BACKGROUND Research data from patient reports indicate that the least bearable part of colonoscopy is the administration of laxatives for bowel preparation.AIM To observe the intestinal cleansing efficacy and safety o...BACKGROUND Research data from patient reports indicate that the least bearable part of colonoscopy is the administration of laxatives for bowel preparation.AIM To observe the intestinal cleansing efficacy and safety of sodium picosulfate/magnesium citrate and to discuss the patients’experiences due to the procedure.METHODS Subjects hospitalized in the International Medical Center Ward of Peking University International Hospital,Beijing,China,from April 29 to October 29,2020,for whom the colonoscopy was planned,were enrolled.Bowel preparation was performed using sodium picosulfate/magnesium citrate.The effect of bowel cleansing was evaluated according to the Ottawa Bowel Preparation Scale,defecation conditions and adverse reactions were recorded,and the comfort level and subjective satisfaction concerning medication were evaluated by the visual analogue scale/score(VAS).RESULTS The bowel preparation procedure was planned for all patients enrolled,which included 42 males and 22 females.The results showed an average liquid rehydration volume of 3000 mL,an average onset of action for the first dose at 89.04 min,an average number of bowel movements of 4.3 following the first dose,an average onset of action for the second dose at 38.90 min and an average number of bowel movements of 5.0 after the second dose.The total average Ottawa Bowel Preparation Scale score was 3.6,with 93.55%of bowel preparations in the“qualified”and 67.74%in the“excellent”grade.The average VAS score of effect on sleep was 0,and the average VAS score of perianal pain was also 0.The average VAS score for ease of taking and taste perception of the bowel cleanser was 10.Side effects included mild to moderate nausea(15.63%),mild vomiting(4.69%),mild to moderate abdominal pain(7.81%),mild to moderate abdominal distension(20.31%),mild palpitation(7.81%)and mild dizziness(4.69%).CONCLUSION Sodium picosulfate/magnesium citrate is effective and safe for bowel preparation before colonoscopy with high subjective patient acceptance,thus improving overall patient compliance.展开更多
Oral purgatives such as sodium phosphate and sodium picosulfate/magnesium citrate (Picolax) combinations are commonly used as a preparation step for colonoscopies in Ireland. These substances can occasionally cause si...Oral purgatives such as sodium phosphate and sodium picosulfate/magnesium citrate (Picolax) combinations are commonly used as a preparation step for colonoscopies in Ireland. These substances can occasionally cause significant electrolyte disturbances including hyponatraemia. Although this is a rare complication of undergoing a colonoscopy, if not treated promptly and appropriately, these electrolyte abnormalities can be associated with life threatening complications. We report cases of symptomatic hyponatraemia in three women aged 65-75 years, following ingestion of Picolax in preparation for a colonoscopy. All three patients had documented previously normal electrolytes and all three required hospital admission for management of their electrolyte disturbance. However, the clinical presentations were variable and depended upon the severity of the hyponatraemia. Patient 1 presented with nausea and vomiting 7 hours post Picolax ingestion. Plasma sodium was 124 mmol/l. She was diagnosed with mild symptomatic hyponatraemia, and treated with anti-emetics and slow intravenous infusion of 0.9% Saline. Patient 2 developed acute confusion 8 hours following ingestion of Picolax. Plasma sodium was 120 mmol/l and she was clinically dehydrated. She was also treated with intravenous 0.9% Saline. Patient 3 presented with seizures and reduced GCS, 48 hours post Picolax ingestion. Plasma sodium was 111 mmol/l. As she had severe life threatening hyponatraemia with seizures, she was treated with boluses of 3% hypertonic saline. It is recommended that cleansing agents should be used with caution in the elderly, patients with a low seizure threshold, patients with renal impairment, liver cirrhosis, heart failure, and patients on diuretics. These patients should have plasma sodium monitored pre- and post-colonoscopy to ensure early detection of hyponatraemia if present, and to initiate prompt and appropriate management to prevent the serious complications associated with hyponatraemia.展开更多
AIM:To compare low volume polyethylene glycol with ascorbic acid,sodium picosulfate-magnesium citrate and clear liquid diet alone as bowel preparation prior to small bowel capsule endoscopy(CE).METHODS:We retrospectiv...AIM:To compare low volume polyethylene glycol with ascorbic acid,sodium picosulfate-magnesium citrate and clear liquid diet alone as bowel preparation prior to small bowel capsule endoscopy(CE).METHODS:We retrospectively collected all CE studies done from December 2011 to July 2013 at a single institution.CE studies were reviewed only if low volume polyethylene glycol with ascorbic acid,sodium picosulfatemagnesium citrate or clear liquid diet alone used as the bowel preparation.The studies were then reviewed by the CE readers who were blinded to the preparation type.Cleanliness and bubble burden were graded independently within the proximal,middle and distal small bowel using a four-point scale according to the percentage of small bowel mucosa free of debris/bubbles:grade 1 = over 90%,grade 2 = between 90%-75%,grade 3 = between 50%-75%,grade 4 = less than 50%.Data are expressed as mean ± SEM.ANOVA and Fishers exact test were used where appropriate.P values < 0.05 were considered statistically significant.RESULTS:A of total of 123 CE studies were reviewed.Twenty-six studies were excluded from analysis because of incomplete small bowel examination.In the remainingstudies,48 patients took low volume polyethylene glycol with ascorbic acid,31 took sodium picosulfate-magnesium citrate and 27 took a clear liquid diet alone after lunch on the day before CE,followed by overnight fasting in all groups.There was no significant difference in small bowel cleanliness(1.98 ± 0.09 vs 1.84 ± 0.08 vs 1.76 ± 0.08) or small bowel transit time(213 ± 13 vs 248 ± 14 ± 225 ± 19 min) for clear liquid diet alone,Movi Prep and PicoSalax respectively.The bubble burden in the mid small bowel was significantly higher in the Movi Prep group(1.6 ± 0.1 vs 1.9 ± 0.1 vs 1.6 ± 0.1,P < 0.05).However this did not result in a significant difference in diagnosis of pathology.CONCLUSION:There was no significant difference in small bowel cleanliness or diagnostic yield of small bowel CE between the three preparations regimens used in this study.展开更多
BACKGROUND Bowel preparation in children can be challenging.AIM To describe the efficacy, safety, and tolerability of sodium picosulfate, magnesium oxide, and citric acid(SPMC) bowel preparation in children.METHODS Ph...BACKGROUND Bowel preparation in children can be challenging.AIM To describe the efficacy, safety, and tolerability of sodium picosulfate, magnesium oxide, and citric acid(SPMC) bowel preparation in children.METHODS Phase 3, randomized, assessor-blinded, multicenter study of low-volume, divided dose SPMC enrolled children 9-16 years undergoing elective colonoscopy. Participants 9-12 years were randomized 1:1:1 to SPMC ? dose × 2, SPMC 1 dose × 2, or polyethylene glycol(PEG). Participants 13-16 years were randomized 1:1 to SPMC 1 dose × 2 or PEG. PEG-based bowel preparations were administered per local protocol. Primary efficacy endpoint for quality of bowel preparation was responders(rating of ‘excellent' or ‘good') by modified Aronchick Scale. Secondary efficacy endpoint was participant's tolerability and satisfaction from a 7-item questionnaire. Safety assessments included adverse events(AEs) and laboratory evaluations.RESULTS 78 participants were randomized, 48 were 9-12 years, 30 were 13-16 years. For the primary efficacy endpoint in 9-12 years, 50.0%, 87.5%, and 81.3% were responders for SPMC ? dose × 2, SPMC 1 dose × 2, and PEG groups, respectively. Responder rates for 13-16 years were 81.3% for SPMC 1 dose × 2 and 85.7% for PEG. Overall, 43.8% of participants receiving SPMC 1 dose × 2 reported it was ‘very easy' or ‘easy' to drink, compared with 20.0% receiving PEG. Treatment-emergent AEs were reported by 45.5% of participants receiving SPMC 1 dose × 2 and 63.0% receiving PEG.CONCLUSION SPMC was an efficacious and safe for bowel preparation in children 9-16 years, with comparable efficacy to PEG. Tolerability for SPMC was higher compared to PEG.展开更多
