Dietary knowledge-attitude-practice status in hemodialysis patients: a latent profile analysis.

BACKGROUND: Hemodialysis patients require a reasonable dietary intake to manage their disease progression effectively. However, there is limited research on these patients' overall dietary knowledge, attitude, and practice (KAP) status. This study aimed to investigate the dietary KAP status and latent profiles in hemodialysis patients and identify sociodemographic and disease-related factors associated with these profiles and dietary practice. METHODS: A multicenter cross-sectional study involving 425 hemodialysis patients was conducted. A dietary KAP questionnaire in hemodialysis patients was used to evaluate the dietary KAP of the patients. A structural equation model was employed to analyze the correlations between dietary knowledge, attitude, and practice. Multiple linear regression analysis was used to identify factors associated with dietary practice scores. Latent profile analysis was conducted to determine the latent profiles of dietary KAP, and binary logistic regression was used to explore the sociodemographic and disease-related characteristics associated with each KAP profile in hemodialysis patients. RESULTS: The normalized average scores for dietary knowledge, attitude, and practice in hemodialysis patients were 0.58, 0.82, and 0.58, respectively. The structural equation model revealed significant positive correlations between dietary knowledge and attitude, and attitude and practice. Attitude played an indirect effect between knowledge and practice. Gender, cerebrovascular disease, and dietary attitude scores were identified as independent influencing factors for dietary practice scores. Two dietary KAP profiles were developed: a profile with general knowledge and attitude but low practice (40.2%) and a profile with general knowledge and attitude and high practice (59.8%). Binary logistic regression analysis indicated gender and monthly income per household significantly predicted membership in each KAP profile. CONCLUSIONS: The dietary practice of hemodialysis patients requires improvement. It is necessary to develop more individualized dietary interventions for these patients. Further exploration is needed to understand the motivation of patients to change their dietary behavior.

Composite Microfluidic Petri Dish-Chip (MPD-Chip) without Protein Coating for 2D Cell Culture.

Hydrophilicity is a requisite attribute for the 2D cell culture substrate's surface, facilitating cell adhesion and spreading. Conventional poly(dimethylsiloxane) (PDMS) microfluidic chips necessitate protein coatings to enhance hydrophilicity; however, this approach is afflicted by issues of transient efficacy, interference with cell analysis, and high costs. This paper presents a protein-free microfluidic chip, termed a "microfluidic Petri dish-chip (MPD-chip)", integrating PDMS as the cover and a tissue culture-treated (TC-treated) Petri dish as the substrate. Microstructures are hot-embossed onto the Petri dish substrate using a silicon mold. This meticulous replication process serves to establish stable flow field dynamics within the chip. A simplified method for irreversible bonding, utilizing plasma activation and silylation, is proposed for affixing the PDMS cover onto the microstructured Petri dish substrate. The prepared composite chip exhibits remarkable tightness, boasting a notable bond strength of 2825 kPa. Furthermore, the composite microfluidic chip demonstrates the capability to withstand flow velocities of at least 200 µL/min, effectively meeting the required injection standards for both cell suspension and culture medium. SH-SY5Y and HeLa cells are cultured dynamically in the MPD-chip and control groups. Outcomes encompassing normalized cell density, cell adhesion area, and cell viability metrics unequivocally highlight the superiority of the MPD-chip in facilitating long-term two-dimensional (2D) cell cultures.

A cell-electrode interface signal-to-noise ratio model for 3D micro-nano electrode.

