Search

It is impossible to obtain the forming limit curve (FLC) by full zone hydraulic forming test under quasi-static (QS) condition since the liquid will leak from the notches of the specimen once the pressure increases. In this study, a novel method is proposed to investigate the frictionless full zone hydraulic FLC of AA5A06 under high strain rate (HSR) condition based on the impact hydroforming technology (IHF). It is found that the FLC is increased significantly by IHF compared with the quasi-static rigid punch (QS-R) forming and the quasi-static hydraulic (QS-H) forming. Differentiating with the QS-H, the increase amounts of FLC at the biaxial tension zone and the tension-compression zone are notably different for IHF. Additionally, the theoretical calculations of FLC is conducted by using M-K model combining with Hill48 anisotropic yield criterion under QS and HSR conditions. The results calculated by the M-K model reasonably agree with the ones obtained from experimentation under QS and HSR condition, and a higher initial thickness ratio is assigned for HSR considering the neck postponing effect of inertia.

In this paper, it was investigated that the defects of the bright and dark lines on the inner wall of a thin-walled copper tube by drawing with a floating plug based on analyzing the stress distribution. The experiments were conducted by employing a stereomicroscope, metallographic microscope and scanning electron microscope, respectively, meanwhile the three-dimensional finite element was applied to study the defect. It was demonstrated by the research results that the large gap between the sizing section of the plug and the outer die caused the inner wall bright and dark lines. The wall thickness was increased when the tube passed by the area without inner support which gave rise to local material uplift along the radial direction. The raised material became folds due to the effect of “leveling” when the tube pass by the conical section and the sizing sections. The fold was the essence of the bright and dark line by macroscopic scale observation. The bright and dark line was ultimately eliminated by adopting the drawing die with reasonable geometrical parameters according to experimental and simulated results.

The defect of the jump ring on the surface of the thin wall copper tube by drawing with a floating plug was analyzed, experiment was based on a direct reading spectrometer, metallographic microscope, SEM, and 3D surface topography instrument. Research shows that: when the plug position was over the extreme for-most position, the copper tube was extruded between the drawing die and mandrel, forming a localized necking state; when the plug position was over the extreme rear-most position, the copper tube was drawing in the empty sinking state. The plug does not play a finishing affection, which causes local projections of surface materials. The jump ring macro showed a ring bamboo section scar with bright and dark, micro performance for the uneven wall thickness.

In order to solve the problem that current robots are difficult to achieve accurate 6DoF pose estimation under the environment of occluded objects and insufficient lighting, in this paper, a pixel-level based neural network framework is proposed, which includes three modules, the RGB feature extraction networks module, the pixel-level fusion module and the 6D pose regression network module. The RGB feature extraction networks module firstly segments the target objects and then extracts the objects?? features. The pixel-level fusion module is applied for fusing RGB features with 3D multi-view features. And the last module fuses 3D point cloud pixels and outputs the 6D pose of the objects. The experiments conducted on the YCB-Video dataset, the LINEMOD dataset, and the YCB-Occlusion dataset processed in this paper manifest that the framework proposed can effectively predict the 6D pose of the objects even when the objects are occluded or the point clouds of the object are lost. Furthermore, compared with other frameworks, this framework is more robust and the efficiency is improved by hundreds of times only with a small loss of accuracy.

Extracellular vesicles from highly metastatic tumor cells have been shown to mediate epithelial-mesenchymal transition (EMT)-related events in recipient cells. In endometrial epithelial cells, EMT processes are known to be involved in the development of adenomyosis. We aimed to investigate whether adenomyosis-derived extracellular vesicles (AMEVs) are able to induce an EMT process in endometrial epithelial cells. In this study, AMEVs were isolated from patients with adenomyosis and characterized by transmission electron microscopy, Western blot, and nanoparticle tracking. Primary endometrial epithelial cells (EECs) were derived from normal endometrium tissues from patients with leiomyoma and co-cultured with AMEVs in vitro. AMEV uptake was examined by fluorescence confocal microscopy. The invasion of EECs was confirmed by Transwell assay. Immunohistochemistry, Western blot, and qRT-PCR were performed on EECs to illustrate the expression levels of cytokeratin 19, E-cadherin, vimentin, and zinc finger E-box-binding homeobox 1 (ZEB1). The results indicated that the cellular fluorescence intensity gradually increased after 48 h of co-culture, but decreased after 72 h. After co-culturing with AMEVs for 72 h, EECs expressed significantly lower levels of cytokeratin 19 and E-cadherin, and significantly higher levels of vimentin and ZEB1. Together these results demonstrated that AMEVs induce an EMT process and enhance the invasion of EECs. These changes may contribute to the pathogenesis and progression of adenomyosis.

