Different while being similar: The dual institutional process and differential organizational status.

Connecting the neoinstitutional theory with Bourdieu's field theory, we develop a framework on the dual institutional process of integration and differentiation in a field. While the neoinstitutional theory has focused on similar organizational structures, we shift the research focus to offer an institutional explanation of differential organizational status. Drawing insights from Bourdieu's theory and key concepts, we highlight that the very institutional mechanisms causing isomorphism-regulative forces, normative pressures, and cognitive processes-also generate systematic status differentiation among organizations via their different levels of capital, homologous structures, and various habitus in a field. Our extended framework has theoretical significance in advancing the neoinstitutional theory, the research of status in organizational and economic sociology, and the Bourdieusian perspective. By theorizing status differentiation among organizations, it also adds an important dimension to enrich our understanding of multilevel status and social hierarchies.

Photocatalytic degradation of (micro)plastics using TiO2-based and other catalysts: Properties, influencing factor, and mechanism.

(Micro)plastics pollution has raised global concern because of its potential threat to the biota. The review on recent developments of photocatalytic degradation of (micro)plastics is still insufficient. In this study, we have discussed various bare and composites photocatalysts involved in the photocatalytic degradation of (micro)plastics. The photocatalytic mechanisms and factors affecting the degradation were also discussed. To improve the performance of photocatalysts, their surface is modified with metal or non-metal dopants. These doped photocatalysts are then compounded with a variety of environmentally friendly and nontoxic polymers to prepare multifunctional composites. The generation of reactive oxygen species (ROS) plays an important role in the photocatalytic degradation of (micro)plastics, and superoxide ions (O2-) and hydroxyl radicals (OH) participate in the photocatalytic degradation, leading to the breaking of the polymer chain and the production of some intermediates. Although satisfactory progress has been achieved in the photodegradation of (micro)plastics, most photocatalytic degradation technologies investigated to date cannot realize the complete mineralization of (micro)plastics. Furthermore, based on the current challenges of the existing photocatalytic degradation technologies, perspectives for future research directions have been proposed. This review presents a systematic summary of the progress made in the photocatalytic degradation of (micro)plastics and offers a comprehensive reference for future research on improving the (micro)plastics photocatalytic degradation efficiency.

Sorption of tylosin and sulfamethazine on solid humic acid.

Tylosin (TYL) and sulfamethazine (SMT) are ionizable and polar antimicrobial compounds, which have seeped into the environment in substantial amounts via fertilizing land with manure or sewage. Sorption of TYL and SMT onto humic acid (HA) may affect their environmental fate. In this study, the sorption of TYL and SMT on HA at different conditions (pH, ionic strength) was investigated. All sorption isotherms fitted well to the Henry and Freundlich models and they were highly nonlinear with values of n between 0.5 and 0.8, which suggested that the HA had high heterogeneity. The sorption of TYL and SMT on HA decreased with increasing pH (2.0-7.5), implying that the primary sorption mechanism could be due to cation exchange interactions between TYL(+)/SMT(+) species and the functional groups of HA. Increasing ionic strength resulted in a considerable reduction in the Kd values of TYL and SMT, hinting that interactions between H bonds and π-π EDA might be an important factor in the sorption of TYL and SMT on HA. Results of Fourier transform infrared (FT-IR) and (13)C-nuclear magnetic resonance (NMR) analysis further demonstrated that carboxyl groups and O-alkyl structures in the HA could interact with TYL and SMT via ionic interactions and H bonds, respectively. Overall, this work gives new insights into the mechanisms of sorption of TYL and SMT on HA and hence aids us in assessing the environmental risk of TYL and SMT under diverse conditions.

[Identification of different varieties of Rhei Radix et Rhizoma based on chemical analysis].

A HPLC method was established to determine the contents of the five anthraquinones and rhaponticin in the different varieties of Rhei Radix et Rhizoma. The difference existed in different varieties. The results showed that rhein and rhaponticin were marker substances which could be used to distinguish palm leaf groups rhubarb and wave leaf groups rhubarb. Authentic rhubarb didn't contain rhaponticin. Falsify rhubarb contains trace amounts of rhein. Rheum tanguticum contains abundant rhein. The ratio value of the content of rhein to chrysophanol could be used to distinguish R. tanguticum from the other two authentic varieties (R. palmatum and R. officinale). The content of rhaponticin varied largely in different varieties of wave leaf groups rhubarb.