Objective. Three-dimensional micro-nano electrodes (MNEs) with the vertical nanopillar array distributed on the surface play an increasingly important role in neural science research. The geometric parameters of the nanopillar array and the cell adhesion state on the nanopillar array are the factors that may affect the MNE recording. However, the quantified relationship between these parameters and the signal-to-noise ratio (SNR) is still unclear. This paper establishes a cell-MNE interface SNR model and obtains the mathematical relationship between the above parameters and SNR.Approach. The equivalent electrical circuit and numerical simulation are used to study the sensing performance of the cell-electrode interface. The adhesion state of cells on MNE is quantified as engulfment percentage, and an equivalent cleft width is proposed to describe the signal loss caused by clefts between the cell membrane and the electrode surface.Main results. Whether the planar substrate is insulated or not, the SNR of MNE is greater than planar microelectrode only when the engulfment percentage is greater than a certain value. Under the premise of maximum engulfment percentage, the spacing and height of nanopillars should be minimized, and the radius of the nanopillar should be maximized for better signal quality.Significance. The model can clarify the mechanism of improving SNR by nanopillar arrays and provides the theoretical basis for the design of such nanopillar neural electrodes.

A microfluidic device inspired by leaky tumor vessels for hematogenous metastasis mechanism research.

Endothelial intercellular pores of tumor vessels generally lead to enhanced interstitial flow and may facilitate the migration of tumor cells. The permeability of tumor vessels causes a concentration gradient of growth factors (CGGF) from blood vessels to tumor tissues, which is opposite to the direction of interstitial flow. In this work, exogenous chemotaxis under the CGGF is demonstrated as a mechanism of hematogenous metastasis. A bionic microfluidic device inspired by endothelial intercellular pores of tumor vessels has been designed to study the mechanism. A porous membrane vertically integrated into the device using a novel compound mold is utilized to mimic the leaky vascular wall. The formation mechanism of the CGGF caused by endothelial intercellular pores is numerically analyzed and experimentally verified. The migration behavior of U-2OS cells is studied in the microfluidic device. The device is divided into three regions of interest (ROI): primary site, migration zone, and tumor vessel. The number of cells in the migration zone increases significantly under the CGGF, but decreases under no CGGF, indicating tumor cells may be guided to the vascellum by exogenous chemotaxis. Transendothelial migration is subsequently monitored, demonstrating the successful replication of the key steps in vitro in the metastatic cascade by the bionic microfluidic device.

Permeation-Enhanced Degassing Method Based on Xylem Embolism Repair and Gas Permeable Materials.

Microfluidic devices have developed a wide range of applications in the fields of biomedicine, chemistry, and analytical science. But it is easy to form and accumulate bubbles in microfluidic devices. These bubbles could decrease the detection sensitivity, cause inaccurate analysis results, and even damage the functional region of the device. Inspired by the embolism repair mechanism of angiosperms and the permeability of gas permeable materials, this work proposes a bioinspired permeation-enhanced degassing method. Bionic redundant pits are used in this method to keep bubbles from spreading between microchannels and maintain the continuity of the flow. A hydrophobic gas permeable material is used to enhance the bubble capture capability and accelerate the degassing process. This method can eliminate bubbles automatically and continuously in real time without auxiliary equipment. Compared to the bubble removal only depending on solution in water, the degassing effect of the permeation-enhanced degassing method shows about 1.6 times improvement in the same conditions, and the capability of trapping bubbles is improved by 1.33 times. In this paper, this method was integrated into a concentration gradient generator and a cell culture device. The results show that the concentration gradient generator with degassing structures can dissolve bubbles in a rapid way and reach the stability of the concentration gradient within 5-15 min. The degassing method can run for a long time and improve the cell density and cell viability of HeLa cells up to 2.64 and 1.12 times, respectively. The method has a broad application prospect in microfluidic fields including biomedical fluid processing, virus detection, and microscale reactor operation.

Engineering a dynamic three-dimensional cell culturing microenvironment using a 'sandwich' structure-liked microfluidic device with 3D printing scaffold.

