Enhanced initial biodegradation resistance of the biomedical Mg-Cu alloy by surface nanomodification

Mg-Cu alloys are promising antibacterial implant materials.However,their clinical applications have been impeded by their high initial biodegradation rate,which can be alleviated using nanotechnology by for example surface nanomodification to obtain a gradient nanostructured surface layer.The present work(i)produced a gradient nanostructured surface layer with a∼500µm thickness on a Mg-0.2 Cu alloy by a surface mechanical grinding treatment(SMGT),and(ii)studied the biodegradation behavior in Hank's solution.The initial biodegradation rate of the SMGTed samples was significantly lower than that of the unSMGTed original counterparts,which was attributed to the surface nanocrystallization,and the fragmentation and re-dissolution of Mg_(2)Cu particles in the surface of the SMGTed Mg-0.2 Cu alloy.Furthermore,the SMGTed Mg-0.2 Cu alloy had good antibacterial efficacy.This work creatively used SMGT technology to produce a high-performance Mg alloy implant material.

The immunomodulatory effects and mechanisms of magnesium-containing implants in bone regeneration:A review

Traditional designs and developments of bone biomaterials mostly concentrate on the positive regulation of osteoblast lineage cells,but often ignore the importance of immune responses and the equilibrium between bone resorption mediated by osteoclasts and bone formation mediated by osteoblasts.Immune dysregulation is associated with an imbalance between pro-inflammatory and anti-inflammatory processes,which may influence the efficacy of bone therapy.Therefore,implanted biomaterials should appropriately and precisely modulate subsequent immune responses.Magnesium(Mg)has been used to fabricate various Mg alloys for bone repair because of its favorable attributes such as osteogenic potential,immune regulation characteristics,biodegradability,and biocompatibility.Various basic research and clinical trials have been already conducted in many countries to explore the physical properties of Mg-containing implants and their clinical outcomes in bone fracture and defect repair.Therefore,this review summarizes the immune response to Mg-containing implants,and further organizes the current research and development progress of Mg-containing implants.The review aims to offer an overview of the current knowledge on immunomodulation of Mg-containing implants and future challenges in their clinical application,which could provide further insight in the development of better strategies for the treatment of bone defect and fracture.

Degradable magnesium alloy suture promotes fibrocartilaginous interface regeneration in a rat rotator cuff transosseous repair model

Despite transosseous rotator cuff tear repair using sutures is widely accepted for tendon-bone fixation,the fibrocartilaginous enthesis regeneration is still hardly achieved with the traditional sutures.In the present work,degradable magnesium(Mg)alloy wire was applied to suture supraspinatus tendon in a rat acute rotator cuff tear model with Vicryl Plus 4±0 absorbable suture as control.The shoulder joint humerus-supraspinatus tendon complex specimens were retrieved at 4,8,and 12 weeks after operation.The Mg alloy suture groups showed better biomechanical properties in terms of ultimate load to failure.Gross observation showed that hyperplastic response of the scar tissue at the tendon-bone interface is progressively alleviated over time in the both Mg alloy suture and Vicryl suture groups.In the histological analysis,for Mg alloy suture groups,chondrocytes appear to proliferate at 4 weeks postoperatively,and the tendon-bone interface showed an orderly structural transition zone at 8 weeks postoperatively.The collagenous fiber tended to be aligned and the tendon-bone interlocking structures apparently formed,where transitional structure from unmineralized fibrocartilage to mineralized fibrocartilage was closer to the native fibrocartilaginous enthesis.In vivo degradation of the magnesium alloy wire was completed within 12 weeks.The results indicated that Mg alloy wire was promising as degradable suture with the potential to promotes fibrocartilaginous interface regeneration in rotator cuff repair.

Diagnosis of Acute Q Fever in an Elderly Patient Using Metagenomic Next-Generation Sequencing:A Case Report

Query fever(Q fever)is a globally spread zoonotic disease caused by Coxiella burnetii,commonly found in natural foci but rarely seen in Hebei Province.The clinical manifestations of Q fever are diverse and nonspecific,which often leads to missed or incorrect diagnoses in clinical practice.This article reports a case of acute Q fever diagnosed in an elderly patient using metagenomic next-generation sequencing.

