Fabrication of graphene oxide-based pretreatment filter and Electrochemical-CRISPR biosensor for the field-ready cyanobacteria monitoring system.

Microcystis aeruginosa (M. aeruginosa) cause the eutrophication of lakes and rivers. To effectively control the overgrowth of M. aeruginosa, a suitable measurement method should be required in the aquatic fields. To address this, we developed a field-ready cyanobacterial pretreatment device and an electrochemical clustered regularly interspaced short palindromic repeats (EC-CRISPR) biosensor. The cyanobacterial pretreatment device consists of a syringe, glass bead, and graphene oxide (GO) bead. Then, the M. aeruginosa dissolved in the freshwater sample was added to fabricated filter. After filtration, the purified gene was loaded onto a CRISPR-based electrochemical biosensor chip to detect M. aeruginosa gene fragments. The biosensor was composed of CRISPR/Cpf1 protein conjugated with MXene on an Au microgap electrode (AuMGE) integrated into a printed circuit board (PCB). This AuMGE/PCB system maximizes the signal-to-noise ratio, which controls the working and counter electrode areas requiring only 3 µL samples to obtain high reliability. Using the extracted M. aeruginosa gene with a pre-treatment filter, the CRISPR biosensor showed a limit of detection of 0.089 pg/µl in fresh water. Moreover, selectivity test and matrix condition test carried out using the EC-CRISPR biosensor. These handheld pre-treatment kit and biosensors can enable field-ready detection of CyanoHABs.

Rapid electrochemical dual-target biosensor composed of an Aptamer/MXene hybrid on Au microgap electrodes for cytokines detection.

Rapid detection methods for cytokine storm markers, such as tumor necrosis factor α (TNF-α) and interferon gamma (IFN-γ), are required. Herein, we describe the fabrication of a rapid electrochemical dual-target biosensor composed of aptamer/MXene (Ti3C2) nanosheet on an Au microgap electrode. Alternating current electrothermal flow (ACEF) significantly reduced the detection time (<10 min) to achieve the rapid biosensor construction. Additionally, MXene nanosheet was synthesized to improve the detection sensitivity. A dual-type Au microgap electrode was designed to measure TNF-α and IFN-γ levels using a single biosensor. Moreover, it performs 12 measurements using a small sample volume. To reduce detection time with stable aptamer-target complex formation, various ACEF conditions were evaluated and optimized to 10 min. Using the optimal conditions, the limit of detection (LOD) and selectivity were determined by electrochemical impedance spectroscopy (EIS). A linear region was observed in the concentration range of 1 pg/mL to 10 ng/mL of TNF-α and IFN-γ. The LOD of TNF-α and IFN-γ were 0.15 pg/mL and 0.12 pg/mL within 10 min, respectively. Furthermore, the proposed biosensor detected TNF-α and IFN-γ diluted in 10% human serum in the concentration range of 1 pg/mL to 10 ng/mL with LODs of 0.25 pg/mL and 0.26 pg/mL, respectively.

Fabrication of MERS-nanovesicle biosensor composed of multi-functional DNA aptamer/graphene-MoS2 nanocomposite based on electrochemical and surface-enhanced Raman spectroscopy.

Middle East respiratory syndrome coronavirus (MERS-CoV) is one of the most harmful viruses for humans in nowadays. To prevent the spread of MERS-CoV, a valid detection method is highly needed. For the first time, a MERS-nanovesicle (NV) biosensor composed of multi-functional DNA aptamer and graphene oxide encapsulated molybdenum disulfide (GO-MoS2) hybrid nanocomposite was fabricated based on electrochemical (EC) and surface-enhanced Raman spectroscopy (SERS) techniques. The MERS-NV aptamer was designed for specifically binding to the spike protein on MERS-NVs and it is prepared using the systematic evolution of ligands by exponential enrichment (SELEX) technique. For constructing a multi-functional MERS aptamer (MF-aptamer), the prepared aptamer was connected to the DNA 3-way junction (3WJ) structure. DNA 3WJ has the three arms that can connect the three individual functional groups including MERS aptamer (bioprobe), methylene blue (signal reporter) and thiol group (linker) Then, GO-MoS2 hybrid nanocomposite was prepared for the substrate of EC/SERS-based MERS-NV biosensor construction. Then, the assembled multifunctional (MF) DNA aptamer was immobilized on GO-MoS2. The proposed biosensor can detect MERS-NVs not only in a phosphate-buffered saline (PBS) solution (SERS LOD: 0.176 pg/ml, EIS LOD: 0.405 pg/ml) but also in diluted 10% saliva (SERS LOD: 0.525 pg/ml, EIS LOD: 0.645 pg/ml).

