Influence of introducing Zr,Ti,Nb and Ce elements on externally solidified crystals and mechanical properties of high-pressure die-casting Al–Si alloy

High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile industry.Mg can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress arouses the deformation of large integrated die-castings.Herein,the development of non-heat treatment Al alloys is becoming the hot topic.In addition,HPDC contains externally solidified crystals(ESCs),which are detrimental to the mechanical properties of castings.To achieve high strength and toughness of non-heat treatment die-casting Al-Si alloy,we used AlSi9Mn alloy as matrix with the introduction of Zr,Ti,Nb,and Ce.Their influences on ESCs and mechanical properties were systematically investigated through three-dimensional reconstruction and thermodynamic simulation.Our results reveal that the addition of Ti increased ESCs'size and porosity,while the introduction of Nb refined ESCs and decreased porosity.Meanwhile,large-sized Al_3(Zr,Ti)phases formed and degraded the mechanical properties.Subsequent introduction of Ce resulted in the poisoning effect and reduced mechanical properties.

Investigation on the temperature distribution and strength of flat steel ribbon wound cryogenic high-pressure vessel

By analyzing heat transfer on the wall of fiat steel ribbon wound vessel （FSRWV）, a numerical model of temperature distribution on the entire wall （including inner core wall, flat steel ribbons, outside cylinder of jacket and insulating layer） was established by the authors. With the model, the temperature distribution and the length change in the vessel walls and flat steel ribbons in low temperature are calculated and analyzed. The results show that the flat steel ribbon wound cryogenic high-pressure vessel is simpler in structure, safer and easier to manufacture than those of conventional ones.

Bio-Inspired Screwed Conduits from the Microfluidic Rope-Coiling Effect for Microvessels and Bronchioles

Tubular microfibers have recently attracted extensive interest for applications in tissue engineering.However,the fabrication of tubular fibers with intricate hierarchical structures remains a major challenge.Here,we present a novel one-step microfluidic spinning method to generate bio-inspired screwed conduits(BSCs).Based on the microfluidic rope-coiling effect,a viscous hydrogel precursor is first curved into a helix stream in the channel,and then consecutively packed as a hollow structured stream and gelated into a screwed conduit(SC)via ionic and covalent crosslinking.By taking advantage of the excellent fluid-controlling ability of microfluidics,various tubes with diverse structures are fabricated via simple control over fluid velocities and multiple microfluidic device designs.The perfusability and permeability results,as well as the encapsulation and culture of human umbilical vein endothelial cells(HUVECs),human pulmonary alveolar epithelial cells(HPAs),and myogenic cells(C2C12),demonstrate that these SCs have good perfusability and permeability and the ability to induce the formation of functional biostructures.These features support the uniqueness and potential applications of these BSCs as biomimetic blood vessels and bronchiole tissues in combination with tissue microstructures,with likely application possibilities in biomedical engineering.

Nano-scale Reinforcements and Properties of Al-Si-Cu Alloy Processed by High-Pressure Torsion

To improve the comprehensive mechanical properties of Al-Si-Cu alloy,it was treated by a high-pressure torsion process,and the effect of the deformation degree on the microstructure and properties of the Al-Si-Cu alloy was studied.The results show that the reinforcements(β-Si andθ-CuAl_(2)phases)of the Al-Si-Cu alloy are dispersed in theα-Al matrix phase with finer phase size after the treatment.The processed samples exhibit grain sizes in the submicron or even nanometer range,which effectively improves the mechanical properties of the material.The hardness and strength of the deformed alloy are both significantly raised to 268 HV and 390.04 MPa by 10 turns HPT process,and the fracture morphology shows that the material gradually transits from brittle to plastic before and after deformation.The elements interdiffusion at the interface between the phases has also been effectively enhanced.In addition,it is found that the severe plastic deformation at room temperature induces a ternary eutectic reaction,resulting in the formation of ternary Al+Si+CuAl_(2)eutectic.

Experimental and Finite Element Analysis of Corroded High-Pressure Pipeline Repaired by Laminated Composite

Repairs of corroded high-pressure pipelines are essential for fluids transportation under high pressure.One of the methods used in their repairs is the use of layered composites.The composite used must have the necessary strength.Therefore,the experiments and analytical solutions presented in this paper are performed according to the relevant standards and codes,including ASME PCC-2,ASME B31.8S,ASME B31.4,ISO 24817 and ASME B31.G.In addition,the experimental tests are replicated numerically using the finite element method.Setting the strain gauges at different distances from the defect location,can reduce the nonlinear effects,deformation,and fluctuations due to the high pressure.The direct relationship between the depth of an axial defect and the stress concentration is observed at the inner side edges of the defect.Composite reparation reduces the non-linearities related to the sharp variation of the geometry and a more reliable numerical simulation could be performed.

