Functionalized Fluorescent Organic Nanoparticles Based AIE Enabling Effectively Targeting Cancer Cell Imaging

We report a fluorescent dye TM by incorporating the tetraphenylethylene (TPE) and cholesterol components into perylene bisimides (PBI) derivative. Fluorescence emission spectrum shows that the dye has stable red emission and aggregation-induced emission (AIE) characteristics. The incorporation of cholesterol components triggers TM to show induced chirality through supramolecular self-assembly. The cRGD-functionalized nanoparticles were prepared by encapsulating fluorescent dyes with amphiphilic polymer matrix. The functionalized fluorescent organic nanoparticles exhibit excellent biocompatibility, large Stokes' shift and good photostability, which make them effective fluorescent probes for targeting cancer cells with high fluorescence contrast.

Reservoir computing-based digital signal equalizer for equivalent-time sampling

A sampling oscilloscope is an important instrument for evaluating the quality of optical communication signals. Since its working principle is equivalent-time sampling, the data obtained for digital signals with random characteristics do not have continuity, which makes it impossible to use methods such as filtering and averaging to equalize the signal. For this reason, this paper proposes a signal equalization method based on reservoir computing. Through training of the reservoir model, an equivalent-time equalizer is established to solve the problem that the sampling oscilloscope cannot equalize random digital signals. Compared with the continuous-time equalizer, the coincidence degree exceeds 95%. The eye height and eye width are increased by 7 and 1.6, respectively, while the jitter in the eye diagram is reduced by 2.3 times, which solves the problem that the sampling oscilloscope cannot equalize random digital signals.

A Space-Dependent 'Enzyme-Substrate' Type Probe based on 'Carboxylesterase-Amide Group' for Ultrafast Fluorescent Imaging Orthotopic Hepatocellular Carcinoma

Fast and selective fluorescence imaging for a biomarker to related-disease diagnosis remains a significant challenge due to complex physical environment. Human carboxylesterase (CE) is expected to be a potential biomarker of hepatocellular carcinoma (HCC) to improve the accuracy of diagnosis. However, existing probes for CE has slow response rate and low selectivity. Herein, the amide group is selected as CE-responsive sites based on the "substrate-hydrolysis enzymatic reaction" approach. From a series of off-on probes with leave groups in the amide unit, probe J_Fast is screened with the optimal combination of rapid response rate and high selectivity toward CE. J_Fast requires only 150 s to reach the maximum fluorescence at 676 nm in the presence of CE and free from the interference of other esterase. Computational docking simulations indicate the shortest distance between the CE and active site of J_Fast . Cell and in vivo imaging present that the probe can turn on the liver cancer cells and tumor region precisely. Importantly, J_Fast is allowed to specifically image orthotopic liver tumor rather than metastatic tumor and distinguish human primary liver cancer tissue from adjacent ones. This study provides a new tool for CE detection and promotes advancements in accurate HCC diagnosis.

An optimized method for neutron dose evaluation based on24Na activity distribution in the human body

The neutron dose resulting from external irradiation can be evaluated by measuring the counts of characteristicγrays produced by²⁴Na in the human body. The detection geometry with the highest detection efficiency for measuring the whole-body²⁴Na activity has not been studied. In this work, the MCNP code is used to calculate the spatial distribution of²⁴Na in the human body irradiated by neutrons with different energies in different irradiation geometries. The fluence distribution of²⁴Na characteristicγrays on the body surface is calculated. The counts of²⁴Na characteristicγrays induced by monochromatic neutron irradiation are simulated to fit the scenarios of neutron irradiation by a continuous energy spectrum neutron. When the spontaneous neutrons from²⁵²Cf with 1Gy dose irradiate the human body, (3.63-4.35) × 10^{10 24}Na atoms are produced. The lower detection limit for the neutron absorption dose is reduced from ∼100 to less than 1 mGy when the radiation detector is placed over the back of the human body close to the liver. The relative error between the measured counts of²⁴Na characteristic γ rays caused by²⁵²Cf neutron irradiation and the counts fitted by monochromatic neutron irradiation data is less than 5.7%. The neutron dose received from a continuous energy spectrum neutron can be acquired quickly and accurately by weighted summing of the data for monochromatic neutron irradiations calculated in this paper, which is more convenient and practical than the previous method.

