. Inter-device reproducibility was evaluated without internal standard (%RSD 8.2–19.3%), and using two methods of introducing a single deuterated internal standard (imipramine-D3) either prior to (%RSDs 5.6–13.9%) or after (%RSDs 4.9–10.2%) sample loading to the device. Although the intention of this study was to introduce a single use device for rapid and easy analysis, reusability showed the feasibility of 15 consecutive extractions using same device without any performance loss. The optimized method revealed excellent linearity (R2 > 0.99) in the range of 1–1000 ng mL−1, with good intra- and inter-day accuracy (81.4–118%) and precision (≤12%) in human plasma.

Monetary Value of Live Trade in a Commonly Traded Primate, the Long-Tailed Macaque, Based on Global Trade Statistics

Non-human primates (primates) are regarded as key research subjects for pre-clinical trials of several drugs aimed to alleviate human suffering. It has long been suggested that the predominant species in the international trade in live primates for use in research is the long-tailed macaque (Macaca fascicularis). However, little is still known about the value of this international trade. Whilst the international trade to supply the requirement for biomedical testing is known to encourage illegal wildlife trade, we lack a detailed understanding of the overall value and magnitude of this trade. Such information is vital to facilitate the design of effective conservation strategies in range countries, in order to mitigate the exploitation of wild populations by organized crime networks. Here, data from CITES and the UN Comtrade databases were combined to calculate the value of this trade. We also compared the number of individual primates traded as reported in the two databases to investigate possible correlations. Results show that, from 2010 to 2019, the international trade in long-tailed macaques constituted a market worth of ~US $1.25 billion. We found a positive correlation between individual primates traded in the UN Comtrade Database and individual long-tailed macaques reported in the CITES Trade Database, suggesting that we can use the UN Comtrade database to investigate values and magnitude of the international legal trade in wildlife, and that legal trade in live primates is primarily constituted of long-tailed macaques alone.

Development and Characterization of a Superresolution Ultrasonic Transducer.

Highly sensitive ultrasound probes are needed to expand the capabilities of biomedical ultrasound and industrial nondestructive testing (NDT). Pursuing better imaging quality, while keeping fabrication costs low, is an important trend in the current development of ultrasound imaging systems. In this article, we report the development and characterization of an ultrasonic transducer that (super)focuses ultrasonic waves beyond the so-called diffraction limit, that is, the beamwaist is roughly narrower than one wavelength. The transducer comprises an additive manufactured case with a circular flat piezoelectric actuator fixed at the bottom and a core-shell lens (with a stainless steel core and a polymer shell) placed at the probe's conical tip. The core-shell lens is responsible to superfocusing effect of ultrasonic waves. Operating at approximately 3 MHz, the transverse and axial resolution for C- and B-scan images are, respectively, 0.65λ and 3λ/2 , with the wavelength being [Formula: see text]. The system depth-of-field is 6.3λ . To demonstrate the transducer capability to resolve subwavelength structures, we successfully obtain images of a copper wire forming a Y-intersection, whose branches a diameter similar to human hair ( [Formula: see text]). Our results represent a solid step toward the development of ultrasonic superresolution transducer applied for biomedical imaging and shallow NDT of materials.

Reliability of prisoners\u2019 survey responses: comparison of self-reported health and biomedical data from an australian prisoner cohort

ObjectivePrisoner health surveys primarily rely on self-report data. However, it is unclear whether prisoners are reliable health survey respondents. This paper aimed to determine the level of agreement between self-report and biomedical tests for a number of chronic health conditions.MethodThis study was a secondary analysis of existing data from three waves (1996, 2001, 2009) of the New South Wales (NSW) Inmate Health Survey. The health surveys were cross-sectional in nature and included a stratified random sample of men (n=2,114) from all NSW prisons. Self-reported histories of hepatitis, sexually transmissible infections, and diabetes were compared to objective biomedical measures of these conditions.ResultsOverall, the sensitivity (i.e., the respondents who self-reported having the condition also had markers indicative of the condition using biomedical tests) was high for hepatitis C (96%) and hepatitis B (83%), but low for all other assessed conditions (ranging from 9.1% for syphilis using RPR to 64% for diabetes). However, Kappa scores indicated substantial agreement only for hepatitis C. That is, there were false positives and false negatives which occurred outside of chance leading to poor agreement for all other assessed conditions.ConclusionsPrisoners may have been exposed to serious health conditions while failing to report a history of infection. It may be possible that prisoners do not get tested given the asymptomatic presentation of some conditions, were unaware of their health status, have limited health-service usage preventing the opportunity for detection, or are subject to forgetting or misunderstanding prior test results. These findings demonstrate the importance of the custodial environment in screening for health conditions and referral for treatment should this be needed. Testing on entry, periodically during incarceration, and prior to release is recommended.

