Development of a thermotaxis and rheotaxis microfluidic device for motile spermatozoa sorting

Male infertility is a pervasive global reproductive challenge, primarily attributed to a decline in semen quality. Addressing this concern, there has been a growing focus on spermatozoa sorting in assisted reproductive technology. This study introduces a groundbreaking development in the form of a thermotaxis and rheotaxis microfluidic (TRMC) device designed for efficient motile spermatozoa sorting within a short 15-min timeframe. The TRMC device mimics the natural sperm sorting mechanism of the oviduct, selecting spermatozoa with superior motility and DNA integrity. The experimental outcomes demonstrate a remarkable enhancement in the percentage of progressive spermatozoa following sorting, soaring from 3.90% to an impressive 96.11% when subjected to a temperature decrease from 38 °C to 35 °C. Notably, sperm motility exhibited a substantial 69% improvement. The TRMC device exhibited a commendable recovery rate of 60.93%, surpassing current clinical requirements. Furthermore, the sorted spermatozoa displayed a notable reduction in the DNA fragmentation index to 6.94%, signifying a substantial 90% enhancement in DNA integrity. This remarkable advancement positions the TRMC device as highly suitable for applications in in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), offering a promising solution to male infertility challenges.

Antifouling Properties of Amine-Oxide-Containing Zwitterionic Polymers

Biofouling due to nonspecific proteins or cells on the material surfaces is a major challenge in a range of applications such as biosensors, medical devices, and implants. Even though poly(ethylene glycol) (PEG) has become the most widely used stealth material in medical and pharmaceutical products, the number of reported cases of PEG-triggered rare allergic responses continues to increase in the past decades. Herein, a new type of antifouling material poly(amine oxide) (PAO) has been evaluated as an alternative to overcome nonspecific foulant adsorption and impart comparable biocompatibility. Alkyl-substituted PAO containing diethyl, dibutyl, and dihexyl substituents are prepared, and their solution properties are studied. Photoreactive copolymers containing benzophenone as the photo-cross-linker are prepared by reversible addition-fragmentation chain-transfer polymerization and fully characterized by gel permeation chromatography and dynamic light scattering. Then, these water-soluble polymers are anchored onto a silicon wafer with the aid of UV irradiation. By evaluating the fouling resistance properties of these modified surfaces against various types of foulants, protein adsorption and bacterial attachment assays show that the cross-linked PAO-modified surface can efficiently inhibit biofouling. Furthermore, human blood cell adhesion experiments demonstrate that our PAO polymer could be used as a novel surface modifier for biomedical devices.

Design of a gradient-rheotaxis microfluidic chip for sorting of high-quality Sperm with progressive motility

Assisted reproductive technology (ART) is an important invention for the treatment of human infertility, and the isolation of high-quality sperm with progressive motility is one of the most critical steps that eventually affect the fertilization rate. Conventional sperm separation approaches include the swim-up method and density gradient centrifugation. However, the quality of isolated sperm obtained from both approaches can still be improved by improving sorted sperm motility, minimizing the DNA fragmentation rate, and removing abnormal phenotypes. Here, we report a Progressive Sperm Sorting Chip (PSSC) for high-quality sperm isolation. Based on the rheotaxis behavior of sperm, a gradient flow field is created in the chip for progressive sperm sorting. Clinical experiment results for 10 volunteers showed that greater than 90% of isolated sperm exhibit high motility (> 25 μm/s), high linearity (0.8), and a very low DNA fragmentation rate (< 5%). In addition, the whole process is label and chemical free. These features aid in gentle sperm sorting to obtain healthy sperm. This device uniquely enables the selection of high-quality sperm with progressive motility and might be clinically applied for infertility treatment in the near future.

Wearable Microfluidics for Continuous Assay

The development of wearable devices provides approaches for the realization of self-health care. Easily carried wearable devices allow individual health monitoring at any place whenever necessary. There are various interesting monitoring targets, including body motion, organ pressure, and biomarkers. An efficient use of space in one small device is a promising resolution to increase the functions of wearable devices. Through integration of a microfluidic system into wearable devices, embedding complicated structures in one design becomes possible and can enable multifunction analyses within a limited device volume. This article reviews the reported microfluidic wearable devices, introduces applications to different biofluids, discusses characteristics of the design strategies and sensing principles, and highlights the attractive configurations of each device. This review seeks to provide a detailed summary of recent advanced microfluidic wearable devices. The overview of advanced key components is the basis for the development of future microfluidic wearable devices.

Rapid detection of live bacteria in water using nylon filter membrane-integrated centrifugal microfluidics

Water is one of the most indispensable elements for human beings. People can live without food for a couple of weeks but cannot live without water for a couple of days. Unfortunately, drinking water is not always safe around the world; in many areas, the water for drinking could be contaminated with various microbes. However, the total viable microbe count in water still relies on culture-based methods in laboratories. Therefore, in this work, we report a novel, simple, and highly efficient strategy to detect live bacteria in water via a nylon membrane-integrated centrifugal microfluidic device. A handheld fan and a rechargeable hand warmer were utilized as the centrifugal rotor and the heat resource for reactions, respectively. The bacteria in water can be rapidly concentrated >500-fold by our centrifugation system. After incubation with water-soluble tetrazolium-8 (WST-8), the color change of the nylon membranes can be visually interpreted directly by the naked eye or recorded with a smartphone camera. The whole process can be finished in 3 h, and the detection limit can reach 10² CFU/mL. The detection range ranges from 10² CFU/mL to 10⁵ CFU/mL. The cell counting results of our platform are highly positively correlated with the results of cell counting by the conventional lysogeny broth (LB) agar plate approach or the commercial 3 M Petrifilm™ cell counting plate. Our platform provides a convenient and sensitive strategy for rapid monitoring. We highly anticipate that this platform can improve water quality monitoring in resource-poor countries in the near future.

