A self-adaptive multi-color fluorescent pH probe with the ability of whole cell imaging

Fluorescent pH probes are promising for both in vitro and in vivo pH detections in chemical and biochemical systems. Previously, the multi-color and whole cell pH sensing is a challenge for conventional fluorescent nanomaterials. In this work, we report an N, S co-doped carbon dots (N, S-CDs)-based fluorescent pH probe that can response to different incident light with tunable wavelength. The emission wavelength is tunable and correlated to the excitation wavelength, enabling self-adaptive multi-color sensing. The N, S-CDs was synthesized by a one-step hydrothermal method utilizing glucose, ammonium persulfate and ethylenediamine as precursors. The fluorescence of N, S-CDs shows a good linear relationship against pH values from 3.0 to 10.0 with a linear correlation coefficient of 0.996. The good biocompatibility and small size fulfill the demand of whole cell intracellular imaging. We have demonstrated that the N, S-CDs have successfully applied in HepG2 cells for the self-adaptive multi-color imaging.

A novel electrochemical enzyme biosensor for detection of 17β-estradiol by mediated electron-transfer system

An extremely sensitive enzyme sensor for detection of 17β-estradiol based on electropolymerized L-lysine molecules on a glassy carbon electrode (GCE) modified with critic acid@graphene (CA-GR) and cross-linked with laccase enzyme has been developed in this work. As the laccase immobilization, glutaraldehyde was chosen as cross-linker through the groups reactions. The novel enzyme sensor could recognize and determinate 17β-estradiol effectively. The morphology of the enzyme modified electrode was characterized by transmission electron microscopy (TEM) and electron microscopy (SEM). The amino interaction between cross-linker and enzyme was characterized by Fourier transform infrared spectroscopy (FTIR). Under the optimal experimental conditions, good linear relationships were achieved in the range of 4 × 10^-13 - 5.7 × 10^-11 M and a limit of detection as low as 1.3 × 10^-13 M. Moreover, the enzyme sensor exhibited good reproducibility, stability and high selectivity to 17β-estradiol. Excellent performance was showed in the human urine samples analysis, thus confirming great prospect for further application in clinic diagnosis and biological research.

MiR-125a-5p ameliorates monocrotaline-induced pulmonary arterial hypertension by targeting the TGF-β1 and IL-6/STAT3 signaling pathways

Pulmonary vascular remodeling due to excessive proliferation and resistance to apoptosis of pulmonary artery smooth muscle cells (PASMCs) is the hallmark feature of pulmonary arterial hypertension (PAH). Recent evidence suggests that miR-125a-5p plays a role in a rat model of monocrotaline-induced PAH (MCT-PAH); however, the underlying mechanism is currently unknown. Here, we examined the expression profile of miR-125a-5p in MCT-PAH rats and investigated the putative therapeutic effect of miR-125a-5p using the miR-125a-5p agomir. In addition, the miR-125a-5p agomir or antagomir was transfected into rat PASMCs, and proliferation and apoptosis were measured. Activity of the miR-125a-5p target STAT3 was measured using a luciferase reporter assay, and the expression of downstream molecules was measured using RT–qPCR and/or western blot analysis. Importantly, inducing miR-125a-5p expression in vivo slowed the progression of MCT-PAH by reducing systolic pulmonary arterial pressure, the Fulton index, and pulmonary vascular remodeling. Moreover, overexpressing miR-125a-5p inhibited the proliferation and promoted the apoptosis of PASMCs. In addition, stimulating PASMCs with TGF-β1 or IL-6 upregulated miR-125a-5p expression, whereas overexpressing miR-125a-5p reduced TGF-β1 and IL-6 production, as well as the expression of their downstream targets STAT3 and Smad2/3; in contrast, downregulating miR-125a-5p increased TGF-β1 and IL-6 production. Finally, a dual-luciferase reporter assay revealed that miR-125a-5p targets the 3′-UTR of STAT3, suppressing the downstream molecules PCNA, Bcl-2, and Survivin. Taken together, these findings suggest that miR-125a-5p ameliorates MCT-PAH in rats, has a negative feedback regulation with TGF-β1 and IL-6, and regulates the proliferation and apoptosis of PASMCs by directly targeting STAT3.