Study on β-TCP Coated Porous Mg as a Bone Tissue Engineering Scaffold Material

Three-dimensional honeycomb-structured magnesium （Mg） scaffolds with interconnected pores of accurately controlled pore size and porosity were fabricated by laser perforation technique. Biodegradable and bioactiveβ- tricalcium phosphate （β-TCP） coatings were prepared on and the biodegradation mechanism was simply evaluated the porous Mg to further improve its biocompatibility, in vitro. It was found that the mechanical properties of this type of porous Mg significantly depended on its porosity. Elastic modulus and compressive strength similar to human bones could be obtained for the porous Mg with porosity of 42.6%-51%. It was observed that the human osteosarcoma cells （UMR106） were well adhered and proliferated on the surface of the β- TCP coated porous Mg, which indicates that theβ-TCP coated porous Mg is promising to be a bone tissue engineering scaffold material.

Magnesium alloys for orthopedic applications:A review on the mechanisms driving bone healing

Magnesium(Mg) alloys have attracted a wealth of attention in orthopedic fields for their superior mechanical properties, degradability,and excellent biocompatibility. Consistently, to resolve the issues on rapid degradation, more studies are dedicated to the researches on the composition design, preparation and processing, surface modification, the degradation modes of Mg alloys. Nevertheless, the mechanisms by which Mg alloys promote bone healing remain elusive. This review gives an account of specific mechanisms on Mg alloys promoting bone healing from four aspects, immunomodulatory, angiogenesis, osteogenesis and regulation of osteoclast function. We highlight the regulation of Mg alloys on the functional status and interactions of numerous cells that are involved in bone healing, including immune cells, osteogenicrelated cells, osteoclasts, endothelial cells(ECs), nerve cells, etc., and summarize the signaling pathways involved, with the aim to provide the basis and support on future investigation on mechanisms on Mg alloys driving bone regeneration. More importantly, it provides a rationale and a general new basis for the application of Mg alloys in orthopedic fields.

Analysis of the Influence of Operating Room Nursing Care Management on the Incidence Rate of Nosocomial Infection in Orthopedic Surgery Patients

Objective:To analysis the influence of operating room nursing care management on the incidence rate of nosocomial infection in orthopedic surgery patients.Methodology:Fifty six orthopedic surgery patients who admitted into the hospital between January to December 2018 were enrolled into this study and randomly divided into two groups,which were the control group(under general management)and the observation group(under the operating room nursing care management).Further,the incidence rate of nosocomial infections,the incidence rate of irregular nursing care phenomena,the satisfaction score of nursing care management,and the quality of life score were observed and recorded.Result:The incidence rate of nosocomial infection,the incidence rate of irregular nursing care management,the satisfaction score of nursing care management,and the quality of life score of the observation group were compared to that of the control group,and the result showed P<0.05,indicates the statistical significance between the data indicators.Conclusion:The use of operating room nursing care management in patients with orthopedic surgery has shown a significant effect.

Role of bimodal-grained structure with random texture on mechanical and corrosion properties of a Mg-Zn-Nd alloy

Fine grained ZN20 alloy was obtained by combining equal-channel angular pressing(ECAP)with extrusion.Microstructural observation showed an obvious grain refinement with an average grain size of 10μm after ECAP.The original bimodal-grained structure composed of coarse grains with strong basal texture and fine grains with random texture was substituted by a new kind of bimodal-grained structure with finer grains and more random texture after 4 passes ECAP at 300℃.The combination of grain refinement and texture weakening caused the ductility can be increased by 40%compared with the as-extruded alloy.Immersion test in simulated intestinal fluid revealed an improvement of corrosion resistance after ECAP.Grain refinement can stable the corrosion product layer and basal texture is more beneficial for the corrosion resistance than the non-basal texture.

