Comparative study of boron and neon injections on divertor heat fluxes using SOLPS-ITER simulations

Based on the EAST equilibrium,the effects of boron(B)and neon(Ne)injected at different locations on the target heat load,and the distributions of B and Ne particles were investigated by transport code SOLPS-ITER.It was found that the B injection was more sensitive to the injection location for heat flux control than impurity Ne.The high electron and ion densities near the inner target in the discharge with impurity B injected from over X-point(R1)led to plasma detachment only at the inner target,and the localized B ions in the cases with injection from outer target location(R2)and upstream location(R3)led to far-SOL detachment at the outer target,but not at the inner target.In contrast,for Ne,the spatial distributions of Ne ions and electrons were found to be similar in all the cases at the three injection locations,and the detached plasma was achieved at the inner target and the electron temperature was reduced at the outer target.For locations R2 and R3,impurity B showed a more pronounced effect on the heat flux at the far-SOL of the outer target.Further analysis indicated that Ne atoms came mainly from the recycling sources,whereas B atoms came mainly from injection,and that their distinct atomic distributions resulted from the difference in the ionization threshold and ionization mean free path.In addition,the radiation proportion of B in the divertor region was larger than that of Ne when the total radiation power was similar,which suggests that B has less influence on the core region.

Background diseases and the number of previous intravitreal aflibercept injections on immediate intraocular pressure increase and vitreous reflux rate in phakic eyes

●AIM:To evaluate the effect of background diseases and number of previous intravitreal aflibercept injections(IVAIs)on immediate intraocular pressure(IOP)increase and vitreous reflux(VR)rate and to evaluate the correlation of both age and axial length with immediate IOP increase and VR rate.●METHODS:This study included 105 patients with cystoid macular edema secondary to retinal vein occlusion,35 patients with diabetic macular edema,69 patients with neovascular age-related macular degeneration(nAMD),and 12 patients with myopic choroidal neovascularization,which underwent first-time IVAI.The correlation of immediate IOP increase and VR rates with the four background diseases was investigated.Moreover,the correlation of age with immediate IOP increase and VR rate as well as correlation of axial length with immediate IOP increase and VR rate were evaluated.Further,54 patients with nAMD were treated with IVAI>10 times(multiple IVAIs).Moreover,the correlation of immediate IOP increase and VR rates with first-time and multiple IVAIs in nAMD was determined.●RESULTS:The immediate IOP increase(P=0.16)and VR rates(P=0.50)were almost similar among the four background diseases.The immediate postinjection IOP and age,VR rate and age,immediate postinjection IOP and axial length,or VR rate and axial length were not correlated in the four background diseases.The immediate IOP increase(P=0.66)and VR rates(P=0.28)did not significantly differ between first-time and multiple IVAIs in nAMD.●CONCLUSION:Background diseases and number of previous IVAIs have no effect on immediate IOP increase and VR rate.Further,age and axial length have no correlation on immediate IOP increase and VR rate.

Intralesional corticosteroid injections for infantile hemangioma

Infantile hemangiomas(IHs) are the most common benign soft-tissue tumors in infancy;about 10%–15% of them may result in various complications that require active management. The current first-line treatment for IH is oral propranolol;however, some studies recommend intralesional corticosteroid injections for small, limited, deep, or prominent tumors because of concern regarding serious systemic complications related to propranolol. This review summarizes and analyzes the current clinical studies on corticosteroid injections in IHs, discusses treatment norms, and explores future research directions.

Effects of the Treatment of Carpal Tunnel Syndrome with Surgery and Injections on the Hospital Anxiety and Depression Scale (HADS)

