[Application of modified acetabular anteversion and inclination angles test system in patients undergoing total hip arthroplasty after lumbar fusion].

Objective: To investigate the accuracy and effectiveness of acetabular cup placement in total hip arthroplasty (THA) after lumbar fusion applying of modified acetabular anteversion and inclination angles test system. Methods: A clinical data of 45 patients undergoing THA for osteoarthritis between January 2018 and June 2023 was retrospectively analyzed. All patients had previously received lumbar fusion. The modified acetabular anteversion and inclination angle test system was used in 26 cases (observation group) and not used in 19 cases (control group) during THA. There was no significant difference in baseline data such as gender, age, body mass index, operative side, number of lumbar fusion segments, and preoperative Harris score between the two groups ( P>0.05). The position of acetabular prosthesis, hip function (Harris score), and incidence of complications were compared between the two groups. Results: In the observation group, all acetabular cups were in the safe zone (anteversion angle, 25°-30°) during operation, and 1 acetabular cup (3.85%) was not in the safe zone after operation. In the control group, 9 acetabular cups (47.37%) were not in the safe zone. The postoperative difference between the two groups was significant ( P<0.05). There was no significant difference between intra- and post-operative acetabular inclination angles in the observation group ( P>0.05), and the postoperative acetabular inclination angle was significantly smaller in the observation group than in the control group ( P<0.05). All incisions healed by first intention and no infection occurred. All patients were followed up 6 months. There was no significant difference in Harris score between the two groups at different time point ( P>0.05), and there were significant differences between different time points in the two groups ( P<0.05). No joint dislocation occurred in the observation group during follow-up, while dislocation occurred in 2 cases and femoral impingement syndrome occurred in 1 case of the control group. There was no significant difference in the incidence of complications between the two groups ( P>0.05). Conclusion: For THA patients with lumbar fusion, the ideal placement angle of the acetabular cup can be obtained by using the modified acetabular anteversion and inclination angles test system during operation.

Relationship between lysine methyltransferase levels and heterochromatin gene repression in living cells and in silico.

Gene regulation plays essential roles in all multicellular organisms, allowing for different specialized tissue types to be generated from a complex genome. Heterochromatin-driven gene repression, associated with a physical compaction of the genome, is a pathway involving core components that are conserved from yeast to human. Posttranslational modification of chromatin is a critical component of gene regulation. Specifically, tri-methylation of the nucleosome component histone 3 at lysine 9 (H3K9me3) is a key feature of this pathway along with the hallmark heterochromatin protein 1 (HP1). Histone methyltransferases are recruited by HP1 to deposit H3K9me3 marks which nucleate and recruit more HP1 in a process that spreads from the targeting site to signal for gene repression. One of the enzymes recruited is SETDB1, a methyltransferase which putatively catalyzes posttranslational methylation marks on H3K9. To better understand the contribution of SETDB1 in heterochromatin formation, we downregulated SETDB1 through knockdown by a dCas9-KRAB system and examined heterochromatin formation in a chromatin in vivo assay (CiA-Oct4). We studied the contribution of SETDB1 to heterochromatin formation kinetics in a developmentally crucial locus, Oct4. Our data demonstrate that SETDB1 reduction led to a delay in both gene silencing and in H3K9me3 accumulation. Importantly, SETDB1 knockdown to a ∼50% level did not stop heterochromatin formation completely. Particle-based Monte Carlo simulations in 3D space with explicit representation of key molecular processes enabled the elucidation of how SETDB1 downregulation affects the individual molecular processes underlying heterochromatin formation.

LncRNA HAGLR silencing inhibits IL-1ß-induced chondrocytes inflammatory injury via miR-130a-3p/JAK1 axis.