Recent progress of organic small molecule-based fluorescent probes for intracellular pH sensing

Fluorescent probes along with fluorescence microscopy are essential tools for biomedical research. Various cellular ubiquitous chemical factors such as pH, H₂O₂, and Ca²⁺ are labeled and traced using specific fluorescent probes, therefore helping us to explore their physiological function and pathological change. Among them, intracellular pH value is an important factor that governs biological processes, generally ∼7.2. Furthermore, specific organelles within cells possess unique acid-base homeostasis, involving the acidic lysosomes, alkalescent mitochondria, and neutral endoplasmic reticulum and Golgi apparatus, which undergo various physiological processes such as intracellular digestion, ATP production, and protein folding and processing. In this review, recently reported fluorescent probes targeted toward the lysosomes, mitochondria, endoplasmic reticulum, Golgi apparatus, and cytoplasm for sensing pH change are discussed, which involves molecular structures, fluorescence behavior, and biological applications.

MiR-21-5p in macrophage-derived extracellular vesicles affects podocyte pyroptosis in diabetic nephropathy by regulating A20

OBJECTIVES

Podocyte pyroptosis, characterized by inflammasome activation, plays an important role in inflammation-mediated diabetic nephropathy (DN). Our study aimed to investigate whether miR-21-5p in macrophage-derived extracellular vesicles (EVs) could affect podocyte injury in DN.

METHODS

EVs were extracted after the treatment of RAW 264.7 (mouse macrophage line) with high glucose (HG). The podocyte pyroptosis was determined using the flow cytometry and the western blot. After the knockdown of miR-21-5p in HG-induced RAW264.7 cells, we injected the extracted EVs into DN model mice.

RESULTS

The level of miR-21-5p was higher in HG-stimulated macrophage-derived EVs than in normal glucose-cultured macrophage-derived EVs. The co-culture of EVs and podocytes promoted reactive oxygen species (ROS) production and activation of inflammatory in MPC5 cells (mouse podocyte line). However, restraint of miR-21-5p in EVs reduced ROS production and inhibit inflammasome activation in MPC5 cells, thereby reducing podocytes injury. Meanwhile, we found that miR-21-5p inhibited the A20 expression through binding with its 3'-untranslated regions in MPC5 cells. Further studies showed that A20 was also involved in the regulation of miR-21-5p of RAW 264.7-derived EVs on MPC5 injury. At the same time, it was also proved in the DN model mice that miR-21-5p in macrophage-derived EVs could regulate podocyte injury.

CONCLUSION

MiR-21-5p in macrophage-derived EVs can regulate pyroptosis-mediated podocyte injury by A20 in DN.

Expression of CUE domain containing 2 protein in serous ovarian cancer tissue: predicting disease-free and overall survival of patients

Objective

The aim of this study was to predict disease-free (DFS) and overall (OS) survival of cancer patients through expression of CUE domain containing 2 (CUEDC2) protein.

Methods

In this retrospective study, we investigated CUEDC2 expression in 75 serous ovarian cancer tissues and 34 tubal fimbria tissues by immunohistochemistry. Chemoresistance was analyzed using clinical follow-up data.

Results

CUEDC2 expression scores were 1.35 ± 0.60, 1.54 ± 0.57, 1.78 ± 0.71, and 2.13 ± 0.27 for International Federation of Gynecology and Obstetrics (FIGO) stages I, II, III, and IV tissues, respectively, indicating that CUEDC2 expression increased with stage and that scores differed between patients with early and advanced cancers. We found no differences in CUEDC2 expression for tissues with low, medium, and high differentiation. CUEDC2 expression was unrelated to patient age, pathological grade, or presence or absence of lymph node metastasis, but was related to tumor stage. For CUEDC2-positive patients, median DFS and OS survival were 32.6 and 54.3 months, respectively. For CUEDC2-negative patients, median DFS and OS were 51.9 and 63.5 months, respectively. Expression of CUEDC2 was correlated with DFS but not OS.

Conclusion

CUEDC2 is highly expressed in ovarian cancer tissues and is related to tumor stage and DFS.

An improved method of nasal swab analysis for assessing alpha internal radioactive contaminants

When responding to nuclear and radiological emergencies, rapid and on-site detections of possible internal radioactive contaminants are required for early dose estimation and medical triage. Nasal swab analysis is an effective method to provide valuable information for early and fast estimates of alpha radionuclide inhalation intakes and resultant doses. In this study, to improve the quality of nasal swab measurements, a specialised double-detector alpha counter was designed. Various parameters including swab materials, sample pre-preparation, angle-dependence and vacuum dependence were investigated to optimise the reliability and convenience of the nasal swab method. An improved procedure of direct nasal swab measurement was eventually established, which could be used to obtain early data for initial dose assessment during the first response of nuclear and radiological emergencies.

