Characterization of distinct microbiota associated with androgenetic alopecia patients treated and untreated with platelet-rich plasma(PRP)

Background:Androgenic alopecia(AGA)is the most common type of hair loss in men,and there are many studies on the treatment of hair loss by platelet-rich plasma(PRP).The human scalp contains a huge microbiome,but its role in the process of hair loss remains unclear,and the relationship between PRP and the microbiome needs further study.Therefore,the purpose of this study was to investigate the effect of PRP treatment on scalp microbiota composition.Methods:We performed PRP treatment on 14 patients with AGA,observed their clinical efficacy,and collected scalp swab samples before and after treatment.The scalp microflora of AGA patients before and after treatment was characterized by amplifying the V3-V4 region of the 16 s RNA gene and sequencing for bacterial identification.Results:The results showed that PRP was effective in the treatment of AGA patients,and the hair growth increased significantly.The results of relative abundance analysis of microbiota showed that after treatment,g_Cutibacterium increased and g_Staphylococcus decreased,which played a stable role in scalp microbiota.In addition,g_Lawsonella decreased,indicating that the scalp oil production decreased after treatment.Conclusions:The findings suggest that PRP may play a role in treating AGA through scalp microbiome rebalancing.

Efficacy of intraovarian autologous platelet-rich plasma administration in women with low ovarian reserve: A systematic review and meta-analysis

Objective:To conduct a systematic examination and meta-analysis of the most reliable data from experimental studies evaluating the efficacy of autologous platelet-rich plasma(PRP)on low ovarian reserve.Methods:A comprehensive search was performed utilizing pertinent search terms across electronic databases,including PubMed,Cochrane,and Google Scholar.We included studies that assigned infertile women with low ovarian reserve in experimental studies.Ovarian reserve parameters were measured before and after PRP injection into ovaries.The data of each study was retrieved and subsequently compiled.Results:Of 301 articles collected and reviewed,six studies were finally included in the meta-analysis.Following PRP injection,infertile women showed a non-significant increase in anti-Mullerian hormone(AMH)level(MD=0.10;95%CI-0.04,0.23),a significant increase in antral follicular count(AFC)(MD=1.88;95%CI 0.47,3.29),and a non-significant reduction in follicle-stimulating hormone(FSH)level(MD=-0.22;95%CI-8.32,7.87).Conclusions:Autologous PRP may increase AFC,but not AMH.Although it is found beneficial in enhancing ovarian reserve(AFC),further research with strong evidence is still required.

Adenylate cyclase activates the cAMP signalling pathway to enhance platelet-rich plasma-treated Achilles tendon disease,a theoretical bioinformatics-based study

The effectiveness of platelet-rich plasma(PRP)for the treatment of Achilles tendon disorders still needs to be evaluated through a series of prospective studies,but genomic analysis can reveal the existence of complementary PRP treatment options.Based on the 96 platelet activation-related genes in the Kyoto Encyclopedia of Genes and Genomes(KEGG)database,we performed Gene Ontology functional enrichment analysis and KEGG enrichment analysis,pathway correlation analysis,and enrichment mapping to determine the enrichment results of the gene set enrichment analysis and found that the cAMP signalling pathway may be the key to enhancing the effectiveness of PRP treatment.The cAMP signalling pathway interacts with the Rap1 signalling pathway and cGMPPKG signalling pathway to mediate the entire pathophy-siological process of Achilles tendon disease.Moreover,ADCY1-9 may be the key to the activation of the cAMP signalling network.Further based on the data in the Gene Expression Omnibus database,it was found that ADCY4 and ADCY7 may be the players that play a major role,associated with the STAT4-ADCY4-LAMA5 axis and the GRbeta-ADCY7-SEMA3C axis,which is expected to be a complementary target for enhancing the efficacy of PRP in the treatment of Achilles tendon disease.