BACKGROUND: Osteoarthritis (OA), the most common form of arthritis, is accompanied by destruction of articular cartilage, development of osteophyte and sclerosis of subchondral bone. This study aims to explore whether lncRNA HAGLR can play a role in OA, and further clarify the potential mechanism. MATERIAL AND METHODS: StarBase and luciferase reporter assay were applied for predicting and confirming the interaction between lncRNA HAGLR, miR-130a-3p and JAK1. The levels of lncRNA HAGLR and miR-130a-3p were analyzed using quantitative reverse transcription PCR (qRT-PCR). The proliferation, cytotoxicity and apoptosis of CHON-001 cells were evaluated by MTT, lactate dehydrogenase assay (LDH) and Flow cytometry (FCM) analysis, respectively. Moreover, expression of cleaved Caspase3 protein were determined by Western blot assay. The release of inflammatory factors (TNF-α, IL-8, and IL-6) was detected by ELISA. RESULTS: lncRNA HAGLR directly targets miR-130a-3p. Level of lncRNA HAGLR was substantially higher and miR-130a-3p level was memorably lower in IL-1ß stimulated CHON-001 cells than that in Control group. Furthermore, lncRNA HAGLR silencing alleviated IL-1ß induce chondrocyte inflammatory injury, as evidenced by increased cell viability, reduced LDH release, decreased apoptotic cells, inhibited cleaved-Caspase3 expression, and reduced secretion of secretion of inflammatory factors. However, miR-130a-3p-inhibitor reversed these findings. We also found miR-130a-3p directly targeted JAK1 and negatively regulated JAK1 expression in CHON-001 cells. In addition, JAK1-plasmid reversed the effects of miR-130a-3p mimic on IL-1ß-induced chondrocytes inflammatory injury. CONCLUSION: Silencing of lncRNA HAGLR alleviated IL-1ß-stimulated CHON-001 cells injury through miR-130a-3p/JAK1 axis, revealing lncRNA HAGLR may be a valuable therapeutic target for OA therapy.

Research on Rheology and Formability of SiO2 Ceramic Slurry Based on Additive Manufacturing Technology via a Light Curing Method.

SiO2 ceramic parts with complex structures were formed by additive manufacturing technology via a light curing method combined with a heat treatment process. To reveal the influence mechanism of rheology and formability of SiO2 ceramic slurry, the microstructure, morphology, and properties of light-cured SiO2 ceramic samples were characterized by a viscosity test, thermogravimetric analysis (TG-DTG), X-ray diffraction (XRD), a scanning electron microscope (SEM), and a series of tests for physical properties (bending strength, mass burning rate, and densification). The results indicate that the main effect of the dispersant-type factor was more significant than the pH value. When the dispersant was ammonium polyacrylate (PMAA-NH4) with a content of 1.0 wt % and the pH value of the slurry system was 9, the viscosity of SiO2 ceramic slurry could be controlled to the lowest. It was also found that the sintering temperature in the experiment had no effect on the crystalline phase of SiO2 ceramics. When the sintering temperature was 1250 °C and the solid content was 65 vol %, the micromorphology of the samples was uniform. Under this condition, the bending strength of the sample reached 14.9 MPa and the densification was 76.43%.

Long non-coding RNA HCG11 enhances osteosarcoma phenotypes by sponging miR-1245b-5p that directly inhibits plakophilin 2.

Long non-coding RNA (lncRNA) HCG11 can regulate various cancers through the ceRNA network. However, its role in osteosarcoma (OS) remains unknown. The HOS and Saos-2 cell lines were used for in vitro analyses. HCG11 and plakophilin 2 (PKP2) silencers, a miR-1245b-5p mimic, and a miR-1245b-5p inhibitor were utilized for the regulation analysis of lncRNA HCG11, miR-1245b-5p, and PKP2. Cell Counting Kit-8, wound healing, and transwell assays were used for cell proliferation, migration, and invasion analyses, and caspase-3 activity assay was used to measure cell apoptosis. The expression levels of lncRNA HCG11, miR-1245b-5p, and PKP2 were evaluated by quantitative real-time PCR and Western blotting. The distribution of lncRNA HCG11 was assessed using the RNA-FISH assay. The sponging and targeting roles of HCG11 and PKP2 on miR-1245b-5p were confirmed by dual-luciferase reporter analysis. An RNA immunoprecipitation assay was used to assess the binding between lncRNA HCG11 and miRNA-1245b-5p. We found that the lncRNA HCG11 was significantly upregulated in OS. LncRNA HCG11 silencing inhibits OS progression by repressing cell proliferation, migration, and invasion, and promoting cell apoptosis. RNA-FISH analysis indicated that lncRNA HCG11 was located in the cytoplasm. Mechanistic experiments showed that lncRNA HCG11 sponges miR-1245b-5p and negatively regulates miR-1245b-5p expression. Upregulated lncRNA HCG11 promotes proliferation, migration, and invasion, and inhibits apoptosis by inhibiting miR-1245b-5p in OS cells. PKP2 was verified as a target gene of miR-1245b-5p. Upregulated PKP2 promotes proliferation, migration, and invasion, and inhibits apoptosis by inhibiting miR-1245b-5p in OS. In conclusion, the HCG11/miR-1245b-5p/PKP2 axis promotes OS expression by promoting cell proliferation, migration, and invasion, and inhibiting apoptosis.

