Parallel analysis of transcription, integration, and sequence of single HIV-1 proviruses.

HIV-1-infected cells that persist despite antiretroviral therapy (ART) are frequently considered "transcriptionally silent," but active viral gene expression may occur in some cells, challenging the concept of viral latency. Applying an assay for profiling the transcriptional activity and the chromosomal locations of individual proviruses, we describe a global genomic and epigenetic map of transcriptionally active and silent proviral species and evaluate their longitudinal evolution in persons receiving suppressive ART. Using genome-wide epigenetic reference data, we show that proviral transcriptional activity is associated with activating epigenetic chromatin features in linear proximity of integration sites and in their inter- and intrachromosomal contact regions. Transcriptionally active proviruses were actively selected against during prolonged ART; however, this pattern was violated by large clones of virally infected cells that may outcompete negative selection forces through elevated intrinsic proliferative activity. Our results suggest that transcriptionally active proviruses are dynamically evolving under selection pressure by host factors.

Loss of Bcl-6-Expressing T Follicular Helper Cells and Germinal Centers in COVID-19.

Humoral responses in coronavirus disease 2019 (COVID-19) are often of limited durability, as seen with other human coronavirus epidemics. To address the underlying etiology, we examined post mortem thoracic lymph nodes and spleens in acute SARS-CoV-2 infection and observed the absence of germinal centers and a striking reduction in Bcl-6+ germinal center B cells but preservation of AID+ B cells. Absence of germinal centers correlated with an early specific block in Bcl-6+ TFH cell differentiation together with an increase in T-bet+ TH1 cells and aberrant extra-follicular TNF-α accumulation. Parallel peripheral blood studies revealed loss of transitional and follicular B cells in severe disease and accumulation of SARS-CoV-2-specific "disease-related" B cell populations. These data identify defective Bcl-6+ TFH cell generation and dysregulated humoral immune induction early in COVID-19 disease, providing a mechanistic explanation for the limited durability of antibody responses in coronavirus infections, and suggest that achieving herd immunity through natural infection may be difficult.

Functional impairment of HIV-specific CD8+ T cells precedes aborted spontaneous control of viremia.

Spontaneous control of HIV infection has been repeatedly linked to antiviral CD8+ T cells but is not always permanent. To address mechanisms of durable and aborted control of viremia, we evaluated immunologic and virologic parameters longitudinally among 34 HIV-infected subjects with differential outcomes. Despite sustained recognition of autologous virus, HIV-specific proliferative and cytolytic T cell effector functions became selectively and intrinsically impaired prior to aborted control. Longitudinal transcriptomic profiling of functionally impaired HIV-specific CD8+ T cells revealed altered expression of genes related to activation, cytokine-mediated signaling, and cell cycle regulation, including increased expression of the antiproliferative transcription factor KLF2 but not of genes associated with canonical exhaustion. Lymphoid HIV-specific CD8+ T cells also exhibited poor functionality during aborted control relative to durable control. Our results identify selective functional impairment of HIV-specific CD8+ T cells as prognostic of impending aborted HIV control, with implications for clinical monitoring and immunotherapeutic strategies.

Phenotypic signatures of immune selection in HIV-1 reservoir cells.

Human immunodeficiency virus 1 (HIV-1) reservoir cells persist lifelong despite antiretroviral treatment1,2 but may be vulnerable to host immune responses that could be exploited in strategies to cure HIV-1. Here we used a single-cell, next-generation sequencing approach for the direct ex vivo phenotypic profiling of individual HIV-1-infected memory CD4+ T cells from peripheral blood and lymph nodes of people living with HIV-1 and receiving antiretroviral treatment for approximately 10 years. We demonstrate that in peripheral blood, cells harbouring genome-intact proviruses and large clones of virally infected cells frequently express ensemble signatures of surface markers conferring increased resistance to immune-mediated killing by cytotoxic T and natural killer cells, paired with elevated levels of expression of immune checkpoint markers likely to limit proviral gene transcription; this phenotypic profile might reduce HIV-1 reservoir cell exposure to and killing by cellular host immune responses. Viral reservoir cells harbouring intact HIV-1 from lymph nodes exhibited a phenotypic signature primarily characterized by upregulation of surface markers promoting cell survival, including CD44, CD28, CD127 and the IL-21 receptor. Together, these results suggest compartmentalized phenotypic signatures of immune selection in HIV-1 reservoir cells, implying that only small subsets of infected cells with optimal adaptation to their anatomical immune microenvironment are able to survive during long-term antiretroviral treatment. The identification of phenotypic markers distinguishing viral reservoir cells may inform future approaches for strategies to cure and eradicate HIV-1.