A study in rats suggests that the small RNA molecule miR-125a-5p is a promising therapeutic target for treating pulmonary arterial hypertension (PAH). This type of high blood pressure is due to the narrowing of arteries that carry blood from the heart to the lungs and at present has no cure. Jieyan Shen at Shanghai Jiao Tong University, China, and colleagues found that PAH lowers the levels of miR-125a-5p in rat pulmonary arteries and that administration of miR-125a-5p as an early preventative treatment reduced disease progression. miR-125a-5p slowed the proliferation of pulmonary artery smooth muscle cells and triggered cell death by directly interacting with a gene expression regulator and reducing the production of certain pro-inflammatory signaling molecules. Targeting miR-125a-5p’s mechanism of action could represent a new treatment approach for this chronic, life-changing disease.

Study on the relationship between social support and mental health of the elderly in China: a case study of Xi'an city, Shaanxi province

BACKGROUND

The elderly's mental health is becoming more and more severe under the aging society in China (one third of the elderly had the symptom of depression according to the statistics). It is urgent to explore how the social support system of the elderly can influence their mental health and how to enhance their mental care from the perspective of social support.

AIMS

This article analyzes the relationship between social support and mental health of the elderly using quantitative and qualitative data. Methods results: This study relies on a survey did in 2016 in Xi'an among elderly over the age of 60, mainly using structural questionnaires and assisted with interviews for some specific people. The study finds that the status of mental health of the elderly in Xi'an maintains a medium-to-high level (the minimum value is 8, the maximum is 32, the average is 24.06 and the standard deviation is 4.278).

CONCLUSIONS

The children's support plays a decisive role in the elderly's mental health, which is a hygiene factor; friends, neighbors and social participation for the elderly also contribute to the mental health, which is a motivator factor. Besides, some special cases, such as those elderly who lost their only child, those migrating to other cities and those empty nesters, have become the vulnerable groups in mental health.

The further exploration of hidden blood loss in posterior lumbar fusion surgery

PURPOSE

Hidden blood loss (HBL) plays an important role in lumbar fusion surgery. However, there was huge computation error when calculating hidden loss in previous studies because they regarded the volume of drainage as postoperative blood loss. We should not ignore the fact that the composition of drainage varies from person to person and also with time-lapse after operation. The purpose of this study was to demonstrate a more accurate HBL calculation formula by comparing it with previous formula and to address the importance of HBL in patients undergoing posterior lumbar fusion surgeries.

METHODS

For each patient, the HBL was calculated by previous formula and our recommendable formula. We compared the result of HBL calculated by two different methods. At the same time, we explored the HBL in patients undergoing posterior lumbar fusion surgeries with various levels.

RESULTS

In our study, the average total blood loss was 771ml. The mean intraoperative blood loss was 268ml, and the total volume of post-operative drainage is 276ml. The mean hidden loss of 90 patients calculated with previous method was 227ml and 29.4% of total loss. When taking change of drainage HCT into account, the mean hidden loss calculated with our recommendable method was 362.8ml and 47% of total loss. The results were significantly different (P<0.01). There was no significant difference in the percentage of the HBL between patients with single or multiple surgical levels.

CONCLUSIONS

There is often a substantial unmeasured blood loss in lumbar fusion surgeries. However, the component of drainage changed radically with time, we should take the true blood contained in drainage into considerations when calculating the HBL.

LEVEL OF EVIDENCE

Our research is a case-control study and the level of proof is III.

Near-Infrared-Triggered Photodynamic Therapy with Multitasking Upconversion Nanoparticles in Combination with Checkpoint Blockade for Immunotherapy of Colorectal Cancer

While immunotherapy has become a highly promising paradigm for cancer treatment in recent years, it has long been recognized that photodynamic therapy (PDT) has the ability to trigger antitumor immune responses. However, conventional PDT triggered by visible light has limited penetration depth, and its generated immune responses may not be robust enough to eliminate tumors. Herein, upconversion nanoparticles (UCNPs) are simultaneously loaded with chlorin e6 (Ce6), a photosensitizer, and imiquimod (R837), a Toll-like-receptor-7 agonist. The obtained multitasking UCNP-Ce6-R837 nanoparticles under near-infrared (NIR) irradiation with enhanced tissue penetration depth would enable effective photodynamic destruction of tumors to generate a pool of tumor-associated antigens, which in the presence of those R837-containing nanoparticles as the adjuvant are able to promote strong antitumor immune responses. More significantly, PDT with UCNP-Ce6-R837 in combination with the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) checkpoint blockade not only shows excellent efficacy in eliminating tumors exposed to the NIR laser but also results in strong antitumor immunities to inhibit the growth of distant tumors left behind after PDT treatment. Furthermore, such a cancer immunotherapy strategy has a long-term immune memory function to protect treated mice from tumor cell rechallenge. This work presents an immune-stimulating UCNP-based PDT strategy in combination with CTLA-4 checkpoint blockade to effectively destroy primary tumors under light exposure, inhibit distant tumors that can hardly be reached by light, and prevent tumor reoccurrence via the immune memory effect.