Inter-provincial embodied carbon emission space and industrial transfer paths in China.

To bolster the dual-circulation development model and green economy, this study delves into the spatiotemporal dynamics of implied carbon transfer in China's inter-provincial and inter-industrial trade, emphasizing its significance for the "dual carbon" objectives. Utilizing multi-regional input-output data from 2012, 2015, and 2017, we employed the multi-region input-output model to gauge embodied carbon transfers across 31 provinces and 28 industries. The Structural Decomposition Analysis (SDA) model further decomposed the growth of trade-related carbon emissions. Key findings include: (1) The electricity and thermal power sectors dominate carbon transfers, with secondary industries seeing rapid growth; (2) Northern provinces significantly outweigh southern ones in carbon transfers and the main direction of it is towards affluent southern coastal regions; (3) Scale effect plays a pivotal role in these transfers. Conclusively, it is crucial for regulatory authorities to rationally formulate region-specific emission policies for inter-regional coordination, and future studies can focus on industrial and spatial clustering effects.

circ_0029463 promotes osteoclast differentiation by mediating miR-134-5p/Rab27a axis.

OBJECTIVE: Osteoporosis is the imbalance in bone homeostasis between osteoblasts and osteoclasts. In this study, we investigated the effects of the circ_0029463/miR-134-5p/Rab27a axis on RANKL-induced osteoclast differentiation. METHODS: RT-qPCR and western blotting were used to detect the expression of circ_0029463, miR-134-5p, and Rab27a in tissues from patients with osteoporosis and in RANKL-induced osteoclasts. Osteoclast differentiation was verified by TRAP staining. Osteoclast biomarkers, including NFATc1, TRAP, and CTSK, were measured. The target and regulatory relationships between circ_0029463, miR-134-5p, and the Rab27a axis were verified using RIP, dual-luciferase reporter gene, and RNA pull-down assays. RESULTS: Elevated expression of circ_0029463 and Rab27a and decreased miR-134-5p expression were observed in the tissues of patients with osteoporosis, and a similar expression pattern was observed in RANKL-induced osteoclasts. Suppression of circ_0029463 expression or miR-134-5p overexpression curbed RANKL-induced osteoclast differentiation, whereas such an effect was abolished by Rab27 overexpression. circ_0029463 sponges miR-134-5p to induce Rab27a expression. CONCLUSION: circ_0029463 sponges miR-134-5p to abolish its suppressive effect of miR-134-5p on Rab27a expression, thereby promoting osteoclast differentiation.

[Preparation and properties of a new artificial bone composite material].

Objective: To study the preparation and properties of the hyaluronic acid (HA)/α-calcium sulfate hemihydrate (α-CSH)/ß-tricalcium phosphate (ß-TCP) material (hereinafter referred to as composite material). Methods: Firstly, the α-CSH was prepared from calcium sulfate dihydrate by hydrothermal method, and the ß-TCP was prepared by wet reaction of soluble calcium salt and phosphate. Secondly, the α-CSH and ß-TCP were mixed in different proportions (10∶0, 9∶1, 8∶2, 7∶3, 5∶5, and 3∶7), and then mixed with HA solutions with concentrations of 0.1%, 0.25%, 0.5%, 1.0%, and 2.0%, respectively, at a liquid-solid ratio of 0.30 and 0.35 respectively to prepare HA/α-CSH/ ß-TCP composite material. The α-CSH/ß-TCP composite material prepared with α-CSH, ß-TCP, and deionized water was used as the control. The composite material was analyzed by scanning electron microscope, X-ray diffraction analysis, initial/final setting time, degradation, compressive strength, dispersion, injectability, and cytotoxicity. Results: The HA/α-CSH/ß-TCP composite material was prepared successfully. The composite material has rough surface, densely packed irregular block particles and strip particles, and microporous structures, with the pore size mainly between 5 and 15 µm. When the content of ß-TCP increased, the initial/final setting time of composite material increased, the degradation rate decreased, and the compressive strength showed a trend of first increasing and then weakening; there were significant differences between the composite materials with different α-CSH/ß-TCP proportion ( P<0.05). Adding HA improved the injectable property of the composite material, and it showed an increasing trend with the increase of concentration ( P<0.05), but it has no obvious effect on the setting time of composite material ( P>0.05). The cytotoxicity level of HA/α-CSH/ß-TCP composite material ranged from 0 to 1, without cytotoxicity. Conclusion: The HA/α-CSH/ß-TCP composite materials have good biocompatibility. Theoretically, it can meet the clinical needs of bone defect repairing, and may be a new artificial bone material with potential clinical application prospect.