Platelet-rich plasma promotes peripheral nerve regeneration after sciatic nerve injury

The effect of platelet-rich plasma on nerve regeneration remains controversial.In this study,we established a rabbit model of sciatic nerve small-gap defects with preserved epineurium and then filled the gaps with platelet-rich plasma.Twenty-eight rabbits were divided into the following groups(7 rabbits/group):model,low-concentrati on PRP(2.5-3.5-fold concentration of whole blood platelets),medium-concentration PRP(4.5-6.5-fold concentration of whole blood platelets),and high-concentration PRP(7.5-8.5-fold concentration of whole blood platelets).Electrophysiological and histomorphometrical assessments and proteomics analysis we re used to evaluate regeneration of the sciatic nerve.Our results showed that platelet-rich plasma containing 4.5-6.5-and 7.5-8.5-fold concentrations of whole blood platelets promoted repair of sciatic nerve injury.Proteomics analysis was performed to investigate the possible mechanism by which platelet-rich plasma promoted nerve regeneration.Proteomics analysis showed that after sciatic nerve injury,platelet-rich plasma increased the expression of integrin subunitβ-8(ITGB8),which participates in angiogenesis,and differentially expressed proteins were mainly enriched in focal adhesion pathways.Additionally,two key proteins,ribosomal protein S27 a(RSP27 a)and ubiquilin 1(UBQLN1),which were selected after protein-protein interaction analysis,are involved in the regulation of ubiquitin levels in vivo.These data suggest that platelet-rich plasma promotes peripheral nerve regeneration after sciatic nerve injury by affecting angiogenesis and intracellular ubiquitin levels.

Effectiveness of platelet-rich plasma in the treatment of Achilles tendon disease

BACKGROUND The effectiveness of Platelet-Rich Plasma(PRP)in the treatment of patients with Achilles tendon rupture(ATR)and Achilles tendinopathy(AT)has been controversial.AIM To assess PRP injections’effectiveness in treating ATR and AT.METHODS A comprehensive review of relevant literature was conducted utilizing multiple databases such as Cochrane Library,PubMed,Web of Science,Chinese Science and Technology Journal,EMBASE,and China Biomedical CD-ROM.The present investigation integrated randomized controlled trials that assessed the effectiveness of platelet-rich plasma injections in managing individuals with Achilles tendon rupture and tendinopathy.The eligibility criteria for the trials encompassed publications that were published within the timeframe of January 1,1966 to December 2022.The statistical analysis was performed utilizing the Review Manager 5.4.1,the visual analogue scale(VAS),Victorian Institute Ankle Function Scale(VISA-A),and Achilles Tendon Thickness were used to assess outcomes.RESULTS This meta-analysis included 13 randomized controlled trials,8 of which were randomized controlled trials of PRP for AT and 5 of which were randomized controlled trials of PRP for ATR.PRP for AT at 6 wk[weighted mean difference(WMD)=1.92,95%CI:-0.54 to 4.38,I2=34%],at 3 mo[WMD=0.20,95%CI:-2.65 to 3.05,I2=60%],and 6 mo[WMD=2.75,95%CI:-2.76 to 8.26,I2=87%)after which there was no significant difference in VISA-A scores between the PRP and control groups.There was no significant difference in VAS scores between the PRP group and the control group after 6 wk[WMD=6.75,95%CI:-6.12 to 19.62,I2=69%]and 6 mo[WMD=10.46,95%CI:-2.44 to 23.37,I2=69%]of treatment,and at mid-treatment at 3 mo[WMD=11.30,95%CI:7.33 to 15.27,I2=0%]after mid-treatment,the PRP group demonstrated better outcomes than the control group.Post-treatment patient satisfaction[WMD=1.07,95%CI:0.84 to 1.35,I2=0%],Achilles tendon thickness[WMD=0.34,95%CI:-0.04 to 0.71,I2=61%]and return to sport[WMD=1.11,95%CI:0.87 to 1.42,I2=0%]were not significantly different between the PRP and control groups.The study did not find any statistically significant distinction between the groups that received PRP treatment and those that did not,regarding the Victorian Institute of Sport Assessment-Achilles scores at 3 mo[WMD=-1.49,95%CI:-5.24 to 2.25,I2=0%],6 mo[WMD=-0.24,95%CI:-3.80 to 3.32,I2=0%],and 12 mo[WMD=-2.02,95%CI:-5.34 to 1.29,I2=87%]for ATR patients.Additionally,no significant difference was observed between the PRP and the control groups in improving Heel lift height respectively at 6 mo[WMD=-3.96,95%CI:-8.61 to 0.69,I2=0%]and 12 mo[WMD=-1.66,95%CI:-11.15 to 7.83,I2=0%]for ATR patients.There was no significant difference in calf circumference between the PRP group and the control group after 6 mo[WMD=1.01,95%CI:-0.78 to 2.80,I2=54%]and 12 mo[WMD=-0.55,95%CI:-2.2 to 1.09,I2=0%]of treatment.There was no significant difference in ankle mobility between the PRP and control groups at 6 mo of treatment[WMD=-0.38,95%CI:-2.34 to 1.58,I2=82%]and after 12 mo of treatment[WMD=-0.98,95%CI:-1.41 to-0.56,I2=10%]there was a significant improvement in ankle mobility between the PRP and control groups.There was no significant difference in the rate of return to exercise after treatment[WMD=1.20,95%CI:0.77 to 1.87,I2=0%]and the rate of adverse events[WMD=0.85,95%CI:0.50 to 1.45,I2=0%]between the PRP group and the control group.CONCLUSION The use of PRP for AT improved the patient’s immediate VAS scores but not VISA-A scores,changes in Achilles tendon thickness,patient satisfaction,or return to sport.Treatment of ATR with PRP injections alone improved long-term ankle mobility but had no significant effect on VISA-A scores,single heel lift height,calf circumference or return to sport.Additional research employing more extensive sampling sizes,more strict experimental methods,and standard methodologies may be necessary to yield more dependable and precise findings.

