Cardiovascular diseases (CVDs) pose a significant threat to human health and place considerable strain on healthcare systems. Therefore, it is crucial to maximize the acquisition of cardiovascular information (CVI) through non-invasive methods to enhance early screening, diagnosis, and evaluation of CVDs. Numerous studies have demonstrated that obtaining more CVI by simultaneously acquiring multi-site signals and applying pressure stimulation at specific sites, such as blood pressure measurement, is an effective approach. Based on this evidence, we proposed a novel signal acquisition-and-analysis system to gather comprehensive CVI through a combination of a non-pressure and six pressure-stimulation sub-processes. This system involves the novelty of applying slowly gradual decrease, personalized maximum-pulse amplitude, and blocking blood-flow pressure to six cuffs placed on both arms, wrists, and ankles in a predetermined time sequence. During each sub-process, the system has newly integrated the multi-site simultaneous collection of 27-channel non-invasive signals, including electrocardiogram, heart sound, lung sound, photoplethysmographic-and-pressure pulse. To ensure measurement accuracy, three types of verification-and-calibration instruments were employed. Our results demonstrate that the system can achieve simultaneous acquisition of 27-channel signals during each sub-process, yielding both novel and traditional cardiovascular parameters with high accuracy and good stability. Furthermore, the results suggest that the system can facilitate in-depth research into the relationships between collected signals and CVDs, provide rich raw data for cardiovascular health assessment and disease prediction models based on machine learning algorithms, and offer a new non-invasive method for early diagnosis, evaluation, and prediction of CVDs.

Coronary artery disease (CAD) is a prevalent condition among chest pain patients, and accurate prediction of the disease is crucial to ensure timely interventions and improve patient outcomes. We aim to elaborate a prediction model for CAD in chest pain patients using machine learning approaches. A retrospective analysis was performed using electronic health records of patients who presented with chest pain at seven hospitals. A total of 8474 patients were included in the study, where 63.25% were diagnosed with CAD. The data included demographic information, medical history, and laboratory results. Machine learning algorithms, including Random Forest, CatBoost, XGBoosting, Gradient Boosting, Light Gradient, AdaBoost, Ridge Classifier, Linear Discriminant, Logistic Regression, Decision Tree, SVM, Quadratic Discriminant, K Neighbors, Naive Bayes, and Dummy Classifier were trained and evaluated to predict the presence of CAD.The prediction model achieved an overall accuracy of 0.766 in identifying CAD in chest pain patients. The sensitivity and precision were 0.938 and 0.746, respectively. Important predictors for CAD included age, pulse rate, monocyte, and red cell distribution width SD. The eXtreme Gradient Boosting showed the best performance (area under the receiver operating characteristics, AUROC, 0.820, and 95% CI, 0.801–0.839) Additionally, the model demonstrated robust performance in the validation group. This study successfully developed and validated a prediction model for CAD in chest pain patients using machine learning techniques. The model exhibited good predictive ability and could aid in the early identification of CAD in clinical practice, potentially leading to appropriate interventions and improved patient outcomes.

In recent years, hydrogels had a wide range of applications in wearable devices, human health monitoring, or implantable sensors because of their good properties such as stretchability, conductivity, frost resistance, and transparency. However, the simultaneous integration of excellent mechanical properties and high electrical conductivity in a hydrogel sample still needs to be improved. In this work, silk fibroin (SF) and poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) were introduced into a poly(vinyl alcohol)/poly(acrylic amide) (PVA/PAM) double-network hydrogel to prepare PVA/PAM/SF/PEDOT:PSS hydrogel electrolytes via a one-pot method. Adding SF also enhances the mechanical properties of the hydrogel, making it three times stronger than the PVA/PAM double-network hydrogel. The hydrogel is versatile, with a strain range of 1–300

Fexible wearable sensors (FWSs), a hot research topic, have been widely used in the field of electronic skin, personal wear, electric equipment, and human–computer interaction because of their excellent flexibility, breathability, and sensing performance. However, the biocompatibility, flexibility, antibacterial activity, and breathability of FWS need to be investigated further. Herein, we propose a silk fibroin (SF)/propolis (EEP)/graphene(GR)/MXene nanocomposite-based FWS with antibacterial properties. This breathable and highly sensitive sensor was prepared by sequentially spraying GR and MXene dispersions onto SF/EEP nanocomposite fiber membranes. On testing, this sensor exhibited a wide sensing range (1–50 kPa), certain repeatability (100 cycles), high sensitivity (3 kPa −1 ), reliable breathability, excellent antibacterial properties, and superior biocompatibility. Moreover, this FWS can be used for human health monitoring, including motions of human fingers, elbows, knees, and other parts. Therefore, the sensor is expected to have a wide range of applications in health care detection and intelligent robots used for long-term continuous monitoring of human health.