[Seasonal Variation and Influencing Factors of Bacterial Communities in Storage Reservoirs].

In order to explore the seasonal variation and influencing factors of bacterial community structure in storage reservoirs, the impact of environmental factors must first be examined. In this study, the seasonal variation in bacterial community structure and its response to water quality factors were explored by monitoring the water quality of Qingdao Jihongtan Reservoir, the only reservoir of the Yellow River diversion project, using high-throughput sequencing technology and symbiotic network analysis. The results showed that the diversity and richness of bacterial communities were highest in summer and lowest in winter, and those in the inlet were higher than those in the outlet. The structure of the bacterial community was similar in spring and winter and in summer to autumn. The dominant bacteria phyla were:Actinobacteriota (6.63%-57.38%), Proteobacteria (11.32%-48.60%), Bacteroidota (5.05%-25.74%), and Cyanobacteria (0.65%-24.74%). Additionally, the abundances of Chloroflexi, Dependentiae, Fusobacteriota, and Margulisbacteria were the highest in autumn and the lowest in winter. The dominant bacterial genera were:hgcI_clade (3.72%-34.66%), CL500_29_marine_group (0.31%-20.13%), and Limnohabitans (0.16%-10.37%). Further, the abundances of Flavobacterium, Polaromonas, and Rhodoferax were the highest in winter and the lowest in summer; the trend of Domibacillus and Limnobacter was the opposite. The abundance of Proteobacteria and Campilobacteria in the inlet was significantly higher than that in the outlet, and the Planctomycetota showed the opposite. The abundances of Dinghuibacter, Arenimonas, and Rhodobacter in the inlet were significantly higher than those in the outlet. Competition and antagonism dominated the interaction relationship of bacterial communities in spring, whereas mutualism dominated in winter. There were significant differences among key species in the symbiotic network at different seasons and sampling sites. Water temperature, DO, water storage capacity, and water storage sources had a great influence on bacterial community structure in the Jihongtan Reservoir.

Crustal melting in orogenic belts revealed by eclogite thermal properties.

Partial melting in the continental crust may play a critical role on the behavior of continents during collision. However, the occurrence of partial melt in orogenic continental crust is not well understood. Since the temperature of the orogen is controlled by the thermal properties of constituent rocks, we measured the thermal conductivity and diffusivity of eclogite, the most important ultrahigh pressure metamorphic rocks, as a function of pressure, temperature, composition, and water content, and simulated the thermal structure of the Sulu and Himalaya-Tibet orogens in eastern and southwestern China, respectively. Our results show that the temperature at ~30-km depth beneath the orogens reaches the solidus of wet granite and phengite (~940 K), therefore, the partial melting in the orogenic continental crust is well explained. The melt may facilitate the exhumation of subducted crust, produce the low seismic-velocity zone, and cause the high-conductivity anomaly in the shallow depth of orogenic belts.

Synthesis and Properties of Magnetic Fe3O4/PCL Porous Biocomposite Scaffolds with Different Sizes and Quantities of Fe3O4 Particles.