Experimental and numerical study of hypervelocity impact damage on composite overwrapped pressure vessels

Ground-based tests are important for studying hypervelocity impact(HVI)damage to spacecraft pressure vessels in the orbital debris environment.We analyzed the damage to composite overwrapped pressure vessels(COPVs)in the HVI tests and classified the damage into non-catastrophic damage and catastrophic damage.We proposed a numerical simulation method to further study non-catastrophic damage and revealed the characteristics and mechanisms of non-catastrophic damage affected by impact conditions and internal pressures.The fragments of the catastrophically damaged COPVs were collected after the tests.The crack distribution and propagation process of the catastrophic ruptures of the COPVs were analyzed.Our findings contribute to understanding the damage characteristics and mechanisms of COPVs by HVIs.

CO_(2)high-pressure miscible flooding and storage technology and its application in Shengli Oilfield,China

There are various issues for CO_(2)flooding and storage in Shengli Oilfield,which are characterized by low light hydrocarbon content of oil and high miscible pressure,strong reservoir heterogeneity and low sweep efficiency,gas channeling and difficult whole-process control.Through laboratory experiments,technical research and field practice,the theory and technology of CO_(2)high pressure miscible flooding and storage are established.By increasing the formation pressure to 1.2 times the minimum miscible pressure,the miscibility of the medium-heavy components can be improved,the production percentage of oil in small pores can be increased,the displacing front developed evenly,and the swept volume expanded.Rapid high-pressure miscibility is realized through advanced pressure flooding and energy replenishment,and technologies of cascade water-alternating-gas(WAG),injection and production coupling and multistage chemical plugging are used for dynamic control of flow resistance,so as to obtain the optimum of oil recovery and CO_(2)storage factor.The research results have been applied to the Gao89-Fan142 in carbon capture,utilization and storage(CCUS)demonstration site,where the daily oil production of the block has increased from 254.6 t to 358.2 t,and the recovery degree is expected to increase by 11.6 percentage points in 15 years,providing theoretical and technical support for the large-scale development of CCUS.

Nomogram prediction of vessels encapsulating tumor clusters in small hepatocellular carcinoma≤3 cm based on enhanced magnetic resonance imaging

BACKGROUND Vessels encapsulating tumor clusters(VETC)represent a recently discovered vascular pattern associated with novel metastasis mechanisms in hepatocellular carcinoma(HCC).However,it seems that no one have focused on predicting VETC status in small HCC(sHCC).This study aimed to develop a new nomogram for predicting VETC positivity using preoperative clinical data and image features in sHCC(≤3 cm)patients.AIM To construct a nomogram that combines preoperative clinical parameters and image features to predict patterns of VETC and evaluate the prognosis of sHCC patients.METHODS A total of 309 patients with sHCC,who underwent segmental resection and had their VETC status confirmed,were included in the study.These patients were recruited from three different hospitals:Hospital 1 contributed 177 patients for the training set,Hospital 2 provided 78 patients for the test set,and Hospital 3 provided 54 patients for the validation set.Independent predictors of VETC were identified through univariate and multivariate logistic analyses.These independent predictors were then used to construct a VETC prediction model for sHCC.The model’s performance was evaluated using the area under the curve(AUC),calibration curve,and clinical decision curve.Additionally,Kaplan-Meier survival analysis was performed to confirm whether the predicted VETC status by the model is associated with early recurrence,just as it is with the actual VETC status and early recurrence.RESULTS Alpha-fetoprotein_lg10,carbohydrate antigen 199,irregular shape,non-smooth margin,and arterial peritumoral enhancement were identified as independent predictors of VETC.The model incorporating these predictors demonstrated strong predictive performance.The AUC was 0.811 for the training set,0.800 for the test set,and 0.791 for the validation set.The calibration curve indicated that the predicted probability was consistent with the actual VETC status in all three sets.Furthermore,the decision curve analysis demonstrated the clinical benefits of our model for patients with sHCC.Finally,early recurrence was more likely to occur in the VETC-positive group compared to the VETC-negative group,regardless of whether considering the actual or predicted VETC status.CONCLUSION Our novel prediction model demonstrates strong performance in predicting VETC positivity in sHCC(≤3 cm)patients,and it holds potential for predicting early recurrence.This model equips clinicians with valuable information to make informed clinical treatment decisions.