Recent Developments in Artificial Super-Wettable Surfaces Based on Bioinspired Polymeric Materials for Biomedical Applications.

Inspired by nature, significant research efforts have been made to discover the diverse range of biomaterials for various biomedical applications such as drug development, disease diagnosis, biomedical testing, therapy, etc. Polymers as bioinspired materials with extreme wettable properties, such as superhydrophilic and superhydrophobic surfaces, have received considerable interest in the past due to their multiple applications in anti-fogging, anti-icing, self-cleaning, oil–water separation, biosensing, and effective transportation of water. Apart from the numerous technological applications for extreme wetting and self-cleaning products, recently, super-wettable surfaces based on polymeric materials have also emerged as excellent candidates in studying biological processes. In this review, we systematically illustrate the designing and processing of artificial, super-wettable surfaces by using different polymeric materials for a variety of biomedical applications including tissue engineering, drug/gene delivery, molecular recognition, and diagnosis. Special attention has been paid to applications concerning the identification, control, and analysis of exceedingly small molecular amounts and applications permitting high cell and biomaterial cell screening. Current outlook and future prospects are also provided.

A novel secure artificial bee colony with advanced encryption standard technique for biomedical signal processing

Over the years, the privacy of a biomedical signal processing is protected using the encryption techniques design and meta-heuristic algorithms which are significant domain and it will be more significant shortly. Present biomedical signal processing research contained security because of their critical role in any developing technology that contains applications of cryptography and health deployment. Furthermore, implementing public-key cryptography in biomedical signal processing sequence testing equipment needs a high level of skill. Whatever key is being broken with enough computing capabilities using brute-force attack. As a result, developing a biomedical signal processing cryptography model is critical for improving the connection between existing and emerging technology. Furthermore, public-key cryptography implementation for meta-heuristic-based bio medical signal processing sequence test equipment necessitates a high level of skill. The suggested novel technique can be used to develop a secure algorithm of artificial bee colony, which depend on the advanced encryption standard (AES). AES can be used to reduce the encryption time and to increase the protection capacity for health systems. The novel secure can protect the biomedical signal processing against plain text attacks.

Undiagnosed hypertension in Sudan: results of the cross-sectional national STEPS survey in 2016.

Introductionthe rate of hypertension has been increasing in Africa. The study aimed to estimate the prevalence and associated factors of undiagnosed hypertension (HTN) among adults in Sudan.Methodscross-sectional data were analyzed from 7,226 persons (18-69 years, median 37 years, interquartile range 27-49 years, 4557 were females) who participated in the 2016 Sudan STEPS survey, had complete blood pressure measurement and non-pregnant, and responded to a questionnaire, physical measures, and biomedical tests. Logistic regression was used to determine the predictors of undiagnosed HTN.Resultsthe prevalence of undiagnosed HTN was 26.2% (n=2057) (79.2% of total HTN), diagnosed HTN 6.9% (n=690) and total HTN 33.1% (n=2747). In multivariable analysis older age (50-69 years) (adjusted risk ratio-aRR: 2.49, 95% CI: 2.02-3.09; p<0.001), obesity (aRR: 2.51, 95% CI: 1.97-3.21; p<0.001), diabetes (aRR: 1.59, 95% CI: 1.17-2.16; p=0.002) and elevated total cholesterol (aRR: 1.48, 95% CI: 1.19-1.84; p<0.001) were positively associated and health care advice (aRR: 0.79, 95% CI: 0.64-0.98; p=0.036) was negatively associated with undiagnosed HTN versus no HTN. Male sex (adjusted odds ratio-aOR: 2.22, 95% CI: 1.63-3.01; p<0.001) was positively associated, and older age (50-69 years) (aOR: 0.31, 95% CI: 0.21-0.46; p<0.001), married (aOR: 0.45, 95% CI: 0.33-0.62; p<0.001), urban residence (aOR: 0.70, 95% CI: 0.51-0.96; p=0.022), health care advice (aOR: 0.32, 95% CI: 0.22-0.45; p<0.001), ever cholesterol measured (aOR: 0.43, 95% CI: 0.27-0.67; p<0.001), overweight (aOR: 0.63, 95% CI: 0.47-0.85; p=0.003) and heart attack or stroke (aOR: 0.31, 95% CI: 0.17-0.55; p<0.001) were negatively associated with undiagnosed HTN versus diagnosed HTN.Conclusionone in four adults in Sudan had undiagnosed HTN (eight in ten of total HTN) and several associated factors that can help guide interventions were identified.