Distinct viral reservoirs in individuals with spontaneous control of HIV-1.

Sustained, drug-free control of HIV-1 replication is naturally achieved in less than 0.5% of infected individuals (here termed 'elite controllers'), despite the presence of a replication-competent viral reservoir1. Inducing such an ability to spontaneously maintain undetectable plasma viraemia is a major objective of HIV-1 cure research, but the characteristics of proviral reservoirs in elite controllers remain to be determined. Here, using next-generation sequencing of near-full-length single HIV-1 genomes and corresponding chromosomal integration sites, we show that the proviral reservoirs of elite controllers frequently consist of oligoclonal to near-monoclonal clusters of intact proviral sequences. In contrast to individuals treated with long-term antiretroviral therapy, intact proviral sequences from elite controllers were integrated at highly distinct sites in the human genome and were preferentially located in centromeric satellite DNA or in Krüppel-associated box domain-containing zinc finger genes on chromosome 19, both of which are associated with heterochromatin features. Moreover, the integration sites of intact proviral sequences from elite controllers showed an increased distance to transcriptional start sites and accessible chromatin of the host genome and were enriched in repressive chromatin marks. These data suggest that a distinct configuration of the proviral reservoir represents a structural correlate of natural viral control, and that the quality, rather than the quantity, of viral reservoirs can be an important distinguishing feature for a functional cure of HIV-1 infection. Moreover, in one elite controller, we were unable to detect intact proviral sequences despite analysing more than 1.5 billion peripheral blood mononuclear cells, which raises the possibility that a sterilizing cure of HIV-1 infection, which has previously been observed only following allogeneic haematopoietic stem cell transplantation2,3, may be feasible in rare instances.

The lncRNA1-miR6288b-3p-PpTCP4-PpD2 module regulates peach branch number by affecting brassinosteroid biosynthesis.

Branch number is one of the most important agronomic traits of fruit trees such as peach. Little is known about how LncRNA and/or miRNA modules regulate branching through transcription factors. Here, we used molecular and genetic tools to clarify the molecular mechanisms underlying brassinosteroid (BR) altering plant branching. We found that the number of sylleptic branch and BR content in pillar peach ('Zhaoshouhong') was lower than those of standard type ('Okubo'), and exogenous BR application could significantly promote branching. PpTCP4 expressed great differentially comparing 'Zhaoshouhong' with 'Okubo'. PpTCP4 could directly bind to DWARF2 (PpD2) and inhibited its expression. PpD2 was the only one differentially expressed key gene in the path of BR biosynthesis. At the same time, PpTCP4 was identified as a target of miR6288b-3p. LncRNA1 could act as the endogenous target mimic of miR6288b-3p and repress expression of miR6288b-3p. Three deletions and five SNP sites of lncRNA1 promoter were found in 'Zhaoshouhong', which was an important cause of different mRNA level of PpTCP4 and BR content. Moreover, overexpressed PpTCP4 significantly inhibited branching. A novel mechanism in which the lncRNA1-miR6288b-3p-PpTCP4-PpD2 module regulates peach branching number was proposed.

Revealing the Mechanism of Ink Flaking from Surfaces of Palm Leaves (Corypha umbraculifera).