Role of platelet-rich plasma in the treatment of rotator cuff tendinopathy

Shoulder pain is a common musculoskeletal complaint,and rotator cuff(RC)pathologies are one of the main causes.The RC undergoes various tendinopathic and avascular changes during the aging process.Other degenerative changes affecting its healing potential make it an appealing target for biological agents.Platelet-rich plasma(PRP)has demonstrated the potential to deliver a high concentration of several growth factors and anti-inflammatory mediators,and its clinical use is mainly supported by experiments that demonstrated its positive effect on muscle,ligaments,and tendinous cells.This review aimed to specify the role of PRP and its future applications in RC tendinopathies based on the current clinical evidence.Due to the different characteristics and conflicting outcomes,clinicians should use PRP with moderate expectations until more consistent evidence is available.However,it is reasonable to consider PRP in patients with contraindications to corticosteroid injections or those with risk factors for inadequate healing.Its autologous origin makes it a safe treatment,and its characteristics make it a promising option for treating RC tendinopathy,but the efficacy has yet to be established.

Value of Intrauterine Autologous Platelet-Rich Plasma Therapy on Endometrial Receptivity:A Literature Review

Endometrial receptivity is an important factor that influences embryo implantation.Thus,it is important to identify an applicable approach to improve endometrial receptivity in women undergoing assisted reproductive technology.Recently,growing evidence has indicated that intrauterine platelet-rich plasma(PRP)infusion is an effective method to obtain a satisfactory reproductive outcome by increasing endometrial thickness and improving endometrial receptivity.Therefore,the present review aims to outline the possible mechanisms of PRP on endometrial receptivity and summarize the present literature on the effects of PRP therapy in improving endometrial receptivity.

Efficacy of tibial transverse transport combined with platelet-rich plasma versus platelet-rich plasma alone in the treatment of diabetic foot ulcers:A meta-analysis