Background: The prevalence of carpal tunnel syndrome (CTS) and of anxiety and depression in primary care practice are high. Different studies had shown an increased prevalence of anxiety and depression in CTS patients. Nevertheless, few papers had been published studying the anxiety and depression scales in the treatment of CTS, either with corticosteroid injections (I) or with surgical decompression (S). Objective: To assess whether clinical improvement observed after the treatment of CTS either with I or with S correlates with an improvement in the punctuations of the Hospital Anxiety and Depression scales (HADS), at 3, 6 and 12-month follow-up. Methods: Randomized and open-label clinical trial, comparing I and S. Patients with symptoms suggestive of CTS (nocturnal paraesthesias) of at least 3 months duration and neurophysiological confirmation were included. Patients with clinically apparent motor impairment were excluded. The subjective evaluation of symptoms was carried out using the visual-analogue scale of pain (VAS-p). Clinical reviews were performed 3, 6 and 12 months after treatment. Each patient completed the HADS questionnaire and a VAS-p at 0, 3, 6, and 12 months. Statistical significance was established using the Student’s t test and the Mann-Whitney U test when necessary. A linear regression analysis was used to know the effect of the treatment adjusted for the initial score of both scales. Results: 65 patients were included (30 in group I and 35 in group S). There was no statistical difference between both groups in terms of age, gender distribution, disease duration, VAS-p, neurophysiological testing severity of CTS or the 8 subscales of HADS. Both groups improved significantly in relation to the baseline VAS-p values, in the reviews at 3, 6 and 12 months, with no significant differences between I and S. At 6 months, the reduction in the anxiety scale was around 3 points for both treatments (S = 3.6 and I = 3.2), without reaching significant differences. At 12 months, it was somewhat higher for those treated with I, but always around 3 points and without significant differences. The Depression scale score was slightly reduced at 6 months, and in a similar way for both groups (I = 1 and S = 1.19;p = 0.8). After 12 months, group I doubled the previous reduction, with group S experiencing a very slight change (I = 1.96 and S = 1.03;p = 0.3). When analysing the effect of group S on group I, the result was a reduction of 0.25 points for Anxiety (p = 0.7) and of 0.02 points for Depression (p = 0.9). Conclusions: Treatment of CTS with I or S results in a similar and discrete improvement in Anxiety scores on the HADS scale at 6 and 12 months. For both types of treatment, the Depression scores barely changed at 6 months, being somewhat higher in group I after 12-month follow-up. The independent effect of the S on both scales is small and not significant.

Posterior pedicle screw fixation combined with local steroid injections for treating axial eosinophilic granulomas and atlantoaxial dislocation:A case report

BACKGROUND Eosinophilic granuloma(EG)is a proliferative condition that affects the cells of bone tissue.There are no specific clinical signs or imaging manifestations in the early stages of the disease,making it simple to overlook and misdiagnose.Because of the disease's rarity,there is presently no standardized treatment principle.There are few accounts of such occurrences affecting the axis among children.We discovered a case of a child whose EG resulted in atlantoaxial joint dislocation and destruction of the axial bone.CASE SUMMARY After having pharyngeal discomfort for more than six months without a clear explanation,a 6-year-old boy was brought to our hospital.Following a careful evaluation,the pathology indicated a strong likelihood of an axial EG.Ultimately,we decided to treat the boy with posterior pedicle screw fixation and local steroid injections.CONCLUSION EGs of the upper cervical spine are quite uncommon in children,and they are exceedingly easy to overlook or misdiagnose.Posterior pedicle screw fixation and local steroid injections are effective treatments for patients with axial EGs affecting the atlantoaxial junction.

An intra-articular injectable phospholipids-based gel for the treatment of rheumatoid arthritis

Rheumatoid arthritis(RA)is a chronic inflammatory and destructive arthropathy with a high deformity rate.Despite numerous studies and clinical trials,no curative treatment is available for large weight-bearing joints.Intra-articular(IA)injections could deliver high concentrations of drug to the afflicted joint and improve the drug efficacy while reducing systemic toxicity.However,free drugs are rapidly cleared from synovial fluid and do not significantly halt the progression of joint disease.Herein,a phospholipids-based controlledrelease gel was prepared for sustained IA delivery of celastrol(CEL)and the therapeutic efficiencywas evaluated in a rheumatoid arthritis rabbitmodel.The CEL-loaded gel(CEL-gel)contained up to 70%phospholipids yetwas easy to inject.After injecting into the joint cavity,CEL-gel achieved sol to gel phase transition without special stimuli and gelling agent.In vitro release and in vivo pharmacokinetic studies evidenced the stable and sustained release action of CEL-gel.A single IA injection of CEL-gel could maintain therapeutic efficiency for about 25 d and showed much better anti-arthritic efficacy compared to repeated injections of free drug solution(CEL-sol).Furthermore,the IA injection of CEL-gel greatly reduced the systemic toxicity of CEL.With good biocompatibility and biodegradability,CEL-gel might be a promising IA drug delivery system.