Successful Treatment of White Lung in Elderly Patients with COVID-19

Novel coronavirus(SARS-CoV-2,hereby known as COVID-19)has the characteristics of rapid variation and multiple variants,which has caused a huge impact on human health worldwide.At the end of 2022,the Omicron variant was widely spread in China,and the patients infected with COVID-19 were mainly concentrated in the elderly over 80 years old and people with serious basic diseases.Pathologically,diffuse lung injury can be seen in the advanced stage of severe and critical diseases,with a large number of inflammatory cells and fibrous mucus exudation,alveolar epithelial cells shedding and necrosis,severe pulmonary edema,hyaline membrane formation,and diffuse ground-glass shadow or consolidation on imaging,which is manifested as“white lung”[1],and its mortality rate has significantly increased.This study reported two cases of elderly patients admitted to the Affiliated Hospital of Hebei University for the treatment of COVID-19.

A Case Study of Severe QT Interval Prolongation Caused by Antidepressants

QT interval prolongation can be categorized into primary and secondary types according to its etiology.In this paper,we report a case of severe asymptomatic QT interval prolongation secondary to antidepressants.Regular follow-up and electrocardiogram monitoring is crucial when applying antidepressants,especially for patients without cardiac symptoms.This article presents case studies and examines existing literature on long QT syndrome to enhance the diagnosis and management of QT interval prolongation.This is especially relevant for non-psychiatric healthcare professionals who need to be attentive to the side effects of antidepressants to prevent potential adverse consequences resulting from oversight.

Enhancing General Corrosion Resistance of Biomedical High Nitrogen Nickel-Free Stainless Steel by Nitric Acid Passivation

A systematic study of nitric acid passivation was investigated to enhance the general corrosion resistance of biomedical high-nitrogen nickel-free stainless steels(HNSs).After passivation,the corrosion rate of HNS could dramatically reduce to 1/20 of the untreated in 37℃0.9 wt% NaCl solutions.Then,the passive film on HNS was analyzed by X-ray photoelectron spectroscopy.It was found that chromium enrichment in the passive film and nitrogen enrichment in the film/metal interface contributed to the improvement in general corrosion resistance of HNS.

The mechanical property and corrosion resistance of Mg-Zn-Nd alloy fine wires in vitro and in vivo

Titanium and its alloy are commonly used as surgical staples in the reconstruction of intestinal tract and stomach,however they cannot be absorbed in human body,which may cause a series of complications to influence further diagnosis.Magnesium and its alloy have great potential as surgical staples,because they can be degraded in human body and have good mechanical properties and biocompatibility.In this study,Mg-2Zn-0.5Nd(ZN20)alloy fine wires showed great potential as surgical staples.The ultimate tensile strength and elongation of ZN20 alloy fine wires were 248 MPa and 13%,respectively,which could be benefit for the deformation of the surgical staples from U-shape to B-shape.The bursting pressure of the wire was about 40 kPa,implying that it can supply sufficient mechanical support after anastomosis.Biochemical test and histological analysis illustrated good biocompatibility and biological safety of ZN20 alloy fine wire.The residual tensile stress formed on the outside of ZN20 fine wire during drawing would accelerate the corrosion.The second phase had a negative influence on corrosion property due to galvanic corrosion.The corrosion rate in vitro was faster than that in vivo due to the capsule formed on the surface of ZN20 alloy fine wire.

Study on corrosion resistance of pure magnesium with CaSiO_3 contained coating in NaCl solution

A composite coating was fabricated on pure magnesium by hydrothermal treatment in order to reduce its degradation in body environment. The coating was character- ized by scanning electron microscopy （SEM） and X-ray diffraction （XRD）. The XRD pattern showed that the main composition of the coating was a mixture of CaSiO3, MgSiO3 and Mg（OH）2. Electrochemical test showed that the corrosion current den- sity （icor~） of the coated magnesium was decreased by about two orders of magnitude compared with that of the bare magnesium, and the EIS measurement also showed that the corrosion resistant performance of the coated magnesium was significantly enhanced. Meanwhile, weight loss test showed that the weight loss of the coated magnesium was lower than that of the bare magnesium. Hence, the present study indicated that the composite coating could greatly slow down the degradation of pure magnesium.