Application of aminobenzoic acid electrodeposited screen-printed carbon electrode in the beta-amyloid electrochemical impedance spectroscopy immunoassay

Alzheimer's disease (AD) is one of the important neurodegenerative diseases, in the modern aging society, it has become an issue people need to work on. Of the pathogenic factor which leads to AD, beta-amyloid (Aβ) is the most important one. It can form the senile plaque which aggregates in the neuron and interrupts the signal transmission. This research is based on the electrochemical system and screen-printed carbon electrode (SPCE) incorporated with pretreatment, electrodeposition, electrochemical impedance spectroscopy (EIS), antibody, and blocking agent. This immunosensor is applied to detect the different concentrations of Aβ. The standard curve between electrical impedance and concentration of Aβ is calculated. The specificity of the immunosensor is tested. This survey optimizes the electrodeposition condition for 4-aminobenzoic acid (4-ABA) and the parameter for antibody and blocking agents. This study fabricates a more dense, uniform, and stable film of 4-ABA. This sensor presents a range of detection from 1 fg/ml to 100 pg/ml and a limit of detection to 3.84 fg/ml. This sensor can identify the isoform of Aβ. This research shortens the fabricating time to 3.5 h. This study fabricates a label-free and low-cost immunosensor for Aβ with a short fabricating time, high stability, wide range of detection, low limit of detection, and good specificity. The impedance of the carbon printed electrodes is very high and is always measured by its current but this study provides a fabrication technique for high-efficiency carbon printed electrodes for electrochemical impedance spectroscopy sensing.

Hand-Powered Point-of-Care: Centrifugal Microfluidic Platform for Urine Routine Examination (μCUREX)

Urinalysis is one of the simplest and most common medical tests in modern cities. With the assistance of professional technicians and equipment, people in metropolitan areas can effortlessly acquire information about their physiological conditions from traditional clinical laboratories. However, the threshold, including precise benchtop equipment and well-trained personnel, still remains a considerable dilemma for residents in healthcare-poor areas. Hence, it is a crucial and urgent topic to develop a smart and affordable widget to address this challenge. To improve the healthcare rights of residents, we proposed a disposable centrifugal microfluidic urine routine examination platform (named μCUREX) actuated with a modified hand-powered fan. Two parts of urinalysis (sediment test and chemical strip test) were integrated into the μCUREX disc. The influence on sedimentation by variant hand-powered manipulation was simulated using COMSOL. As a result, more than 70% of the sediment can be collected. Moreover, the color change of chemical strip papers (indicators for glucose, pH, protein, and occult blood) was recorded with a 3D-printed studio and analyzed after reaction with chemical-spiked and pH-adjusted artificial and human urine specimens. The whole process can be completed within 10 min, with only 200 μL of urine needed. In conclusion, we successfully constructed an ultra-low-cost point-of-care platform for urinalysis in extremely resource-poor settings. The handy size, high affordability, and user-friendliness of the μCUREX disc provide strong potential and feasibility in solving problems in resource-poor settings. Furthermore, we highly expect the μCUREX platform to improve the level of healthcare in resource-limited areas.

[Analysis of the diagnostic performance of MRI Liver Imaging Reporting and Data System version 2018 for intrahepatic parenchymal substantial lesions ≤3.0 cm]

Objective: To investigate the diagnostic performance of MRI Liver Imaging Reporting and Data System version 2018 in high-risk hepatocellular carcinoma (HCC) patients with intrahepatic parenchymal substantial lesions ≤3.0 cm. Methods: A retrospective analysis was conducted in hospitals between September 2014 to April 2020. 131 pathologically confirmed non-HCC cases with lesions ≤3.0 cm in diameter were randomly matched with 131 cases with lesions ≤3.0 cm in diameter and divided into benign (56 cases), other hepatic malignant tumor (OM, 75 cases), and HCC group (131 cases) in a 1:1 ratio. MRI features of the lesions were analyzed and classified according to LI-RADS v2018 criteria (tie-break rule was applied to lesions with both HCC and LR-M features). Taking the pathological results as the gold standard, the sensitivity and specificity of the LI-RADS v2018 classification criteria and the more stringent LR-5 criteria (with three main signs of HCC at the same time) were calculated for HCC, OM or benign lesions diagnosis. Mann -Whitney U test was used to compare the classification results. Results: The number of cases classified as LR-M, LR-1, LR-2, LR-3, LR-4, and LR-5 in HCC group after applying the tie-break rule were 14, 0, 0, 12, 28, and 77, respectively. There were 40, 0, 0, 4, 17, 14 and 8, 5, 1, 26, 13, 3 cases in benign and OM group, respectively. There were 41 (41/77), 4 (4/14) and 1 (1/3) lesion case in the HCC, OM and benign group, respectively, that met the more stringent LR-5 criteria. The sensitivity of LR-4 combined with LR-5 (LR-4/5) criteria, LR-5 criteria and more stringent LR-5 criteria for HCC diagnosis were 80.2% (105/131), 58.8% (77/131) and 31.3% (41/131), respectively, and the specificity were 64.1% (84/131), 87.0% (114/131) and 96.2% (126/131), respectively. The sensitivity and specificity of LR-M were 53.3% (40/75) and 88.2% (165/187), respectively. The sensitivity and specificity using LR-1 combined with LR-2 (LR-1/2) criteria for the diagnosis of benign liver lesions were 10.7% (6/56) and 100% (206/206), respectively. Conclusions: LR-1/2, LR-5, and LR-M criteria have high diagnostic specificity for intrahepatic lesions with a diameter of ≤3.0 cm. Lesions classified as LR-3 are more likely to be benign. The specificity of LR-4/5 criteria is low, while the more stringent LR-5 criteria has a high specificity for HCC diagnosis.