Predictive visual field outcomes after optic chiasm decompressive surgery by retinal vessels parameters using optical coherence tomography angiography

AIM:To evaluate the predictive value of superficial retinal capillary plexus(SRCP)and radial peripapillary capillary(RPC)for visual field recovery after optic cross decompression and compare them with peripapillary nerve fiber layer(pRNFL)and ganglion cell complex(GCC).METHODS:This prospective longitudinal observational study included patients with chiasmal compression due to sellar region mass scheduled for decompressive surgery.Generalized estimating equations were used to compare retinal vessel density and retinal layer thickness preand post-operatively and with healthy controls.Logistic regression models were used to assess the relationship between preoperative GCC,pRNFL,SRCP,and RPC parameters and visual field recovery after surgery.RESULTS:The study included 43 eyes of 24 patients and 48 eyes of 24 healthy controls.Preoperative RPC and SRCP vessel density and pRNFL and GCC thickness were lower than healthy controls and higher than postoperative values.The best predictive GCC and pRNFL models were based on the superior GCC[area under the curve(AUC)=0.866]and the tempo-inferior pRNFL(AUC=0.824),and the best predictive SRCP and RPC models were based on the nasal SRCP(AUC=0.718)and tempo-inferior RPC(AUC=0.825).There was no statistical difference in the predictive value of the superior GCC,tempo-inferior pRNFL,and tempo-inferior RPC(all P>0.05).CONCLUSION:Compression of the optic chiasm by tumors in the saddle area can reduce retinal thickness and blood perfusion.This reduction persists despite the recovery of the visual field after decompression surgery.GCC,pRNFL,and RPC can be used as sensitive predictors of visual field recovery after decompression surgery.

Preoperatively predicting vessels encapsulating tumor clusters in hepatocellular carcinoma:Machine learning model based on contrast-enhanced computed tomography

BACKGROUND Recently,vessels encapsulating tumor clusters(VETC)was considered as a distinct pattern of tumor vascularization which can primarily facilitate the entry of the whole tumor cluster into the bloodstream in an invasion independent manner,and was regarded as an independent risk factor for poor prognosis in hepatocellular carcinoma(HCC).AIM To develop and validate a preoperative nomogram using contrast-enhanced computed tomography(CECT)to predict the presence of VETC+in HCC.METHODS We retrospectively evaluated 190 patients with pathologically confirmed HCC who underwent CECT scanning and immunochemical staining for cluster of differentiation 34 at two medical centers.Radiomics analysis was conducted on intratumoral and peritumoral regions in the portal vein phase.Radiomics features,essential for identifying VETC+HCC,were extracted and utilized to develop a radiomics model using machine learning algorithms in the training set.The model’s performance was validated on two separate test sets.Receiver operating characteristic(ROC)analysis was employed to compare the identified performance of three models in predicting the VETC status of HCC on both training and test sets.The most predictive model was then used to constructed a radiomics nomogram that integrated the independent clinical-radiological features.ROC and decision curve analysis were used to assess the performance characteristics of the clinical-radiological features,the radiomics features and the radiomics nomogram.RESULTS The study included 190 individuals from two independent centers,with the majority being male(81%)and a median age of 57 years(interquartile range:51-66).The area under the curve(AUC)for the combined radiomics features selected from the intratumoral and peritumoral areas were 0.825,0.788,and 0.680 in the training set and the two test sets.A total of 13 features were selected to construct the Rad-score.The nomogram,combining clinicalradiological and combined radiomics features could accurately predict VETC+in all three sets,with AUC values of 0.859,0.848 and 0.757.Decision curve analysis revealed that the radiomics nomogram was more clinically useful than both the clinical-radiological feature and the combined radiomics models.CONCLUSION This study demonstrates the potential utility of a CECT-based radiomics nomogram,incorporating clinicalradiological features and combined radiomics features,in the identification of VETC+HCC.