Human perception of stimulus is divided into quantity perception and quality perception. Whether it’s Weber-Fechner’s logarithmic sensation law or Stevens’s power function sensation law are both such a law that is about the quantitative relationship between the sensation and one-dimensional luminance stimulus. The image belongs to the stimulus with bi-dimensional luminance distribution characteristics. This article studies the perception of the quality of bi-dimensional luminance stimuli, that is, the perception of the quality of bi-dimensional luminance stimuli. The extent in good or bad of quality is a fuzzy psychological concept, so we need to use fuzzy mathematics to quantify the degree in good or bad of visual perception quality of an image.

人类对刺激量的感知分为数量感知和质量感知。无论是韦伯-费克纳(Weber-Fechner)的对数感觉定律还是史蒂文斯(Stevens)的幂函数感觉定律，都是关于感觉量与一维亮度刺激之间定量关系的定律。图像属于具有二维亮度分布特征的刺激量。本文研究的是二维亮度刺激的质量的感知，即二维亮度刺激质量好坏程度的感知。好坏程度是一个模糊的心理学概念，因此我们需要用模糊数学的方法来量化图像视觉感知质量的好坏程度，即建立一个模糊隶属函数PQ来定量表示图像视觉质量的好与坏的程度。

In this work, a novel, simple and label-free line-pad-line electrode (LPLE) biosensor was developed for detection of vascular endothelial growth factor (VEGF(165)). DNA aptamer was used as a recognition element for high specificity to VEGF(165), and original LPLE as the substrate electrode for high sensitivity of the biosensor. This sensor was prepared by immobilizing anti-VEGF(165) aptamers on the LPLE surface through gold-sulfur (Au-S) bonding. Upon the addition of VEGF(165), a large target-induced conformational change in the surface-immobilized aptamer was generated and caused variations in the interfacial properties,which led to a corresponding increase in the impedance magnitude of the LPLE. Finally, our results demonstrate that the calibration curve for VEGF(165)determination was linear over the range of 0.026-31.4 fM with a detection limit as low as 0.017 fM.Additionally, our sensor was fabricated on printed circuit board (PCB) with a new electrode construction, and can potentially be implemented with the advantages of simplicity, low-cost and easy mass production. Besides, considering its desirable sensitivity and specificity, the proposed use of LPLE provided a promising strategy for a wide variety of sensing applications.

An aptamer based liquid crystal biosensor was firstly developed for sulfadimethoxine detection achieving a lower detection limit of 10 μg L−1.

In recent years,the rapid development of the Internet of things technology has opened up broad prospects for the integration of the Internet of things technology into medical education to train interdisciplinary talents who master knowledge in both medicine and engineering.The researchers incorporated the Internet of things technology in the experimental teaching of the course "Biomedical sensors",reformed the contents and methods of experimental teaching,and developed and designed a biomedical sensor experimental teaching system based on the Internet of things technology.As a result,the new experimental teaching can help students understand the system design methods of the Internet of things in smart medical devices and cultivate their practical ability and innovative ability,which has obtained preliminary teaching results.

Liquid crystal (LC)-based sensors have the advantageous properties of being fast, sensitive, and label-free, the results of which can be accessed directly only through the naked eye. However, the inherent disadvantages possessed by LC sensors, such as relying heavily on polarizing microscopes and the difficulty to quantify, have limited the possibility of field applications. Herein, we have addressed these issues by constructing a portable polarized detection system with constant temperature control. This system is mainly composed of four parts: the LC cell, the optics unit, the automatic temperature control unit, and the image processing unit. The LC cell was based on the ordering transitions of LCs in the presence of analytes. The optics unit based on the imaging principle of LCs was designed to substitute the polarizing microscope for the real-time observation. The image processing unit is expected to quantify the concentration of analytes. The results have shown that the presented system can detect dimethyl methyl phosphonate (a stimulant for organophosphorus nerve gas) within 25 s, and the limit of detection is about 10 ppb. In all, our portable system has potential in field applications.

To build a microfluidic device with various morphological features of the tumor vasculature for study of the effects of tumor vascular structures on the flow field and tumor cellular flow behaviors. The designed microfluidic device was able to approximatively simulate the in vivo structures of tumor vessels and the flow within it. In this models, the influences of the angle of bifurcation, the number of branches, and the narrow channels on the flow field and the influence of vorticity on the retention of HepG2 cells were significant. Additionally, shear stress below physiological conditions of blood circulation has considerable effect on the formation of the lumen-like structures (LLSs) of HepG2 cells. These results can provide some data and reference in the understanding of the interaction between hemorheological properties and tumor vascular structures in solid tumors.