Unlike growth on tissue, microbes can grow freely on implantable devices with minimal immune system intervention and often form resilient biofilms that continuously pump out pathogenic cells. The efficacy of antibiotics used to treat infection is declining due to increased rates of pathogenic resistance. A simple, one-step zwitterionic surface modification is developed to significantly reduce protein and microbial adhesion to synthetic materials and demonstrate the successful modification of several clinically relevant materials, including recalcitrant materials such as elastomeric polydimethylsiloxane. The treated surfaces exhibit robust adhesion resistance against proteins and microorganisms in both static and flow conditions. Furthermore, the surface treatment prevents the adhesion of mammalian fibroblast cells while displaying no cytotoxicity. To demonstrate the clinical efficacy of the novel technology in the real-world, a surface-treated, commercial silicone foley catheter is developed that is cleared for use by the U.S. Food and Drug Administration (K192034). 16long-term catheterized patients received surface-treated catheters and completed a Patient Global Impression of Improvement (PGI-I) questionnaire. 10out of 16patients described their urinary tract condition post implantation as "much better" or "very much better" and 72% (n=13) of patients desire to continue using the surface-treated catheter over conventional latex or silicone catheters.

Extracellular vesicles (EVs) carry specific proteins involved in intercellular communication. EVs with different protein contents are released into circulation in different diseases. Recent studies have identified proteins in adenomyosis (AM)-derived EVs (AMEVs) from blood as biomarkers for this disease. AM is an extension of endometrial tissue into the uterine myometrium. Magnetic resonance imaging (MRI) is the most accurate imaging tool for identifying adenomyosis. Therefore, the present study aimed to investigate the role of EVs in diagnosing AM. In the present study, tissue AMEVs (T-AMEVs) were isolated from lesion homogenates of patients with adenomyosis, and blood AMEVs (B-AMEVs) were isolated from peripheral blood of patients with AM via differential centrifugation and density gradient centrifugation. T-AMEVs and B-AMEVs were characterized by electron microscopy, western blotting and mass spectrometry and analysed using FunRich3.1.3 software. T-AMEVs (average diameter, 150.9±102.2 nm) and B-AMEVs (194.1±66.81 nm) expressed the CD9, CD63 and flotillin-2 EV markers. A total of 211 proteins expressed in T-AMEVs and B-AMEVs overlapped with Vesiclepedia database entries, including 2 epithelial-to-mesenchymal transition (EMT)-associated proteins and 6 invasion-associated proteins. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that these 211 proteins were associated with the 'regulation of cell morphogenesis' and 'cytoskeletal organization' terms, as well as the PPAR and HIF-1 signalling pathways, which are related to the proliferation and metastasis of endometrial cells that cannot invade the myometrium under normal circumstances. Among the 211 proteins, HSP90A, STIP1 and TAGLN-2 were expressed in T-AMEVs and B-AMEVs, but not in serum EVs of women without adenomyosis/endometriosis, and these proteins might be the potential biomarkers for adenomyosis. These findings provide insights into the molecular features of adenomyosis and the new candidate biomarkers for diagnosis.