Background:Diabetic foot ulcers(DBFU)are one of the main complications of diabetes.Platelet-rich plasma(PRP)treatment is a commonly used treatment option.Tibial transverse transport(TTT)also has a therapeutic effect on DBFU.Some studies have found that the TTT combined with PRP(TTT&PRP)has a significant effect on DBFU.Methods:PubMed,Cochrane Library,Web of Science,EMBASE,Chinese Biomedical Literature,CNKI,VIP,and Wanfang databases were used to find literature on the treatment of DBFUs using the TTT and PRP treatment according to the inclusion criteria.The specific inclusion criteria are as follows:(1)research type:clinical controlled trials,including retrospective cohort and randomized controlled studies;(2)diagnosis of DBFUs that does not include a definitively diagnosed traumatic ulcer;(3)original materials of Chinese and English literature published in full text.The exclusion criteria are:(1)the research group was not defined or grouped;(2)nonrandomized controlled trials,non-cohort studies,non-case-control studies,retrospective studies,and case reports;(3)repetitive research and animal experimentation;(4)ulcers caused by other diseases;(5)conservative treatment or no use of invasive treatment methods.Review Manager software(version 5.3)was used to conduct a meta-analysis of the included results.Result:The literature included 6 randomized controlled studies,including 508 patients,254 patients in the PRP treatment group,and 254 patients in the TTT&PRP group.The meta-analysis results showed that in terms of treatment efficacy,the TTT&PRP combined treatment group had a higher efficacy than the PRP group.After treatment,the TTT&PRP group had better treatment effects in psychological function,physiological function,and social function compared to the PRP group.After treatment,the TTT&PRP group showed a significant increase in serum epidermal growth factor(EGF),vascular endothelial growth factor(VEGF),basic fibroblast growth factor(bFGF),and platelet-derived growth factor(PDGF)levels compared to the PRP group.In terms of wound healing after treatment,the TTT&PRP group performed better than the PRP group in terms of postoperative wound reduction rate,bacterial clearance rate,granulation tissue coverage rate,and granulation tissue growth thickness.Conclusion:TTT combined with PRP was more effective than PRP alone in treating DBFUs.

Clinical and Magnetic Resonance Image Changes of Platelet-Rich Plasma Therapy in Combination with Human Mesenchymal Stem Cells from Autologous Adipose Tissue for Knee Osteoarthritis Treatment

Objective: To evaluate the efficacy based on clinical symptom and on magnetic resonance image of platelet-rich plasma therapy in combination with mesenchymal stem cells from autologous adipose tissue for knee osteoarthritis treatment. Patients and Method: 30 patients including 26 females and 4 males;correspondingly, 60 knee joints were diagnosed with osteoarthritis with stages II - III of Kellgren and Lawrence, their mean age was 58.63 ± 11.11. All were injected with autologous platelet-rich plasma that was extracted by PRP set, APC 30 PRP PRCEDURE PRAK and autologously extracted mesenchymal stem cells from abdominal adipose tissue using the ADI-25-01 ADIPOSEPRCEDURE PRAK of USA. Results: After 12 months: the pain level according to VAS score at the right knee joint was decreased from 6.0 ± 1.28 before treatment to 1.9 ± 0.3;VAS score at the left knee joint was decreased from 6.43 ± 1.19 to 2.25 ± 0.43. Total Lequene score at right knee joint was decreased from 16.04 ± 1.57 before treatment to 4.31 ± 1.04, at left knee joint was decreased from 17.52 ± 1.74 before treatment to 5.15 ± 1.48. Total WOMAC score at right knee joint was decreased from 55.93 ± 5.56 to 10.37 ± 1.56;at left knee joint was decreased from 53.97 ± 5.57 to 10.07 ± 1.59. There were 86.77% joints with cartilage thickness change and the patellar cartilage thickness was increased from 1.56 ± 0.09 mm before treatment to 1.65 ± 0.09 mm. Conclusion: The treatment of knee osteoarthritis by platelet-rich plasma therapyin combination with mesenchymal stem cells from autologous adipose tissue is effective in reducing pain, improving patient's mobility and walking function, reforming articular cartilage thickness on magnetic resonance image.