A novel impedimetric sensor, based on DNA intercalator, GR-5 DNAzyme and the low-cost gold interdigitated electrodes (GID), was studied to detect lead ions in this paper. It takes GR-5 DNAzyme as the recognition element immobilized on GID and anthraquinone-2-sulfonic acid (AQMS) as the DNA intercalator for improving its sensitivity of lead ions detection. When the GID modified with GR-5 DNAzyme were incubated in intercalator solution, AQMS will intercalate into the base-pairing regions of GR-5 DNAzyme. In the presence of Pb2+ ions, the GR-5 DNAzyme was activated and the substrate strand was cleaved into two parts at the RNA site (rA), which results in the releasing of AQMS from the GR-5 DNAzyme. With the decrease of AQMS, the magnitudes of the impedance increased, which relates to the Pb2+ concentration, was obtained. Our results demonstrate that the proposed sensor has a detection limit of 0.33 nM, and the linear range from 1 nM to 100 nM with a high selectivity. Finally, the sensor shows an average recovery of 99.31-107.85% when it was used to detect Pb2+ in water samples. Additionally, the GID were made on printed circuit board (PCB) which was cost-effective and mass production because of the mature produce technology. Furthermore, the application of AQMS leads to significantly decrease of the detection limit of the Pb2+. Therefore, the strategy shown that a promising applications in environmental and food-field monitoring.

针对《医学物理学》教学中存在的主要问题,本文从八个方面讲述了如何提高《医学物理学》教学质量的方法,以此来激发学生的学习兴趣,引导学生如何将理论联系医学应用实际,最终达到提升教学质量的目的.

Gene markers of oral squamous cell carcinoma (OSCC) have great significance on early diagnosis and treatment of clinical oral cancer. In this study, we used RNA-Seq data from OSCC patients and filtered differentially-expressed long non-coding RNA (lncRNA) to further clarify the molecular mechanism. Firstly, we downloaded datasets of OSCC from National Center for Biotechnology Information(NCBI), which were predicted and analyzed by cufflinks and tophat. Then, differentially expressed lncRNA enrichment was performed with The Database for Annotation, Visualization and Integrated Discovery (DAVID). Finally, we verified the gene expression via in vitro assays. Results showed that 52 lncRNAs were significantly differentially expressed compared to those in normal oral tissues, three highly expressed genes (XLOC_002599, XLOC_002634 and XLOC_132858) were verified by RT-PCR, which was consistent with the prediction. XLOC_002634 (GAS5) transcript levels were reduced both in vivo and in vitro assays, which confirmed that the expression of GAS5 was comparatively low in OSCC. Over-expression of GAS5 in cancer cells inhibited cell proliferation. Moreover, the migration and invasion potential of cancer cells were inhibited compared to control groups. All in all, the study indicated that the decrease in GAS5 expression may contribute to OSCC tumor pathogenesis and serve as a potential target for cancer therapy.

The authors have investigated (a) the self-assembly of single-stranded DNA (ssDNA) on glass surfaces, and (b) the interaction of DNA with liquid crystals (LCs) on solid surfaces. The results suggest that ssDNA (compared to dsDNA) on the solid interface causes particularly different orientations in LCs. The LC molecules assume a uniform homeotropic orientation on the surface with a typical surface ssDNA coverage of ~2.4 × 1012 molecules per square cm. Once complementary DNA is hybridized on the surface, the homotropic orientation of the LCs becomes disrupted. This orientation transition can be visually observed by using a crossed polarizer. The findings were exploiting to design an assay for target DNA (= analyte DNA) that has an ~0.1 nM detection limit. The assay is highly selective and can easily differentiate target DNA from single-base mismatch and non-complementary DNA. In our perception, it represents a powerful, label-free and portable DNA detection scheme.

As lead poses a serious threat to humans even in small amounts, all kinds of lead detection sensors with high sensitivity and selectivity are being constantly improved and put forward. In this report, a novel, simple and label-free quartz crystal microbalance (QCM) biosensor is proposed for detecting lead ions (Pb2+). The biosensor takes full advantage of the high specificity of GR-5 DNAzyme to Pb2+ and the high sensitivity of QCM. In particular, nanomagnetic beads (NMBs) are used as a novel and effective mean of signal amplification in the biosensor because of their mass and their ability to enhance the inductive effect, which are very beneficial for both higher sensitivity and a lower detection limit. In practice, GR-5 DNAzyme, innovatively combined with NMBs, was modified on the gold electrode of the QCM through gold-sulfur self-assembly. When the electrode was exposed to Pb2+ solution, DNAzyme was severed into two parts at the RNA site (rA), along with the release of NMBs, which caused a great increase in frequency shift of the QCM electrode. Finally, a perfect linear correlation between the logarithm of Pb2+ concentration and the change in frequency was obtained from 1 pM to 50 nM, with a detection limit as low as 0.3 pM. Moreover, the biosensor shows both an average recovery of 97 ± 6% in a drinking water sample and an excellent specificity for Pb2+ compared with other metal ions.