In clinical practice, to treat diseases such as osteosarcoma or chondrosarcoma with broad surgical ostectomy, it would be ideal to have scaffolds that not only fill up the bone void but also possess the ability to regulate the subsequent regimes for targeted chemotherapy and/or bone regeneration. Magnetic targeting of therapeutic agents to specific sites in the body provides certain advantages such as minimal side-effects of anti-cancer drugs. The objective of this study was to characterize novel magnetic scaffolds that can be used as a central station to regulate the drug delivery of a magnetic nanoparticle system. Different sizes and quantities of Fe3O4 particles were mixed with poly-ε-caprolactone (PCL) to construct the magnetic scaffolds, and their mechanical properties, degradation performance, and cell biocompatibility were evaluated. It appeared that the presence of Fe3O4 particles influenced the magnetic, mechanical, and biological performances of the scaffolds. The prepared bio-nanocomposite scaffolds provided predominantly magnetic/superparamagnetic properties. Scaffolds with a micron-sized Fe3O4 to PCL weight (wt) ratio of 0.1:0.9 exhibited higher mechanical performances among samples, with Young's modulus reaching 1 MPa and stiffness, 13 N/mm. Although an increased Fe3O4 particle proportion mildly influenced cell growth during the biocompatibility test, none of the Fe3O4/PCL scaffolds showed a cytotoxic effect.

Glomus Tumors of the Distal Phalanx: A Retrospective Review of Clinical Diagnosis and Treatment.

Glomus tumors (GTs) are rare and typically occur in distal digital bones, with a majority of cases comprising benign vascular tumors. The current study retrospectively reviewed 10 cases of GTs treated by the authors between January 2009 and December 2016. In 9 cases, the GTs were subungual; 1 case was periungual. The affected fingers included 2 thumbs, 3 index fingers, 3 middle fingers, and 2 little fingers. The GTs showed characteristic signs and symptoms. All patients underwent tumor excision. Pathological examination found a thin layer of fibrous membrane surrounding the excised tumor body, which contained small vessels surrounded by multilayered tumor cells. No recurrence was seen during follow-up. The results of this study suggested the following: (1) whole tumor excision is key to preventing GT recurrence; and (2) in case of considerable phalangeal cortex erosion, K-wire fixation followed by autogenous bone grafting can produce satisfactory outcomes, although accurate evidence-based indications for this management need to be established. [Orthopedics. 2022;45(2):e101-e106.].

Investigation of the electrocatalytic mechanisms of urea oxidation reaction on the surface of transition metal oxides.

Urea oxidation reaction (UOR) has been widely considered as an alternative anodic reaction to water oxidation for the green production of hydrogen fuel. Due to the high catalytic activity of transition metal oxides towards UOR, various strategies have been developed to improve their syntheses and catalytic properties. However, little is known about the underlying mechanisms of UOR on catalyst surface. In this work, three transition metal oxides, including NiO, Co3O4, and Fe2O3 are investigated as model catalysts. Through analyzing the electrochemical properties by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and operando Raman spectroscopy, it is revealed that NiO has a unique high catalytic activity towards UOR due to simultaneous formation of a thin layer of oxyhydroxide species above 1.40 V vs. RHE in alkaline media. In addition, density functional theory (DFT) calculations further suggest that the adsorption of urea molecules is largely affected by surface interactions resulting in different space configurations, which impose large influences on the consecutive deprotonation and NN formation processes. Overall, results of this work point to the subtle adsorption - kinetics relationship in UOR and highlight the importance of the interfacial electronic interactions on catalyst surface.

CircFADS2 is downregulated in osteoarthritis and suppresses LPS-induced apoptosis of chondrocytes by regulating miR-195-5p methylation.