Therapeutic Effectiveness of Leukocyte-and Platelet-rich Fibrin for Diabetic Foot Ulcers:A Retrospective Study

Objective Diabetic foot ulcer(DFU)is one of the most serious complications of diabetes.Leukocyte-and platelet-rich fibrin(L-PRF)is a second-generation autologous platelet-rich plasma.This study aims to investigate the clinical effects of L-PRF in patients with diabetes in real clinical practice.Methods Patients with DFU who received L-PRF treatment and standard of care(SOC)from 2018 to 2019 in Tongji Hospital were enrolled.The clinical information including patient characteristics,wound evaluation(area,severity,infection,blood supply),SOC of DFU,and images of ulcers was retrospectively extracted and analyzed.L-PRF treatment was performed every 7±2 days until the ulcer exhibited complete epithelialization or an overall percent volume reduction(PVR)greater than 80%.Therapeutic effectiveness,including overall PVR and the overall and weekly healing rates,was evaluated.Results Totally,26 patients with DFU were enrolled,and they had an ulcer duration of 47.0(35.0,72.3)days.The severity and infection of ulcers varied,as indicated by the Site,Ischemia,Neuropathy,Bacterial Infection,and Depth(SINBAD)scores of 2–6,Wagner grades of 1–4,and the Perfusion,Extent,Depth,Infection and Sensation(PEDIS)scores of 2–4.The initial ulcer volume before L-PRF treatment was 4.94(1.50,13.83)cm3,and the final ulcer volume was 0.35(0.03,1.76)cm3.The median number of L-PRF doses was 3(2,5).A total of 11 patients achieved complete epithelialization after the fifth week of treatment,and 19 patients achieved at least an 80%volume reduction after the seventh week.The overall wound-healing rate was 1.47(0.63,3.29)cm3/week,and the healing rate was faster in the first 2 weeks than in the remaining weeks.Concurrent treatment did not change the percentage of complete epithelialization or healing rate.Conclusion Adding L-PRF to SOC significantly improved wound healing in patients with DFU independent of the ankle brachial index,SINBAD score,or Wagner grade,indicating that this method is appropriate for DFU treatment under different clinical conditions.

Study of plasma parameters of coaxial plasma source using triple Langmuir probe and Faraday cup diagnostics

Coaxial plasma guns are a type of plasma source that produces plasma which propagates radially and axially controlled by the shape of the ground electrode, which has attracted much interest in several applications. In this work, a 120° opening angle of CPG nozzle is used as a plasma gun configuration that operates at the energy of 150 J. The ionization of polyethylene insulator between the electrodes of the gun produces a cloud of hydrogen and carbon plasma.The triple Langmuir probe and Faraday cup are used to measure plasma density and plasma temperature. These methods are used to measure the on-axis and off-axis plasma divergence of the coaxial plasma gun. The peak values of ion densities measured at a distance of 25 mm on-axis from the plasma gun are(1.6±0.5)×10^(19)m^(-3)and(2.8±0.6)×10^(19)m^(-3)for hydrogen and carbon plasma respectively and the peak temperature is 3.02±0.5 eV. The mean propagation velocity of plasma is calculated using the transit times of plasma at different distances from the plasma gun and is found to be 4.54±0.25 cm/μs and 1.81±0.18 cm/μs for hydrogen and carbon plasma respectively. The Debye radius is obtained from the measured experimental data that satisfies the thin sheath approximation. The shot-to-shot stability of plasma parameters facilitates the use of plasma guns in laboratory experiments. These types of plasma sources can be used in many applications like plasma opening switches, plasma devices, and as plasma sources.

Final results of the first phase of the PROTO-SPHERA experiment: obtainment of the full current stable screw pinch and first evidences of the jet + torus combined plasma configuration

In astrophysics, the boundary conditions for plasma phenomena are provided by nature and the astronomer faces the problem of understanding them from a variety of observations [Hester J J et al 1996 Astrophys. J. 456 225], on the other hand, in laboratory plasma experiments the electromagnetic boundary conditions become a major problem in the set-up of the machine that produces the plasma, an issue that has to be investigated step by step and to be modified and adapted with great patience, in particular in the case of an innovative plasma confinement experiment. The PROTO-SPHERA machine [Alladio F et al 2006 Nucl. Fusion 46 S613] is a magnetic confinement experiment, that emulates in the laboratory the jet + torus plasma configurations often observed in astrophysics: an inner magnetized jet of plasma centered on the(approximate) axis of symmetry and surrounded by a magnetized plasma torus orthogonal to this jet. The PROTO-SPHERA plasma is simply connected, i.e., no metal current conducting rod is linked to the plasma torus, while instead it is the inner magnetized plasma jet(in the following always called the plasma centerpost) that is linked to the torus. It is mandatory that no spurious plasma current path modifies the optimal shape of the plasma centerpost. Moreover, as the plasma torus is produced and sustained, in absence of any applied inductive electric field, by the inner plasma centerpost through magnetic reconnections [Taylor J B and Turner M F 1989 Nucl.Fusion 29 219], it is required as well that spurious current paths do not surround the torus on its outboard, in order not to lower the efficiency of the magnetic reconnections that maintain the plasma torus at the expense of the plasma centerpost. Boundary conditions have been corrected,up to the point that the first sustainment in steady state has been achieved for the combined plasma.