BACKGROUND: Lumbar disc herniation (LDH) can cause lumbar nerve root compression, which can lead to denervated atrophy of paraspinal muscles theoretically, however, the conclusions of morphological alteration in multifidus with LDH remain controversial. Transforming growth factor-beta 1 (TGF-β1) plays an essential role in the development of tissue fibrosis and is a molecular marker in the study of muscle fibrosis, but no relevant studies on TGF-β1 expression in multifidus have been reported so far. This study is to observe altered morphology of multifidus in patients with LDH, and to explore the correlation between multifidus fibrosis and TGF-β1 expression. MATERIALS AND METHODS: 46 LDH patients with low back pain combined with unilateral leg radiation pain and/or numbness were selected. Patients were divided into four groups according to their medical histories. Group 1: medical history less than 6 months (15 cases); group 2: a medical history of 6–12 months (10 cases); group 3: a medical history of 12–24 months (13 cases); and group 4: medical history > 24 months (8 cases). Bilateral multifidus specimens were taken from compressed nerve root segments, and morphological changes in multifidus were determined. Multi-parameter changes in TGF-β1 expression in multifidus were observed by immunohistochemistry and immunofluorescence. RESULTS: HE staining showed that the cross-sectional area (CSA) of multifidus in the involved sides decreased and muscle fibers atrophied. Masson’s trichrome staining showed a decrease in the sectional area ratio of myofibers to collagen fibers in the involved side. In groups 1 and 2, there were no significant differences in the aforementioned parameters. In groups 3 and 4, statistically significant differences in the sectional area ratio of myofibers to collagen fibers in both sides were seen (P

Asphaltenes, heavy aromatic components of crude oil, are known to adsorb on surfaces and can lead to pipe clogging or hinder oil recovery. Because of their multicomponent structure, the details of their interactions with surfaces are complex. We investigate the effect of the physicochemical properties of the substrate on the extent and mechanism of this adsorption. Using wetting measurements, we relate the initial kinetics of deposition to the interfacial energy of the surface. We then quantify the long-term adsorption dynamics using a quartz crystal microbalance and ellipsometry. Finally, we investigate the mechanism and morphology of adsorption with force spectroscopy measurements as a function of surface chemistry. We determine different adsorption regimes differing in orientation, packing density, and initial kinetics on different substrate functionalizations. Specifically, we find that alkane substrates delay the initial monolayer formation, fluorinated surfaces exhibit fast adsorption but low bonding strength, and hydroxyl substrates lead to a different adsorption orientation and a high packing density of the asphaltene layer.

The impact of antibiotics on H

We measure the light shift of the rubidium atomic clock under interaction of a 780 nm laser, which has potential application in the laser power stabilization. At the same time, in order to improve the performance of rubidium clock, we demonstrate a Faraday laser of which the cavity mode is locked to the peak of the transition spectrum, thus suppressing the otherwise existed power and frequency noise caused by the cavity mode fluctuations. This Faraday laser is suitable for the optical pumped rubidium atomic clock with the frequency being stably on resonance with the rubidium 780nm transition, and has potential applications on the cesium beam clocks and fountain clocks.

A flexible and flame-retarding thermoplastic polyurethane (TPU)-based electromagnetic interference (EMI)-shielding composite with multilayered structure was fabricated via coextrusion technology. The layer multiplication could not only create numerous layer interfaces, but also tailor the selective distribution of flame retardants (FRs) and carbon nanotubes (CNTs) endowing each extrudate excellent flexibility. When the layer numbers reached 32, synergistic flame-retarding and EMI-shielding multiple functional networks were generated and performed the optimum comprehensive performances, overcoming the major disadvantage of the conventional composites where the networks may breakup each other. Due to the interfacial polarization loss caused by the impedance difference between conducting and flame-retarding layers, the maximum shielding effectiveness (SE) of 38.5 dB was obtained with less than 4 wt% CNTs. Besides, superior flame retardancy rated by V-0 with quick self-extinguishment and low heat release was achieved owning to the production of continuous and foaming carbonaceous structure among layers. More significantly, the SE of the char residue, which was less concerned in conventional composite systems, was even beyond 60 dB. The maintenance of the multilayered architecture and the generation of atmosphere cavities were regarded to benefit for providing numerous impedance-mismatched interfaces and extending the transmission path of the microwaves. Consequently, the multilayer-assembled strategy was proposed to balance the mechanical, flame-retarding and EMI-shielding performances for satisfying with the stringent requirements of protective materials.