Recent Advances in Aptasensor for Cytokine Detection: A Review.

Cytokines are proteins secreted by immune cells. They promote cell signal transduction and are involved in cell replication, death, and recovery. Cytokines are immune modulators, but their excessive secretion causes uncontrolled inflammation that attacks normal cells. Considering the properties of cytokines, monitoring the secretion of cytokines in vivo is of great value for medical and biological research. In this review, we offer a report on recent studies for cytokine detection, especially studies on aptasensors using aptamers. Aptamers are single strand nucleic acids that form a stable three-dimensional structure and have been receiving attention due to various characteristics such as simple production methods, low molecular weight, and ease of modification while performing a physiological role similar to antibodies.

Fabrication of an Electrochemical Aptasensor Composed of Multifunctional DNA Three-Way Junction on Au Microgap Electrode for Interferon Gamma Detection in Human Serum.

Interferon gamma (IFN-γ) is an important cytokine with antiviral, antibacterial, and immunosuppressive properties. It has been used as a biomarker for the early detection of several diseases, including cancer, human immunodeficiency virus (HIV), tuberculosis, and paratuberculosis. In this study, we developed an electrochemical biosensor composed of multifunctional DNA 3WJ to detect IFN-γ level with high sensitivity. Each multifunctional triple-stranded aptamer (MF-3WJ) was designed to have an IFN-γ aptamer sequence, anchoring region (thiol group), and 4C-C (cytosine-cytosine) mismatch sequence (signal generation), which could introduce silver ions. To generate the electrochemical signal, four Ag+ ions were intercalated (3wj b-3wj c) in the 4C-C mismatch sequence. MF-3WJ was assembled through the annealing step, and the assembly of MF-3WJ was confirmed by 8% tris-boric-EDTA native polyacrylamide gel electrophoresis. The Au microgap electrode was manufactured to load sample volumes of 5 µL. The reliability of electrochemical biosensor measurement was established by enabling the measurement of seven samples from one Au microgap electrode. MF-3WJ was immobilized on the Au microgap electrode. Then, cyclic voltammetry and electrochemical impedance spectroscopy were performed to confirm the electrochemical properties of MF-3WJ. To test the electrochemical biosensor's ability to detect IFN-γ, the limit of detection (LOD) and selectivity tests were performed by square wave voltammetry. A linear region was observed in the concentration range of 1 pg/mL-10 ng/mL of IFN-γ. The LOD of the fabricated electrochemical biosensor was 0.67 pg/mL. In addition, for the clinical test, the LOD test was carried out for IFN-γ diluted in 10% human serum samples in the concentration range of 1 pg/mL-10 ng/mL, and the LOD was obtained at 0.42 pg/mL.

Recent Advances in CRP Biosensor Based on Electrical, Electrochemical and Optical Methods.

C-reactive protein (CRP) is an acute-phase reactive protein that appears in the bloodstream in response to inflammatory cytokines such as interleukin-6 produced by adipocytes and macrophages during the acute phase of the inflammatory/infectious process. CRP measurement is widely used as a representative acute and chronic inflammatory disease marker. With the development of diagnostic techniques measuring CRP more precisely than before, CRP is being used not only as a traditional biomarker but also as a biomarker for various diseases. The existing commercialized CRP assays are dominated by enzyme-linked immunosorbent assay (ELISA). ELISA has high selectivity and sensitivity, but its limitations include requiring complex analytic processes, long analysis times, and professional manpower. To overcome these problems, nanobiotechnology is able to provide alternative diagnostic tools. By introducing the nanobio hybrid material to the CRP biosensors, CRP can be measured more quickly and accurately, and highly sensitive biosensors can be used as portable devices. In this review, we discuss the recent advancements in electrochemical, electricity, and spectroscopy-based CRP biosensors composed of biomaterial and nanomaterial hybrids.