The multi-peak point phenomenon of broadband microwave reflection caused by inhomogeneous plasma

During spacecraft re-entry,the challenge of measuring plasma sheath parameters directly contributes to difficulties in addressing communication blackout.In this work,we have discovered a phenomenon of multiple peaks in reflection data caused by the inhomogeneous plasma.Simulation results show that the multi-peak points fade away as the characteristic frequency is approached,resembling a series of gradually decreasing peaks.The positions and quantities of these points are positively correlated with electron density,yet they show no relation to collision frequency.This phenomenon is of significant reference value for future studies on the spatial distribution of plasmas,particularly for using microwave reflection signals in diagnosing the plasma sheath.

Customized modulation on plasma uniformity by non-uniform magnetic field in capacitively coupled plasma

A two-dimensional fluid model based on COMSOL Multiphysics is developed to investigate the modulation of static magnetic field on plasma homogeneity in a capacitively coupled plasma(CCP)chamber. To generate a static magnetic field, direct current is applied to a circular coil located at the top of the chamber. By adjusting the magnetic field's configuration, which is done by altering the coil current and position, both the plasma uniformity and density can be significantly modulated. In the absence of the magnetic field, the plasma density exhibits an inhomogeneous distribution characterized by higher values at the plasma edge and lower values at the center. The introduction of a magnetic field generated by coils results in a significant increase in electron density near the coils. Furthermore, an increase in the sets of coils improves the uniformity of the plasma. By flexibly adjusting the positions of the coils and the applied current,a substantial enhancement in overall uniformity can be achieved. These findings demonstrate the feasibility of using this method for achieving uniform plasma densities in industrial applications.

Experimental confirmation of the linear relation between plasma current and external vertical magnetic field in EXL-50 spherical torus energetic electron plasmas

A three-fluid equilibrium plasma with bulk plasma and energetic electrons has been observed on the Xuanlong-50(EXL-50) spherical torus, where the energetic electrons play a crucial role in sustaining the plasma current and pressure. In this study, the equilibrium of a multi-fluid plasma was investigated by analyzing the relationship between the external vertical magnetic field(B_(V)),plasma current(I_(p)), the poloidal ratio(β_(p)) and the Shafranov formula. Remarkably, our research demonstrates some validity of the Shafranov formula in the presence of multi-fluid plasma in EXL-50 spherical torus. This finding holds significant importance for future reactors as it allows for differentiation between alpha particles and background plasma. The study of multi-fluid plasma provides a significant reference value for the equilibrium reconstruction of burning plasma involving alpha particles.

A research on the effect of plasma spectrum collection device on LIBS spectral intensity

Only a small amount of spectral information is collected because the collection solid angle of the optical fiber probe and lens is very limited when collecting spectral information.To overcome this limitation,this study presents a novel method for acquiring plasma spectral information from various spatial directions.A parabolic-shaped plasma spectral collection device(PSCD)is employed to effectively collect more spectral information into the spectrometer,thereby enhancing the overall spectral intensity.The research objects in this study were soil samples containing different concentrations of heavy metals Pb,Cr,and Cd.The results indicate that the PSCD significantly enhances the spectral signal,with an enhancement rate of up to 45%.Moreover,the signal-to-noise ratio also increases by as much as 36%.Simultaneously,when compared to the absence of a device,it is found that there is no significant variation in plasma temperature when the PSCD is utilized.This observation eliminates the impact of the spatial effect caused by the PSCD on the spectral intensity.Consequently,a concentrationspectral intensity relationship curve is established under the PSCD.The results revealed that the linear fitting R^(2)for Pb,Cr,and Cd increased by 0.011,0.001,and 0.054,respectively.Additionally,the limit of detection(LOD)decreased by 0.361 ppm,0.901 ppm,and 0.602 ppm,respectively.These findings indicate that the spectral enhancement rate elevates with the increase in heavy metal concentration.Hence,the PSCD can effectively enhance the spectral intensity and reduce the detection limit of heavy metals in soil.