Injections Attacks Efficient and Secure Techniques Based on Bidirectional Long Short Time Memory Model

E-commerce,online ticketing,online banking,and other web-based applications that handle sensitive data,such as passwords,payment information,and financial information,are widely used.Various web developers may have varying levels of understanding when it comes to securing an online application.Structured Query language SQL injection and cross-site scripting are the two vulnerabilities defined by the OpenWeb Application Security Project(OWASP)for its 2017 Top Ten List Cross Site Scripting(XSS).An attacker can exploit these two flaws and launch malicious web-based actions as a result of these flaws.Many published articles focused on these attacks’binary classification.This article described a novel deep-learning approach for detecting SQL injection and XSS attacks.The datasets for SQL injection and XSS payloads are combined into a single dataset.The dataset is labeledmanually into three labels,each representing a kind of attack.This work implements some pre-processing algorithms,including Porter stemming,one-hot encoding,and the word-embedding method to convert a word’s text into a vector.Our model used bidirectional long short-term memory(BiLSTM)to extract features automatically,train,and test the payload dataset.The payloads were classified into three types by BiLSTM:XSS,SQL injection attacks,and normal.The outcomes demonstrated excellent performance in classifying payloads into XSS attacks,injection attacks,and non-malicious payloads.BiLSTM’s high performance was demonstrated by its accuracy of 99.26%.

Iridociliary Body Metastasis of Atypical Carcinoid: Case Management with Intravitreal Anti-Vascular Endothelial Growth Factor Injections

We report a rare case involving a 52-year-old female diagnosed with an atypical bronchial carcinoid tumor with metastases to the mediastinum, hilar lymph nodes, breast, and pancreas. In additional, the patient had metastases to the iris and ciliary body, resulting in progressive vision loss in her left eye. Treatment was successful by intravitreal injections of anti-vascular endothelial growth factor.

A randomized clinical trial assessing the efficacy of single and multiple intralesional collagenase injections for treating contracted scars

Background:Scar contractions caused by trauma or burns can cause secondary physical dysfunction and disfigurement.Many minimally invasive methods for scar contraction have shown limited applicability and efficacy.This study investigated the feasibility and efficacy of intralesional collagenase injections for scar contraction treatment.Methods:Patients with contracted scars who had limited joint movement and physical disfiguration for>1 year were enrolled in this single-blind,randomized clinical trial from July 2017 to February 2018 at Shanghai Ninth People’s Hospital.Collagenase was injected into the firm-contracted scar(15 U/cm^(2))three times at 4-week intervals in the multiple treatment group and once in the single treatment group,and a placebo injection was performed in the control group.Scar length and skin texture were documented at the 4-and 12-week follow-ups.The safety of the collagenase treatment was also evaluated.Results:The contracted scar was significantly elongated after both single and multiple collagenase treatments.The results showed that,compared to a one-time treatment,repeated injections were more effective at 12 weeks,with an average improvement of 26.83(15.79%).At 12 weeks,78.9% of the patients in the multiple group and 52.9%in the single group achieved significant improvement at 12 weeks.No severe adverse events were observed.Conclusion:Intralesional collagenase injection showed promising results in improving scar contraction and provides an alternative treatment for patients.

Comparison of different noble gas injections by massive gas injection on plasma disruption mitigation on Experimental Advanced Superconducting Tokamak

Massive gas injection(MGI)is a traditional plasma disruption mitigation method.This method directly injected massive gas into the pre-disruption plasma and had been developed on the Experimental Advanced Superconducting Tokamak(EAST).Different noble gas injection experiments,including He,Ne,and Ar,were performed to compare the mitigation effect of plasma disruption by evaluating the key parameters such as flight time,pre-thermal quench(pre-TQ),and current quench(CQ).The flight time was shorter for low atomic number(Z)gas,and the decrease in flight time by increasing the amount of gas was insignificant.However,both pre-TQ and CQ durations decreased considerably with the increase in gas injection amount.The effect of atomic mass on pre-TQ and CQ durations showed the opposite trend.The observed trend could help in controlling CQ duration in a reasonable area.Moreover,the analysis of radiation distribution with different impurity injections indicated that low Z impurity could reduce the asymmetry of radiation,which is valuable in mitigating plasma disruption.These results provided essential data support for plasma disruption mitigation on EAST and future fusion devices.

Archival Examination of the Change in Packaging Materials of Chemical Injections

Based on the deepening awareness of the risk of changing packaging materials of injections,the national regulatory authorities and the China National Pharmaceutical Packaging Association have issued the relevant guidelines and group standards for changing packaging materials in recent years,greatly improving the research and development and technical requirements of packaging materials of injections.In 2021,Guangdong Province carried out the archival examination of the change of listed drugs,among which the proportion of the acceptance of changed injection packaging materials has increased year by year.On the basis of sorting out the archival examination work and combining with the cases of changing packaging materials of chemical injections accepted by Guangdong Province during 2021-2022,the requirements and problems of archival examination were analyzed and discussed to provide a reference and idea for applicants when studying the change in packaging materials.