Recent Development of Aptasensor for Influenza Virus Detection.

In nowadays, we have entered the new era of pandemics and the significance of virus detection deeply impacts human society. Viruses with genetic mutations are reported nearly every year, and people have prepared tools to detect the virus and vaccines to ensure proper treatments. Influenza virus (IV) is one of the most harmful viruses reporting various mutations, sub-types, and rapid infection speed for humans and animals including swine and poultry. Moreover, IV infection presents several harmful symptoms including cough, fever, diarrhea, chills, even causing death. To reduce the IV-induced harm, its proper and rapid detection is highly required. Conventional techniques were used against various IV sub-types including H1N1, H3N2, and H5N1. However, some of the techniques are time-consuming, expensive, or labor-intensive for detecting IV. Recently, the nucleic acid-based aptamer has gained attention as a novel bioprobe for constructing a biosensor. In this review, the authors discuss the recent progress in aptasensors for detecting IV in terms of an electrochemical and an optical biosensor.

Cuff-Less Blood Pressure Estimation Using Pulse Waveform Analysis and Pulse Arrival Time.

Using the massive MIMIC physiological database, we tried to validate pulse wave analysis (PWA) based on multiparameters model whether it can continuously estimate blood pressure (BP) values on single site of one hand. In addition, to consider the limitation of insufficient data acquirement for home user, we used pulse arrival time (PAT) driven BP information to determine the individual scale factors of the PWA-BP estimation model. Experimental results indicate that the accuracy of the average regression model has error standard deviations of  mmHg (PAT),  mmHg (PWA) for SBP and  mmHg (PAT),  mmHg (PWA) for DBP on 23 subjects over a 1 day period. We defined a local-model which is extracted regression model from sparsely selected small dataset, contrast to full dataset for 24h (average-model). The limit of BP estimation accuracy from the local-model of PWA is lower than that of PAT-BP average-model. Whereas the error of the BP estimation local-model was reduced using more data for scaling, it required more than four times the 1 min data extracted over the 12 h calibration period to predict BP for 1 day. This study shows that PWA has possibility to estimate BP value and PAT-driven BP information could be used to determine the individual scale factors of the PWA-BP estimation model for home users.

Estimation of Thermal Sensation Based on Wrist Skin Temperatures.

Thermal comfort is an essential environmental factor related to quality of life and work effectiveness. We assessed the feasibility of wrist skin temperature monitoring for estimating subjective thermal sensation. We invented a wrist band that simultaneously monitors skin temperatures from the wrist (i.e., the radial artery and ulnar artery regions, and upper wrist) and the fingertip. Skin temperatures from eight healthy subjects were acquired while thermal sensation varied. To develop a thermal sensation estimation model, the mean skin temperature, temperature gradient, time differential of the temperatures, and average power of frequency band were calculated. A thermal sensation estimation model using temperatures of the fingertip and wrist showed the highest accuracy (mean root mean square error [RMSE]: 1.26 ± 0.31). An estimation model based on the three wrist skin temperatures showed a slightly better result to the model that used a single fingertip skin temperature (mean RMSE: 1.39 ± 0.18). When a personalized thermal sensation estimation model based on three wrist skin temperatures was used, the mean RMSE was 1.06 ± 0.29, and the correlation coefficient was 0.89. Thermal sensation estimation technology based on wrist skin temperatures, and combined with wearable devices may facilitate intelligent control of one's thermal environment.

Smartphone-Based Urine Reagent Strip Test in the Emergency Department.