Most ofin vivotissue cells reside in 3D extracellular matrix (ECM) with fluid flow. To better study cell physiology and pathophysiology, there has been an increasing need in the development of methods for culturing cells inin vivolike microenvironments with a number of strategies currently being investigated including hydrogels, spheroids, tissue scaffolds and very promising microfluidic systems. In this paper, a 'sandwich' structure-liked microfluidic device integrated with a 3D printing scaffold is proposed for three-dimensional and dynamic cell culture. The device consists of three layers, i.e. upper layer, scaffold layer and bottom layer. The upper layer is used for introducing cells and fixing scaffold, the scaffold layer mimicking ECM is used for providing 3D attachment areas, and the bottom layer mimicking blood vessels is used for supplying dynamic medium for cells. Thermally assisted electrohydrodynamic jet (TAEJ) printing technology and microfabrication technology are combined to fabricate the device. The flow field in the chamber of device is evaluated by numerical simulation and particle tracking technology to investigate the effects of scaffold on fluid microenvironment. The cell culturing processes are presented by the flow behaviors of inks with different colors. The densities and viabilities of HeLa cells are evaluated and compared after 72 h of culturing in the microfluidic devices and 48-well plate. The dose-dependent cell responses to doxorubicin hydrochloride (DOX) are observed after 24 h treatment at different concentrations. These experimental results, including the evaluation of cell proliferation andin vitrocytotoxicity assessment of DOX in the devices and plate, demonstrate that the presented microfluidic device has good biocompatibility and feasibility, which have great potential in providing native microenvironments forin vitrocell studies, tissue engineering and drug screening for tumor therapy.

A microfluidic platform culturing two cell lines paralleled under in-vivo like fluidic microenvironment for testing the tumor targeting of nanoparticles.

Nanoparticles are attractive in medicine because their surfaces can be chemically modified for targeting specific disease cells, especially for cancer. Providing an in-vivo like platform is crucial to evaluate the biological behaviours of nanoparticles. This paper presents a microfluidic device that could culture two cell lines in parallel in in-vivo like fluidic microenvironments and be used for testing the tumor targeting of folic acid - cholesterol - chitosan (FACC) nanoparticles. The uniformity and uniformity of flow fields inside the cell culture units are investigated using the finite element method and particle tracking technology. HeLa and A549 cells are cultured in the microfluidic chip under continuous media supplementation, mimicking the fluid microenvironment in vivo. Cell introducing processes are presented by the flow behaviours of inks with different colours. The two cell lines are identified by detecting folate receptors on the cellular membranes. The growth curves of the two cell lines are measured. The two cell lines cultured paralleled inside the microfluidic device are treated with FITC-FACC to investigate the targeting of FACC. The tumor targeting of FACC are also detected by in vivo imaging of HeLa cells growth in nude mice models. The results indicate that the microfluidic device could provide a dynamic, uniform and stable fluidic microenvironment to test the tumor targeting of FACC nanoparticles.

Meta-analysis of the association between four CAPN10 gene variants and gestational diabetes mellitus.

PURPOSE: The purpose of the meta-analysis is to evaluate the association between calpain-10 (CANP10) gene polymorphisms and gestational diabetes mellitus (GDM). METHODS: A computer-based retrieval was performed in Web of Science, Embase and PubMed databases for eligible studies. The genotype data from four variants in CANP10 [single-nucleotide polymorphisms (SNP) 19, 43, 44, and 63] were collected. The pooled Odds ratios (ORs) with 95 % confidence intervals (CI) were conducted for five genetic models. RESULTS: Five studies containing 1003 GDMs and 1788 controls are included in this meta-analysis. The overall combined odds ratios show that SNP 19 and SNP 43 are not associated with increased risk of GDM in all genetic models. The association between SNP 63 and GDM is only significant in the heterozygous model (OR 2.79, 95 % CI 1.15-6.74). The SNP 44 is associated with increased risk of GDM in the recessive model (OR 1.75, 95 % CI 1.07-2.85), but only two studies are included. CONCLUSIONS: This meta-analysis indicates that women carriage of TT genotype in SNP 63 (rs5030952) is associated with increased risk in GDM.