Accuracy of shoulder joint injections with ultrasound guidance:Confirmed by magnetic resonance arthrography

BACKGROUND Intra-articular glenohumeral joint injections are essential procedures for treating various shoulder disorders. Fluoroscopy-guided injections have been extensively used;however, they pose a risk of radiation exposure and are expensive and timeconsuming. Recently, it has been suggested that ultrasound-guided injections are accurate and cost effective procedures.AIM To evaluate the accuracy of ultrasound-guided glenohumeral injections using a posterior approach that is confirmed using magnetic resonance arthrography(MRA).METHODS The study included 179 shoulders of patients with recurrent anterior instability(150 patients;103 and 76 right and left shoulders, respectively;160 males and 19 females;average age = 20.5 years;age range: 14-63 years) who underwent MRA for preoperative diagnosis. They were injected with 12 m L lidocaine(1%) using the ultrasound-guided posterior approach and then underwent magnetic resonance imaging. Two shoulder surgeons, except for the injector, evaluated the transverse relaxation(T2)-weighted images of axial planes and classified the intraarticular condition of injected contrast into three groups based on one of the three following scenarios: no leakage, injection into the glenohumeral joint without leakage;minor leakage, practical intra-articular injection with some leakage outside the posterior rotator cuffs;and major leakage, inaccurate injection with mass leakage without any contrast into the joint. The inter-rater reliability between two assessors was also evaluated by calculating Cohen’s kappa coefficient. The learning curve was assessed regarding the inaccurate injection rate by analyzing Spearman’s rank correlation coefficient.RESULTS Of the 179 injections, 163 shoulders(91.0%) had no leakage, 10 shoulders(5.6%) had minor leakage, and six shoulders(3.4%) had major leakage. In total, 173 shoulders(96.6%) were intraarticularly injected;thus, we could detect anterior labrum and capsular pathologies. Regarding the inter-rater reliability, the kappa coefficient was 0.925, indicating consistency in the evaluations by both examiners. Regression analysis of the inaccurate injection rate for assessingtechnical learning showed a logarithmic curve with a downward trend(R;= 0.887, P < 0.001). Three(50%) of the six inaccurate injections classified into “major leakage” were observed in the first 30 injections, indicating that the accurate injection showed a leaning effect.CONCLUSION Ultrasound-guided intra-articular glenohumeral injections using a posterior approach had high accuracy;however, injection accuracy depends on clinical experience.

Intraarticular injections(corticosteroid, hyaluronic acid, platelet rich plasma) for the knee osteoarthritis

Osteoarthritis(OA)is a complex"whole joint"disease pursued by inflammatory mediators,rather than purely a process of"wear and tear".Besides cartilage degradation,synovitis,subchondral bone remodeling,degeneration of ligaments and menisci,and hypertrophy of the joint capsule take parts in the pathogenesis.Pain is the hallmark symptom of OA,but the extent to which structural pathology in OA contributes to the pain experience is still not well known.For the knee OA,intraarticular(IA)injection(corticosteroids,viscosupplements,blood-derived products)is preferred as the last nonoperative modality,if the other conservative treatment modalities are ineffective.IA corticosteroid injections provide short term reduction in OA pain and can be considered as an adjunct to core treatment for the relief of moderate to severe pain in people with OA.IA hyaluronic acid(HA)injections might have efficacy and might provide pain reduction in mild OA of knee up to 24 wk.But for HA injections,the costeffectiveness is an important concern that patients must be informed about the efficacy of these preparations.Although more high-quality evidence is needed,recent studies indicate that IA platelet rich plasma injections are promising for relieving pain,improving knee function and quality of life,especially in younger patients,and in mild OA cases.The current literature and our experience indicate that IA injections are safe and have positive effects for patient satisfaction.But,there is no data that any of the IA injections will cause osteophytes to regress or cartilage and meniscus to regenerate in patients with substantial and irreversible bone and cartilage damage.