A target-agnostic screen identifies approved drugs to stabilize the endoplasmic reticulum-resident proteome.

Endoplasmic reticulum (ER) dysregulation is associated with pathologies including neurodegenerative, muscular, and diabetic conditions. Depletion of ER calcium can lead to the loss of resident proteins in a process termed exodosis. To identify compounds that attenuate the redistribution of ER proteins under pathological conditions, we performed a quantitative high-throughput screen using the Gaussia luciferase (GLuc)-secreted ER calcium modulated protein (SERCaMP) assay, which monitors secretion of ER-resident proteins triggered by calcium depletion. We identify several clinically used drugs, including bromocriptine, and further characterize them using assays to measure effects on ER calcium, ER stress, and ER exodosis. Bromocriptine elicits protective effects in cell-based models of exodosis as well as in vivo models of stroke and diabetes. Bromocriptine analogs with reduced dopamine receptor activity retain similar efficacy in stabilizing the ER proteome, indicating a non-canonical mechanism of action. This study describes a strategic approach to identify small-molecule drugs capable of improving ER proteostasis in human disease conditions.

Determination and modulation of the typical interactions among dispersed phases relevant to flotation applications: A review.

Flotation is a process involving multi-components, multi-scales, and gas-liquid-solid three phases, where the material separation is achieved based on the difference in surface hydrophobicity of various constituents. In a flotation system, fluids are usually regarded as the continuous phase, while the dispersed phases refer to scattered particles, bubbles, and droplets with low solubility as a dispersion that is surrounded by the aqueous environment. Fundamentally, the interactions among dispersed phases exist throughout the flotation process, and play distinct roles during different periods. For example, the liquid collector-solid, solid-solid, bubble-bubble and gas bubble-solid interactions are closely associated with the particle surface modification, particle behavior, bubble size evolution and separation in flotation, respectively. Therefore, the influences of each stage are all worthy of concern, and should be spared sufficient attention, which requires to formulate a horizontal writing structure. In this review, instead of summarizing all available characterization techniques or measurements, certain typical examples or methods were consciously chosen to perform analysis or comparison, aiming to summarize recent studies on the determination and modulation of dispersed phase interactions. The determination on the interactions among dispersed phases is helpful for fundamentally understanding the microcosmic process connotations, and their modulation contributes to firmly providing macroscopic optimization schemes for practical applications. By integrating some typically available theoretical calculations and experimental measurements related to the dispersed phase interactions, the present article is devoted to revealing the influential factors, finding out the current challenges or knowledge gaps, and affording certain references or suggestions for future investigations.

Comprehensive nucleosome interactome screen establishes fundamental principles of nucleosome binding.

Nuclear proteins bind chromatin to execute and regulate genome-templated processes. While studies of individual nucleosome interactions have suggested that an acidic patch on the nucleosome disk may be a common site for recruitment to chromatin, the pervasiveness of acidic patch binding and whether other nucleosome binding hot-spots exist remain unclear. Here, we use nucleosome affinity proteomics with a library of nucleosomes that disrupts all exposed histone surfaces to comprehensively assess how proteins recognize nucleosomes. We find that the acidic patch and two adjacent surfaces are the primary hot-spots for nucleosome disk interactions, whereas nearly half of the nucleosome disk participates only minimally in protein binding. Our screen defines nucleosome surface requirements of nearly 300 nucleosome interacting proteins implicated in diverse nuclear processes including transcription, DNA damage repair, cell cycle regulation and nuclear architecture. Building from our screen, we demonstrate that the Anaphase-Promoting Complex/Cyclosome directly engages the acidic patch, and we elucidate a redundant mechanism of acidic patch binding by nuclear pore protein ELYS. Overall, our interactome screen illuminates a highly competitive nucleosome binding hub and establishes universal principles of nucleosome recognition.