Palm leaves are the primary literary support in South and Southeast Asia before the widespread use of paper. However, palm leaf manuscripts face the threat of information loss due to the persistent issue of ink flaking during long-term preservation. Herein, we focus on studying the botanical structure, surface properties, and surface composition of palm leaves to gain an insightful understanding of the mechanism of ink flaking. According to the surface energy analysis, the surface of palm leaves is dominated by the dispersive component due to the presence of hydrophobic substances, resulting in the weak interaction between the handwriting and palm leaves. Moreover, the accumulation of silicon on palm leaves creates a "cuticle-silicon double layer", leading to a dense structure that hinders deep ink absorption. These two main reasons are considered to cause the ink flaking easily, which is further proven by the ink flaking test with the simulated palm leaf manuscripts. To the best of our knowledge, this is the first in-depth technical study on the adhesion performance of handwriting on plant leaves. This work also provides a theoretical basis for the study of the deterioration, adhesive repair, enhancement of flexibility, handwriting reinforcement, and beyond, which contributes to the conservation of precious palm leaf manuscripts.

Stabilizing Liquid in Precise Nonequilibrium Shapes via Fast Interfacial Polymerization.

Due to the minimization of interface area caused by surface tension, the stabilization of liquid in complex and precise nonequilibrium shapes is challenging. In this work, a simple, surfactant-free, and covalent strategy to stabilize liquid in precise nonequilibrium shapes via fast interfacial polymerization (FIP) of highly reactive n-butyl cyanoacrylate (BCA) monomer triggered by water-soluble nucleophiles is described. Full interfacial coverage can be achieved instantly, and the resultant polyBCA film anchored at the interface can support the unequal interface stress, which allows the production of non-spherical droplets with complex shapes. Notably, the formulation of internal aqueous phase is nearly unaffected since no specific additive is required. Moreover, considering the excellent biocompatibility of BCA and polyBCA, the produced droplets can be used as micro-bioreactor for enzyme catalysis and even bacterial culture, which well mimic the morphology of cells and bacteria to achieve the biochemical reaction in non-spherical droplets. The present work not only opens a new sight for the stabilization of liquid in nonequilibrium shapes, but may also promote the development of synthetic biology based on non-spherical droplets, and tremendous potential applications are anticipated.

Fast Interfacial Polymerization for Stabilizing Emulsion Droplets with Polymer Films beyond Emulsifiers.

Stabilizing emulsion droplets with amphiphilic emulsifiers are the current prevailing method, but the extensive use of such amphiphilic substances has caused widespread concerns. In this Perspective, three traditional methods for the stabilization of emulsion droplets according to the type of emulsifiers used are outlined, and the emphasis is placed on the mechanism of steric hindrance for emulsion stabilization. Then, we provide a concise introduction and discussion of the fast interfacial polymerization method as a new strategy for preparing stable emulsifier-free emulsion droplets with a polymer film, including its research background, current progress, and possible development directions. It is anticipated that this paper will promote the development of emulsifier-free emulsion production via fast interfacial polymerization and other related methods.

Uniformly Hybrid Surface Containing Adjustable Hydrophobic/Hydrophilic Components Obtained by Programmed Strain for Synergistic Anti-Icing.

Sufficient efforts have been put into the design of anti-icing materials to eliminate the icing hazard. Among the currently approved anti-icing concepts, hydrophilic/hydrophobic hybrid anti-icing materials inspired by antifreeze proteins show excellent properties in inhibiting ice nucleation, inhibiting ice crystal growth, and reducing ice adhesion. However, it is still a great challenge to accurately regulate the hydrophilic and hydrophobic hybrid components of the coating surface to clarify the synergistic mechanism. This work proposes a strain-manipulated surface modification strategy, and an anti-icing coating with adjustable hydrophilic/hydrophobic hybrid components prepared by combining chemical vapor deposition and siloxane chemistry is obtained. According to the ice resistance experiment at -15 °C, the performance of anti-icing is closely related to the proportion of hydrophilic and hydrophobic hybrids. The icing delay time and ice adhesion strength of the material with the optimal hydrophilic/hydrophobic components are 280 s and 18.6 kPa, respectively. These unique properties can be attributed to the synergistic effect of hydrophilic and hydrophobic structures on the regulation of interfacial water.