Rechargeable magnesium batteries(RMBs)have been considered a promising“post lithium-ion battery”system to meet the rapidly increasing demand of the emerging electric vehicle and grid energy storage market.However,th...Rechargeable magnesium batteries(RMBs)have been considered a promising“post lithium-ion battery”system to meet the rapidly increasing demand of the emerging electric vehicle and grid energy storage market.However,the sluggish diffusion kinetics of bivalent Mg^(2+)in the host material,related to the strong Coulomb effect between Mg^(2+)and host anion lattices,hinders their further development toward practical applications.Defect engineering,regarded as an effective strategy to break through the slow migration puzzle,has been validated in various cathode materials for RMBs.In this review,we first thoroughly understand the intrinsic mechanism of Mg^(2+)diffusion in cathode materials,from which the key factors affecting ion diffusion are further presented.Then,the positive effects of purposely introduced defects,including vacancy and doping,and the corresponding strategies for introducing various defects are discussed.The applications of defect engineering in cathode materials for RMBs with advanced electrochemical properties are also summarized.Finally,the existing challenges and future perspectives of defect engineering in cathode materials for the overall high-performance RMBs are described.展开更多
Background: Quality of life (QoL) is impaired in chronic constipation. Among nonprescription laxatives QoL data out of randomized controlled trials are available only for bisacodyl and sodium picosulfate (SPS). Method...Background: Quality of life (QoL) is impaired in chronic constipation. Among nonprescription laxatives QoL data out of randomized controlled trials are available only for bisacodyl and sodium picosulfate (SPS). Methods: In two randomized, double-blind, placebo-controlled, parallel-group trials, the efficacy and safety of treatment with either bisacodyl or SPS, respectively, were assessed. After a 2-week baseline period patients with functional constipation were randomized to a 4-week treatment with either bisacodyl (2 tablets = 10 mg), SPS (18 drops = 10 mg), or matching placebo in a ratio of active drug to placebo of 2:1. Dose reduction as well as resuming the original dose was permitted. Patients who did not experience a bowel movement for more than 72 h were allowed to use a bisacodyl suppository. The primary endpoint was the mean number of Complete Spontaneous Bowel Movements (CSBMs) per week during the trial. QoL was assessed using the Patient Assessment of Constipation (PAC)-QoL questionnaire. Results: Active treatment led to a greater improvement of PAC-QoL scores for every domain. Active treatment was also superior to placebo for all individual questions of the questionnaire. Of note, SPS or bisacodyl not only improved satisfaction with stool patterns (“quite a bit/extremely satisfied” in 12.8% of patients on placebo and 50.3% on active treatment) but bloating was also considerably ameliorated (“not at all feeling bloated” in 24.5% on placebo and 41.4% on active treatment). Conclusion: Bisacodyl and SPS not only improve stool variables but also quality of life in patients with chronic functional constipation. (EudraCT Nos. 2007-001991-34 and 2007-002087-10).展开更多
A selective, precise and stability-indicating, high performance liquid chromatographic method was developed for the analysis of active ingredient sodium Picosulfate and forced degradation behavior was studied. The cur...A selective, precise and stability-indicating, high performance liquid chromatographic method was developed for the analysis of active ingredient sodium Picosulfate and forced degradation behavior was studied. The current article describes forced degradation behavior of the Sodium Picosulfate drug substance in detail by analyzing 15 process related/degradants in a single HPLC method under ICH recommended stressed conditions. Mobile phase comprised of 0.01 M of Disodium hydrogen phosphate and 0.01 M of potassium phosphate monobasic buffer and 1 mL of triethyl amine in 1000 mL water adjusted to pH 7.5 with 10% phosphoric acid. Acetonitrile was used as Mobile Phase B. The separation was achieved on a gradient method. The reversed phase chromatography was performed in Hypersil BDS C18 5.0 μm, 4.6 × 250 mm column maintained at temperature 35°C. Injection volume was 60 μL. Milli-Q water used as diluent. The mobile phase was pumped at 0.9 mL/min<sup>-1</sup>. The eluted compounds were monitored at 220 nm. Secondary wavelength of the 263 nm was studied to check any further degradants during the forced degradation studies. New additional degradants Sodium Picosulfate Benzyl alcohol Impurity and N oxide degradations were discussed and studied during the forced degradation to understand the chemical stability of the drug substance.展开更多
AIM To compare the efficacy of fixed-time split dose and split dose of an oral sodium picosulfate for bowel preparation.METHODS This is study was prospective, randomized controlled study performed at a single Institut...AIM To compare the efficacy of fixed-time split dose and split dose of an oral sodium picosulfate for bowel preparation.METHODS This is study was prospective, randomized controlled study performed at a single Institution(2013-058). A total of 204 subjects were assigned to receive one of two sodium picosulfate regimens(i.e., fixed-time split or split) prior to colonoscopy. Main outcome measurements were bowel preparation quality and subject tolerability.RESULTS There was no statistical difference between the fixedtime split dose regimen group and the split dose regimen group(Ottawa score mean 2.57 ± 1.91 vs 2.80 ± 2.51, P = 0.457). Cecal intubation time and physician's satisfaction of inspection were not significantly different between the two groups(P = 0.428, P = 0.489). On subgroup analysis, for afternoon procedures, the fixed-time split dose regimen was equally effective as compared with the split dose regimen(Ottawa score mean 2.56 ± 1.78 vs 2.59 ± 2.27, P = 0.932). There was no difference in tolerability or compliance between the two groups. Nausea was 21.2% in the fixed-time split dose group and 14.3% in the split dose group(P = 0.136). Vomiting was 7.1% and 2.9%(P = 0.164), abdominal discomfort 7.1% and 4.8%(P = 0.484), dizziness 1% and 4.8%(P = 0.113), cold sweating 1% and 0%(P = 0.302) and palpitation 0% and 1%(P = 0.330), respectively. Sleep disturbance was two(2%) patients in the fixed-time split dose group and zero(0%) patient in the split dose preparation(P = 0.143) group.CONCLUSION A fixed-time split dose regimen with sodium picosulfate is not inferior to a split dose regimen for bowel preparation and equally effective for afternoon colonoscopy.展开更多
Magnesium alloys are nontoxic and promising as orthopedic metallic implants,but preparing a biocompatible Mg(OH)_(2)layer with high corrosion protection ability remains challenging.It is generally believed that the Mg...Magnesium alloys are nontoxic and promising as orthopedic metallic implants,but preparing a biocompatible Mg(OH)_(2)layer with high corrosion protection ability remains challenging.It is generally believed that the Mg(OH)_(2)layer,especially that formed in a natural condition,cannot provide desirable corrosion resistance in the community of corrosion and protection.Here,several Mg(OH)_(2)coatings were prepared by changing the pH values of sodium hydroxide solutions.These coatings were composed of innumerable nanoplatelets with different orientations and showed distinguished capability in corrosion resistance.The nanoplatelets were well-oriented with their ab-planes parallel to,instead of perpendicular to,the magnesium alloy surface by raising the pH value to 14.0.This specific orientation resulted in the optimal coating showing long-term corrosion protection in both in vitro and in vivo environments and good osteogenic capability.These finds manifest that the environment-friendly Mg(OH)_(2)coating can also provide comparable and better corrosion protection than many traditional chemical conversion films(such as phosphate,and fluoride).展开更多
Magnesium and magnesium alloy foils have great potential for application in battery anodes,electromagnetic shielding,optics and acoustics,and biology because of their excellent specific damping,internal dissipation co...Magnesium and magnesium alloy foils have great potential for application in battery anodes,electromagnetic shielding,optics and acoustics,and biology because of their excellent specific damping,internal dissipation coefficients,magnetic and electrical conductivities,as well as high theoretical specific capacity.However,magnesium alloys exhibit poor deformation ability due to their hexagonal close-packed crystal structure.Preparing magnesium and magnesium alloy foils with thicknesses of less than 0.1 mm is difficult because of surface oxidation and grain growth at high temperatures or severe anisotropy after cold rolling that leads to cracks.Numerous methods have been applied to prepare magnesium alloy foils.They include warm rolling,cold rolling,accumulative roll bonding,electric plastic rolling,and on-line heating rolling.Defects of magnesium and magnesium alloy foils during preparation,such as edge cracks and breakage,are important factors for consideration.Herein,the current status of the research on magnesium and magnesium alloy foils is summarized from the aspects of foil preparation,defect control,performance characterization,and application prospects.The advantages and disadvantages of different preparation methods and defect(edge cracks and breakage)mechanisms in the preparation of foils are identified.展开更多