Effect of different lens status on intraocular pressure elevation in patients treated with anti-vascular endothelial growth factor injections

AIM: To assess the effect of lens status on sustained intraocular pressure(IOP) elevation in patients treated intravitreally with anti-vascular endothelial growth factor(VEGF) agents. METHODS: Data were retrospectively collected for all patients treated with intravitreal injections of anti-VEGF medication at a tertiary medical center in July 2015. Findings were analyzed by lens status during 6 months' follow-up. The main outcome measure was a sustained increase in IOP(≥21 mm Hg or change of ≥6 mm Hg from baseline on ≥2 consecutive visits, or addition of a new IOPlowering medication during follow-up). RESULTS: A total of 119 eyes of 100 patients met the study criteria: 40 phakic, 40 pseudophakic, and 39 pseudophakic after Nd:YAG capsulotomy. The rate of sustained IOP elevation was significantly higher in the postcapsulotomy group(23.1%) than in the phakic/pseudophakic groups(8.1%;P=0.032), with no statistically significant differences among the 3 groups in mean number of injections, either total(P=0.82) or by type of anti-VEGF mediation(bevacizumab: P=0.19;ranibizumab: P=0.13), or mean follow-up time(P=0.70). CONCLUSION: Nd:YAG capsulotomy appears to be a risk factor for sustained IOP elevation in patients receiving intravitreal anti-VEGF injections. This finding has important implications given the growing use of anti-VEGF treatment and the irreversible effects of elevated IOP.

Long-term treatment with intracavernosal injections in diabetic men with erectile dysfunction

Aim： To assess the behavior of patients with diabetes mellitus （DM） and erectile dysfunction （ED） during 10 consecutive years of treatment with self-injection of vasoactive drugs. Methods： Thirty-eight diabetic men, including 12 with type Ⅰ and 26 with type Ⅱ diabetes, were followed up regularly for 10 years after they began self-injecting for severe ED. Real time rigidity assessment was used for the objective determination of the initial dosage and then doses were regulated in order to introduce an erection suitable for penetration and maintenance of erection for approximately 30 min. Patients were followed up every two months, and doses were increased only when the treatment response was not satisfactory. Results： The number of injections used per year by the patients was reduced each year （mean numbers： 50 in the first year and 22.5 in the 10th） and treatment shifted towards stronger therapeutic modalities （mixtures of vasoactive drugs instead of prostaglandin E1 alone）. Type Ⅰ diabetic men were standardized to a level of treatment as early as 5 years after the initiation of treatment. That level was finally reached by type Ⅱ patients after another 4-5 years. Conclusion： Treatment with self-injections of vasoactive drugs in diabetic men with severe El） is a safe and effective alternative in the long term. Diabetic men of both types show the same preferences in quality and quantity of treatment after 10 years. The key point for maintenance in treatment is the adjustment of the therapeutic method and dosage to optimal levels for satisfactory erections. （Asian J Androl 2006 Mar; 8： 219-224）

Chinese Association for the Study of Pain:Experts consensus on ultrasound-guided injections for the treatment of spinal pain in China(2020 edition)

Spinal pain(SP)is a common condition that has a major negative impact on a patient’s quality of life.Recent developments in ultrasound-guided injections for the treatment of SP are increasingly being used in clinical practice.This clinical expert consensus describes the purpose,significance,implementation methods,indications,contraindications,and techniques of ultrasound-guided injections.This consensus offers a practical reference point for physicians to implement successfully ultrasound-guided injections in the treatment of chronic SP.

Can bedside needle arthroscopy of the ankle be an accurate option for intra-articular delivery of injectable agents?

BACKGROUND Bedside needle arthroscopy of the ankle under local anesthesia has been proposed for intra-articular delivery of injectable agents.Accuracy and tolerability of this approach in the clinical setting–including patients with end-stage ankle pathology and/or a history of prior surgery–is not known.AIM To assess clinical accuracy and tolerability of bedside needle arthroscopy as a delivery system for injectable agents into the tibiotalar joint.METHODS This was a prospective study that included adult patients who were scheduled for an injection with hyaluronic acid to the tibiotalar joint.In our center,these injections are used as a last resort prior to extensive surgery.The primary outcome was injection accuracy,which was defined as injecting through the arthroscopic cannula with intra-articular positioning confirmed by a clear arthroscopic view of the joint space.Secondary outcome measures included a patientreported numeric rating scale(NRS,0-10)of pain during the procedure and willingness of patients to return for the same procedure.NRS of ankle pain at rest and during walking was collected at baseline and at 2-wk follow-up.Complications were monitored from inclusion up to a 2-wk control visit.RESULTS We performed 24 inspection-injections.Eleven(46%)participants were male,and mean age was 46.8±14.5 years.Osteoarthritis was the indication for injection in 20(83%)cases,of which 8(33%)patients suffered from osteoarthritis Kellgren-Lawrence grade IV,and 10(42%)patients from Kellgren-Lawrence grade III.An osteochondral defect was the indication for injection in 4(17%)cases.A history of ankle surgery was present in 14(58%)participants and a history of multiple ankle surgeries in 11(46%)participants.It was possible to confirm accuracy in 21(88%)procedures.The 3(12%)participants where needle arthroscopy did not reach a clear view of the joint space all suffered from Kellgren-Lawrence grade IV osteoarthritis.Pain during the procedure was reported with a median of 1[interquartile ranges(IQR):0–2].Willingness to return was 100%.Pain in rest decreased from a median NRS of 4(IQR:2–7)at baseline to a median of 3(IQR:1–5)at follow-up(P<0.01).Pain during walking decreased from a median NRS of 8(IQR:6–9)to a median of 7(IQR:4–8)(P<0.01).Infections or other complications were not encountered.CONCLUSION Clinical accuracy and tolerability of bedside needle arthroscopy of the ankle as a delivery system for injectable agents are excellent.Accuracy was 100%in patients without total ventral joint obliteration.