Toxic trans-crotonaldehyde in mitochondria intercepted by oxyresveratrol contributing to anticancer

The aim of this study was to explore how the toxic trans-crotonaldehyde (TCA) in mitochondria or aldehyde dehydrogenase (ALDH) at different pHs was intercepted by oxyresveratrol (Oxy-Res) contributing to anticancer. Ultraviolet-visible (UV-vis) spectroscopy and Raman spectroscopy were employed. UV-vis spectra showed that the Oxy-Res red shifted the peak of the toxic TCA from 316 nm to 325 nm, while the peaks of the Oxy-Res shifted from 329 nm with 290 nm and 300 nm to 325 nm with 303 nm. In the mitochondria, the Oxy-Res blue shifted the peaks of the toxic TCA from 325 nm with 303 nm to 321 nm with 301 nm. Raman spectra revealed that the Oxy-Res caused shifting of the CHO of the toxic TCA from 1,689 cm^-1 to 1,671 cm^-1 with band decline. The CC of the toxic TCA at 1641 cm^-1 was split into 1,639 cm^-1 and 1,642 cm^-1 with band decline. The bands of the Oxy-Res at 1634 cm^-1 , 1,617 cm^-1 , and 1,595 cm^-1 disappeared. In the mitochondria, the CC of the toxic TCA at 1641 cm^-1 splitting disappeared. In ALDH, with the decrease of pH from 7.8 to 6.5, the CHO of the toxic TCA did not red shift from 1,689 cm^-1 to 1,674 cm^-1 up to pH 6.5. There was no change in the CC of the toxic TCA at 1640 cm^-1 in ALDH at different pHs. The conclusion of the study was that the CHO of the toxic TCA was intercepted by the Oxy-Res under the action of ALDH in the mitochondria, particularly at pH 7.8. © 2019 IUBMB Life, 2019.

Spectropolarimetric measurement based on a fast-axis-adjustable photoelastic modulator

A fast-axis-adjustable photoelastic modulator (Faa-PEM) is developed and studied, and a spectropolarimetric imaging method using the Faa-PEM and an acousto-optic tunable filter is presented. The Faa-PEM modulation retardation amplitude and fast-axis direction of the Faa-PEM can be adjusted by adjusting the two drives with no mechanical rotation. The I, Q, and U of the Stokes parameters of the incident light can be obtained by adjusting the retardation amplitude and fast-axis direction of the Faa-PEM. This measurement method does not require high-frequency components, and thus a general area array detector can realize the measurement. Theoretical simulation analyses show that the relative errors ΔI/I, ΔQ/Q, ΔU/U, and ΔDoLP/DoLP are less than 5.6% and that the deviation error ΔAoLP is less than 0.2° (at I=1.00, Q=0.707, U=0.707, V=0.0, -0.1°≤Δθ₀≤0.1°, and -0.05  rad≤Δδ₀≤0.05  rad). A prototype was developed and tested. The test results show that the average absolute relative error of the degree of linear polarization is 0.36%, and the average absolute deviation error of the angle of linear polarization is 0.048°. The method has potential application value in spectropolarimetric imaging technology.

Reduced TRPC6 mRNA levels in the blood cells of patients with Alzheimer's disease and mild cognitive impairment

Transient receptor potential canonical 6 (TRPC6) inhibits β-amyloid (Aβ) production. Hyperforin, the TRPC6 agonist, reduces Aβ levels and improves cognitive performance in Alzheimer's disease (AD) models. However, it's unknown whether TRPC6 expression is changed in AD patients. In this case-control study, we measured TRPC6 expression levels in the peripheral blood cells of four independent AD sets from five hospitals and one mild cognitive impairment (MCI) set from a local community (229 AD, 70 MCI, 40 Parkinson disease and 359 controls from China, total n=698) using quantitative real-time PCR assay. We found a specific reduction of TRPC6 mRNA levels in four AD sets and one MCI set. The median TRPC6 mRNA levels were lower in the following: (1) combined AD patients than in age-matched controls (0.78 vs 1.73, P<0.001); (2) mild-to-moderate AD patients than in age-matched controls (0.81 vs 1.73, P<0.001); and (3) MCI patients than in age-matched controls (0.76 vs 1.72, P<0.001). In the receiver-operating characteristic curve analysis, the area under curve was 0.85 for combined AD, 0.84 for mild-to-moderate AD and 0.79 for MCI. In a subgroup of AD patients with brain Aβ examination, TRPC6 was associated with standardized uptake value ratio of Pittsburgh Compound B (Spearman's r=-0.49, P=0.04) and cerebrospinal fluid Aβ42 (Spearman's r=0.43, P=0.04). The TRPC6 reduction in AD patients was further confirmed in blood RNA samples from The Australian Imaging, Biomarkers and Lifestyle Flagship Study of Aging, in post-mortem brain tissues from The Netherlands Brain Bank and in induced pluripotent stem cells-derived neurons from Chinese donors. We conclude that TRPC6 mRNA levels in the blood cells are specifically reduced in AD and MCI patients, and TRPC6 might be a biomarker for the early diagnosis of AD.