Enhanced mechanical and electrical properties of multi-walled carbon nanotubes reinforced Cu/Ti_(3)SiC_(2)/C nanocomposites via high-pressure torsion

In order to achieve combined mechanical and electrical properties,multi-walled carbon nanotubes(MWCNTs)reinforced Cu/Ti_(3)SiC_(2)/C nanocomposites were further processed by high-pressure torsion(HPT).The maximum microhardness values of central and edge from the composites with 1 wt.%MWCNTs reached HV 130.0 and HV 363.5,which were 43.9%and 39.5%higher than those of the original samples,respectively.With the same content of MWCNTs,its electrical conductivity achieved 3.42×10^(7) S/m,which was increased by 78.1%compared with that of original samples.The synergistic improvement of mechanical and electrical properties is attributed to the obtained microstructure with increased homogenization and refinement,as well as improved interfacial bonding and reduced porosity.The strengthening mechanisms include dispersion and refinement strengthening for mechanical properties,as well as reduced electron scattering for electrical properties.

Reduction of photodynamic damage of blood vessels in the protected region by(–)-epigallocatechin gallate

Photodynamic therapy(PDT)has been increasingly used in the clinical treatment of neoplastic,inflammatory and infectious skin diseases.However,the generation of reactive oxygen species(ROS)may induce undesired side effects in normal tissue surrounding the treatment lesion,which is a big challenge for the clinical application of PDT.To date,(–)-Epigallocatechin gallate(EGCG)has been widely proposed as an antiangiogenic and antitumor agent for the protection of normal tissue from ROS-mediated oxidative damage.This study evaluates the regulation ability of EGCG for photodynamic damage of blood vessels during hematoporphyrin monomethyl ether(Hemoporfin)-mediated PDT.The quenching rate constants of EGCG for the triplet-state Hemoporfin and photosensitized 1O2 generation are determined to be 6.8×10^(8)M^(−1)S^(−1),respectively.The vasoconstriction of blood vessels in the protected region treated with EGCG hydrogel after PDT is lower than that of the control region treated with pure hydrogel,suggesting an efficiently reduced photodamage of Hemoporfin for blood vessels treated with EGCG.This study indicates that EGCG is an efficient quencher for triplet-state Hemoporfin and 1O2,and EGCG could be potentially used to reduce the undesired photodamage of normal tissue in clinical PDT.

Exploration on the Optimization Strategy for the Layup of Composite Material Pressure Vessels Based on Advanced Algorithms

This study aims to explore the influence of the laying angle on the pressure shell structure made of composite materials under the condition of a fixed shape. By using a composite material composed of a mixture of T800 carbon fiber and AG80 epoxy resin to design pressure vessels, this material combination can significantly improve the interlaminar shear strength and heat resistance. The article elaborates on the basic concepts and failure criteria of composite materials, such as the maximum stress criterion, the maximum strain criterion, the Tsai-Hill criterion, etc. With the help of the APDL parametric modeling language, the arc-shaped, parabolic, elliptical, and fitting curve-shaped pressure vessel models are accurately constructed, and the material property settings and mesh division are completed. Subsequently, APDL is used for static analysis, and the genetic algorithm toolbox built into Matlab is combined to carry out optimization calculations to determine the optimal laying angle. The research results show that the equivalent stress corresponding to the optimal laying angle of the arc-shaped pressure vessel is 5.3685e+08 Pa, the elliptical one is 5.1969e+08 Pa, the parabolic one is 5.8692e+08 Pa, and the fitting curve-shaped one is 5.36862e+08 Pa. Among them, the stress distribution of the fitting curve-shaped pressure vessel is relatively more uniform, with a deformation of 0.568E−03 m, a minimum equivalent stress value of 0.261E+09 Pa, a maximum equivalent stress value of 0.537E+09 Pa, and a ratio of 0.48, which conforms to the equivalent stress criterion. In addition, the fitting curve of this model can adapt to various models and has higher practical value. However, the stress distribution of the elliptical and parabolic pressure vessels is uneven, and their applicability is poor. In the future, further exploration can be conducted on the application of the fitting curve model in composite materials to optimize the design of pressure vessels. This study provides important theoretical support and practical guidance for the design of composite material pressure vessels.

Evaluation on Safety and Reliability of High-Pressure Vessel in Missile System

Through theoretical analysis of reliability and simulation analysis of dispersivi of d a/ d N based on Monte Carlo method, the distribution function of n and c was set up. Meanwhile, the distribution of critical opening displacement(COD)δ c was defined by the use of coherent coefficient method, and the probabilistic model of defects assessment of military special vessel was built. Thereby the theoretical and practical fundamental research on evaluation of reliability of military high pressure vessels was carried out.