BACKGROUND: Although a smartphone could be used for a urine reagent strip test, few studies have reported on the reliability of the test in a clinical setting. The objective of our study was to access the smartphone-based urine reagent strip test in the clinical emergency department (ED). MATERIALS AND METHODS: We developed a smartphone-based urine reagent strip reader for a rapid and accurate screening of leukocyte esterase (LE) and nitrite (NIT) in urine. The developed reader was evaluated with the clinical urine samples (n = 81). The detection performance of the reader for LE and NIT was evaluated to assess reliability of the reader; turnaround times (TATs) for analysis and the time for the entire study procedure were also calculated to assess the efficiency of the reader. A photometric analyzer (model US-3100R Plus(®); Eiken Chemical, Ltd., Tokyo, Japan) was used as a reference. RESULTS: The proposed reader showed high accuracy (85.2% for LE and 97.5% for NIT), exhibiting close agreement with the true values (κ = 0.903 for LE; κ = 1.000 for NIT). The reader also exhibited a lower median TAT for analysis than the photometric analyzer (3.0 min versus 33.0 min; p < 0.001). This reduction of TAT in the reader was even more evident considering the required time for delivery of urine samples for the photometric analyzer (3.0 min versus 62.0 min; p < 0.001). CONCLUSIONS: Our results demonstrated the clinical capability of a smartphone-based urine reagent strip test, and this reader is expected to enable a more rapid and reliable colorimetric test for screening of LE and NIT at the clinical setting and the point of care.

A grip force model for the da Vinci end-effector to predict a compensation force.

A torque transfer system (TTS) that measures grip forces is developed to resolve a potential drawback of the current da Vinci robot system whose grip forces vary according to the different postures of its EndoWrist. A preliminary model of EndoWrist Inner Mechanism Model (EIMM) is also developed and validated with real grip force measurements. EndoWrist's grip forces, posture angles, and transferred torque are measured by using TTS. The mean measured grip forces of three different EndoWrist for 27 different postures were very diverse. The EndoWrist exerted different grip forces, with a minimum of 1.84-times more and a maximum of 3.37-times more in specific posture even if the surgeon exerted the same amount of force. Using the posture angles as input and the grip forces as output, the EIMM is constructed. Then, expected grip force values obtained from EIMM are compared with actual measurements of da Vinci EndoWrist to validate the proposed model. From these results, surgeons will be beneficial with the understandings of actual grip force being applied to tissue and mechanical properties of robotic system. The EIMM could provide a baseline in designing a force-feedback system for surgical robot. These are significantly important to prevent serious injury by maintaining a proper force to tissue.

A study on the development of a robot-assisted automatic laser hair removal system.

UNLABELLED: Abstract Background and Objective: The robot-assisted automatic laser hair removal (LHR) system is developed to automatically detect any arbitrary shape of the desired LHR treatment area and to provide uniform laser irradiation to the designated skin area. METHODS: For uniform delivery of laser energy, a unit of a commercial LHR device, a laser distance sensor, and a high-resolution webcam are attached at the six axis industrial robot's end-effector, which can be easily controlled using a graphical user interface (GUI). During the treatment, the system provides real-time treatment progress as well as the total number of "pick and place" automatically. RESULTS: During the test, it was demonstrated that the arbitrary shapes were detected, and that the laser was delivered uniformly. The localization error test and the area-per-spot test produced satisfactory outcome averages of 1.04 mm error and 38.22 mm(2)/spot, respectively. CONCLUSIONS: RESULTS showed that the system successfully demonstrated accuracy and effectiveness. The proposed system is expected to become a promising device in LHR treatment.

Pneumatic-type surgical robot end-effector for laparoscopic surgical-operation-by-wire.