Wearable hydrogel patch with noninvasive, electrochemical glucose sensor for natural sweat detection

Recent advances in microelectronics and electrochemical sensing platforms have preceded the development of devices for personal monitoring and managing physiological and metabolic information that exploit sweat as a noninvasive, convenient approach for providing information about underlying health conditions, such as glucose level monitoring. Although most sweat glucose sensors have targeted applications during exercise and other active stimulation induced-sweat, natural sweating offers an attractive alternative with minimal effect on users that can be accessed during routine and sedentary activities without impeding personal lifestyle and preserves the correlation between blood and sweat glucose. Here, we present a noninvasive sweat glucose sensor with convenient hydrogel patches for rapid sampling of natural perspiration without external activities that stimulate sweating. The wearable hydrogel patch rapidly takes up natural sweat from the hand and serves as a medium for electrochemical sensing. A prussian blue-doped poly(3,4-ethylenedioxythiophene nanocomposite (PB-PEDOT NC) electrode provides cost-effective, stable and excellent electrocatalytic activity in sweat glucose measurements. We demonstrated sweat glucose sensor functionality by long-term measurements of glucose in sweat from human subjects consuming food and drinks. By enabling the analysis of sweat glucose during routine and sedentary activities, the sweat glucose sensor shows great promise for clinical-grade glucose management and enlarges the scope of next-generation noninvasive sensing systems.

[Effects of K-ras gene silence on the expression of oncogenes in HBE cells treated with PM(2.5)]

Objective: To explore the effects of K-ras gene on the expressions of oncogenes and cancer suppressor genes in human bronchial epithelial (HBE) cells which were exposed to PM(2.5). Methods: According to the mRNA sequence of K-ras gene provided by GenBank in September 2019, interference sequences were designed and synthesized, and the recombinant lentiviral vector was transfected into HBE cell to construct the K-ras gene-silenced cells. HBE cells and K-ras gene-silenced cells were exposed to 10 μg/ml, 50 μg/ml PM(2.5) suspension and 10 μmol/L Cr(6+). Real-time fluorescent quantitative PCR was used to detect the mRNA expression levels of c-myc, c-fos, N-ras, cyclin-D1, p16 and p53 genes, the expression levels of p53 and c-myc proteins were detected by Western blot. Results: In K-ras silenced cell group, K-ras mRNA expression level decreased (80.5%±3.6%) and K-ras protein level decreased (58.9%±4.7%) when compared with the control group (P<0.01) . Compared with the correspoding cell control group without exposure, the mRNA expression levels of c-myc, c-fos, N-ras and cyclin-D1 genes in HBE cell group exposed to different concentrations of PM(2.5), K-ras silenced cell group exposed to different concentrations of PM(2.5), HBE cell group exposed to 10 μmol/L Cr(6+) and K-ras silenced cell group exposed to 10 μmol/L Cr(6+) were increased, the mRNA expressions of p16 and p53 genes were decreased (P<0.01) . Compared with HBE cell group exposed to 10 μg/ml PM(2.5), the mRNA expressions of c-myc, c-fos and p16 genes in K-ras silenced cells exposed to 10 μg/ml PM(2.5) were decreased, and the p53 mRNA level was increased (P<0.01) . Compared with HBE cell group exposed to 50 μg/ml PM(2.5), the mRNA expression levels of c-fos, N-ras, cyclin-D1, p16 and p53 genes in K-ras silenced cell group exposed to 50 μg/ml PM(2.5) were decreased (P<0.01) . Compared with the HBE cell group without exposure, c-myc protein increased and p53 protein decreased in HBE cells exposed to 50 μg/ml PM(2.5) (P<0.05) . Compared with the K-ras silenced cell group without exposure, c-myc protein increased in K-ras silenced cells exposed to 50 μg/ml PM(2.5) (P<0.05) . Conclusion: PM(2.5) can increase the expression levels of oncogenes in HBE cells, and K-ras gene silencing can inhibit the expression levels of oncogenes in HBE cells treated with PM(2.5).

Passively driven microfluidic device with simple operation in the development of nanolitre droplet assay in nucleic acid detection

Since nucleic acid amplification technology has become a vital tool for disease diagnosis, the development of precise applied nucleic acid detection technologies in point-of care testing (POCT) has become more significant. The microfluidic-based nucleic acid detection platform offers a great opportunity for on-site diagnosis efficiency, and the system is aimed at user-friendly access. Herein, we demonstrate a microfluidic system with simple operation that provides reliable nucleic acid results from 18 uniform droplets via LAMP detection. By using only micropipette regulation, users are able to control the nanoliter scale of the droplets in this valve-free and pump-free microfluidic (MF) chip. Based on the oil enclosure method and impermeable fabrication, we successfully preserved the reagent inside the microfluidic system, which significantly reduced the fluid loss and condensation. The relative standard deviation (RSD) of the fluorescence intensity between the droplets and during the heating process was < 5% and 2.0%, respectively. Additionally, for different nucleic acid detection methods, the MF-LAMP chip in this study showed good applicability to both genome detection and gene expression analysis.

Integration of Ni/NiO nanoparticles and a microfluidic ELISA chip to generate a sensing platform for Streptococcus pneumoniae detection

Enzyme-linked immunosorbent assays (ELISAs) are tests that uses antibody recognition and enzyme catalytic activity to identify a substance, and they have been widely used as a diagnostic tool in the clinic.