Laser powder bed fusion(L-PBF)of Mg alloys has provided tremendous opportunities for customized production of aeronautical and medical parts.Layer thickness(LT)is of great significance to the L-PBF process but has not...Laser powder bed fusion(L-PBF)of Mg alloys has provided tremendous opportunities for customized production of aeronautical and medical parts.Layer thickness(LT)is of great significance to the L-PBF process but has not been studied for Mg alloys.In this study,WE43 Mg alloy bulk cubes,porous scaffolds,and thin walls with layer thicknesses of 10,20,30,and 40μm were fabricated.The required laser energy input increased with increasing layer thickness and was different for the bulk cubes and porous scaffolds.Porosity tended to occur at the connection joints in porous scaffolds for LT40 and could be eliminated by reducing the laser energy input.For thin wall parts,a large overhang angle or a small wall thickness resulted in porosity when a large layer thicknesses was used,and the porosity disappeared by reducing the layer thickness or laser energy input.A deeper keyhole penetration was found in all occasions with porosity,explaining the influence of layer thickness,geometrical structure,and laser energy input on the porosity.All the samples achieved a high fusion quality with a relative density of over 99.5%using the optimized laser energy input.The increased layer thickness resulted to more precipitation phases,finer grain sizes and decreased grain texture.With the similar high fusion quality,the tensile strength and elongation of bulk samples were significantly improved from 257 MPa and 1.41%with the 10μm layer to 287 MPa and 15.12%with the 40μm layer,in accordance with the microstructural change.The effect of layer thickness on the compressive properties of porous scaffolds was limited.However,the corrosion rate of bulk samples accelerated with increasing the layer thickness,mainly attributed to the increased number of precipitation phases.展开更多
Historically,the rapid degradation and massive gas release from magnesium(Mg)implants resulted in severe emphysema and mechanical failure.With the advent of new alloys and surface treatment methods,optimized Mg implan...Historically,the rapid degradation and massive gas release from magnesium(Mg)implants resulted in severe emphysema and mechanical failure.With the advent of new alloys and surface treatment methods,optimized Mg implants have re-entered clinics since last decade with reliable performance.However,the optimization aims at slowing down the degradation process,rather than exemption of the gas release.This study involved a systematic evaluation of current preclinical and clinical evidence,regarding the physical signs,symptoms,radiological features,pathological findings and complications potentially associated with peri±implant gas accumulation(PIGA)after musculoskeletal Mg implantation.The literature search identified 196 potentially relevant publications,and 51 papers were enrolled for further analysis,including 22 preclinical tests and 29 clinical studies published from 2005 to 2023.Various Mg-based materials have been evaluated in animal research,and the application of pure Mg and Mg alloys have been reported in clinical follow-ups involving multiple anatomical sites and musculoskeletal disorders.Soft tissue and intraosseous PIGA are common in both animal tests and clinical follow-ups,and potentially associated with certain adverse events.Radiological examinations especially micro-CT and clinical CT scans provide valuable information for quantitative and longitudinal analysis.While according to simulation tests involving Mg implantation and chemical processing,tissue fixation could lead to an increase in the volume of gas cavity,thus the results obtained from ex vivo imaging or histopathological evaluations should be interpreted with caution.There still lacks standardized procedures or consensus for both preclinical and clinical evaluation of PIGA.However,by providing focused insights into the topic,this evidence-based study will facilitate future animal tests and clinical evaluations,and support developing biocompatible Mg implants for the treatment of musculoskeletal disorders.展开更多
Texture regulation is a prominent method to modify the mechanical properties and anisotropy of magnesium alloy.In this work,the Mg-1Al-0.3Ca-0.5Mn-0.2Gd(wt.%)alloy sheet with TD-tilted and circular texture was fabrica...Texture regulation is a prominent method to modify the mechanical properties and anisotropy of magnesium alloy.In this work,the Mg-1Al-0.3Ca-0.5Mn-0.2Gd(wt.%)alloy sheet with TD-tilted and circular texture was fabricated by unidirectional rolling(UR)and multidirectional rolling(MR)method,respectively.Unlike generating a strong in-plane mechanical anisotropy in conventional TD-tilted texture,the novel circular texture sample possessed a weak in-plane yield anisotropy.This can be rationalized by the similar proportion of soft grains with favorable orientation for basalslip and{10.12}tensile twinning during the uniaxial tension of circular-texture sample along different directions.Moreover,compared with the TD-tilted texture,the circular texture improved the elongation to failure both along the rolling direction(RD)and transverse direction(TD).By quasi-in-situ EBSD-assisted slip trace analysis,higher activation of basal slip was observed in the circular-texture sample during RD tension,contributing to its excellent ductility.When loading along the TD,the TD-tilted texture promoted the activation of{10.12}tensile twins significantly,thus providing nucleation sites for cracks and deteriorating the ductility.This research may shed new insights into the development of formable and ductile Mg alloy sheets by texture modification.展开更多
The clinical application of magnesium(Mg)and its alloys for bone fractures has been well supported by in vitro and in vivo trials.However,there were studies indicating negative effects of high dose Mg intake and susta...The clinical application of magnesium(Mg)and its alloys for bone fractures has been well supported by in vitro and in vivo trials.However,there were studies indicating negative effects of high dose Mg intake and sustained local release of Mg ions on bone metabolism or repair,which should not be ignored when developing Mg-based implants.Thus,it remains necessary to assess the biological effects of Mg implants in animal models relevant to clinical treatment modalities.The primary purpose of this study was to validate the beneficial effects of intramedullary Mg implants on the healing outcome of femoral fractures in a modified rat model.In addition,the mineralization parameters at multiple anatomical sites were evaluated,to investigate their association with healing outcome and potential clinical applications.Compared to the control group without Mg implantation,postoperative imaging at week 12 demonstrated better healing outcomes in the Mg group,with more stable unions in 3D analysis and high-mineralized bridging in 2D evaluation.The bone tissue mineral density(TMD)was higher in the Mg group at the non-operated femur and lumbar vertebra,while no differences between groups were identified regarding the bone tissue volume(TV),TMD and bone mineral content(BMC)in humerus.In the surgical femur,the Mg group presented higher TMD,but lower TV and BMC in the distal metaphyseal region,as well as reduced BMC at the osteotomy site.Principal component analysis(PCA)-based machine learning revealed that by selecting clinically relevant parameters,radiological markers could be constructed for differentiation of healing outcomes,with better performance than 2D scoring.The study provides insights and preclinical evidence for the rational investigation of bioactive materials,the identification of potential adverse effects,and the promotion of diagnostic capabilities for fracture healing.展开更多
Biomedical magnesium(Mg)alloys have garnered significant attention because of their unique biodegradability,favorable biocompatibility,and suitable mechanical properties.The incorporation of rare earth(RE)elements,wit...Biomedical magnesium(Mg)alloys have garnered significant attention because of their unique biodegradability,favorable biocompatibility,and suitable mechanical properties.The incorporation of rare earth(RE)elements,with their distinct physical and chemical properties,has greatly contributed to enhancing the mechanical performance,degradation behavior,and biological performance of biomedical Mg alloys.Currently,a series of RE-Mg alloys are being designed and investigated for orthopedic implants and cardiovascular stents,achieving substantial and encouraging research progress.In this work,a comprehensive summary of the state-of-the-art in biomedical RE-Mg alloys is provided.The physiological effects and design standards of RE elements in biomedical Mg alloys are discussed.Particularly,the degradation behavior and mechanical properties,including their underlying action are studied in-depth.Furthermore,the preparation techniques and current application status of RE-Mg alloys are reviewed.Finally,we address the ongoing challenges and propose future prospects to guide the development of high-performance biomedical Mg-RE alloys.展开更多