BACKGROUND: CircRNA circFADS2 has been reported to protect cells from LPS (Lipopolysaccharide)-induced cell injury, which contributes to osteoarthritis (OA). This study was carried out to study the role of circFADS2 in OA. METHODS: The expression of circFADS2 and miR-195-5p in synovial fluid samples from 63 OA patients and 63 healthy controls were detected by RT-qPCRs. The effects of overexpression of circFADS2 on the expression of miR-195-5p and the methylation of miR-195-5p gene in chondrocytes were evaluated by RT-qPCRs and MSPs, respectively. The roles of circFADS2 and miR-195-5p in regulating the LPS-induced apoptosis of chondrocytes were explored by cell apoptosis assay. RESULTS: CircFADS2 was downregulated in OA and inversely correlated with miR-195-5p. In chondrocytes, overexpression of circFADS2 and downregulation of miR-195-5p were observed after LPS treatment. In chondrocytes, overexpression of circFADS2 decreased the expression levels of miR-195-5p, and increased the methylation of miR-195-5p gene. Cell apoptosis assay showed that overexpression of circFADS2 reduced the apoptosis of chondrocytes under LPS treatment. Overexpression of miR-195-5p increased cell apoptosis and attenuated the effects of overexpression of circFADS2 on cell apoptosis. CONCLUSION: CircFADS2 may downregulate miR-19-5p through methylation to suppress LPS-induced apoptosis of chondrocytes, thereby suppressing OA.

Long non-coding RNA (LncRNA) MRPL23-AS1 promotes tumor progression and carcinogenesis in osteosarcoma by activating Wnt/ß-catenin signaling via inhibiting microRNA miR-30b and upregulating myosin heavy chain 9 (MYH9).

Long non-coding RNA (LncRNA) contributes to the occurrence and development of osteosarcoma (OS), although the underlying mechanism is not clear. In the present study, we showed that lncRNA MRPL23-AS1 was remarkably increased in OS tissues and cell lines. Stable knockdown of MRPL23-AS1 evidently attenuated cell viability and invasive ability, meanwhile inhibited in vivo tumor growth and dissemination. In terms of mechanism, luciferase reporter, RNA pull-down and fluorescence in situ hybridization (FISH) assays showed that MRPL23-AS1 competitively interacted with miR-30b, increasing myosin heavy chain 9 (MYH9) expression, a trans- activator of ß-catenin, resulting in the activation of Wnt/ß-catenin pathway, thereby promoting OS tumorigenesis and metastasis. Importantly, high MRPL23-AS1 was positively correlated with MYH9, while conversely correlated with miR-30b, suggesting that the regulatory axis of MRPL23-AS1/miR-30b/MYH9 does exist in OS. Clinically, OS patients with high MRPL23-AS1 had larger tumor size, higher stage and easier metastasis than those with low MRPL23-AS1, moreover, MRPL23-AS1 was identified as an adverse prognostic factor for OS survival. In conclusion, our results show that MRPL23-AS1 is a key oncogenic lncRNA in OS, targeting of MRPL23-AS1 may be a promising treatment for OS patients.

Z-scheme heterojunction based on NiWO4/WO3 microspheres with enhanced photocatalytic performance under visible light.

The green treatment of dye wastewater has always been a research hotspot in the environmental field. The photocatalytic technology is considered to be a simple and effective strategy to remove dyes in wastewater. A new type of NiWO4/WO3 Z-scheme heterojunction microspheres were synthesized by a simple hydrothermal method and impregnation-calcination process. The crystal structure, microscopic morphology, optical and electrochemical properties of the samples were systematically characterized. The photocatalytic activity of methylene blue (MB) was studied by visible light irradiation. The results show that the direct Z-scheme heterojunction formed by NiWO4/WO3 effectively reduces the transfer resistance of photogenerated carriers and improves the separation efficiency of photogenerated carriers. The degradation rates of NiWO4/WO3-4 Z-scheme heterojunction microspheres to MB dye are 1.8 and 3.2 times higher than that of pure WO3·2H2O and WO3 microspheres, respectively. Combined with the Mott-Schottky curve and the active species capture experiments, a possible Z-scheme photogenerated carrier transfer mechanism is proposed. This study provides a method for the development and design of Z-scheme heterojunction photocatalysts in the field of wastewater purification.

Review of the toxic effect of microplastics on terrestrial and aquatic plants.