A Noninvasive Wearable Device for Real-Time Monitoring of Secretion Sweat Pressure by Digital Display

Sweat-based wearable devices have attracted increasing attention by providing abundant physiological information and continuous measurement through noninvasive healthcare monitoring. Sweat pressure generated via sweat glands to the skin surface associated with osmotic effects may help to elucidate such parameters as physiological conditions and psychological factors. This study introduces a wearable device for measuring secretion sweat pressure through noninvasive, continuous monitoring. Secretion pressure is detected by a microfluidic chip that shows the resistance variance from a paired electrode pattern and transfers digital signals to a smartphone for real-time display. A human study demonstrates this measurement with different exercise activities, showing the pressure ranges from 1.3 to 2.5 kPa. This device is user-friendly and applicable to exercise training and personal health care. The convenience and easy-to-wear characteristics of this device may establish a foundation for future research investigating sweat physiology and personal health care.

[Effect of p38MAPK gene silencing on expression of oncogenes and apoptotic genes induced by PM(2.5) in hepatocytes]

Objective: To study the effect of p38 mitogen-activated protein kinase (MAPK) gene silencing on expression of apoptotic genes and oncogenes in hepatocytes treated with PM(2.5). Methods: From June to September 2019, according to the p38MAPK gene mRNA sequence provided by GenBank, three interfering sequences were designed and synthesized, ligated into PLVX-shRNA2-puro after annealing, and the recombinant lentiviral vector was transfected into L02 hepatocytes. The p38MAPK silencing cells were identified by real-time fluorescent quantitative PCR and western blotting. The normal L02 cells and p38MAPK silencing cells were treated with 50 μg/mL PM(2.5) water soluble solution, 10 μmol/L positive control Cr(6+), and a blank control group was set up, the treatment time was 24 h. The mRNA levels of oncogenes (c-fos, c-myc, k-ras) , tumor suppressor gene (p53) and apoptotic genes (Caspase-3, Caspase-8, Caspase-9) were detected by real-time PCR. The protein levels of oncogenes and apoptotic genes were detected by Western blotting. Results: The expression levels of p38MAPK mRNA and protein in p38MAPK gene silencing cells were significantly lower than those in L02 hepatocytes (P<0.05) , and the p38MAPK gene silencing cell line was successfully constructed. Compared with the blank control group, the expression levels of the oncogenes c-fos, c-myc, k-ras and the apoptosis genes Caspase-3, Caspase-8 and Caspase-9 increased, the expression level of tumor suppressor gene p53 decreased in the L02 hepatocyte group treated with PM(2.5) water soluble matter, and the differences were statistically significant (P<0.05) . Compared with the L02 hepatocytes group treated with PM(2.5) water soluble matter, the expression levels of the oncogenes c-fos, c-myc, k-ras and apoptosis genes Caspase-3, Caspase-8 and Caspase-9 decreased, the expression level of tumor suppressor gene p53 increased in the p38MAPK gene silencing cells group treated with PM(2.5) water soluble matter, and the differences were statistically significant (P<0.05) . Conclusion: PM(2.5) has effects on the expression of oncogenes, tumor suppressor genes and apoptotic genes in L02 hepatocytes, while p38MAPK gene silencing can inhibit the effects of PM(2.5) on L02 hepatocytes.

[Effect of c-myc gene silence on the expression of oncogenes and apoptotic genes in hepatocytes treated with PM(2).5]

Objective: To construct the c-myc gene silenced hepatocytes, study the effect of c-myc gene silence on expression of oncogenes and apoptosis genes in hepatocytes treated with PM2.5. Methods: According to the c-myc gene mRNA sequence provided by GenBank, three interfering sequences were designed and synthesized, the recombinant lentiviral vector was transfected into L02 hepatocytes. The real-time quantitative PCR and western blotting were used to identify the effect of c-myc gene silencing. L02 cells and c-myc gene silenced cells were used as experimental subjects. The normal L02 cells and c-myc silenced cells were treated with 50 μg/ml PM(2.5) water soluble solution, 10 μM positive control Cr(6+) and a blank control, the treatment period was 24 h. The mRNA levels of oncogenes (c-myc, c-fos, k-ras, p53) and apoptotic genes (Caspase-3, Caspase-8, Caspase-9) were detected by real-time PCR. The protein levels of oncogenes and apoptotic genes were detected by western blotting. Results: The mRNA level and protein level of c-myc decreased by 81% and 70% in c-myc silenced cells when compared with the normal L02 hepatocytes, the above results indicate that c-myc gene silenced cells were successfully constructed. After c-myc silenced cells were treated with PM2.5 water soluble solution, The mRNA levels of c-myc, c-fos, and k-ras decreased by 84.1%, 45.4%, and 54.6% (P<0.05) , p53 increased by 192.9% (P<0.05) , and the expression of Caspase-3, Caspase-8, and Caspase-9 decreased by 24.4%, 36.1%, 60.9% (P<0.05) . In the Cr(6+) positive control group, the expression of c-myc, c-fos, and k-ras decreased by 72.1%, 82.2%, and 54.0% (P<0.05) , p53 increased by 250.0% (P<0.05) , the expression of Caspase-3, Caspase-8, and Caspase-9 decreased by 34.6%, 36.0%, 68.9% (P<0.05) , respectively, when compared with the normal L02 hepatocytes (P<0.05) . Western blotting results showed that the protein levels of c-myc and c-fos increased, p53 decreased after PM(2.5) exposure; the protein levels of Caspase-3, Caspase-8, Caspase-9 increased after PM(2.5) exposure (P<0.05) . When in comparison with the c-myc silenced group, the protein levels of c-myc and c-fos decreased, p53 protein increased in PM(2).5 exposed group (P<0.05) . Conclusion: c-myc gene silenced cells were successfully constructed in this paper. PM(2.5) could promote the expression of oncogenes and apoptotic genes in L02 cells, and c-myc gene silencing can inhibit the expression of oncogenes and apoptotic genes after PM(2.5) treatment in L02 cells.