A Possible Sterilizing Cure of HIV-1 Infection Without Stem Cell Transplantation.

BACKGROUND: A sterilizing cure of HIV-1 infection has been reported in 2 persons living with HIV-1 who underwent allogeneic hematopoietic stem cell transplantations from donors who were homozygous for the CCR5Δ32 gene polymorphism. However, this has been considered elusive during natural infection. OBJECTIVE: To evaluate persistent HIV-1 reservoir cells in an elite controller with undetectable HIV-1 viremia for more than 8 years in the absence of antiretroviral therapy. DESIGN: Detailed investigation of virologic and immunologic characteristics. SETTING: Tertiary care centers in Buenos Aires, Argentina, and Boston, Massachusetts. PATIENT: A patient with HIV-1 infection and durable drug-free suppression of HIV-1 replication. MEASUREMENTS: Analysis of genome-intact and replication-competent HIV-1 using near-full-length individual proviral sequencing and viral outgrowth assays, respectively; analysis of HIV-1 plasma RNA by ultrasensitive HIV-1 viral load testing. RESULTS: No genome-intact HIV-1 proviruses were detected in analysis of a total of 1.188 billion peripheral blood mononuclear cells and 503 million mononuclear cells from placental tissues. Seven defective proviruses, some of them derived from clonally expanded cells, were detected. A viral outgrowth assay failed to retrieve replication-competent HIV-1 from 150 million resting CD4+ T cells. No HIV-1 RNA was detected in 4.5 mL of plasma. LIMITATIONS: Absence of evidence for intact HIV-1 proviruses in large numbers of cells is not evidence of absence of intact HIV-1 proviruses. A sterilizing cure of HIV-1 can never be empirically proved. CONCLUSION: Genome-intact and replication-competent HIV-1 were not detected in an elite controller despite analysis of massive numbers of cells from blood and tissues, suggesting that this patient may have naturally achieved a sterilizing cure of HIV-1 infection. These observations raise the possibility that a sterilizing cure may be an extremely rare but possible outcome of HIV-1 infection. PRIMARY FUNDING SOURCE: National Institutes of Health and Bill & Melinda Gates Foundation.

Administration of a new nano delivery system coated with Tirofiban to prevent early thrombosis of vein graft.

OBJECTIVE: To verify the administration of a new nano delivery system coated with Tirofiban on preventing early thrombosis in vein graft. METHODS: Forty New Zealand white rabbits were randomly divided into five groups with eight rabbits in each group. The rabbits of all groups underwent jugular vein transplantation, except group I with only neck opening and closing operation. Vein grafts of group II were preprocessed by intravenous injection of normal saline; group III were preprocessed by tirofiban alone; group IV were preprocessed by unloaded nanoparticles of PLGA-PEG; group V were preprocessed by PLGA-PEG coated with tirofiban. Coagulation and platelet function of peripheral and vein graft blood were detected at 1, 2, 4, 12 h and 1, 3, 7, 10, 14 days after operation. Patency rate of vein graft and blood flow index were measured by vascular ultrasound at third, seventh, 10th, and 14th days after operation; two rabbits in each group were randomly sacrificed at the corresponding time of detection. Pathological differences of vein grafts were observed by HE stainin. RESULTS: The patency rate of vein grafts in group V was significantly higher than that in group II to IV. The platelet and platelet aggregation rate in group V were inhibited in vein graft blood significantly. The post-operative PT and APTT in vein graft blood in group V were increased obviously while the FBG, D-dimer and FDP were significantly inhibited. Except group I, the lumen loss rate of vein grafts in group V was significantly lower than that in other groups, and vein graft blood in group V had a significant lower expression of platelet P-selectin and GP IIb/IIIa receptor than that in other groups. CONCLUSION: This study proves that PEG-PLGA coated with tirofiban can effectively prevent early vein graft stenosis from thrombosis by inhibition of platelet function, coagulation function.