Thermal stability control system of photo-elastic interferometer in the PEM-FTs

A drifting model for the resonant frequency and retardation amplitude of a photo-elastic modulator (PEM) in the photo-elastic modulated Fourier transform spectrometer (PEM-FTs) is presented. A multi-parameter broadband-matching driving control method is proposed to improve the thermal stability of the PEM interferometer. The automatically frequency-modulated technology of the driving signal based on digital phase-locked technology is used to track the PEM's changing resonant frequency. Simultaneously the maximum optical-path-difference of a laser's interferogram is measured to adjust the amplitude of the PEM's driving signal so that the spectral resolution is stable. In the experiment, the multi-parameter broadband-matching control method is applied to the driving control system of the PEM-FTs. Control of resonant frequency and retardation amplitude stabilizes the maximum optical-path-difference to approximately 236 μm and results in a spectral resolution of 42 cm^-1. This corresponds to a relative error smaller than 2.16% (4.28 standard deviation). The experiment shows that the method can effectively stabilize the spectral resolution of the PEM-FTs.

Fast and Sensitive Ellipsometry-Based Biosensing

In this work, a biosensing method based on in situ, fast, and sensitive measurements of ellipsometric parameters (Ψ, ∆) is proposed. Bare silicon wafer substrate is functionalized and used to bind biomolecules in the solution. Coupled with a 45° dual-drive symmetric photoelastic modulator-based ellipsometry, the parameters Ψ and ∆ of biolayer arising due to biomolecular interactions are determined directly, and the refractive index (RI) of the solution and the effective thickness and surface mass density of the biolayer for various interaction time can be further monitored simultaneously. To illustrate the performance of the biosensing method, immunosensing for immunoglobulin G (IgG) was taken as a case study. The experiment results show that the biosensor response of the limit of detection for IgG is 15 ng/mL, and the data collection time is in milliseconds. Moreover, the method demonstrates a good specificity. Such technique is a promising candidate in developing a novel sensor which can realize fast and sensitive, label-free, easy operation, and cost-effective biosensing.

Refractive index sensor based on a multi-notched plastic optical fiber

We propose a plastic optical fiber (POF) with a multi-notched structure as a long-period grating for refractive index (RI) sensing. A new approach to modify the structure of POFs with enhanced RI sensitivity was carried out. The multi-notched structure was made on the surface of the fiber by pressing a thread rod against the POF. The RI sensing performances for straight and macro-bending (U-shaped) POFs with this structure were studied. It is found that the POF probes with straight multi-notched structures were not sensitive enough for RI measurements. After bending the multi-notched structure into U-shaped probes, the RI sensing performance was improved markedly. By altering the structural parameters, the RI sensing performance of the U-shaped POF probes with multi-notched structures were optimized, and the highest sensitivity of 1130%/RIU with a resolution of 8.44×10^-4RIU in the RI range of 1.333-1.410 was obtained. In addition, the characteristic of the temperature dependence of the sensor was presented. The probe is a low-cost solution for RI sensing purpose, which has the features of simple structure, easy fabrication, compact size, and intensity modulation at visible wavelengths.