For the past 30 years, thin-film membrane composites have been the state-of-the-art technology for reverse osmosis, nanofiltration, ultrafiltration, and gas separation. However, traditional membrane casting techniques, such as phase inversion and interfacial polymerization, limit the types of material that are used for the membrane separation layer. Here, we describe a novel thin-film liftoff (T-FLO) technique that enables the fabrication of thin-film composite membranes with new materials for desalination, organic solvent nanofiltration, and gas separation. The active layer is cast separately from the porous support layer, allowing for the tuning of the thickness and chemistry of the active layer. A fiber-reinforced, epoxy-based resin is then cured on top of the active layer to form a covalently bound support layer. Upon submersion in water, the cured membrane lifts off from the substrate to produce a robust, freestanding, asymmetric membrane composite. We demonstrate the fabrication of three novel T-FLO membranes for chlorine-tolerant reverse osmosis, organic solvent nanofiltration, and gas separation. The isolable nature of support and active-layer formation paves the way for the discovery of the transport and selectivity properties of new polymeric materials. This work introduces the foundation for T-FLO membranes and enables exciting new materials to be implemented as the active layers of thin-film membranes, including high-performance polymers, two-dimensional materials, and metal-organic frameworks.

Graphical abstract, Highlights • The mechanical behavior of AA2060 was investigated under HSR deformation and at room temperature. • A novel gripping method was designed to prevent the distortion of strain waves during HSR experiments. • The ductility of AA2060 was enhanced due to the adiabatic softening and inertia effect. • The fracture behavior of AA2060-T8 was changed from brittle to ductile behavior under HSR deformation. • Johnson-Cook constitutive model was modified to predict the dynamic flow behavior of AA2060-T8., Since AA2060-T8 was introduced in the past few years, investigating the mechanical response, fracture mechanisms, and anisotropic behaviour of AA2060-T8 sheets under high strain rate deformation has been crucial. Thus, uniaxial tensile tests were performed under quasi-static, intermediate, and high strain rate conditions using universal testing machines as well as split Hopkinson tensile bars. The experimental results showed that the ductility of AA2060-T8 sheets was improved during high strain rate deformation because of the adiabatic softening and the inertia effect which contribute to slow down the necking development, and these results were verified by the fracture morphologies of high strain rate tensile samples. Furthermore, the strain rate hardening influence of AA2060-T8 was significant. Therefore, the Johnson–Cook constitutive model was modified to consider the effects of both strain and strain rates on the strain hardening coefficient. The results obtained from the improved Johnson–Cook constitutive model are in remarkable accordance with those obtained from experimental work. Thus, the improved Johnson–Cook model can predict the flow behavior of AA2060-T8 sheets at room temperature over a wide range of strain rates. The results of the present study can efficiently be used to develop a new manufacturing route based on impact hydroforming technology (IHF) to manufacture sound thin-walled-complex shape components from AA2060-T8 sheets at room temperature.

Metal oxides have a large storage capacity when employed as anode materials for lithium-ion batteries (LIBs). However, they often suffer from poor capacity retention due to their low electrical conductivity and huge volume variation during the charge-discharge process. To overcome these limitations, fabrication of metal oxides/carbon hybrids with hollow structures can be expected to further improve their electrochemical properties. Herein, ZnO-Co3O4 nanocomposites embedded in N-doped carbon (ZnO-Co3O4@N-C) nanocages with hollow dodecahedral shapes have been prepared successfully by the simple carbonizing and oxidizing of metal-organic frameworks (MOFs). Benefiting from the advantages of the structural features, i.e. the conductive N-doped carbon coating, the porous structure of the nanocages and the synergistic effects of different components, the as-prepared ZnO-Co3O4@N-C not only avoids particle aggregation and nanostructure cracking but also facilitates the transport of ions and electrons. As a result, the resultant ZnO-Co3O4@N-C shows a discharge capacity of 2373 mAh g(-1) at the first cycle and exhibits a retention capacity of 1305 mAh g(-1) even after 300 cycles at 0.1 A g(-1). In addition, a reversible capacity of 948 mAh g(-1) is obtained at a current density of 2 A g(-1), which delivers an excellent high-rate cycle ability. Funding Agencies|National Natural Science Foundation of China [21601120, 1375111, 11575105]; Science and Technology Commission of Shanghai Municipality [17ZR1410500]; Key Natural Science Foundation of Anhui Provincial Education Commission [KJ2016A510]; Anhui Provincial Science Foundation for Excellent Youth Talents; Educational Quality and Innovation Project of Anhui Province [2015jyxm398]