On the utilization of waste fried oil as flotation collector to remove carbon from coal fly ash.

In this paper, the waste fried oil was used to remove the unburned carbon in coal fly ash during flotation process, and found that the waste fried oil could be a novel collector for the removal of carbon from coal fly ash. The results implied that the wetting rate of the fly ash after treated by waste fried oil was decreased, meanwhile the contact angle was increased. A significant decrease in wetting heat was observed, which indicated a weaker interaction between deionized water and fly ash after treatment with waste fried oil. Flotation tests showed that the content of unburned carbon could be reduced effectively through froth flotation when took waste fried oil as collector. FTIR analysis testified that waste fried oil had abundant oxygen-containing groups that could be adsorbed in a carbonaceous matter to achieve hydrophobization. X-ray photoelectron spectroscopy, scanning electron microscope, and energy dispersive analyses showed that the main compositions of flotation concentrate products were unburned carbon, whereas the tailing products consist of aluminum and silicon, which confirmed the superior separation performance when the waste fried oil was used as a collector in coal fly ash flotation. This investigation provides an approach to remove the unburned carbon in coal fly ash based on the principle of "waste control through waste", which can solve the environmental problems brought by large amounts of both coal fly ash and waste fried oils.

Design of a debinding process for polymetallic material green parts fabricated via metal paste injection 3D printing with dual nozzles.

Debinding is one of the most critical processes in metal paste injection 3D printing technology (MPI). In order to design the optimal debinding parameters, the debinding temperature, debinding time and heating rate were discussed from the perspective of dynamics. The results showed that there was a peak in liquid phase mass transfer during debinding, exhibiting the characteristics of migration with debinding temperatures. For gas phase mass transfer, when the temperature was 300 °C, the thermal debinding diffusion coefficient was the largest (9.7 × 10-5 cm2 s-1) and the corresponding debinding time was 3.5 h. By analyzing the activation energy of the debinding reaction, when the heating rate was 10 °C min-1, the activation energy required for the thermal debinding reaction was the smallest. Combined with the sintering process, the interwoven structural parts of the copper and cupronickel components were finally obtained. The average hardness of the polymetallic parts was 78.8 HV, and the density was 8.1 g cm-3.

Effects of particle size on the flotation behavior of coal fly ash.

The effect of particle size on the flotation behavior of coal fly ash was investigated in this study. Three narrow particle size fractions, -125 + 74 µm, -74 + 45 µm, and -45 µm, and the unclassified particle size fraction of -500 µm of coal fly ash were chosen to study the basic properties by the measurement of induction time, contact angle, and wetting heat. Furthermore, flotation kinetic tests of coal fly ash with different particle size fractions were conducted. The results show that particle size significantly affects the flotation kinetics of coal fly ash, and the intermediate particle size fractions of -125 + 74 µm and -74 + 45 µm had better flotation performance and higher flotation rate than the fine particle size of -45 µm. Six flotation kinetic models were used to fit the test data of the cumulative unburned carbon recovery in the coal fly ash flotation. The parameters of flotation rate (k), maximum unburned carbon recovery (ε∞), and correlation coefficient (R2) were analyzed in detail. The fitted results from the data showed that, for each size fraction, the froth flotation of coal fly ash can be best described by the classical first-order model.

Thermal debinding mass transfer mechanism and dynamics of copper green parts fabricated by an innovative 3D printing method.

To explore the thermal debinding mass transfer mechanism and dynamics of an innovative copper paste injection 3D printing method, the thermal behavior of the copper paste was investigated to clarify the stages of the debinding process. Furthermore, the debinding ratio, burnout ratio, shrinkage and microstructures were characterized to study the mass transfer channel and dynamics. The dynamics equation of diffusion mass transfer was analyzed. The activation energy and pre-exponential factor were calculated. The results revealed that gas phase mass transfer was the main mass transfer path and the diffusion coefficient in the carbon powder embedded environment (2.68 × 10-5 cm2 s-1) was higher than that in air atmosphere (1.96 × 10-5 cm2 s-1). Moreover, the migration of solid phase materials and the diffusion of atoms are also discussed. When combined with the sintering process, the sintered metal parts had a smooth surface flatness and excellent metallurgical bonding, the thin wall of which was only 340 µm thick.