Rapid purification of lung cancer cells in pleural effusion through spiral microfluidic channels for diagnosis improvement

Lung cancer is one of the leading causes of death worldwide. Fifteen percent of lung cancer patients will present with malignant pleural effusion initially, and up to 50% will have malignant pleural effusion throughout the course of the disease. In this study, we developed a spiral microfluidic device that can rapidly isolate cancer cells and improve their purity through fluid dynamics. This label-free, high-throughput device continuously isolates cancer cells and other unrelated molecules from pleural effusion. Most of the background cells that affect interpretation are flushed to outlets 1 to 3, and cancer cells are hydrodynamically concentrated to outlet 4, with 90% of lung cancer cells flowing to this outlet. After processing, the purity of cancer cells identified in pleural effusion by CD45 and epithelial cell adhesion molecule (EpCAM) antibodies in flow cytometry will be increased by 6 to 24 times. The microfluidic device presented here has the advantages of rapid processing and low cost, which are conducive to rapid and accurate clinical diagnosis.

Construction of the Nickel Oxide Nanocoral Structure on Microscope Slides for Total Self-Assembly-Oriented Probe Immobilization and Signal Enhancement

Proper orientation of probes and the binding capacity of surfaces will determine the performance of bio-applications. It has been reported that immobilizing through bio-/chemical affinity is an efficient but gentle strategy to solve the above-mentioned issue. Herein, we introduce a total self-assembly approach via the strong affinity of nickel oxide (NiO) to the polyhistidine-tag (His-tag). It allows the efficient immobilizing His-tagged proteins with orientation. Furthermore, we find that the nanocoral structure can be formed after applying rapid thermal annealing at 1100 °C, which could increase the His-tagged protein binding capacity efficiently by the enhanced surface-to-volume ratio. Lastly, we demonstrate the NiO thin film with the nanocoral structure, which has great potential for universal biosensing with a wide range of biomolecules, including DNA, protein, and bacteria. Through His-tagged monomer streptavidin (His₆-mSA) or His-tagged protein G (His₆-protein G), the biotinylated DNA or antibody could be immobilized with proper orientation on the surface consequently to complete a sensitive biomolecule detection. Moreover, the NiO nanocoral structure has the advantages of high hydrophilicity, transmittance, and pH stability that are promising to develop into several kinds of bio-applications in the near future.

[Effect of sedation weaning pattern on withdrawal syndrome in pediatric intensive care unit]

Objective: To investigate the sedation weaning strategies in critically ill patients with mechanical ventilation in pediatric intensive care unit (PICU) and to explore the effect of different sedative weaning patterns on withdrawal syndrome. Methods: A single-center prospective cohort study was conducted from April 1, 2016 to April 30, 2017. One hundred and twelve patients who required mechanical ventilation and benzodiazepines and (or) opioids for at least 5 consecutive days in PICU of Shanghai Children's Medical Center were enrolled. Twenty patients (17.9%) had an intermittent weaning pattern, defined as a 50% or greater increase in daily benzodiazepine and (or) opioid dose after the start of weaning, and the remaining 92 cases (82.1%) had a steady weaning pattern. The demographic and clinical features, duration and dose of sedative and analgesics, and the incidence of withdrawal syndrome were evaluated. Mann-Whitney U test was used for comparison about clinical features between different weaning pattern groups and children with withdrawal syndrome or not. Logistic regression was used to explore the risk factors of withdrawal syndrome. Results: Among the 112 patients, 46 (41.1%) had withdrawal syndrome. The patients with the intermittent weaning pattern had a high score of pediatric risk of mortality Ⅲ (PRISM-Ⅲ) (10.0 (3.5, 12.0) vs. 6.0 (2.0, 10.0), U=654.50, P=0.043) and were prone to re-intubation (35.0% (7/20) vs. 7.6% (7/92), P=0.003). The patients with withdrawal syndrome had longer duration of sedation (19.5 (16.8, 24.3) vs. 10.0 (7.0, 17.3) days, U=743.50, P<0.01), higher incidence of intermittent weaning pattern (32.6% (15/46) vs. 7.6% (5/66),χ(2)=11.58, P=0.001), longer PICU hospitalization (19.0 (15.8, 25.3) vs. 12.0 (8.8, 17.0) days, U=755.00, P<0.01) and higher cost (89 (57,109) vs. 53 (32, 79) thousand yuan, U=804.00, P<0.01). Logistic regression showed that intermittent weaning pattern (odds ratio (OR)=4.85, 95% confidence interval (CI) 1.39-16.91, P=0.013), perioperative period of liver transplantation (OR=6.97, 95%CI 1.25-39.04, P=0.027) and a cumulative dose of midazolam ≥ 34.7 mg/kg (OR=8.12, 95%CI 3.09-21.37, P<0.01) were risk factors of withdrawal syndrome. Conclusions: Withdrawal syndrome is more likely to occur in children who are intermittently weaned from sedation. Steady weaning strategy may help prevent iatrogenic withdrawal syndrome.