[Photo-Elastic Modulation Fourier Transform Spectrum Phase Correction and DSP Implementation]

Photo-elastic modulation Fourier transform spectrum (PEM-FTS) has the characteristics of fast modulation speed and large amount of information. However, because of the sampling position error and other reasons, there exists phase difference in the output interference data, which affects the accuracy of the reconstructed spectrum. Therefore, a phase correction scheme with high computing speed must be adopted. The 300K infrared blackbody was used as the radiant source in the experiment, and interference data were generated by the photo-elastic modulation interferometer. Mertz method is used to correct the phase of photo-elastic modulation interference data on the TMS320C6713 DSP (digital signal processor) chip. First a complete double interference data is extracted befroe the apodization processing to calculate the phase error of small double interference data, which takes the zero optical path as the center. Then a whole interference figure error phase is acquired with interpolating zero and the spectrum of the complete interference data and correcting phase are obtained at last . With two-norm to define the accuracy of corrected spectrum ,and using the method of calculating timer period register to count code running time, and observing program and data memory space in the file of command. The correction results of Mertz method and modulus square method were analysed comparatively. Experimental results show that Mertz method has advantages of fast speed, occupying less storage space and less correction error when implement phase correction on the DSP. And the operation time of Mertz phase correction method is 20 times faster than that of modulus square method.Consequently, it is suitable for high speed and accurate phase correction of PEM-FTS interference data.

Relationship between the gene polymorphism of osteoprotegerin and bone mineral density in hemodialysis patients

OBJECTIVE

To investigate the relationship between the gene polymorphism of osteoprotegerin (OPG) and bone mineral density (BMD) in hemodialysis patients.

PATIENTS AND METHODS

A total of 147 patients with end-stage renal disease (ESRD) who were admitted to the Weifang People's Hospital for maintenance hemodialysis between January 2014 and December 2015 were enrolled. Peripheral blood was collected from the subjects for assay of the polymorphism of A163G and G1181C loci of OPG. The measurements of the levels of RANK, RANKL, TNF-α, IL-6, PINP, CTX-I, CTX-II and TRACP5 in the isolated serum were taken.

RESULTS

For the polymorphism of A163G locus on the OPG gene, the BMDs of left femoral neck and lumbar poster anterior L1-L4 of the AA genotype were significantly higher than those of the AG and GG genotypes. There was no significant difference in comparison of BMDs at the forearm (distal 1/3) between the AA genotype and AG and GG genotypes. No significant differences were found in the comparison of BMDs at all sites between AG and GG genotypes. The serum level of RANKL of the AA genotype was significantly higher than levels of AG and GG genotypes, but the levels of RANK, TNF-α, IL-6, PINP, CTX-I, CTX-II and TRACP5 were prominently lower than those levels of AG and GG genotypes. For the polymorphism of G1181C locus on the OPG gene, the BMDs of left femoral neck and lumbar poster anterior L1-L4 of the CC genotype were significantly higher than the BMDs of GG and GC genotypes, There was no significant difference in the comparison of BMDs at the forearm (distal 1/3) between the CC genotype and GG and GC genotypes. No significant differences were found in the comparison of BMDs at all sites between GG and GC genotypes. The serum level of RANKL of the CC genotype was significantly higher than the level of GG and GC genotypes. However, the levels of RANK, TNF-α, IL-6, PINP, CTX-I, CTX-II and TRACP5 were prominently lower than those levels of GG and GC genotypes.

CONCLUSIONS

The polymorphisms of A163G and G1181C loci on the OPG gene were correlated with the BMD of hemodialysis patients. The genotype AA of A163G and genotype CC of G1181C were identified as the protective factors for BMD.

Temperature dependence of a refractive index sensor based on a macrobending micro-plastic optical fiber

We investigate the temperature dependence of a refractive index (RI) sensor based on a macrobending micro-plastic optical fiber (m-POF) both theoretically and experimentally. The performance of the RI sensor at different temperatures (10°C-70°C) is measured and simulated over an RI range from 1.33 to 1.45. It is found that the temperature dependent bending loss and RI measurement deviation monotonically change with temperature, and the RI deviation has a higher gradient with temperature variation for a higher measured RI. Because of the linear trend of temperature dependence of the sensor, it is feasible to correct for changes in ambient temperature.

Investigation of a macrobending micro-plastic optical fiber for refractive index sensing

This paper investigates a refractive index (RI) sensor based on a macrobending micro-plastic optical fiber (m-POF), which is used as a sensitive probe. The m-POFs are fabricated from commercial POFs using a heating and pulling method. The m-POFs have diameters of approximately 20-40 μm and act as multimode fibers at visible wavelengths. The macrobending structure of the m-POFs is simulated and optimized using the ray tracing method. The RI sensitivity and the range of RI measurements are affected by the structure parameter R/ρ, which is the ratio of the radius of curvature of the macrobending fiber to the radius of the fiber itself. A linear RI sensing response is obtained when R/ρ=20 and the sensitivity reaches 500%/RIU. The experimental results coincide well with the simulation results.