Proximal femoral bionic nail (PFBN)-an innovative surgical method for unstable femoral intertrochanteric fractures.

PURPOSE: Intertrochanteric femoral fractures (IFF) are one of the most common traumatic conditions, but there are no established treatment methods for this condition due to implant failure and re-operation rates. The proximal femoral bionic nail (PFBN), which is a new design of the cephalomedullary nail, was developed by our team. The objective of this study was to assess the clinical and radiographic outcomes of PFBN in patients with unstable IFF. METHODS: From October 2020 to August 2021, 12 patients diagnosed with unstable IFF (31-A2, 3) were treated with PFBN at the Third Hospital of Hebei Medical University. We evaluated the clinical therapeutic effects of this treatment by measuring peri-operative indicators and post-operative complications. Clinical outcomes, specific radiographic parameters, and post-operative complications were collected and analyzed within the first post-operative year. RESULTS: The average age of the patients was 72.4 ± 16.1 years (five males and seven females). The mean operation time was 90.4 ± 16.0 min, whereas the operation time of 31-A2 fractures (83.1 ± 12.2 min) was shorter than that of 31-A3 fractures (105.0 ± 12.9 min) (p < 0.05). The blood loss was 175 ml (range: 50 to 500 ml), and the length of hospitalization was 10.0 ± 1.9 days. The prognosis evaluation was assessed at three, six and 12 months after the operation; for these time points, the Harris hip scores were 69.6 ± 4.1, 77.8 ± 3.8, and 82.6 ± 4.6, respectively, and the Parker-Palmer scores were 5.3 (5.0, 7.0), 6.3 (5.3, 7.0), and 7.8 (7.0, 8.0), respectively. CONCLUSION: PFBN has shown advantages in the treatment of unstable IFF (particularly in geriatric patients) and possesses both stability and safety. This innovative method may provide a new option for treating unstable IFFs.

De novo chromosome-level genome of a semi-dwarf cultivar of Prunus persica identifies the aquaporin PpTIP2 as responsible for temperature-sensitive semi-dwarf trait and PpB3-1 for flower type and size.

Peach (Prunus persica) is one of the most important fruit crops globally, but its cultivation can be hindered by large tree size. 'Zhongyoutao 14' (CN14) is a temperature-sensitive semi-dwarf (TSSD) cultivar which might be useful as breeding stock. The genome of CN14 was sequenced and assembled de novo using single-molecule real-time sequencing and chromosome conformation capture assembly. A high-quality genome was assembled and annotated, with 228.82 Mb mapped to eight chromosomes. Eighty-six re-sequenced F1 individuals and 334 previously re-sequenced accessions were used to identify candidate genes controlling TSSD and flower type and size. An aquaporin tonoplast intrinsic protein (PpTIP2) was a strong candidate gene for control of TSSD. Sequence variations in the upstream regulatory region of PpTIP2 correlated with different transcriptional activity at different temperatures. PpB3-1, a candidate gene for flower type (SH) and flower size, contributed to petal development and promoted petal enlargement. The locus of another 12 agronomic traits was identified through genome-wide association study. Most of these loci exhibited consistent and precise association signals, except for flesh texture and flesh adhesion. A 6015-bp insertion in exon 3 and a 26-bp insertion upstream of PpMYB25 were associated with fruit hairless. Along with a 70.5-Kb gap at the F-M locus in CN14, another two new alleles were identified in peach accessions. Our findings will not only promote genomic research and agronomic breeding in peach but also provide a foundation for the peach pan-genome.

Iodine-Oxidized Diene-Based Rubbers as Anti-icing and Deicing Polymer Coatings.