Polyaniline was first confirmed as a dark green precipitate on an electrode during the electrochemical polymerization of aniline in 1862. Since then, scientists have been studying the kinetics and growth mechanisms of polyaniline through the electrochemical approach. Studies have shown that p-phenylenediamine, p-aminodiphenylamine, and other aromatic small molecules may serve as initiators for accelerating the polymerization reaction due to the autocatalytic effect of polyaniline. However, little research has been focused on the catalytic effects of introducing oligoanilines. In this paper, quantitative rate constants for the electrochemical polymerization of aniline in both HCl and acetonitrile/HCl solutions with 0.5 mol % of added oligoanilines including diphenylamine, N-phenyl-p-phenylenediamine, 1,4-phenylenediamine, N,N′-diphenyl-1,4-phenylenediamine, 4,4′-diaminodiphenylamine, and tetraaniline in both emeraldine and leucoemeraldine states are reported. Among all the rate constants, N-phenyl-p-phenyl...

Doping technology has been proved to be a productive strategy to realize the multi-functionality of materials. Herein, Ni doped SnO2 quantum dots (QDs) are fabricated through a convenient hydrothermal process. In the fabrication process, Vitamin C (VC) acts as a stabilizer to avoid the precipitating of Sn4+(Ni2+), and Na2CO3 serves as a precipitator to react with Sn4+(Ni2+) to produce Ni doped SnO2 QDs. The influence of the Ni doping amount on the photodegradation performance of SnO2 QDs is studied. It was found that the Ni doped SnO2 QDs with Ni/Sn atomic ratio of 1% display the best photocatalytic performace due to the following advantages: (1) the Ni doping can boost light-harvesting and narrow the band gaps of the SnO2 QDs; (2) the SnO2 QDs with ultra small particle size and large specific surface area can supply more reactive centers for photocatalytic reactions. The two important factors contribute to enhancing the photocatalytic performance of the 1% Ni doped SnO2 QDs. As a result, the 1% Ni doped SnO2 QDs photodegrade 91.5% Rhodamine B after being illuminated by solar light for 28 min, obviously surpassing that of their pure counterparts.

One-dimensional (1D) heterostructured photocatalysts with controllable texture properties and compositions have attracted increasing interest owing to their unique optical, structural, and electronic advantages. Herein, 1D Co3O4-SnO2 heteronanorods were rationally designed and synthesized through a facile solution-based approach. Benefiting from both of their heterostructural and compositional characteristics, the resulting Co3O4-SnO2 heteronanorods exhibit high photocatalytic performance for the degradation of Rhodamine B (RhB) under visible-light irridation. In particular, the photocatalyst with a Co3O4/SnO2 mass ratio of 1:1 provides the best photocatalytic performance, which can degrade 90% RhB within 120 min. Besides, several reaction parameters affecting RhB degradation, such as churning time, calcination temperature and pH value, are investigated in detail. The enhanced photocatalytic activity can be attributed to the broadening of absorption spectrum to visible-light regions and the efficient charge separation of photogenerated electron-hole pairs due to the formed p-n heterojunctions. The strategy reported here can be able to expand to fabricate other heterostructured photocatalysts for practical applications in the fields of photocatalysis, water splitting, and solar cells.