Alternatives to Laboratory Animals: Trends in Replacement and the Three Rs.

The significance of contributions in volumes 11-46 (1983 to 2018) of Alternatives to Laboratory Animals in relation to the reduction, refinement and replacement of animal experimentation in biomedical research and testing is reviewed and discussed by the journal's former editor-in-chief, with particular emphasis on the development and production of the journal itself, FRAME, the European Centre for the Validation of Alternative Methods and other organisations. The role of the journal in promoting the principles of humane research (as spelled out by William Russell and Rex Burch) and highlighting a range of important issues and focus topics is explored. These include: botulinum toxin potency testing; ethical issues; the use of human volunteers, and human cells and tissues; the use of non-human primates (especially chimpanzees) and dogs as laboratory animals; toxicity testing in relation to cosmetics, pharmaceuticals and chemicals; UK and EU politics and legislation; and test validation and invalidation. The review concludes by identifying some of the issues that still need to be discussed and some of the questions that urgently need to be addressed.

Research progress of tunneling magnetoresistance sensor

Sensors play an important role in Internet of Things (IoT) industry and account for a rapidly growing market share. Among them, the magnetic sensor based on tunneling magnetoresistance (TMR) effect possesses great potential applications in the fields of biomedical, navigation, positioning, current detection, and non-destructive testing due to its extremely high sensitivity, small device size and low power consumption. In this paper, we focus on the development of TMR sensor technology routes, covering a series of research advances from a sensor transducer to three-dimensional magnetic field detection, and then to the applications. Firstly, we recall the development history of TMR sensors, explain its working principle, and discuss the method to improve the output linearity of single magnetic tunnel junction. Next, we state the Wheatstone-bridge structure, which can inhibit temperature drift in detail and review several methods of fabricating the full bridge of TMR sensors. Furthermore, for the market demand of three-dimensional magnetic field detection, we summarize the methods of designing and fabricating three-dimensional sensing structure of the TMR sensor. At the same time, we list several optimization schemes of TMR sensor performance in terms of sensitivity and noise level. Finally, we discuss two types of emerging applications of TMR sensors in recent years. The TMR sensors can also be used in intelligence healthcare due to their ultra-high sensitivity. In addition, devices from the combination of spin materials and MEMS structure have attracted wide attention, especially, because of the large commercial market of microphones, spin-MEMS microphones utilized TMR techniques will be the next research hotspot in this interdisciplinary field.

Acetoacetate Improves Memory in Alzheimer's Mice via Promoting Brain-Derived Neurotrophic Factor and Inhibiting Inflammation.

The ketone bodies, especially the β-hydroxybutyrate, had been shown to modulate the function of the central nervous system and prevent the pathological progression of Alzheimer's disease (AD). However, little is known about the role of acetoacetate in the AD brain. Thus, we intraventricularly injected acetoacetate into familial AD mice (APPSWE) for 14days and monitored their memory and biochemical changes. During the behavior test, acetoacetate at 100mg/kg led to significant improvement in both Y-maze and novel object recognition tests (NORTs) (both P < .05), indicating ameliorating spatial and recognition memory, respectively. Biomedical tests revealed two mechanisms were involved. Firstly, acetoacetate inhibited the GPR43-pERK pathway, which led to apparent inhibition in tumor necrosis factor-α and Interleukin-6 expression in the hippocampus in a concentration-dependent manner. Secondarily, acetoacetate stimulated the expression of hippocampal brain-derived neurotrophic factor (BDNF). We concluded that acetoacetate could ameliorate AD symptoms and exhibited promising features as a therapeutic for AD.