The Study of Living Conditions and Perceived Needs for Social Security among Clergy in China: A Case Study of Guanzhong Qinling Area

This study used quantitative and qualitative data collected in the Guanzhong Qinling area of China to examine living conditions and perceived needs for social security among men and women of the clergy. The survey finds that most respondent clergy are Buddhists. When the clergy have economic difficulties, their main types of support include self-support (28.8%), help from other believers (25.6%), and assistance from other community residents (18.4%). When the clergy are old, they tend to live alone (25%), receive institutional care from religious organizations (19%), and receive support from other believers (18%). When the clergy are ill, they will often select self-treatment (primarily the use of traditional Chinese medicine [25%], and spiritual healing [25%], including meditation, prayers, and psychotherapy) and receive treatment at hospitals (20%). The study found that the clergy perceived their needs for social security as either great (19.7%) or modest (36.5%). Very few clergy (10%) indicate the absence of social security needs. Most clergy believe that the key social security priorities should be medical care (34%), elderly care (29%), and charitable assistance (21%).

Damage point prediction of a force chain based on the digital image correlation method

The development and evolution of the force chain in a granular system is an important factor that affects the stability of granular systems. In this work, the displacement threshold (S_C) and angle threshold (θ_d) are proposed, and a new method to predict the damage point in the force chain is introduced and verified. A two-dimensional steel ball particle system under concentrated loading is analyzed; during the deformation process, images are constantly recorded by a CCD camera. Based on the digital image correlation method, the displacement and movement direction of each particle in the steel ball particle system is analyzed, and a prediction analysis of the damage point in the force chains is performed.

Mechanical analysis and force chain determination in granular materials using digital image correlation

The mechanical behaviors of granular materials are governed by the grain properties and microstructure of the materials. We conducted experiments to study the force transmission in granular materials using plane strain tests. The large amount of nearly continuous displacement data provided by the advanced noncontact experimental technique of digital image correlation (DIC) has provided a means to quantify local displacements and strains at the particle level. The average strain of each particle could be calculated based on the DIC method, and the average stress could be obtained using Hooke's law. The relationship between the stress and particle force could be obtained based on basic Newtonian mechanics and the balance of linear momentum at the particle level. This methodology is introduced and validated. In the testing procedure, the system is tested in real 2D particle cases, and the contact forces and force chain are obtained and analyzed. The system has great potential for analyzing a real granular system and measuring the contact forces and force chain.

Endoplasmic reticulum stress eIF2α-ATF4 pathway-mediated cyclooxygenase-2 induction regulates cadmium-induced autophagy in kidney

The heavy metal cadmium (Cd) is nephrotoxic. Recent studies show that autophagy plays an essential role in Cd-induced kidney injury. However, the mechanisms of Cd-induced kidney injury accompanied by autophagy are still obscure. In the present study, we first confirmed that Cd induced kidney damage and dysfunction, along with autophagy, both in vivo and in vitro. Then, we observed that cyclooxygenase-2 (COX-2) and the eIF2α-ATF4 pathway of endoplasmic reticulum (ER) stress were induced by Cd in both kidney tissues and cultured cells. Further studies showed that inhibition of COX-2 with celecoxib or RNA interference (RNAi) inhibited the Cd-induced autophagy in kidney cells. In addition, blocking ER stress with 4-phenylbutyrate or RNAi partially counteracted COX-2 overexpression and autophagy induced by Cd, which suggested that ER stress was required for Cd-induced kidney autophagy. Significantly, our results showed that Cd activated ATF4 and induced its translocation to the nucleus. Knockdown of ATF4 inhibited Cd-induced COX-2 overexpression. While COX-2 overexpression is involved in renal dysfunction, there is no prior report on the role of COX-2 in autophagy regulation. The results of the current study suggest a novel molecular mechanism that the ER stress eIF2α-ATF4 pathway-mediated COX-2 overexpression contributes to Cd-induced kidney autophagy and injury. The present study implies that COX-2 may be a potential target for therapy against Cd-induced nephrotoxicity.