The flame propagation processes of MgH_(2)dust clouds with four different particle sizes were recorded by a high-speed camera.The dynamic flame temperature distributions of MgH_(2)dust clouds were reconstructed by the...The flame propagation processes of MgH_(2)dust clouds with four different particle sizes were recorded by a high-speed camera.The dynamic flame temperature distributions of MgH_(2)dust clouds were reconstructed by the two-color pyrometer technique,and the chemical composition of solid combustion residues were analyzed.The experimental results showed that the average flame propagation velocities of 23μm,40μm,60μm and 103μm MgH_(2)dust clouds in the stable propagation stage were 3.7 m/s,2.8 m/s,2.1 m/s and 0.9 m/s,respectively.The dust clouds with smaller particle sizes had faster flame propagation velocity and stronger oscillation intensity,and their flame temperature distributions were more even and the temperature gradients were smaller.The flame structures of MgH_(2)dust clouds were significantly affected by the particle sinking velocity,and the combustion processes were accompanied by micro-explosion of particles.The falling velocities of 23μm and 40μm MgH_(2)particles were 2.24 cm/s and 6.71 cm/s,respectively.While the falling velocities of 60μm and 103μm MgH_(2)particles were as high as 15.07 cm/s and 44.42 cm/s,respectively,leading to a more rapid downward development and irregular shape of the flame.Furthermore,the dehydrogenation reaction had a significant effect on the combustion performance of MgH_(2)dust.The combustion of H_(2)enhanced the ignition and combustion characteristics of MgH_(2)dust,resulting in a much higher explosion power than the pure Mg dust.The micro-structure characteristics and combustion residues composition analysis of MgH_(2)dust indicated that the combustion control mechanism of MgH_(2)dust flame was mainly the heterogeneous reaction,which was affected by the dehydrogenation reaction.展开更多
Hydrogen energy has emerged as a pivotal solution to address the global energy crisis and pave the way for a cleaner,low-carbon,secure,and efficient modern energy system.A key imperative in the utilization of hydrogen...Hydrogen energy has emerged as a pivotal solution to address the global energy crisis and pave the way for a cleaner,low-carbon,secure,and efficient modern energy system.A key imperative in the utilization of hydrogen energy lies in the development of high-performance hydrogen storage materials.Magnesium-based hydrogen storage materials exhibit remarkable advantages,including high hydrogen storage density,cost-effectiveness,and abundant magnesium resources,making them highly promising for the hydrogen energy sector.Nonetheless,practical applications of magnesium hydride for hydrogen storage face significant challenges,primarily due to their slow kinetics and stable thermodynamic properties.Herein,we briefly summarize the thermodynamic and kinetic properties of MgH2,encompassing strategies such as alloying,nanoscaling,catalyst doping,and composite system construction to enhance its hydrogen storage performance.Notably,nanoscaling and catalyst doping have emerged as more effective modification strategies.The discussion focuses on the thermodynamic changes induced by nanoscaling and the kinetic enhancements resulting from catalyst doping.Particular emphasis lies in the synergistic improvement strategy of incorporating nanocatalysts with confinement materials,and we revisit typical works on the multi-strategy optimization of MgH2.In conclusion,we conduct an analysis of outstanding challenges and issues,followed by presenting future research and development prospects for MgH2 as hydrogen storage materials.展开更多
This study offers significant insights into the multi-physics phenomena of the SLM process and the subsequent porosity characteristics of ZK60 Magnesium(Mg)alloys.High-speed in-situ monitoring was employed to visualis...This study offers significant insights into the multi-physics phenomena of the SLM process and the subsequent porosity characteristics of ZK60 Magnesium(Mg)alloys.High-speed in-situ monitoring was employed to visualise process signals in real-time,elucidating the dynamics of melt pools and vapour plumes under varying laser power conditions specifically between 40 W and 60 W.Detailed morphological analysis was performed using Scanning-Electron Microscopy(SEM),demonstrating a critical correlation between laser power and pore formation.Lower laser power led to increased pore coverage,whereas a denser structure was observed at higher laser power.This laser power influence on porosity was further confirmed via Optical Microscopy(OM)conducted on both top and cross-sectional surfaces of the samples.An increase in laser power resulted in a decrease in pore coverage and pore size,potentially leading to a denser printed part of Mg alloy.X-ray Computed Tomography(XCT)augmented these findings by providing a 3D volumetric representation of the sample internal structure,revealing an inverse relationship between laser power and overall pore volume.Lower laser power appeared to favour the formation of interconnected pores,while a reduction in interconnected pores and an increase in isolated pores were observed at higher power.The interplay between melt pool size,vapour plume effects,and laser power was found to significantly influence the resulting porosity,indicating a need for effective management of these factors to optimise the SLM process of Mg alloys.展开更多
Realising the potential of Magnesium(Mg),several globally leading ventures have invested in the Mg industry,but their relatively poor corrosion resistance is a never ending saga till date.The corrosion and bio-corrosi...Realising the potential of Magnesium(Mg),several globally leading ventures have invested in the Mg industry,but their relatively poor corrosion resistance is a never ending saga till date.The corrosion and bio-corrosion behaviour of Mg has gained research attention and still remains a hot topic in the application of automobile,aerospace and biomedical industries.The intrinsic high electrochemical nature of Mg limits their utilization in diverse application.This scenario has prompted the development of Mg composites with an aim to achieve superior corrosion and bio-corrosion resistance.The present review enlightens the influence of grain size(GS),secondary phase,texture,type of matrix and reinforcement on the corrosion and bio-corrosion behaviour of Mg composites.Firstly,the corrosion and bio-corrosion behaviour of Mg composites manufactured by primary and secondary processing routes are elucidated.Secondly,the comprehensive corrosion and bio-corrosion mechanisms of these Mg composites are proposed.Thirdly,the individual role of GS,texture and corrosive medium on corrosion and bio-corrosion behaviour of Mg composites are clarified and revealed.The challenges encountered,unanswered issues in this field are explained in detail and accordingly the scope for future research is framed.The review is presented from basic concrete background to advanced corrosion mechanisms with an aim of creating interest among the readers like students,researchers and industry experts from various research backgrounds.Indeed,the corrosion and bio-corrosion behaviour of Mg composites are critically reviewed for the first time to:(i)contribute to the body of knowledge,(ii)foster research and development,(iii)make breakthrough,and(iv)create life changing innovations in the field of Mg composite corrosion.展开更多
Background: Magnesium, an essential mineral crucial for various bodily functions, has been shown to positively influence sleep patterns. This study aimed to evaluate the efficacy of Food-Grown® magnesium in enhan...Background: Magnesium, an essential mineral crucial for various bodily functions, has been shown to positively influence sleep patterns. This study aimed to evaluate the efficacy of Food-Grown® magnesium in enhancing sleep quality and duration, as well as overall well-being. Methods: Eighty participants were randomly assigned to receive either 80 mg of Food-Grown® magnesium or a placebo (microcrystalline cellulose) daily for 8 weeks. Participants completed questionnaires assessing sleep quality, daytime drowsiness, quality of life, anxiety, and stress levels. Additionally, participants maintained daily sleep diaries and wore wrist-worn actigraphy devices. The primary outcome measured was the change in sleep quality and duration. Results: Seventy-one participants fulfilled all study requirements (35 in the active group and 36 in the placebo group). Magnesium supplementation significantly improved reported sleep quality, with the active group showing a 32% increase compared to 16% in the placebo group (p = 0.034). Moreover, magnesium supplementation led to a decrease in reported stress scores at week 8 compared to the placebo group (3.7 ± 2.6 vs. 5.5 ± 3.1, respectively). Both the magnesium and placebo groups exhibited significant increases in reported sleep duration and reductions in time to fall asleep, sleep disturbance, sleep latency, sleep medication usage, and total Pittsburgh Sleep Quality Index score at week 8 compared to baseline. Conclusion: Magnesium supplementation notably enhanced sleep quality and reduced stress levels compared to the placebo group. These findings highlight the potential of magnesium as a beneficial supplement for improving sleep quality and overall well-being.展开更多
基金Beijing Science and Technology Program,China,Early Endoscopic Diagnosis for Colorectal Cancer—The Guidance Study,No.D17110002617002.