Longitudinal monitoring of Gaussia and Nano luciferase activities to concurrently assess ER calcium homeostasis and ER stress in vivo.

The endoplasmic reticulum (ER) is essential to many cellular processes including protein processing, lipid metabolism and calcium storage. The ability to longitudinally monitor ER homeostasis in the same organism would offer insight into progressive molecular and cellular adaptations to physiologic or pathologic states, but has been challenging. We recently described the creation of a Gaussia luciferase (GLuc)-based secreted ER calcium-modulated protein (SERCaMP or GLuc-SERCaMP) to longitudinally monitor ER calcium homeostasis. Here we describe a complementary tool to measure the unfolded protein response (UPR), utilizing a UPRE-driven secreted Nano luciferase (UPRE-secNLuc) to examine the activating transcription factor-6 (ATF6) and inositol-requiring enzyme 1 (IRE1) pathways of the UPR. We observed an upregulation of endogenous ATF6- and XBP1-regulated genes following pharmacologically-induced ER stress that was consistent with responsiveness of the UPRE sensor. Both GLuc and NLuc-based reporters have favorable properties for in vivo studies, however, they are not easily used in combination due to overlapping substrate activities. We describe a method to measure the enzymatic activities of both reporters from a single sample and validated the approach using culture medium and rat blood samples to measure GLuc-SERCaMP and UPRE-secNLuc. Measuring GLuc and NLuc activities from the same sample allows for the robust and quantitative measurement of two cellular events or cell populations from a single biological sample. This study is the first to describe the in vivo measurement of UPRE activation by sampling blood, using an approach that allows concurrent interrogation of two components of ER homeostasis.

A Low Affinity GCaMP3 Variant (GCaMPer) for Imaging the Endoplasmic Reticulum Calcium Store.

Endoplasmic reticulum calcium homeostasis is critical for cellular functions and is disrupted in diverse pathologies including neurodegeneration and cardiovascular disease. Owing to the high concentration of calcium within the ER, studying this subcellular compartment requires tools that are optimized for these conditions. To develop a single-fluorophore genetically encoded calcium indicator for this organelle, we targeted a low affinity variant of GCaMP3 to the ER lumen (GCaMPer (10.19)). A set of viral vectors was constructed to express GCaMPer in human neuroblastoma cells, rat primary cortical neurons, and human induced pluripotent stem cell-derived cardiomyocytes. We observed dynamic changes in GCaMPer (10.19) fluorescence in response to pharmacologic manipulations of the ER calcium store. Additionally, periodic calcium efflux from the ER was observed during spontaneous beating of cardiomyocytes. GCaMPer (10.19) has utility in imaging ER calcium in living cells and providing insight into luminal calcium dynamics under physiologic and pathologic states.

Monitoring Endoplasmic Reticulum Calcium Homeostasis Using a Gaussia Luciferase SERCaMP.

The endoplasmic reticulum (ER) contains the highest level of intracellular calcium, with concentrations approximately 5,000-fold greater than cytoplasmic levels. Tight control over ER calcium is imperative for protein folding, modification and trafficking. Perturbations to ER calcium can result in the activation of the unfolded protein response, a three-prong ER stress response mechanism, and contribute to pathogenesis in a variety of diseases. The ability to monitor ER calcium alterations during disease onset and progression is important in principle, yet challenging in practice. Currently available methods for monitoring ER calcium, such as calcium-dependent fluorescent dyes and proteins, have provided insight into ER calcium dynamics in cells, however these tools are not well suited for in vivo studies. Our lab has demonstrated that a modification to the carboxy-terminus of Gaussia luciferase confers secretion of the reporter in response to ER calcium depletion. The methods for using a luciferase based, secreted ER calcium monitoring protein (SERCaMP) for in vitro and in vivo applications are described herein. This video highlights hepatic injections, pharmacological manipulation of GLuc-SERCaMP, blood collection and processing, and assay parameters for longitudinal monitoring of ER calcium.