[Whole lung lavage in an infant with pulmonary alveolar proteinosis and literature review]

Objective: To investigate the safety, feasibility and operation key points of whole lung lavage in infants with pulmonary alveolar proteinosis. Methods: The clinical manifestations, genetic screening, therapeutic interventions and outcome of an infant with pulmonary alveolar proteinosis complicated with respiratory failure who received whole lung lavage in November 2018 in Shanghai Children's Medical Center Affiliated to Shanghai Jiaotong University School of Medicine were reported. Websites including PubMed, Springer Link, China National Knowledge Infrastructure (CNKI), Weipu Database, and Wanfang Database were searched using the key words of "whole lung lavage" "pediatric" and "pulmonary alveolar proteinosis" for articles published from their establishments to April 2019. Relevant literature was reviewed. Results: A 3-month-old boy had experienced cough, shortness of breath and cyanosis for 1 week prior to admission to pediatric intensive care unit. Physical examination showed hepatosplenomegaly. Complete blood cell count showed mild anemia (hemoglobin 96 g/L) and normal white blood cells. The patient had normal C-reactive protein and normal blood platelet. Biochemical panel showed hypoalbuminemia (31 g/L), mildly elevated glutamic oxaloacetic transaminase (115 U/L) and blood ammonia (165 μmol/L), extremely elevated lactate dehydrogenase (>6 600 U/L) and hyperferritinemia (>4 500 μg/L). Chest computed tomography (CT) revealed decreased transmittance of both lungs, patchy high density shadow and ground glass opacity. Genetic testing revealed a mutation of c.625+1G>A in SLC7A7. Schiff reaction (PAS staining) in bronchoalveolar lavage fluid was positive. The patient was diagnosed with severe pneumonia, respiratory failure, lysinuria urinary protein intolerance, and pulmonary alveolar proteinosis. The patient received sequential unilateral whole lung lavage in 2 days and was successfully weaned from ventilator. He was discharged home breathing room air. Eleven articles (11 in English and non in Chinese) were reviewed. Twenty-one patients were included. After whole lung lavage, 76% (16/21) of the patients had improvement in respiratory function. Conclusions: Whole lung lavage can effectively improve respiratory failure caused by pulmonary alveolar proteinosis in infant patients. The procedure is feasible and safe.

Antifouling strategies in advanced electrochemical sensors and biosensors

A review presented recent development of antifouling strategies in electrochemical sensors and biosensors based on the modification methods.

Rapid Prototyping of an Open-Surface Microfluidic Platform Using Wettability-Patterned Surfaces Prepared by an Atmospheric-Pressure Plasma Jet

Open-surface microfluidics is promising in terms of enabling economical and rapid biochemical analysis for addressing challenges associated with medical diagnosis and food safety. To this end, we present a simple and economical approach to develop an open-surface microfluidic platform suitable for facile liquid transport and mixing. Customizable patterns with tailored wettability are deposited using a plasma-assisted deposition technique under atmospheric pressure. The flow of the dispensed liquid is driven by gravity, and the tilting angle of the device determines the extent of mixing. First, a hexamethyldisiloxane film was deposited to create hydrophobic patterns on glass, and then, hydrophilic acrylic acid was deposited by a patterned cardboard mask to construct a channel suitable for forming channels to transport aqueous liquids without the need of an external energy input; the liquid can be confined to designated pathways. Several designs including Y-junctions, serpentine-shaped patterns, splitting channels, and concentration gradient generation patterns are presented. The proposed method can spatially pattern a surface with a hydrophobic/hydrophilic area, which can function as a microfluidic channel, and the surface can be applied in microfluidic devices with other types of substrates.

Noninvasive Glucose Monitoring with a Contact Lens and Smartphone

Diabetes has become a chronic metabolic disorder, and the growing diabetes population makes medical care more important. We investigated using a portable and noninvasive contact lens as an ideal sensor for diabetes patients whose tear fluid contains glucose. The key feature is the reversible covalent interaction between boronic acid and glucose, which can provide a noninvasive glucose sensor for diabetes patients. We present a phenylboronic acid (PBA)-based HEMA contact lens that exhibits a reversible swelling/shrinking effect to change its thickness. The difference in thickness can be detected in a picture taken with a smartphone and analyzed using software. Our novel technique offers the following capabilities: (i) non-enzymatic and continuous glucose detection with the contact lens; (ii) no need for an embedded circuit and power source for the glucose sensor; and (iii) the use of a smartphone to detect the change in thickness of the contact lens with no need for additional photo-sensors. This technique is promising for a noninvasive measurement of the glucose level and simple implementation of glucose sensing with a smartphone.

A Novel Metallo-β-Lactamase Involved in the Ampicillin Resistance of Streptococcus pneumoniae ATCC 49136 Strain

Streptococcus pneumoniae, a penicillin-sensitive bacterium, is recognized as a major cause of pneumonia and is treated clinically with penicillin-based antibiotics. The rapid increase in resistance to penicillin and other antibiotics affects 450 million people globally and results in 4 million deaths every year. To unveil the mechanism of resistance of S. pneumoniae is thus an important issue to treat streptococcal disease that might consequently save millions of lives around the world. In this work, we isolated a streptococci-conserved L-ascorbate 6-phosphate lactonase, from S. pneumoniae ATCC 49136. This protein reveals a metallo-β-lactamase activity in vitro, which is able to deactivate an ampicillin-based antibiotic by hydrolyzing the amide bond of the β-lactam ring. The Michaelis parameter (Km) = 25 μM and turnover number (kcat) = 2 s(-1) were obtained when nitrocefin was utilized as an optically measurable substrate. Through confocal images and western blot analyses with a specific antibody, the indigenous protein was recognized in S. pneumoniae ATCC 49136. The protein-overexpressed S. pneumonia exhibits a high ampicillin-tolerance ability in vivo. In contrast, the protein-knockout S. pneumonia reveals the ampicillin-sensitive feature relative to the wild type strain. Based on these results, we propose that this protein is a membrane-associated metallo-β-lactamase (MBL) involved in the antibiotic-resistant property of S. pneumoniae.