文摘BACKGROUND Research data from patient reports indicate that the least bearable part of colonoscopy is the administration of laxatives for bowel preparation.AIM To observe the intestinal cleansing efficacy and safety of sodium picosulfate/magnesium citrate and to discuss the patients’experiences due to the procedure.METHODS Subjects hospitalized in the International Medical Center Ward of Peking University International Hospital,Beijing,China,from April 29 to October 29,2020,for whom the colonoscopy was planned,were enrolled.Bowel preparation was performed using sodium picosulfate/magnesium citrate.The effect of bowel cleansing was evaluated according to the Ottawa Bowel Preparation Scale,defecation conditions and adverse reactions were recorded,and the comfort level and subjective satisfaction concerning medication were evaluated by the visual analogue scale/score(VAS).RESULTS The bowel preparation procedure was planned for all patients enrolled,which included 42 males and 22 females.The results showed an average liquid rehydration volume of 3000 mL,an average onset of action for the first dose at 89.04 min,an average number of bowel movements of 4.3 following the first dose,an average onset of action for the second dose at 38.90 min and an average number of bowel movements of 5.0 after the second dose.The total average Ottawa Bowel Preparation Scale score was 3.6,with 93.55%of bowel preparations in the“qualified”and 67.74%in the“excellent”grade.The average VAS score of effect on sleep was 0,and the average VAS score of perianal pain was also 0.The average VAS score for ease of taking and taste perception of the bowel cleanser was 10.Side effects included mild to moderate nausea(15.63%),mild vomiting(4.69%),mild to moderate abdominal pain(7.81%),mild to moderate abdominal distension(20.31%),mild palpitation(7.81%)and mild dizziness(4.69%).CONCLUSION Sodium picosulfate/magnesium citrate is effective and safe for bowel preparation before colonoscopy with high subjective patient acceptance,thus improving overall patient compliance.
文摘Oral purgatives such as sodium phosphate and sodium picosulfate/magnesium citrate (Picolax) combinations are commonly used as a preparation step for colonoscopies in Ireland. These substances can occasionally cause significant electrolyte disturbances including hyponatraemia. Although this is a rare complication of undergoing a colonoscopy, if not treated promptly and appropriately, these electrolyte abnormalities can be associated with life threatening complications. We report cases of symptomatic hyponatraemia in three women aged 65-75 years, following ingestion of Picolax in preparation for a colonoscopy. All three patients had documented previously normal electrolytes and all three required hospital admission for management of their electrolyte disturbance. However, the clinical presentations were variable and depended upon the severity of the hyponatraemia. Patient 1 presented with nausea and vomiting 7 hours post Picolax ingestion. Plasma sodium was 124 mmol/l. She was diagnosed with mild symptomatic hyponatraemia, and treated with anti-emetics and slow intravenous infusion of 0.9% Saline. Patient 2 developed acute confusion 8 hours following ingestion of Picolax. Plasma sodium was 120 mmol/l and she was clinically dehydrated. She was also treated with intravenous 0.9% Saline. Patient 3 presented with seizures and reduced GCS, 48 hours post Picolax ingestion. Plasma sodium was 111 mmol/l. As she had severe life threatening hyponatraemia with seizures, she was treated with boluses of 3% hypertonic saline. It is recommended that cleansing agents should be used with caution in the elderly, patients with a low seizure threshold, patients with renal impairment, liver cirrhosis, heart failure, and patients on diuretics. These patients should have plasma sodium monitored pre- and post-colonoscopy to ensure early detection of hyponatraemia if present, and to initiate prompt and appropriate management to prevent the serious complications associated with hyponatraemia.
文摘AIM:To compare low volume polyethylene glycol with ascorbic acid,sodium picosulfate-magnesium citrate and clear liquid diet alone as bowel preparation prior to small bowel capsule endoscopy(CE).METHODS:We retrospectively collected all CE studies done from December 2011 to July 2013 at a single institution.CE studies were reviewed only if low volume polyethylene glycol with ascorbic acid,sodium picosulfatemagnesium citrate or clear liquid diet alone used as the bowel preparation.The studies were then reviewed by the CE readers who were blinded to the preparation type.Cleanliness and bubble burden were graded independently within the proximal,middle and distal small bowel using a four-point scale according to the percentage of small bowel mucosa free of debris/bubbles:grade 1 = over 90%,grade 2 = between 90%-75%,grade 3 = between 50%-75%,grade 4 = less than 50%.Data are expressed as mean ± SEM.ANOVA and Fishers exact test were used where appropriate.P values < 0.05 were considered statistically significant.RESULTS:A of total of 123 CE studies were reviewed.Twenty-six studies were excluded from analysis because of incomplete small bowel examination.In the remainingstudies,48 patients took low volume polyethylene glycol with ascorbic acid,31 took sodium picosulfate-magnesium citrate and 27 took a clear liquid diet alone after lunch on the day before CE,followed by overnight fasting in all groups.There was no significant difference in small bowel cleanliness(1.98 ± 0.09 vs 1.84 ± 0.08 vs 1.76 ± 0.08) or small bowel transit time(213 ± 13 vs 248 ± 14 ± 225 ± 19 min) for clear liquid diet alone,Movi Prep and PicoSalax respectively.The bubble burden in the mid small bowel was significantly higher in the Movi Prep group(1.6 ± 0.1 vs 1.9 ± 0.1 vs 1.6 ± 0.1,P < 0.05).However this did not result in a significant difference in diagnosis of pathology.CONCLUSION:There was no significant difference in small bowel cleanliness or diagnostic yield of small bowel CE between the three preparations regimens used in this study.
文摘BACKGROUND Bowel preparation in children can be challenging.AIM To describe the efficacy, safety, and tolerability of sodium picosulfate, magnesium oxide, and citric acid(SPMC) bowel preparation in children.METHODS Phase 3, randomized, assessor-blinded, multicenter study of low-volume, divided dose SPMC enrolled children 9-16 years undergoing elective colonoscopy. Participants 9-12 years were randomized 1:1:1 to SPMC ? dose × 2, SPMC 1 dose × 2, or polyethylene glycol(PEG). Participants 13-16 years were randomized 1:1 to SPMC 1 dose × 2 or PEG. PEG-based bowel preparations were administered per local protocol. Primary efficacy endpoint for quality of bowel preparation was responders(rating of ‘excellent' or ‘good') by modified Aronchick Scale. Secondary efficacy endpoint was participant's tolerability and satisfaction from a 7-item questionnaire. Safety assessments included adverse events(AEs) and laboratory evaluations.RESULTS 78 participants were randomized, 48 were 9-12 years, 30 were 13-16 years. For the primary efficacy endpoint in 9-12 years, 50.0%, 87.5%, and 81.3% were responders for SPMC ? dose × 2, SPMC 1 dose × 2, and PEG groups, respectively. Responder rates for 13-16 years were 81.3% for SPMC 1 dose × 2 and 85.7% for PEG. Overall, 43.8% of participants receiving SPMC 1 dose × 2 reported it was ‘very easy' or ‘easy' to drink, compared with 20.0% receiving PEG. Treatment-emergent AEs were reported by 45.5% of participants receiving SPMC 1 dose × 2 and 63.0% receiving PEG.CONCLUSION SPMC was an efficacious and safe for bowel preparation in children 9-16 years, with comparable efficacy to PEG. Tolerability for SPMC was higher compared to PEG.