Improvement of mechanical property and corrosion resistance of Mg-Zn-Nd alloy by bi-direction drawing

Mg-Zn-Nd alloy is a promising biodegradable metal material for surgical staples during the reconstruction of digestive tract due to its good biocompatibility and suitable mechanical properties.However,its deformation property and corrosion resistance should be improved to make better safety and effectiveness of staples.In the present study,bi-direction drawing was adopted to maintain the initial texture characteristics,and improve mechanical property and corrosion resistance of Mg-2Zn-0.5Nd alloy.The results showed that the microstructure after bi-direction did not change too much,but the texture could maintain its initial characteristics.The ductility of the alloy with 60%accumulative area reduction after bi-direction drawing was increased by 70%,indicating that an outstanding deformation property of Mg-Zn-Nd alloy can be obtained by bi-direction drawing.The corrosion resistance was also improved after bi-direction drawing compared with that under single direction drawing.

A novel biodegradable high nitrogen iron alloy with simultaneous enhancement of corrosion rate and local corrosion resistance

To improve the corrosion rate and suppress the local corrosion,a novel biodegradable high nitrogen(N)FeMnN alloy was developed,and the effects of N content on the corrosion behaviors were systematically investigated.It was found that,as the N content increased,the corrosion rate was significantly enhanced in both Hank’s solution and simulated gastric fluid.Meanwhile,as the N content increased,the size and depth of pits decreased obviously,and the number of pits increased,which presented a more uniform corrosion morphology.X-ray photoelectron spectroscopy(XPS)results indicated that N existed in the form of NH_(4)^(+) in the corrosion products and[FeN]clusters in the matrix.The[FeN]clusters would simultane-ously improve the corrosion rate and suppress the local corrosion,which provides a new perspective for the development of biodegradable Fe alloy.

Fatigue and Corrosion Fatigue Properties of Mg-Zn-Zr-Nd Alloys in Glucose-Containing Simulated Body Fluids

Medical bone implant magnesium(Mg)alloys are subjected to both corrosive environments and complex loads in the human body.The increasing number of hyperglycemic and diabetic patients in recent years has brought new challenges to the fatigue performance of Mg alloys.Therefore,it is significant to study the corrosion fatigue(CF)behavior of medical Mg alloys in glucose-containing simulated body fluids for their clinical applications.Herein,the corrosion and fatigue properties of extruded Mg-Zn-Zr-Nd alloy in Hank’s balanced salt solution(HBSS)containing different concentrations(1 g/L and 3 g/L)of glucose were investigated.The average grain size of the alloy is about 5μm,which provides excellent overall mechanical properties.The conditional fatigue strength of the alloy was 127 MPa in air and 88 MPa and 70 MPa in HBSS containing 1 g/L glucose and 3 g/L glucose,respectively.Fatigue crack initiation points for alloys in air are oxide inclusions and in solution are corrosion pits.The corrosion rate of the alloy is high at the beginning,and decreases as the surface corrosion product layer thickens with the increase of immersion time.The corrosion products of the alloy are mainly Mg(OH)_(2),MgO and a small amount of Ca-P compounds.The electrochemical results indicated that the corrosion rate of the alloys gradually decreased with increasing immersion time,but the corrosion tendency of the alloy was greater in HBSS containing 3 g/L glucose.On the one hand,glucose accelerates the corrosion process by adsorbing large amounts of aggressive Cl^(-)ions.On the other hand,glucose will be oxidized to form gluconic acid,and then reacts with Mg(OH)_(2) and MgO to form Mg gluconate,which destroys the corrosion product film and leads to the aggravation of corrosion and the accumulation of fatigue damage.