BACKGROUND: Although minimally invasive surgery (MIS) affords several advantages compared to conventional open surgery, robotic MIS systems still have many limitations. One of the limitations is the non-uniform gripping force due to mechanical strings of the existing systems. To overcome this limitation, a surgical instrument with a pneumatic gripping system consisting of a compressor, catheter balloon, micro motor, and other parts is developed. METHOD: This study aims to implement a surgical instrument with a pneumatic gripping system and pitching/yawing joints using micro motors and without mechanical strings based on the surgical-operation-by-wire (SOBW) concept. A 6-axis external arm for increasing degrees of freedom (DOFs) is integrated with the surgical instrument using LabVIEW® for laparoscopic procedures. The gripping force is measured over a wide range of pressures and compared with the simulated ideal step function. Furthermore, a kinematic analysis is conducted. To validate and evaluate the system's clinical applicability, a simple peg task experiment and workspace identification experiment are performed with five novice volunteers using the fundamentals of laparoscopic surgery (FLS) board kit. The master interface of the proposed system employs the hands-on-throttle-and-stick (HOTAS) controller used in aerospace engineering. To develop an improved HOTAS (iHOTAS) controller, 6-axis force/torque sensor was integrated in the special housing. RESULTS: The mean gripping force (after 1,000 repetitions) at a pressure of 0.3 MPa was measured to be 5.8 N. The reaction time was found to be 0.4 s, which is almost real-time. All novice volunteers could complete the simple peg task within a mean time of 176 s, and none of them exceeded the 300 s cut-off time. The system's workspace was calculated to be 11,157.0 cm3. CONCLUSIONS: The proposed pneumatic gripping system provides a force consistent with that of other robotic MIS systems. It provides near real-time control. It is more durable than the existing other surgical robot systems. Its workspace is sufficient for clinical surgery. Therefore, the proposed system is expected to be widely used for laparoscopic robotic surgery. This research using iHOTAS will be applied to the tactile force feedback system for surgeon's safe operation.

Tool to visualize and evaluate operator proficiency in laser hair-removal treatments.

BACKGROUND: The uniform delivery of laser energy is particularly important for safe and effective laser hair removal (LHR) treatment. Although it is necessary to quantitatively assess the spatial distribution of the delivered laser, laser spots are difficult to trace owing to a lack of visual cues. This study proposes a novel preclinic tool to evaluate operator proficiency in LHR treatment and applies this tool to train novice operators and compare two different treatment techniques (sliding versus spot-by-spot). METHODS: A simulation bed is constructed to visualize the irradiated laser spots. Six novice operators are recruited to perform four sessions of simulation while changing the treatment techniques and the presence of feedback (sliding without feedback, sliding with feedback, spot-by-spot without feedback, and spot-by-spot with feedback). Laser distribution maps (LDMs) are reconstructed through a series of images processed from the recorded video for each simulation session. Then, an experienced dermatologist classifies the collected LDMs into three different performance groups, which are quantitatively analyzed in terms of four performance indices. RESULTS: The performance groups are characterized by using a combination of four proposed indices. The best-performing group exhibited the lowest amount of randomness in laser delivery and accurate estimation of mean spot distances. The training was only effective in the sliding treatment technique. After the training, omission errors decreased by 6.32% and better estimation of the mean spot distance of the actual size of the laser-emitting window was achieved. Gels required operators to be trained when the spot-by-spot technique was used, and imposed difficulties in maintaining regular laser delivery when the sliding technique was used. CONCLUSIONS: Because the proposed system is simple and highly affordable, it is expected to benefit many operators in clinics to train and maintain skilled performance in LHR treatment, which will eventually lead to accomplishing a uniform laser delivery for safe and effective LHR treatment.

Influence of the washing program on the blood processing performance of a continuous autotransfusion device.

The continuous autotransfusion system has been widely used in surgical operations. It is known that if oil is added to blood, and this mixture is then processed by an autotransfusion device, the added oil is removed and reinfusion of fat is prevented by the device. However, there is no detailed report on the influence of the particular washing program selected on the levels of blood components including blood fat after continuous autotransfusion using such a system. Fresh bovine blood samples were processed by a commercial continuous autotransfusion device using the "emergency," "quality," and "high-quality" programs, applied in random order. Complete blood count (CBC) and serum chemistry were analyzed to determine how the blood processing performance of the device changes with the washing program applied. There was no significant difference in the CBC results obtained with the three washing programs. Although all of the blood lipids in the processed blood were decreased compared to those in the blood before processing, the levels of triglyceride, phospholipid, and total cholesterol after processing via the emergency program were significantly higher than those present after processing via the quality and high-quality programs. Although the continuous autotransfusion device provided consistent hematocrit quality, the levels of some blood lipid components showed significant differences among the washing programs.