基金support of the National Natural Science Foundation of China(Grant No.22225801,22178217 and 22308216)supported by the Fundamental Research Funds for the Central Universities,conducted at Tongji University.
文摘Rechargeable magnesium batteries(RMBs)have been considered a promising“post lithium-ion battery”system to meet the rapidly increasing demand of the emerging electric vehicle and grid energy storage market.However,the sluggish diffusion kinetics of bivalent Mg^(2+)in the host material,related to the strong Coulomb effect between Mg^(2+)and host anion lattices,hinders their further development toward practical applications.Defect engineering,regarded as an effective strategy to break through the slow migration puzzle,has been validated in various cathode materials for RMBs.In this review,we first thoroughly understand the intrinsic mechanism of Mg^(2+)diffusion in cathode materials,from which the key factors affecting ion diffusion are further presented.Then,the positive effects of purposely introduced defects,including vacancy and doping,and the corresponding strategies for introducing various defects are discussed.The applications of defect engineering in cathode materials for RMBs with advanced electrochemical properties are also summarized.Finally,the existing challenges and future perspectives of defect engineering in cathode materials for the overall high-performance RMBs are described.
文摘Background: Quality of life (QoL) is impaired in chronic constipation. Among nonprescription laxatives QoL data out of randomized controlled trials are available only for bisacodyl and sodium picosulfate (SPS). Methods: In two randomized, double-blind, placebo-controlled, parallel-group trials, the efficacy and safety of treatment with either bisacodyl or SPS, respectively, were assessed. After a 2-week baseline period patients with functional constipation were randomized to a 4-week treatment with either bisacodyl (2 tablets = 10 mg), SPS (18 drops = 10 mg), or matching placebo in a ratio of active drug to placebo of 2:1. Dose reduction as well as resuming the original dose was permitted. Patients who did not experience a bowel movement for more than 72 h were allowed to use a bisacodyl suppository. The primary endpoint was the mean number of Complete Spontaneous Bowel Movements (CSBMs) per week during the trial. QoL was assessed using the Patient Assessment of Constipation (PAC)-QoL questionnaire. Results: Active treatment led to a greater improvement of PAC-QoL scores for every domain. Active treatment was also superior to placebo for all individual questions of the questionnaire. Of note, SPS or bisacodyl not only improved satisfaction with stool patterns (“quite a bit/extremely satisfied” in 12.8% of patients on placebo and 50.3% on active treatment) but bloating was also considerably ameliorated (“not at all feeling bloated” in 24.5% on placebo and 41.4% on active treatment). Conclusion: Bisacodyl and SPS not only improve stool variables but also quality of life in patients with chronic functional constipation. (EudraCT Nos. 2007-001991-34 and 2007-002087-10).
文摘A selective, precise and stability-indicating, high performance liquid chromatographic method was developed for the analysis of active ingredient sodium Picosulfate and forced degradation behavior was studied. The current article describes forced degradation behavior of the Sodium Picosulfate drug substance in detail by analyzing 15 process related/degradants in a single HPLC method under ICH recommended stressed conditions. Mobile phase comprised of 0.01 M of Disodium hydrogen phosphate and 0.01 M of potassium phosphate monobasic buffer and 1 mL of triethyl amine in 1000 mL water adjusted to pH 7.5 with 10% phosphoric acid. Acetonitrile was used as Mobile Phase B. The separation was achieved on a gradient method. The reversed phase chromatography was performed in Hypersil BDS C18 5.0 μm, 4.6 × 250 mm column maintained at temperature 35°C. Injection volume was 60 μL. Milli-Q water used as diluent. The mobile phase was pumped at 0.9 mL/min<sup>-1</sup>. The eluted compounds were monitored at 220 nm. Secondary wavelength of the 263 nm was studied to check any further degradants during the forced degradation studies. New additional degradants Sodium Picosulfate Benzyl alcohol Impurity and N oxide degradations were discussed and studied during the forced degradation to understand the chemical stability of the drug substance.
文摘AIM To compare the efficacy of fixed-time split dose and split dose of an oral sodium picosulfate for bowel preparation.METHODS This is study was prospective, randomized controlled study performed at a single Institution(2013-058). A total of 204 subjects were assigned to receive one of two sodium picosulfate regimens(i.e., fixed-time split or split) prior to colonoscopy. Main outcome measurements were bowel preparation quality and subject tolerability.RESULTS There was no statistical difference between the fixedtime split dose regimen group and the split dose regimen group(Ottawa score mean 2.57 ± 1.91 vs 2.80 ± 2.51, P = 0.457). Cecal intubation time and physician's satisfaction of inspection were not significantly different between the two groups(P = 0.428, P = 0.489). On subgroup analysis, for afternoon procedures, the fixed-time split dose regimen was equally effective as compared with the split dose regimen(Ottawa score mean 2.56 ± 1.78 vs 2.59 ± 2.27, P = 0.932). There was no difference in tolerability or compliance between the two groups. Nausea was 21.2% in the fixed-time split dose group and 14.3% in the split dose group(P = 0.136). Vomiting was 7.1% and 2.9%(P = 0.164), abdominal discomfort 7.1% and 4.8%(P = 0.484), dizziness 1% and 4.8%(P = 0.113), cold sweating 1% and 0%(P = 0.302) and palpitation 0% and 1%(P = 0.330), respectively. Sleep disturbance was two(2%) patients in the fixed-time split dose group and zero(0%) patient in the split dose preparation(P = 0.143) group.CONCLUSION A fixed-time split dose regimen with sodium picosulfate is not inferior to a split dose regimen for bowel preparation and equally effective for afternoon colonoscopy.
基金supported by the National Natural Science Foundation of China(NSFC,52271073)the Sichuan Science and Technology Program(2024NSFJQ0034)+3 种基金the Central Government Guided Special Program(No.2021ZYD0049)the Young Elite Scientists Sponsorship Program by CAST(YESS,2018QNRC001)the GDPH Supporting Fund for Talent Program(KY0120220137)the Scientific and Technological Projects of Guangzhou,China(202002030283).
文摘Magnesium alloys are nontoxic and promising as orthopedic metallic implants,but preparing a biocompatible Mg(OH)_(2)layer with high corrosion protection ability remains challenging.It is generally believed that the Mg(OH)_(2)layer,especially that formed in a natural condition,cannot provide desirable corrosion resistance in the community of corrosion and protection.Here,several Mg(OH)_(2)coatings were prepared by changing the pH values of sodium hydroxide solutions.These coatings were composed of innumerable nanoplatelets with different orientations and showed distinguished capability in corrosion resistance.The nanoplatelets were well-oriented with their ab-planes parallel to,instead of perpendicular to,the magnesium alloy surface by raising the pH value to 14.0.This specific orientation resulted in the optimal coating showing long-term corrosion protection in both in vitro and in vivo environments and good osteogenic capability.These finds manifest that the environment-friendly Mg(OH)_(2)coating can also provide comparable and better corrosion protection than many traditional chemical conversion films(such as phosphate,and fluoride).
基金financially supported by the National Key Research and Development Program of China(Nos.2022 YFB3709300 and 2021YFB3701000)the National Natural Science Foundation of China(Nos.52271090 and 52071036)+1 种基金the Guangdong Major Project of Basic and Applied Basic Research(No.2020B0301030006)the Independent Research Project of State Key Laboratory of Mechanical Transmissions(Nos.SKLMT-ZZKT-2022Z01 and S KLMT-ZZKT-2022M12)。
文摘Magnesium and magnesium alloy foils have great potential for application in battery anodes,electromagnetic shielding,optics and acoustics,and biology because of their excellent specific damping,internal dissipation coefficients,magnetic and electrical conductivities,as well as high theoretical specific capacity.However,magnesium alloys exhibit poor deformation ability due to their hexagonal close-packed crystal structure.Preparing magnesium and magnesium alloy foils with thicknesses of less than 0.1 mm is difficult because of surface oxidation and grain growth at high temperatures or severe anisotropy after cold rolling that leads to cracks.Numerous methods have been applied to prepare magnesium alloy foils.They include warm rolling,cold rolling,accumulative roll bonding,electric plastic rolling,and on-line heating rolling.Defects of magnesium and magnesium alloy foils during preparation,such as edge cracks and breakage,are important factors for consideration.Herein,the current status of the research on magnesium and magnesium alloy foils is summarized from the aspects of foil preparation,defect control,performance characterization,and application prospects.The advantages and disadvantages of different preparation methods and defect(edge cracks and breakage)mechanisms in the preparation of foils are identified.