Wave field structure and power coupling features of blue-core helicon plasma driven by various antenna geometries and frequencies

This paper deals with wave propagation and power coupling in blue-core helicon plasma driven by various antennas and frequencies.It is found that compared to non-blue-core mode,for blue-core mode,the wave can propagate in the core region,and it decays sharply outside the core.The power absorption is lower and steeper in radius for blue-core mode.Regarding the effects of antenna geometry for blue-core mode,it shows that half helix antenna yields the strongest wave field and power absorption,while loop antenna yields the lowest.Moreover,near axis,for antennas with m=+1,the wave field increases with axial distance.In the core region,the wave number approaches to a saturation value at much lower frequency for non-blue-core mode compared to blue-core mode.The total loading resistance is much lower for blue-core mode.These findings are valuable to understanding the physics of blue-core helicon discharge and optimizing the experimental performance of blue-core helicon plasma sources for applications such as space propulsion and material treatment.

Effect of coil and chamber structure on plasma radial uniformity in radio frequency inductively coupled plasma

Enhancing plasma uniformity can be achieved by modifying coil and chamber structures in radio frequency inductively coupled plasma(ICP)to meet the demand for large-area and uniformly distributed plasma in industrial manufacturing.This study utilized a two-dimensional self-consistent fluid model to investigate how different coil configurations and chamber aspect ratios affect the radial uniformity of plasma in radio frequency ICP.The findings indicate that optimizing the radial spacing of the coil enhances plasma uniformity but with a reduction in electron density.Furthermore,optimizing the coil within the ICP reactor,using the interior point method in the Interior Point Optimizer significantly enhances plasma uniformity,elevating it from 56%to 96%within the range of the model sizes.Additionally,when the chamber aspect ratio k changes from 2.8 to 4.7,the plasma distribution changes from a center-high to a saddleshaped distribution.Moreover,the plasma uniformity becomes worse.Finally,adjusting process parameters,such as increasing source power and gas pressure,can enhance plasma uniformity.These findings contribute to optimizing the etching process by improving plasma radial uniformity.

Plasma density enhancement in radio-frequency hollow electrode discharge

The plasma density enhancement outside hollow electrodes in capacitively coupled radio-frequency(RF) discharges is investigated by a two-dimensional(2D) particle-in-cell/Monte-Carlo collision(PIC/MCC) model. Results show that plasma exists inside the cavity when the sheath inside the hollow electrode hole is fully collapsed, which is an essential condition for the plasma density enhancement outside hollow electrodes. In addition, the existence of the electron density peak at the orifice is generated via the hollow cathode effect(HCE), which plays an important role in the density enhancement. It is also found that the radial width of bulk plasma at the orifice affects the magnitude of the density enhancement, and narrow radial plasma bulk width at the orifice is not beneficial to obtain high-density plasma outside hollow electrodes.Higher electron density at the orifice, combined with larger radial plasma bulk width at the orifice,causes higher electron density outside hollow electrodes. The results also imply that the HCE strength inside the cavity cannot be determined by the magnitude of the electron density outside hollow electrodes.

Genetically Predicted Plasma Levels of Amino Acids and Endometriosis:A Mendelian Randomization Study

Endometriosis(EMS)is one of the most common disorders among women of reproductive age and affects approximately 6%–10%of the world total population^([1]).Women with EMS often experience symptoms such as dysmenorrhea,infertility,or difficulties in conceiving.Recent studies focusing on amino acids(AAs)metabolism have shed light on the mechanisms underlying the development and progression of EMS^([2]).