As a new pollutant, microplastics (MPs) exhibited more and more significant influence on the organisms in the environment. Especially, the effects on the growth and development of plants by MPs attracted wide attentions in recent period. In the review article, we summarized the important influences of MPs on terrestrial and aquatic plants. The properties, including type, size and oxygen-containing group of MPs on their physical injures toward plants were critically reviewed, which were significantly correlated to the toxicity to plants. The secondary risks of MPs including the additives and MP-derived organic products and the adsorbed environmental pollutants to plants were clearly revealed. The hydrophobic organic pollutants released from MPs showed significant chemical effects on the plants. We also outlined the effects of MPs to the various regions (e.g. the seed and rhizome) of plants and compared the toxic difference of MPs on terrestrial and aquatic plants. Generally, the seed and rhizome of plants were susceptible to MPs, and the effects of MPs on terrestrial and aquatic plants were different. The review paper improves the understanding of potential toxicity of MP themselves and the released and adsorbed chemicals to plants in the environment.

[Double internal fixations of clavicle and scapula and intraoperative reduction of glenopolar angle for treatment of floating shoulder injuries].

OBJECTIVE: To investigate the effectiveness of double internal fixations of clavicle and scapula and intraoperative reduction of glenopolar angle in the treatment of floating shoulder injuries. METHODS: Between January 2010 and June 2019, 13 patients with floating shoulder injury were treated with double internal fixation of clavicle and scapula and intraoperative reduction of glenopolar angle. There were 11 males and 2 females with an average age of 48 years (range, 25-65 years). The causes of injury included falling from height in 2 cases, traffic accident injury in 3 cases, heavy object injury in 2 cases, and other injuries in 6 cases. There were 2 cases of Ⅰ-B-3 type, 1 case of Ⅰ-C-2 type, 1 case of Ⅰ-C-3 type, 3 cases of Ⅱ-B-2 type, 1 case of Ⅱ-B-3 type, 1 case of Ⅱ-B-4 type, 2 cases of Ⅱ-C-2 type, 1 case of Ⅱ-C-4 type, and 1 case of Ⅱ-D-3 type according to the classification of floating shoulder injury. All patients had unilateral clavicle fracture with scapular neck fracture, 1-4 superior shoulder suspensory complex (SSSC) injuries. The time from injury to operation was 7-17 days, with an average of 12 days. The glenopolar angle, subacromail space, anteroposterior inclination angle of scapular glenoid, scapular glenoid up and down angle were measured before and after operation; Constant-Murly score and Herscovici score were used to evaluate the recovery of shoulder joint function. RESULTS: All incisions healed by first intention, and there was no early postoperative complications such as infection. All 13 cases were followed up 12-48 months, with an average of 25.2 months. Both the clavicle and the scapula had bone union, and the average healing time was 6 months and 4 months respectively. There were no complications such as nonunion, shoulder deformity, plate fracture or failure of internal fixation, acromion impingement syndrome, and frozen shoulder. At last follow-up, the glenopolar angle, subacromail space, anteroposterior inclination angle of scapular glenoid, and scapular glenoid up and down angle were all corrected significantly ( P<0.05). The pain, function, activity, muscle strength scores, and total score in Constant-Murly score were significantly improved when compared with preoperative scores ( P<0.05). According to the Herscovici scoring standard, the shoulder joint function was evaluated as excellent in 8 cases, good in 3 cases, and fair in 2 cases. The excellent and good rate was 84.6%. CONCLUSION: Double internal fixation of clavicle and scapula to stabilize SSSC and reduct glenopolar angle during operation is an effective method for treating the floating shoulder injury.

[Degradable performance and bio-mineralization function of PLA-PEG-PLA/PLA tissue engineering scaffold in vitro and in vivo].

The degradable performance and bio-mineralization function of PLA-PEG-PLA/PLA tissue engineering scaffolds in vitro and in vivo were systematically studied. The X-ray diffraction and Fourier transform infrared spectra showed that there was the deposition of bone-like carbonate hydroxyapatite on the surface of scaffolds. We found that the weight of scaffolds did not always decrease with the prolongation of time in vitro. At the same time, we found that after the PLA-PEG-PLA/PLA tissue engineering scaffolds were embedded in skulls of rhesus monkeys, the new bone area reached 75% at the 12th week. Histological observation showed that the new bones were rebuilt and knitted bones were formed at the 12th week. These findings meant that the PLA-PEG-PLA/PLA tissue engineering scaffolds were potential in clinical use.

[Analysis of effectiveness of greater trochanteric osteotomy approach and K-L posterior approach in patients with type â £ Pipkin fracture].