In an effort to prevent or minimize icing hazards, techniques and materials for icing inhibition and deicing have always been highly favored throughout human history. This work discovers the integrated anti-icing and deicing effects of poly(styrene-b-butadiene-b-styrene) triblock rubber (SBS) after its easy oxidation in iodine vapor. Iodine oxidation happens on the block of polybutadiene, featured by the conversion of SBS from hydrophobic to amphiphilic and the improved capability of photothermal conversion. The oxidized SBS can serve as a polymer coating, which possesses intriguing abilities to delay the kinetics of icing on its surface and repel the ice under light illumination. According to characterizations of surface chemistry and mechanical performance, iodine oxidation is assumed to involve the processes of iodine coordination to unsaturated bonds, the formation of radical cations as a result of the redox reaction between iodine and unsaturated carbon-carbon bonds, improved light absorption owing to the formation of polyiodide anions, and intermolecular coupling of radical cations. The appearance of polar moieties/species within the oxidized SBS is attributed to the delayed ice nucleation. The significant photothermal capacity in visible and near-infrared windows enables the iodine-oxidized SBS coating to remove the adhered ice by melting under light illumination when the icing process is inevitable, even at an extremely low temperature (-25 °C).

Phylogenetic and Transcriptional Analyses of the HSP20 Gene Family in Peach Revealed That PpHSP20-32 Is Involved in Plant Height and Heat Tolerance.

The heat shock protein 20 (HSP20) proteins comprise an ancient, diverse, and crucial family of proteins that exists in all organisms. As a family, the HSP20s play an obvious role in thermotolerance, but little is known about their molecular functions in addition to heat acclimation. In this study, 42 PpHSP20 genes were detected in the peach genome and were randomly distributed onto the eight chromosomes. The primary modes of gene duplication of the PpHSP20s were dispersed gene duplication (DSD) and tandem duplication (TD). PpHSP20s in the same class shared similar motifs. Based on phylogenetic analysis of HSP20s in peach, Arabidopsis thaliana, Glycine max, and Oryza sativa, the PpHSP20s were classified into 11 subclasses, except for two unclassified PpHSP20s. cis-elements related to stress and hormone responses were detected in the promoter regions of most PpHSP20s. Gene expression analysis of 42 PpHSP20 genes revealed that the expression pattern of PpHSP20-32 was highly consistent with shoot length changes in the cultivar 'Zhongyoutao 14', which is a temperature-sensitive semi-dwarf. PpHSP20-32 was selected for further functional analysis. The plant heights of three transgenic Arabidopsis lines overexpressing PpHSP20-32 were significantly higher than WT, although there was no significant difference in the number of nodes. In addition, the seeds of three over-expressing lines of PpHSP20-32 treated with high temperature showed enhanced thermotolerance. These results provide a foundation for the functional characterization of PpHSP20 genes and their potential use in the growth and development of peach.

Self-Shaping Microemulsion Gels for Cultural Relic Cleaning.

Cleaning is a foundational and essential operation of protection and restoration of cultural relics, which is also the key step of follow-up works. To overcome the problems of uncontrollable diffusion of cleaning solvents and poor coverage of the cleaning solvent carriers on rough surfaces, here, we propose a strategy of using a self-shaping microemulsion gel that is prepared via emulsifying oleophilic solvents into the specific shear-thinning hydrogel structures. The gel can adaptively cover rough surfaces during the cleaning process coupled with avoidance of unnecessary diffusion of the cleaning solvents, and the mechanical reinforcement of in situ polymerized double-network gels enables its easy peeling off from the surfaces without leaving determinable residues. As a representative demonstration, Paraloid B72, a widely used material for the repair and reinforcement of cultural relics, is employed as a model discolored coating, which can be effectively removed from the rough surface of simulated cultural relics after treatment with the resulting gels. Convincingly, the strategy of constructing agarose/polyacrylamide hybrid double-network gels with shear-thinning and self-shaping performances for the cleaning of cultural relics not only improves the convenience and accuracy of operation but also exhibits an efficient cleaning effect, which will greatly expand the application of microemulsion gels in the cleaning of rough surfaces of cultural relics.

Traction methods in the retrograde intramedullary nailing of femur shaft fractures: the double reverse traction repositor or manual traction.