The alternately-organized poly(vinylidene fluoride) (PVDF)/poly(methyl methacrylate) (PMMA) multilayer materials were prepared through layer-multiplying coextrusion. With the multiplication of layers, the thickness of each layer was reduced in proportion and the layer interfaces were enriched generating a broader and more continuous thermal transition temperature (Ttrans) from PVDF to PMMA layers as mapped by in-situ thermal analysis. The low-Ttrans side originated from the glass transition of PMMA, whereas the high-Ttrans side was dominated by the melting of PVDF crystals based on the heating curves of DMA and DSC. The dielectric spectroscopy and 2D-SAXS were performed and demonstrated that the compositional diffusion not only broadened the relaxation distribution of amorphous chains, but also strengthened the interaction between amorphous and crystalline domains. Therefore, a unique multilayer network, where the crystals in PVDF layers acting as physical networks connected the neighboring amorphous layers, was fabricated and its potential application in obtaining multi-shape memory effect (MSME) was disclosed for the first time. The results exhibited that the 1024-layer specimen owned a better triple- and quadruple-shape memory capacity than conventional blend which possessed the same compositions and a similar Ttrans range. The latter one even failed to successively memorize more than two temporary shapes. A possible mechanism was proposed through polarized IR and creeping-recovery measurements. Higher phase continuity which benefited for the stress transfer was revealed to play a significant role in strengthening the shape-fixing and -recovering ability during each shape-memory progress. Accordingly, a new physically-compounding strategy was addressed to achieve outstanding MSME for meeting complex demands in smart applications.

Construction of heterostructures with proper band alignment and effective transport and separation of photogenerated charges is highly expected for photocatalysis. In this work, Ni-doped SnO2-SnS2 heterostructures (NiSnSO) are simply prepared by thermal oxidation of Ni-doped hierarchical SnS2 microspheres in the air. When applied for the photodegradation of organic contaminants, these NiSnSO exhibit excellent catalytic performance and stability due to the following advantages: (1) Ni doping leads to the enhancement of light harvesting of SnS2 in the visible light regions; (2) the formed heterojunctions promote the transport and separation of photogenerated electrons from SnS2 to SnO2; (3) Ni-SnO2 quantum dots facilitate the enrichment of reactants, provide more reactive centers and accelerate product diffusion in the reactive centers; (4) the SnS2 hierarchical microspheres constituted by nanoplates provide abundant active sites, high structural void porosity and accessible inner surface to faciliate the catalytic reactions. As a result, the optimized NiSnSO can photodegrade 92.7% methyl orange within 80 min under the irradiation of simulated sunlight, greatly higher than those of pure SnS2 (29.8%) and Ni-doped SnS2 (52.1%). These results reveal that the combination of heteroatom doping and heterostructure fabrication is a very promising strategy to deliver nanomaterials for effectively photocatalytic applications.

Three-dimensional (3D) hierarchical architectures are currently attracting extensive interests owing to their fascinating morphology-dependent properties and potential applications. In this work, we have developed a facile template-free hydrothermal method to synthesize various 3D SnO2 hierarchical superstructures. It is found that the amount of urea, pH value and the pre-oxidation process play a crucial role in the micro/nanostructural evolutions of building blocks and final products. Oriented attachment and self-assembling dual-controlled mechanisms are then proposed to illustrate the formation of 3D hierarchical superstructures. The application in photocatalysis for the degradation of methylene blue (MB) demonstrates that the as-synthesized SnO2 hierarchical superstructures have highly efficient photocatalytic activity for the degradation of organic pollutants. Particularly, the SnO2 hierarchical superstructure constructed by ultrathin nanosheets can degrade 93% of MB within 150 min, which is much higher than that of commercial SnO2 powders. The enhanced photocatalytic performances can be attributed to the high surface-to-volume ratio, the abundant active sites and the efficient separation of photogenerated electrons and holes induced by the unique 3D loose and microporous superstructures. These new insights obtained in this study will be beneficial for the practical applications of oxide semiconductor materials for photocatalytic degradation of organic pollutants.

Conjugated polyaniline has shown anticorrosive, hydrophilic, antibacterial, pH-responsive, and pseudocapacitive properties making it of interest in many fields. However, in situ grafting of polyaniline without harsh chemical treatments is challenging. In this study, we report a simple, fast, and non-destructive surface modification method for grafting tetraaniline (TANI), the smallest conjugated repeat unit of polyaniline, onto several materials via perfluorophenylazide photochemistry. The new materials are characterized by nuclear magnetic resonance (NMR) and electrospray ionization (ESI) mass spectroscopy. TANI is shown to be covalently bonded to important carbon materials including graphite, carbon nanotubes (CNTs), and reduced graphene oxide (rGO), as confirmed by transmission electron microscopy (TEM). Furthermore, large area modifications on polyethylene terephthalate (PET) films through dip-coating or spray-coating demonstrate the potential applicability in biomedical applications where high transparency, patternability, and low bio-adhesion are needed. Another important application is preventing biofouling in membranes for water purification. Here we report the first oligoaniline grafted water filtration membranes by modifying commercially available polyethersulfone (PES) ultrafiltration (UF) membranes. The modified membranes are hydrophilic as demonstrated by captive bubble experiments and exhibit extraordinarily low bovine serum albumin (BSA) and Escherichia coli adhesions. Superior membrane performance in terms of flux, BSA rejection and flux recovery after biofouling are demonstrated using a cross-flow system and dead-end cells, showing excellent fouling resistance produced by the in situ modification.