Structural and temporal dynamics analysis of zinc-based biomaterials:History,research hotspots and emerging trends

Objectives:To examine the 16-year developmental history,research hotspots,and emerging trends of zinc-based biodegradable metallic materials from the perspective of structural and temporal dynamics.Methods:The literature on zinc-based biodegradable metallic materials in WoSCC was searched.Historical characteristics,the evolution of active topics and development trends in the field of zinc-based biodegradable metallic materials were analyzed using the bibliometric tools CiteSpace and HistCite.Results:Over the past 16 years,the field of zinc-based biodegradable metal materials has remained in a hotspot stage,with extensive scientific collaboration.In addition,there are 45 subject categories and 51 keywords in different research periods,and 80 papers experience citation bursts.Keyword clustering anchored 3 emerging research subfields,namely,#1 plastic deformation#4 additive manufacturing#5 surface modification.The keyword alluvial map shows that the longest-lasting research concepts in the field are mechanical property,microstructure,corrosion behavior,etc.,and emerging keywords are additive manufacturing,surface modification,dynamic recrystallization,etc.The most recent research on reference clustering has six subfields.Namely,#0 microstructure,#2 sem,#3 additive manufacturing,#4 laser powder bed fusion,#5 implant,and#7 Zn-1Mg.Conclusion:The results of the bibliometric study provide the current status and trends of research on zinc-based biodegradable metallic materials,which can help researchers identify hot spots and explore new research directions in the field.

Biodegradable high-nitrogen iron alloy anastomotic staples:In vitro and in vivo studies

For gastrointestinal anastomosis,metallic biodegradable staples have a broad application potential.However,both magnesium and zinc alloys have relatively low strength to withstand the repeated peristalsis of the gastrointestinal tract.In this study,we developed a novel kind of biodegradable high-nitrogen iron(HN–Fe)alloy wires(0.23 mm),which were fabricated into the staples.The tensile results showed that the ultimate tensile strength and elongation of HN–Fe wires were 1023.2 MPa and 51.0%,respectively,which was much higher than those of other biodegradable wires.The degradation rate in vitro of HN–Fe wires was slightly higher than that of pure Fe wires.After 28 days of immersion,the tensile strength of HN–Fe wires remained not less than 240 MPa,meeting the clinical requirements.Furthermore,sixteen rabbits were enrolled to conduct a comparison experiment using HN–Fe and clinical Ti staples for gastroanastomosis.After 6 months of implantation,a homogeneous degradation product layer on HN–Fe staples was observed and no fracture occurred.The degradation rate of HN–Fe staples in vivo was significantly higher than that in vitro,and they were expected to be completely degraded in 2 years.Meanwhile,both benign cutting and closure performance of HN–Fe staples ensured that all the animals did not experience hemorrhage and anastomotic fistula during the observation.The anastomosis site healed without histopathological change,inflammatory reaction and abnormal blood routine and biochemistry,demonstrating good biocompatibility of HN–Fe staples.Thereby,the favorable performance makes the HN–Fe staples developed in this work a promising candidate for gastrointestinal anastomosis.

Fine-tuning growth in gold nanostructures from achiral 2D to chiral 3D geometries

Enriching the library of chiral plasmonic structures is of significant importance in advancing their applicability across diverse domains such as biosensing,nanophotonics,and catalysis.Here,employing triangle nanoplates as growth seeds,we synthesized a novel class of chiral-shaped plasmonic nanostructures through a wet chemical strategy with dipeptide as chiral inducers,including chiral tri-blade boomerangs,concave rhombic dodecahedrons,and nanoflowers.The structural diversity in chiral plasmonic nanostructures was elucidated through their continuous morphological evolution from two-dimensional to threedimensional architectures.The fine-tuning of chiroptical properties was achieved by precisely manipulating crucial synthetic parameters such as the amount of chiral molecules,seeds,and gold precursor that significantly influenced chiral structure formation.The findings provide a promising avenue for enriching chiral materials with highly sophisticated structures,facilitating a fundamental understanding of the relationship between structural nuances and chiroptical properties.

Effects of COVID-19 pandemic on human fertility:A scientometric and visualized evaluation

CovID-19,also known as coronavirus disease 2019,is a novel coronavirus disease with high infectivity,strong heterogeneity,and long incubation period(generally 3-14 days).Its main symptoms and signs include fever,dry cough,nasal congestion,fatigue,disorientation,lymphopenia,and dyspnea.The short-term and long-term impacts of covID-19 on human health,particularly its effects on human reproduction and offspring development,continue to receive significant concerns,as they may lead to potential sequelae for several decades or even centuries.