OBJECTIVE: The purpose of this prospective study was to compare the double reverse traction repositor (DRTR) and manual traction in retrograde intramedullary nailing (RE-IMN) for femoral shaft fractures. PATIENTS AND METHODS: Seventy-seven patients with femur shaft fractures were randomized to undergo surgery with either DRTR or manual traction (MT) to facilitate RE-IMN between January 2018 and January 2019. Demographics, fracture characteristics, surgical data, post-operative complications, and functional outcomes were assessed. Data from 72 patients completing the final follow-up (12 months) were analysed in this study. RESULTS: The average number of intra-operative perspectives in the DRTR group was 27.7, which was significantly reduced compared with that in the MT group (31.3, p < 0.001). Fewer assistants were required in the DRTR group compared with the MT group (1.1 vs 1.9, p < 0.001). Fewer patients with open reduction were discovered in the DRTR group compared with the MT group (2.8 vs 19.4, p=0.024). Demographics, fracture characteristics, other surgical data, and prognostic parameters were comparative between the two groups. CONCLUSIONS: The DRTR can be effectively and safely used to treat femur shaft fractures with RE-IMN. The DRTR achieves similar results as MT and is also superior to MT in terms of intra-operative perspectives, the number of assistants, and the open reduction rate.

Effect of pH or Metal Ions on the Oil/Water Interfacial Behavior of Humic Acid Based Surfactant.

Humic acid, a kind of widespread organic macromolecule on earth, is naturally formed through the microbial biodegradation of plant, animal, and microorganism residues. Because of the large number of active functional groups (phenolic hydroxyl and carboxyl), humic acid has been considered as a biocompatible, green, and low-cost biosurfactant recently. In this work, based on the sensitivity of humic acid to the external chemical environment, the oil/water interfacial behavior of sodium humate at different pH or in the presence of metal ions is closely investigated. Sodium humate is significantly enriched toward the oil/water interface at either low pH or high metal-ion concentration to adjust the properties of the prepared emulsion, but the mechanisms are proved to be different when considering the influence of pH and metal ions. Besides, to the best of our knowledge, humic acid based surfactant is proposed as a Pickering emulsifier for the first time, known as solid surfactant. This work promises the great potential of humic acid as a natural environment-responsive surfactant and has important implications for the application of humic acid based surfactant in industry and understanding of the role of humic acid in the natural environment.

Percutaneous Reduction and Hollow Screw Fixation Versus Open Reduction and Internal Fixation for Treating Displaced Intra-Articular Calcaneal Fractures.

BACKGROUND We investigated the outcomes of displaced intra-articular calcaneal fractures (DIACFs) treated by percutaneous reduction and hollow screw fixation (PRHCF) versus open reduction and internal fixation (ORIF). MATERIAL AND METHODS Seventy-one patients were randomly allocated to group A (by PRHCF) and group B (by ORIF). Operative time, visual analogue scale (VAS) score, time from injury to operation, postoperative hospital stay, preoperative and postoperative radiographic measurements, and complications were recorded. Functional outcomes were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) scores. RESULTS Finally, 59 patients were followed up for at least 12 months (range, 12-24 months). Group A showed significantly more advantages than group B in term of operative time, intraoperative blood loss, time to operation, postoperative hospital stay, and postoperative pain relief during the first 3 days (P<0.001). However, more intraoperative fluoroscopy was required in group A than in group B (P<0.001). The calcaneal width, height, length, Böhler angle, and Gissane angle in each group were significantly improved postoperatively (all P<0.001), although not significantly different in the postoperative comparisons between both groups. The AOFAS scores were slightly superior in group A than in group B (88.3 vs. 86.4, P=0.08). The rate of incidence of postoperative complications was lower in group A than in group B (3.2% vs. 10.8%, respectively; OR, 0.28, 95% CI, 0.03 to 2.84), although there was no significant difference (P=0.337). CONCLUSIONS PRHCF showed comparable clinical and radiological outcomes as ORIF, demonstrating it is a safe and effective alternative in treating DIACFs.