基金funded by the National Key Research and Development Program of China(2018YFE0104200)National Natural Science Foundation of China(51875310,52175274,82172065)Tsinghua Precision Medicine Foundation.
文摘Laser powder bed fusion(L-PBF)of Mg alloys has provided tremendous opportunities for customized production of aeronautical and medical parts.Layer thickness(LT)is of great significance to the L-PBF process but has not been studied for Mg alloys.In this study,WE43 Mg alloy bulk cubes,porous scaffolds,and thin walls with layer thicknesses of 10,20,30,and 40μm were fabricated.The required laser energy input increased with increasing layer thickness and was different for the bulk cubes and porous scaffolds.Porosity tended to occur at the connection joints in porous scaffolds for LT40 and could be eliminated by reducing the laser energy input.For thin wall parts,a large overhang angle or a small wall thickness resulted in porosity when a large layer thicknesses was used,and the porosity disappeared by reducing the layer thickness or laser energy input.A deeper keyhole penetration was found in all occasions with porosity,explaining the influence of layer thickness,geometrical structure,and laser energy input on the porosity.All the samples achieved a high fusion quality with a relative density of over 99.5%using the optimized laser energy input.The increased layer thickness resulted to more precipitation phases,finer grain sizes and decreased grain texture.With the similar high fusion quality,the tensile strength and elongation of bulk samples were significantly improved from 257 MPa and 1.41%with the 10μm layer to 287 MPa and 15.12%with the 40μm layer,in accordance with the microstructural change.The effect of layer thickness on the compressive properties of porous scaffolds was limited.However,the corrosion rate of bulk samples accelerated with increasing the layer thickness,mainly attributed to the increased number of precipitation phases.
基金a grant from the state of Schleswig-Holstein and the European Union ERDF-European Regional Development Fund(Zukunftsprogramm Wirtschaft)。
文摘Historically,the rapid degradation and massive gas release from magnesium(Mg)implants resulted in severe emphysema and mechanical failure.With the advent of new alloys and surface treatment methods,optimized Mg implants have re-entered clinics since last decade with reliable performance.However,the optimization aims at slowing down the degradation process,rather than exemption of the gas release.This study involved a systematic evaluation of current preclinical and clinical evidence,regarding the physical signs,symptoms,radiological features,pathological findings and complications potentially associated with peri±implant gas accumulation(PIGA)after musculoskeletal Mg implantation.The literature search identified 196 potentially relevant publications,and 51 papers were enrolled for further analysis,including 22 preclinical tests and 29 clinical studies published from 2005 to 2023.Various Mg-based materials have been evaluated in animal research,and the application of pure Mg and Mg alloys have been reported in clinical follow-ups involving multiple anatomical sites and musculoskeletal disorders.Soft tissue and intraosseous PIGA are common in both animal tests and clinical follow-ups,and potentially associated with certain adverse events.Radiological examinations especially micro-CT and clinical CT scans provide valuable information for quantitative and longitudinal analysis.While according to simulation tests involving Mg implantation and chemical processing,tissue fixation could lead to an increase in the volume of gas cavity,thus the results obtained from ex vivo imaging or histopathological evaluations should be interpreted with caution.There still lacks standardized procedures or consensus for both preclinical and clinical evaluation of PIGA.However,by providing focused insights into the topic,this evidence-based study will facilitate future animal tests and clinical evaluations,and support developing biocompatible Mg implants for the treatment of musculoskeletal disorders.
基金supports from The National Natural Science Foundation of China(nos.52222409,52074132,and U19A2084)The National Key Research and Development Program(no.2022YFE0122000)are greatly acknowledgedsupport from The Science and Technology Development Program of Jilin Province(no.20210301025GX).
文摘Texture regulation is a prominent method to modify the mechanical properties and anisotropy of magnesium alloy.In this work,the Mg-1Al-0.3Ca-0.5Mn-0.2Gd(wt.%)alloy sheet with TD-tilted and circular texture was fabricated by unidirectional rolling(UR)and multidirectional rolling(MR)method,respectively.Unlike generating a strong in-plane mechanical anisotropy in conventional TD-tilted texture,the novel circular texture sample possessed a weak in-plane yield anisotropy.This can be rationalized by the similar proportion of soft grains with favorable orientation for basalslip and{10.12}tensile twinning during the uniaxial tension of circular-texture sample along different directions.Moreover,compared with the TD-tilted texture,the circular texture improved the elongation to failure both along the rolling direction(RD)and transverse direction(TD).By quasi-in-situ EBSD-assisted slip trace analysis,higher activation of basal slip was observed in the circular-texture sample during RD tension,contributing to its excellent ductility.When loading along the TD,the TD-tilted texture promoted the activation of{10.12}tensile twins significantly,thus providing nucleation sites for cracks and deteriorating the ductility.This research may shed new insights into the development of formable and ductile Mg alloy sheets by texture modification.
文摘The clinical application of magnesium(Mg)and its alloys for bone fractures has been well supported by in vitro and in vivo trials.However,there were studies indicating negative effects of high dose Mg intake and sustained local release of Mg ions on bone metabolism or repair,which should not be ignored when developing Mg-based implants.Thus,it remains necessary to assess the biological effects of Mg implants in animal models relevant to clinical treatment modalities.The primary purpose of this study was to validate the beneficial effects of intramedullary Mg implants on the healing outcome of femoral fractures in a modified rat model.In addition,the mineralization parameters at multiple anatomical sites were evaluated,to investigate their association with healing outcome and potential clinical applications.Compared to the control group without Mg implantation,postoperative imaging at week 12 demonstrated better healing outcomes in the Mg group,with more stable unions in 3D analysis and high-mineralized bridging in 2D evaluation.The bone tissue mineral density(TMD)was higher in the Mg group at the non-operated femur and lumbar vertebra,while no differences between groups were identified regarding the bone tissue volume(TV),TMD and bone mineral content(BMC)in humerus.In the surgical femur,the Mg group presented higher TMD,but lower TV and BMC in the distal metaphyseal region,as well as reduced BMC at the osteotomy site.Principal component analysis(PCA)-based machine learning revealed that by selecting clinically relevant parameters,radiological markers could be constructed for differentiation of healing outcomes,with better performance than 2D scoring.The study provides insights and preclinical evidence for the rational investigation of bioactive materials,the identification of potential adverse effects,and the promotion of diagnostic capabilities for fracture healing.
基金supported by National Key Research and Development Program of China[2023YFB4605800]National Natural Science Foundation of China[51935014,52165043]+3 种基金JiangXi Provincial Natural Science Foundation of China[20224ACB204013,20224ACB214008]Jiangxi Provincial Cultivation Program for Academic and Technical Leaders of Major Subjects[20225BCJ23008]Anhui Provincial Natural Science Foundation[2308085ME171]The University Synergy Innovation Program of Anhui Province[GXXT-2023-025,GXXT-2023-026].
文摘Biomedical magnesium(Mg)alloys have garnered significant attention because of their unique biodegradability,favorable biocompatibility,and suitable mechanical properties.The incorporation of rare earth(RE)elements,with their distinct physical and chemical properties,has greatly contributed to enhancing the mechanical performance,degradation behavior,and biological performance of biomedical Mg alloys.Currently,a series of RE-Mg alloys are being designed and investigated for orthopedic implants and cardiovascular stents,achieving substantial and encouraging research progress.In this work,a comprehensive summary of the state-of-the-art in biomedical RE-Mg alloys is provided.The physiological effects and design standards of RE elements in biomedical Mg alloys are discussed.Particularly,the degradation behavior and mechanical properties,including their underlying action are studied in-depth.Furthermore,the preparation techniques and current application status of RE-Mg alloys are reviewed.Finally,we address the ongoing challenges and propose future prospects to guide the development of high-performance biomedical Mg-RE alloys.