Advances in nanowire transistors for biological analysis and cellular investigation

Electrical biosensors based on silicon nanowire field-effect transistors (SiNW-FETs) have attracted enormous interest in the biosensing field. SiNW-FETs have proven to be significant and efficient in detecting diverse biomolecular species with the advantages of high probing sensitivity, target selectivity, real-time recording and label-free detection. In recent years, significant advances in biosensors have been achieved, particularly for cellular investigation and biomedical diagnosis. In this critical review, we will report on the latest developments in biosensing with SiNW-FETs and discuss recent advancements in the innovative designs of SiNW-FET devices. This critical review introduces the basic instrumental setup and working principle of SiNW-FETs. Technical approaches that attempted to enhance the detection sensitivity and target selectivity of SiNW-FET sensors are discussed. In terms of applications, we review the recent achievements with SiNW-FET biosensors for the investigations of protein-protein interaction, DNA/RNA/PNA hybridization, virus detection, cellular recording, biological kinetics, and clinical diagnosis. In addition, the novel architecture designs of the SiNW-FET devices are highlighted in studies of live neuron cells, electrophysiological measurements and other signal transduction pathways. Despite these remarkable achievements, certain improvements remain necessary in the device performance and clinical applications of FET-based biosensors; thus, several prospects about the future development of nanowire transistor-based instruments for biosensing employments are discussed at the end of this review.

Silicon nanowire field-effect-transistor based biosensors: from sensitive to ultra-sensitive

Silicon nanowire field effect transistors (SiNW-FETs) have shown great promise as biosensors in highly sensitive, selective, real-time and label-free measurements. While applications of SiNW-FETs for detection of biological species have been described in several publications, less attention has been devoted to summarize the conjugating methods involved in linking organic bio-receptors with the inorganic transducer and the strategies of improving the sensitivity of devices. This article attempts to focus on summarizing the various organic immobilization approaches and discussing various sensitivity improving strategies, that include (I) reducing non-specific binding, (II) alignment of the probes, (III) enhancing signals by charge reporter, (IV) novel architecture structures, and (V) sensing in the sub-threshold regime.

Rapid construction of an effective antifouling layer on a Au surface via electrodeposition

An electrodeposited zwitterion layer enables reduction of non-specific adsorption up to 95% on a gold surface from fetal bovine serum.

An ultrasensitive nanowire-transistor biosensor for detecting dopamine release from living PC12 cells under hypoxic stimulation

Dopamine (DA) is an important neurotransmitter that is involved in neuronal signal transduction and several critical illnesses. However, the concentration of DA is extremely low in patients and is difficult to detect using existing electrochemical biosensors with detection limits typically around nanomolar levels (∼10(-9) M). Here, we developed a nanoelectronic device as a biosensor for ultrasensitive and selective DA detection by modifying DNA-aptamers on a multiple-parallel-connected (MPC) silicon nanowire field-effect transistor (referred to as MPC aptamer/SiNW-FET). Compared with conventional electrochemical methods, the MPC aptamer/SiNW-FET has been demonstrated to improve the limit of DA detection to <10(-11) M and to possess a detection specificity that is able to distinguish DA from other chemical analogues, such as ascorbic acid, catechol, phenethylamine, tyrosine, epinephrine, and norepinephrine. This MPC aptamer/SiNW-FET was also applied to monitor DA release under hypoxic stimulation from living PC12 cells. The real-time recording of the exocytotic DA induced by hypoxia reveals that the increase in intracellular Ca(2+) that is required to trigger DA secretion is dominated by an extracellular Ca(2+) influx, rather than the release of intracellular Ca(2+) stores.

Improved silicon nanowire field-effect transistors for fast protein-protein interaction screening

Understanding how proteins interact with each other is the basis for studying the biological mechanisms behind various physiological activities. Silicon nanowire field-effect transistors (SiNW-FETs) are sensitive sensors used to detect biomolecular interactions in real-time. However, the majority of the applications that use SiNW-FETs are for known interactions between different molecules. To explore the capability of SiNW-FETs as fast screening devices to identify unknown interacting molecules, we applied mass spectrometry (MS) to analyze molecules reversibly bound to the SiNW-FETs. Calmodulin (CaM) is a Ca(2+)-sensing protein that is ubiquitously expressed in cells and its interaction with target molecules is Ca(2+)-dependent. By modifying the SiNW-FET surface with glutathione, glutathione S-transferase (GST)-tagged CaM binds reversibly to the SiNW-FET. We first verified the Ca(2+)-dependent interaction between GST-CaM and purified troponin I, which is involved in muscle contraction, through the conductance changes of the SiNW-FET. Furthermore, the cell lysate containing overexpressed Ca(2+)/CaM-dependent protein kinase IIα induced a conductance change in the GST-CaM-modified SiNW-FET. The bound proteins were eluted and subsequently identified by MS as CaM and kinase. In another example, candidate proteins from neuronal cell lysates interacting with calneuron I (CalnI), a CaM-like protein, were captured with a GST-CalnI-modified SiNW-FET. The proteins that interacted with CalnI were eluted and verified by MS. The Ca(2+)-dependent interaction between GST-CalnI and one of the candidates, heat shock protein 70, was re-confirmed via the SiNW-FET measurement. Our results demonstrate the effectiveness of combining MS with SiNW-FETs to quickly screen interacting molecules from cell lysates.

Structural and Functional Studies on DHC, the Diheme Cytochrome c from Rhodobacter sphaeroides, and Its Interaction with SHP, the sphaeroides Heme Protein,