Cardiovascular diseases (CVDs) are considered the major cause of death worldwide, so more researchers pay more and more attention to the development of a non-invasive method to obtain as much cardiovascular information (CVI) as possible for early screening and diagnosing. It is known that considerable brain information could be probed by a variety of stimuli (such as video, light, and sound). Therefore, it is quite possible that much more CVI could be extracted via giving the human body some special interrelated stimulus. Based on this hypothesis, we designed a novel signal platform to acquire more CVI with a special stimulus, which is to give a gradual decrease and a different settable constant pressure to six air belts placed on two-side brachia, wrists, and ankles, respectively. During the stimulating process, the platform is able to collect 24-channel dynamic signals related with CVI synchronously. Moreover, to improve the measurement accuracy of signal acquisition, a high precision reference chip and a software correction are adopted in this platform. Additionally, we have also shown some collection instances and analysis results in this paper for its reliability. The results suggest that our platform can not only be applied on study in a deep-going way of relationship between collected signals and CVDs but can also serve as the basic tool for developing a new noninvasive cardiovascular function detection instrument and system that can be used both at home and in the hospital.

Microfluidic technology is an important research tool for investigating angiogenesis in vitro. Here, we fabricated a polydimethylsiloxane (PDMS) microfluidic device with five cross-shaped chambers using a coverslip molding method. Then, the perforated PDMS microhole arrays prepared by soft lithography were assembled in the device as barriers; a single microhole had a diameter of 100 μm. After injecting type I collagen into the middle gel chamber, we added a culture medium containing a vascular endothelial growth factor (VEGF) into the middle chamber. It would generate a linear concentration gradient of VEGF across the gel region from the middle chamber to the four peripheral chambers. Human umbilical vein endothelial cells (HUVECs) were then seeded on the microhole barrier. With VEGF stimulation, cells migrated along the inner walls of the microholes, formed annularly distributed cell clusters at the gel-barrier interface, and then three-dimensionally (3D) sprouted into the collagen scaffold. After 4 days of culture, we quantitatively analyzed the sprouting morphogenesis. HUVECs cultured on the microhole barrier had longer sprouts than HUVECs cultured without the barrier (controls). Furthermore, the initial distribution of sprouts was more regular and more connections of tube-like structures were generated when the microhole barrier was used. This study introduces a novel microfluidic device containing both microtopographic structures and 3D collagen. HUVECs cultured with the microhole barrier could form well-interconnected tube-like structures and are thus an ideal in vitro angiogenesis model.

A core module with a novel optical structure is presented to analyze urine by the dry-chemistry method in this paper. It consists of a 32-bit microprocessor, optical fiber bundles, a high precision color sensor and a temperature sensor. The optical fiber bundles are adopted to control the spread path of light and reduce the influence of ambient light and the distance between the strip and sensor effectively. And the temperature sensor is applied to detect the environmental temperature to calibrate the measurement results. Therefore, all these can bring a lot of benefits to the core module, such as improving its test accuracy, reducing its volume and cost, and simplifying its assembly. Additionally, some parameters, including the calculation coefficient about reflectivity of each item, semi-quantitative intervals, the number of test items, may be modified by corresponding instructions in order to enhance its applicability. Meanwhile, its outputs can be chosen among the original data, normalized color values, reflectivity, and the semi-quantitative level of each test item by available instructions. Our results show that the module has high measurement accuracy of more than 95%, good stability, reliability, and consistency and can be easily used in various types of urine analyzers.

A novel, low-cost, label-free impedance biosensor based on gold interdigitated electrodes (GIE) was developed for detection of lead. This sensor was developed by immobilizing GR-5 DNAzymes onto the GIE surface through Au-S bonding. In the presence of lead, the substrate strand was cleaved into two parts at the RNA site (rA) and caused changes in the interfacial properties of the GIE, resulting in a corresponding decrease in the impedance magnitude. Thus, by measuring the decrease, the concentration of lead ion can be determined. And coupled the GIE with GR-5 DNAzyme recognition, our proposed lead biosensor exhibited a high sensitivity with a detection limit of 6.61 nM, which is much lower than the 72 nM defined as the maximum contamination level (MCL) of lead ions in drinking water by The United States Environmental Protection Agency (EPA), at the same time, with a linear range from 10-100 nM and a prominent selectivity against other heavy metal ions. What's more, different from the traditional way, the GIE are made on printed circuit board (PCB), this makes the biosensor has the advantages of simplicity, low cost and easy mass production, and it can easily be widely used.