基金supported by the National Natural Science Foundation of China(Grant Nos.12272001,11972046)the Outstanding Youth Project of Natural Science Foundation of Anhui Province(Grant No.2108085Y02)the Major Project of Anhui University Natural Science Foundation(Grant No.KJ2020ZD30)。
文摘The flame propagation processes of MgH_(2)dust clouds with four different particle sizes were recorded by a high-speed camera.The dynamic flame temperature distributions of MgH_(2)dust clouds were reconstructed by the two-color pyrometer technique,and the chemical composition of solid combustion residues were analyzed.The experimental results showed that the average flame propagation velocities of 23μm,40μm,60μm and 103μm MgH_(2)dust clouds in the stable propagation stage were 3.7 m/s,2.8 m/s,2.1 m/s and 0.9 m/s,respectively.The dust clouds with smaller particle sizes had faster flame propagation velocity and stronger oscillation intensity,and their flame temperature distributions were more even and the temperature gradients were smaller.The flame structures of MgH_(2)dust clouds were significantly affected by the particle sinking velocity,and the combustion processes were accompanied by micro-explosion of particles.The falling velocities of 23μm and 40μm MgH_(2)particles were 2.24 cm/s and 6.71 cm/s,respectively.While the falling velocities of 60μm and 103μm MgH_(2)particles were as high as 15.07 cm/s and 44.42 cm/s,respectively,leading to a more rapid downward development and irregular shape of the flame.Furthermore,the dehydrogenation reaction had a significant effect on the combustion performance of MgH_(2)dust.The combustion of H_(2)enhanced the ignition and combustion characteristics of MgH_(2)dust,resulting in a much higher explosion power than the pure Mg dust.The micro-structure characteristics and combustion residues composition analysis of MgH_(2)dust indicated that the combustion control mechanism of MgH_(2)dust flame was mainly the heterogeneous reaction,which was affected by the dehydrogenation reaction.
基金supported by National Key Research and Development Program of China(2021YFB4000604)National Natural Science Foundation of China(52271220)111 Project(B12015)and the Fundamental Research Funds for the Central Universities.
文摘Hydrogen energy has emerged as a pivotal solution to address the global energy crisis and pave the way for a cleaner,low-carbon,secure,and efficient modern energy system.A key imperative in the utilization of hydrogen energy lies in the development of high-performance hydrogen storage materials.Magnesium-based hydrogen storage materials exhibit remarkable advantages,including high hydrogen storage density,cost-effectiveness,and abundant magnesium resources,making them highly promising for the hydrogen energy sector.Nonetheless,practical applications of magnesium hydride for hydrogen storage face significant challenges,primarily due to their slow kinetics and stable thermodynamic properties.Herein,we briefly summarize the thermodynamic and kinetic properties of MgH2,encompassing strategies such as alloying,nanoscaling,catalyst doping,and composite system construction to enhance its hydrogen storage performance.Notably,nanoscaling and catalyst doping have emerged as more effective modification strategies.The discussion focuses on the thermodynamic changes induced by nanoscaling and the kinetic enhancements resulting from catalyst doping.Particular emphasis lies in the synergistic improvement strategy of incorporating nanocatalysts with confinement materials,and we revisit typical works on the multi-strategy optimization of MgH2.In conclusion,we conduct an analysis of outstanding challenges and issues,followed by presenting future research and development prospects for MgH2 as hydrogen storage materials.
基金supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region(152131/18E).
文摘This study offers significant insights into the multi-physics phenomena of the SLM process and the subsequent porosity characteristics of ZK60 Magnesium(Mg)alloys.High-speed in-situ monitoring was employed to visualise process signals in real-time,elucidating the dynamics of melt pools and vapour plumes under varying laser power conditions specifically between 40 W and 60 W.Detailed morphological analysis was performed using Scanning-Electron Microscopy(SEM),demonstrating a critical correlation between laser power and pore formation.Lower laser power led to increased pore coverage,whereas a denser structure was observed at higher laser power.This laser power influence on porosity was further confirmed via Optical Microscopy(OM)conducted on both top and cross-sectional surfaces of the samples.An increase in laser power resulted in a decrease in pore coverage and pore size,potentially leading to a denser printed part of Mg alloy.X-ray Computed Tomography(XCT)augmented these findings by providing a 3D volumetric representation of the sample internal structure,revealing an inverse relationship between laser power and overall pore volume.Lower laser power appeared to favour the formation of interconnected pores,while a reduction in interconnected pores and an increase in isolated pores were observed at higher power.The interplay between melt pool size,vapour plume effects,and laser power was found to significantly influence the resulting porosity,indicating a need for effective management of these factors to optimise the SLM process of Mg alloys.
文摘Realising the potential of Magnesium(Mg),several globally leading ventures have invested in the Mg industry,but their relatively poor corrosion resistance is a never ending saga till date.The corrosion and bio-corrosion behaviour of Mg has gained research attention and still remains a hot topic in the application of automobile,aerospace and biomedical industries.The intrinsic high electrochemical nature of Mg limits their utilization in diverse application.This scenario has prompted the development of Mg composites with an aim to achieve superior corrosion and bio-corrosion resistance.The present review enlightens the influence of grain size(GS),secondary phase,texture,type of matrix and reinforcement on the corrosion and bio-corrosion behaviour of Mg composites.Firstly,the corrosion and bio-corrosion behaviour of Mg composites manufactured by primary and secondary processing routes are elucidated.Secondly,the comprehensive corrosion and bio-corrosion mechanisms of these Mg composites are proposed.Thirdly,the individual role of GS,texture and corrosive medium on corrosion and bio-corrosion behaviour of Mg composites are clarified and revealed.The challenges encountered,unanswered issues in this field are explained in detail and accordingly the scope for future research is framed.The review is presented from basic concrete background to advanced corrosion mechanisms with an aim of creating interest among the readers like students,researchers and industry experts from various research backgrounds.Indeed,the corrosion and bio-corrosion behaviour of Mg composites are critically reviewed for the first time to:(i)contribute to the body of knowledge,(ii)foster research and development,(iii)make breakthrough,and(iv)create life changing innovations in the field of Mg composite corrosion.
文摘Background: Magnesium, an essential mineral crucial for various bodily functions, has been shown to positively influence sleep patterns. This study aimed to evaluate the efficacy of Food-Grown® magnesium in enhancing sleep quality and duration, as well as overall well-being. Methods: Eighty participants were randomly assigned to receive either 80 mg of Food-Grown® magnesium or a placebo (microcrystalline cellulose) daily for 8 weeks. Participants completed questionnaires assessing sleep quality, daytime drowsiness, quality of life, anxiety, and stress levels. Additionally, participants maintained daily sleep diaries and wore wrist-worn actigraphy devices. The primary outcome measured was the change in sleep quality and duration. Results: Seventy-one participants fulfilled all study requirements (35 in the active group and 36 in the placebo group). Magnesium supplementation significantly improved reported sleep quality, with the active group showing a 32% increase compared to 16% in the placebo group (p = 0.034). Moreover, magnesium supplementation led to a decrease in reported stress scores at week 8 compared to the placebo group (3.7 ± 2.6 vs. 5.5 ± 3.1, respectively). Both the magnesium and placebo groups exhibited significant increases in reported sleep duration and reductions in time to fall asleep, sleep disturbance, sleep latency, sleep medication usage, and total Pittsburgh Sleep Quality Index score at week 8 compared to baseline. Conclusion: Magnesium supplementation notably enhanced sleep quality and reduced stress levels compared to the placebo group. These findings highlight the potential of magnesium as a beneficial supplement for improving sleep quality and overall well-being.