Use of High-Resolution Ultrasound (HRU) in the Assessment of Deep Injections of CHAP-Hyaluronic Acid (CHAP-HA) Fillers for Midface Lift

High-resolution ultrasound (HRU) imaging is a useful tool to study hyaluronic acid (HA) filler injection in the face. It is noninvasive, quick, well-tolerated, and can provide in vivo and dynamic information. The formations of pools or pearls in HA fillers could be observed real time during injection. The plane of injection could be determined accurately, and there were no specimen manipulation artifacts. It was observed that HA gel fillers with differing production technologies showed distinct spread and distribution patterns in the periocular tissues on HRU examination. The authors used HRU to assess deep injections of CHAP-Hyaluronic Acid (CHAP-HA) fillers for midface lift. 10 patients who underwent bilateral midface deep injections using CHAP-HA filler were examined with HRU before and immediately after treatment, and in 2 weeks and one month later. The CHAP-HA appeared as hypoechoic densities within the preperiosteal plane in HRU. CHAP-HA adopted variable morphology within the tissue depending on individual tissue densities and the compliance of the tissues in the plane of injection. CHAP-HA was unidentifiable with surrounding tissue after one month in 13 of the 20 injection sites. HRU allows in vivo study of CHAP-HA injection behavior and could be a tool for further studies of HA-tissue reactions.

Prolotherapy Injections for Diastasis Recti: A Case Report

This case report detailed the history and treatment of a female postpartum patient with diastasis recti. Treatment for this patient included the use of prolotherapy, an injection-based therapy using dextrose as the active compound. The solution used during the course of therapy was composed of 6 mL of 50% dextrose, 3 mL of 1% lidocaine, and 1 mL of methylcobalamin (1000 mcg/mL). Injections were administered every 2 weeks for a total of 7 prolotherapy sessions. Following the series of prolotherapy injections, there was a marked closure observed in the diastasis, decreasing from 2.7 cm to 0.5 cm. The patient did not report any side effects, and no complications were observed or recorded. This appears to be the first case report documenting an improvement in abdominal diastasis recti following a course of prolotherapy. Within the limitations of the study design, further research is recommended to evaluate prolotherapy for diastasis recti in postpartum patients.

The 600 keV electron injections in the Earth's outer radiation belt:A statistical study

Relativistic electron injections are one of the mechanisms of relativistic(≥0.5 MeV) electron enhancements in the Earth’s outer radiation belt. In this study, we present a statistical observation of 600 keV electron injections in the outer radiation belt by using data from the Van Allen Probes. On the basis of the characteristics of different injections, 600 keV electron injections in the outer radiation belt were divided into pulsed electron injections and nonpulsed electron injections. The 600 keV electron injections were observed at 4.5 < L <6.4 under the geomagnetic conditions of 450 nT < AE < 1,450 nT. An L of ~4.5 is an inward limit for 600 keV electron injections. Before the electron injections, a flux negative L shell gradient for ≤0.6 MeV electrons or low electron fluxes in the injected region were observed. For600 keV electron injections at different L shells, the source populations from the Earth’s plasma sheet were different. For 600 keV electron injections at higher L shells, the source populations were higher energy electrons(~200 keV at X ~–9 R_(E)), whereas the source populations for 600 keV electron injections at lower L shells were lower energy electrons(~80 keV at X ~–9 R_(E)). These results are important to further our understanding of electron injections and rapid enhancements of 600 keV electrons in the Earth’s outer radiation belt.