The diheme cytochrome c (DHC) from Rhodobacter sphaeroides is a soluble protein with a mass of 16 kDa that represents a new class of c-type cytochrome [Vandenberghe, I., et al. (1998) Biochemistry 37, 13075-13081]. The gene encoding DHC is associated with another encoding a cytochrome known as SHP (sphaeroides heme protein). It is believed that DHC is the electron donor for SHP, which is known to bind oxygen. To gain further insight into the properties and role of DHC, we have carried out structure-function studies on the protein and examined its interaction with SHP. The crystal structures of native and recombinant DHC have been determined to resolutions of 1.85 and 2.0 A, respectively. The structures show that DHC folds into two distinct domains each containing one heme. While the N-terminal domain is a class I cytochrome c, the C-terminal domain shows no similarity to any existing structures and thus constitutes a novel cytochrome c structural motif. The shortest, edge-to-edge, distance between the heme groups is 10.2 A, and this distance is bridged by Tyr31, thus ensuring fast internal electron transfer. DHC binds strongly to its proposed physiological partner, SHP (K(d) = 0.26 microM in 10 mM HEPES at pH 7.2 and 25 degrees C). However, at higher salt concentrations, the binding becomes much weaker, indicating the importance of electrostatic interactions. DHC is also very efficient in electron transfer to SHP with a second-order rate constant of 1.8 x 10(7) M(-)(1) s(-)(1) (at pH 7.2, 10 degrees C, and I = 500 mM). The reduction potentials of DHC and SHP are also suitably ordered for a favorable reaction with the hemes of DHC showing potentials of -310 and -240 mV, respectively, and that for SHP being -105 mV. These potentials are unaltered upon complex formation.

Identification of a novel microtubule-destabilizing motif in CPAP that binds to tubulin heterodimers and inhibits microtubule assembly

We have previously identified a new centrosomal protein, centrosomal protein 4.1-associated protein (CPAP), which is associated with the gamma-tubulin complex. Here, we report that CPAP carries a novel microtubule-destabilizing motif that not only inhibits microtubule nucleation from the centrosome but also depolymerizes taxol-stabilized microtubules. Deletion mapping and functional analyses have defined a 112-residue CPAP that is necessary and sufficient for microtubule destabilization. This 112-residue CPAP directly recognizes the plus end of a microtubule and inhibits microtubule nucleation from the centrosome. Biochemical and functional analyses revealed that this 112-residue CPAP also binds to tubulin dimers, resulting in the destabilization of microtubules. Using the tetracycline-controlled system (tet-off), we observed that overexpression of this 112-residue CPAP inhibits cell proliferation and induces apoptosis after G2/M arrest. The possible mechanisms of how this 112-residue motif in CPAP that inhibits microtubule nucleation from the centrosome and disassembles preformed microtubules are discussed.

A new experimental and clinical approach of combining usage of highly active tumor-infiltrating lymphocytes and highly sensitive antitumor drugs for the advanced malignant tumor

In recent years, tumor-infiltrating lymphocytes (TILs) have been reported to be effective for tumors in experimental and clinical research. In order to increase the therapeutical effect, we modified some steps of Rosenberg's approach: a. cold digestion with collagenase at 4 degrees C for 24 hours; b. sedimentation instead of centrifugation; c. elimination of tumor cells before the cultivation procedure. Compared with the original approach, the proliferation, activity and cytotoxicity of TILs obtained by the modified procedure were much improved. TILs' expansion-fold was greater than that with the original approach. Cytotoxicity against tumor cells was more potent. Increased TILs' subsets were CD3 and CD8 cells. Meanwhile, we took tumor cells from tumor tissues to test their in vitro chemosensitivities to different drugs in order to select highly sensitive antitumor drugs for treatment of cases with advanced tumors. According to the design of using highly active TILs and highly sensitive drugs (H & H therapy), preliminary clinical results of 50 cases showed higher response rates than those in treatment with TIL/IL2, LAK/IL2 and TIL+IL2+CTX. Less toxic side effects were observed in 14 patients.

[Study on the influence of enzymatic digestion upon tumor-infiltrating lymphocytes]

To get a long-term culture of tumor-infiltrating lymphocytes (TILs) is very difficult. The authors have investigated some suitable enzymes, their digestive conditions such as time and temperature, which may influence the viability and cytotoxicity of TILs. The results showed that collagenase II and IV could keep viability of TILs much longer than those treated with trypsin or hyaluronidase. The digestion with collagenase II or IV at 4 degrees C for 24 hours was much less damage to viability of TILs than those treated at 37 degrees C for one hour. The TILs, which digested at 4 degrees C for 24 hours, still had cytotoxicity against autologous tumor cells as long as sixty to seventy-five days.

[Therapeutic effects of epimeric glycyrrhizic acids on hepatic injury in rats]

The effects of the epimeric glycyrrhizic acids (GA), 18 alpha-form and 18 beta-form, on D-galactosamine (Gal)-induced acute liver injury and fulminating hepatic failure (FHF) in rats were studied. In rats of acute liver injury, extensive liver parenchymal cell damage was observed by the elevation of alanine aminotransferase (ALT) activity and confirmed by significant histopathological changes 24 and 48 h after ip Gal 450 mg.kg-1. Moreover, marked elevation in the liver putrescine levels occurred along with that of serum ALT. The spermidine and spermine levels did not alter significantly. GA 18 alpha-form 300 mg.kg-1 ip suppressed the elevation of serum ALT and liver putrescine levels, and improved all the histopathologic features. On the other hand, GA 18 beta-form 300 mg.kg-1, which exhibited inhibitory effects 24 h after ip Gal, showed no action 48 h after ip Gal. The ALT levels in the serum from GA 18 alpha-form, 18 beta-form, vs control groups after 24 h were 70 +/- 24 (P < 0.01) and 78 +/- 42 (P < 0.01) vs 155 +/- 57, and after 48 h were 74 +/- 25 (P < 0.01) and 258 +/- 99 (P > 0.05) vs 293 +/- 110. The putrescine contents (nmol.g-1) in the liver from GA 18 alpha-form, 18 beta-form, vs control after 24 h were 34 +/- 9 (P < 0.01) and 51 +/- 12 (P < 0.01) vs 139 +/- 29, and after 48 h were 16 +/- 3 (P < 0.01) and 150 +/- 11 (P > 0.05) vs 156 +/- 23.(ABSTRACT TRUNCATED AT 250 WORDS)