Meningeal lymphatic vessel crosstalk with central nervous system immune cells in aging and neurodegenerative diseases

Meningeal lymphatic vessels form a relationship between the nervous system and periphery, which is relevant in both health and disease. Meningeal lymphatic vessels not only play a key role in the drainage of brain metabolites but also contribute to antigen delivery and immune cell activation. The advent of novel genomic technologies has enabled rapid progress in the characterization of myeloid and lymphoid cells and their interactions with meningeal lymphatic vessels within the central nervous system. In this review, we provide an overview of the multifaceted roles of meningeal lymphatic vessels within the context of the central nervous system immune network, highlighting recent discoveries on the immunological niche provided by meningeal lymphatic vessels. Furthermore, we delve into the mechanisms of crosstalk between meningeal lymphatic vessels and immune cells in the central nervous system under both homeostatic conditions and neurodegenerative diseases, discussing how these interactions shape the pathological outcomes. Regulation of meningeal lymphatic vessel function and structure can influence lymphatic drainage, cerebrospinal fluid-borne immune modulators, and immune cell populations in aging and neurodegenerative disorders, thereby playing a key role in shaping meningeal and brain parenchyma immunity.

Research on the Safety Evaluation of a High-pressure Vessel in a Missile System

In reference, we measured fracture properties of raw material, weld seam and heat affected zone of high pressure vessels(HPV); in this paper, we carried out safety evaluation on the basis of the previous work and predicted the lifetime of in service vessels with flaw by use of the fracture criterion for model Ⅰ crack in fracture mechanics. This method reduced the artificial error and the ultrasonic testing operator's work burden. The experimental and theoretical bases for the defect assessment of military HPV were established.

Studies on the Molecular Structure of Vessels in Secondary Xylem of Stem from Three Carambola Varieties

[Objective] The aim of this study was to provide the theoretical basis for variety identification of carambola and pomiculture.[Method] The molecular structure of vessels in stem secondary xylem from three carambola varieties of Malaysia 8,Misi and Malaysia B17 were studied by cell image analysis system and microphotography.[Result] The molecular structure of vessels in stem secondary xylem from carambola was as follows:the first type had tails in two ends,the second type had tail in one end,and the third type had no tails in two ends.The average length of vessel elements was from 328.88 to 366.09 μm,while its average width was from 44.61 to 52.43 μm.Most of the end wall was simple perforation plates,while the alternate-opposite pitting was the major forms of pitting.[Conclusion] Most characteristics of vessel elements from carambola were evolutionary characters of vessel elements in the process of phylogeny,but there were more primitive characters,for example,both two ends of vessel had tails or just one end had tail,and end wall was inclined.The molecular structure of vessel from carambola was in accordance with its ecological adaptability,and the growth characteristics of different varieties were also in accordance with the difference of molecular structure of vessel.

Choke Vessels扩展的研究进展

穿支皮瓣是创伤修复的研究热点,穿支皮瓣研究的重点和难点则在于choke vessels。我们对近年来choke vessels扩展研究的相关文献进行综述,目前的研究主要聚焦于形态学的描述,其扩张机制很可能是剪切力变化,激活TRPV4,通过NF-kb通路而导致choke vessels扩张。

Choke vessels与穿支皮瓣的扩展

近年来随着临床解剖学研究的深入,在皮瓣的血供研究方面取得了新进展。1987年,Taylor等[1]提出了＂血管体（angiosomes）＂理论,所谓血管体是指某一源动脉呈树形分布的所有解剖学区域（anatomical territory）,包括皮肤、浅筋膜、深筋膜及其深层的各种组织。血管体呈树形分支,其口径逐渐变细并与周围邻近血管体的类似血管形成血管网相连接,这种口径逐渐减小而互相吻合的血管网被称之为＂choke vessels＂。

穿支皮瓣choke vessels新生的研究进展

大量研究资料显示：每一皮肤穿支均有一个明确的供血范围,并与周围其它穿支的分支相互吻合形成血管网,即choke vessels。作为血管体间桥梁结构的choke vessels在跨区皮瓣的设计和切取方面起到十分重要的作用。近年来,有关穿支皮瓣跨区供血的基础研究-[1-3]和临床报道-[4-6]屡见不鲜,而本文就其中与choke vessels新生相关的研究综述如下。