OBJECTIVE: To investigate the effectiveness of two surgical approaches in the treatment of type Ⅳ Pipkin fracture. METHODS: The clinical data of 15 patients with type Ⅳ Pipkin fracture treated surgically between July 2013 and June 2018 were retrospectively analyzed. According to different surgical approaches, they were divided into group A (8 cases, using K-L posterior approach) and group B (7 cases, using greater trochanter osteotomy approach). There was no significant difference in gender, age, cause of injury, and interval from injury to operation between the two groups ( P>0.05). The incision length, operation time, intraoperative blood loss, hospital stay, fracture healing time, and complications of the two groups were recorded. Hip joint function recovery was evaluated according to Thompson-Epstein functional evaluation system. RESULTS: All the 15 patients were followed up 1-5 years, with an average of 2.5 years. There was no significant difference in operation time between the two groups ( t=14.681, P=0.100); the incision length, intraoperative blood loss, and fracture healing time in group A were all greater than those in group B, and the hospital stay was shorter than that in group B, showing significant differences ( P<0.05). In group A, 1 patient presented hip pain, clasthenia, and limited mobility after operation, 1 patient presented ossifying myositis, 1 patient presented osteonecrosis of the femoral head, 1 patient presented fat liquefaction of incision, and 1 patient presented sciatica, with a complication incidence of 62.5%. Postoperative hip pain occurred in 1 patient and ossifying myositis in 2 patients in group B, with a complication incidence of 42.9%. There was no significant difference in the incidence of complications between the two groups ( χ 2=-0.735, P=0.462). At last follow-up, according to Thompson-Epstein functional evaluation system, the results in group A were excellent in 3 cases, good in 2 cases, fair in 2 cases, and poor in 1 case, with an excellent and good rate of 62.5%; in group B, the results were excellent in 4 cases, good in 2 cases, and fair in 1 case, and the excellent and good rate was 85.7%. There was no significant difference in good and fair rate between the two groups ( χ 2=-0.990, P=0.322). CONCLUSION: K-L posterior approach is more convenient in the fracture treatment during operation, but it has greater trauma, greater vascular damage, and more blood loss. The greater trochanter osteotomy approach can better protect the blood supply of femoral head, shorten the operation time, reduce intraoperative blood loss, and reduce postoperative complications. It is an ideal way in the surgical treatment of type Ⅳ Pipkin fracture.

3D Bioprinting of shear-thinning hybrid bioinks with excellent bioactivity derived from gellan/alginate and thixotropic magnesium phosphate-based gels.

3D Bioprinting is expected to become a strong tool for regenerative medicine, but satisfactory bioinks for the printing of constructs containing living cells are lacking due to the rigorous requirement of high printability and biocompatibility, which are often contradictory. Here, we have reported the development of a novel hybrid bioink by combining rigid gellan gum (GG), flexible sodium alginate (SA), and a bioactive substance thixotropic magnesium phosphate-based gel (TMP-BG). The ratio of these components was first optimized to obtain satisfactory gelating, mechanical, rheological, and printing properties. The formulated hybrid GG-SA/TMP-BG bioink had a good printability due to the shear-thinning and its multiple cross-linking by Mg2+ and Ca2+. The tunable mechanical performance of the hybrid bioink could simulate various extracellular matrices of the different tissues and support integrity of 3D printing constructs. Moreover, the hybrid bioink induced apatite deposition during immersion in simulated body fluids, and also promoted cell proliferation in vitro. MG-63 osteosarcoma cells were dispersed in the bioink and printed into 3D constructs. The cells exhibited good cell survival due to the shear-thinning property of the bioink and the ion concentration used for cross-linking. The proliferation rate of the cells also significantly exceeded those in non-printed samples. Confocal microscopy revealed a homogeneous distribution of cells in the printed constructs, and survival for more than 7 d. In vivo animal experiments showed that the hybrid bioink without cells could induce osteochondral repair. Therefore, this hybrid bioink has good printability, biocompatibility, mechanical support, and bioactivity, which is expected to have promising applications in 3D bioprinting.