Objective To compare the safety and efficacy of high-intensity focused ultrasound (HIFU) followed by hysteroscopic resection for different placenta accreta spectrum disorders. Materials and methods Thirty-four patients with placenta accreta, placenta increta, or placenta percreta were treated with USgHIFU from January 2016 to December 2019 and were retrospectively reviewed. The patients were classified into three categories according to the relationship between the trophoblastic villi and the myometrium, based on magnetic resonance imaging (MRI). Fifteen patients were classified as placenta accreta, 17 patients were classified as placenta increta, and 2 were classified as placenta percreta. All patients completed follow-up. Treatment efficacy and safety were evaluated. Results No significant differences in baseline characteristics and results of HIFU ablation were observed between the patients with placenta accreta and those with placenta increta. The return of HCG levels to normal was longer in patients with placenta accreta compared with patients with placenta increta, while no significant difference was observed in the amount of intraoperative blood loss, the return of normal menstruation and the length of hospital stay. Conclusions HIFU treatment followed by hysteroscopic resection is safe and effective in the treatment of patients with placenta accreta and placenta increta.

Pulsating hydroforming and impact hydroforming are two advanced technologies to increase the formability of material compared with other traditional forming technologies. They were systematically investigated from aspects of technical principle, forming mechanism, equipment, and applications. Pulsating hydroforming can improve the forming ability by altering the friction condition of sheet/tube parts or by utilizing the effect of transformation induced plasticity of stainless steels under the pulsating loading. As for impact hydroforming, the strain rate can reach 103–104/s and the instantaneous pressure can be GPa level, which can obviously increase the elongation of hard-to-form material by 20–60%. The effect of flexible liquid and impact impulse was investigated by both experiment and simulation, while the mechanisms were related to the compatible deformation of the second phase, strain decentralization, and defect stabilization. The technologies have been used on the manufacturing of complex, thin-walled components for the fields of aeronautics and aerospace, automobile, nuclear power, etc.

Background: Percutaneous kyphoplasty (PKP) is effective for the treatment of Kummell's disease. However, controversy remains regarding whether a unipedicular or bipedicular PKP is superior.Methods: A retrospective study was performed to review 40 patients with stage I and II Kummell's disease who underwent PKP in our hospital from January 2015 to June 2018. Based on the transpedicular approach of PKP, those patients were randomly divided into unipedicular group (n = 19) and bipedicular group (n = 21) . Operative time, bone cement injection volume and cement leakage rate were compared in the two groups. Pre- and post-operative visual analogue score (VAS), local kyphotic angle and average vertebral height were also evaluated.Results: All patients underwent surgery successfully. Compared with preoperative condition, VAS was significantly decreased at 1 day after operation and the last follow-up in both groups (P < 0.05) , and local kyphotic angle and average vertebral height were restored markedly (P < 0.05). Operative time of both groups had no significant difference (P > 0.05). Bone cement injection volume was larger in bipedicular group (P < 0.05). At 1 day after operation and the last follow-up , the local kyphotic angle and average vertebral height in bipedicular group were restored better than those in unipedicular group (P < 0.05). There were 4 cases of cement leakage in both groups, with leakage rates of 21.1% and 19.0%, respectively, and the difference was not significant (P > 0.05).Conclusion: Both unipedicular and bipedicular PKP are effective for treating patients with stage I and II Kummell's disease, while postoperative pain relief and imaging results in bipedicular group were better than those in unipedicular group.