Salvage mandibular reconstruction: multi-institutional analysis of 17 patients

Unsuccessful mandibular reconstruction occasionally occurs, leaving the patient with undesirable function and contours. In such cases, second- or third-time corrective operations are challenging. However, published studies on the complicated retreatment of such patients are scarce. A retrospective analysis covering the years 2015-2019 was conducted in three centers. All 17 patients included had undergone prior failed mandibular reconstructions in other institutions. Salvage secondary or tertiary reconstructive surgeries were attempted and the results are presented. Major factors for these failed reconstructions included exposed non-vascularized bone grafts (n = 7, 41.2%), flap loss (n = 4, 23.5%), exposed artificial joint (n = 3, 17.6%), skewed occlusion with deformity (n = 1, 5.9%), non-union (n = 1, 5.9%), and recurrence (n = 1, 5.9%). Fibula flaps were transferred in 15 patients, while iliac flaps were used in two patients for mandibular re-do reconstructions. Virtual surgical designs were conducted in nine (52.9%) patients, with navigation-guided approaches performed in three cases. Postoperative functions were relatively favorable in these complicated mandibular re-do reconstruction cases. Mandibular symmetry (mandibular length and height; P = 0.002) and condylar position (P < 0.001) were regained after these re-do attempts. Secondary or tertiary mandibular re-do reconstruction can still achieve good functional outcomes with appropriate preoperative selection and well-conceived designs, especially with the aid of virtual surgery and navigation.

Combined analysis of metagenomic data revealed consistent changes of gut microbiome structure and function in inflammatory bowel disease

AIMS

To reveal the consistency and discrepancy in the gut microbial structure and function in inflammatory bowel disease (IBD) patients from different regions.

METHODS AND RESULTS

Gut microbes, antibiotic resistance genes (ARGs) and virulence factors genes (VFGs) were analysed using metagenome data from three cohorts. The abundance of Escherichia coli extensively increased in IBD patients, whereas Subdoligranulum unclassified decreased dramatically in IBD patients from three countries. Escherichia coli showed a positive correlation with multiple ARGs and VFGs in cohorts from China and the United States, including multidrug-related resistance genes and Capsule and LOS-related virulence factors genes. Escherichia coli biofilm synthesis pathways significantly enriched in IBD patients from three different regions. Notably, Subdoligranulum unclassified and Eubacterium hallii were negatively related to ARGs and VFGs.

CONCLUSIONS

Consistent changes of microbiome structure and function were observed in IBD patients from three different regions. As pathogenic bacteria, E. coli may accelerate IBD progression through encapsulation in biofilms by upregulating antibiotic resistance in Crohn's disease patients. Subdoligranulum unclassified and E. hallii may be beneficial for IBD patients and could serve as potential probiotics for IBD treatment.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work dispels worries about the regional differences in gut microbial changes in IBD patients and provides useful guidance for more rational microbiome-based therapies.

Genome sequencing of pancreatic cancer: differential expression by location

The results demonstrated that pancreatic ductal carcinoma (PDAC) of the body/tail was associated with more transcriptional and genomic changes, and correlated with worse prognosis, than PDAC of the pancreatic head. The different mutation types and gene expression of tumour locations provide deep insight into the carcinogenesis or metastasis of PDAC, and suggest different early diagnostic and therapeutic strategies. SNV, single-nucleotide variations; NLS, Nuclear localization sequence; MB, million base-pairs; UTR, untranslated region.

Dark Energy Survey Year 1 Results: Cosmological Constraints from Cluster Abundances, Weak Lensing, and Galaxy Correlations

We present the first joint analysis of cluster abundances and auto or cross-correlations of three cosmic tracer fields: galaxy density, weak gravitational lensing shear, and cluster density split by optical richness. From a joint analysis (4×2pt+N) of cluster abundances, three cluster cross-correlations, and the auto correlations of the galaxy density measured from the first year data of the Dark Energy Survey, we obtain Ω_{m}=0.305_{-0.038}^{+0.055} and σ_{8}=0.783_{-0.054}^{+0.064}. This result is consistent with constraints from the DES-Y1 galaxy clustering and weak lensing two-point correlation functions for the flat νΛCDM model. Consequently, we combine cluster abundances and all two-point correlations from across all three cosmic tracer fields (6×2pt+N) and find improved constraints on cosmological parameters as well as on the cluster observable-mass scaling relation. This analysis is an important advance in both optical cluster cosmology and multiprobe analyses of upcoming wide imaging surveys.

Tobacco smoking confers risk for severe COVID-19 unexplainable by pulmonary imaging

BACKGROUND

COVID-19 is a new pneumonia. It has been hypothesized that tobacco smoking history may increase severity of this disease in the patients once infected by the underlying coronavirus SARS-CoV-2 because smoking and COVID-19 both cause lung damage. However, this hypothesis has not been tested.

OBJECTIVE

Current study was designed to focus on smoking history in patients with COVID-19 and test this hypothesis that tobacco smoking history increases risk for severe COVID-19 by damaging the lungs.

METHODS AND RESULTS

This was a single-site, retrospective case series study of clinical associations, between epidemiological findings and clinical manifestations, radiographical or laboratory results. In our well-characterized cohort of 954 patients including 56 with tobacco smoking history, smoking history increased the risk for severe COVID-19 with an odds ratio (OR) of 5.5 (95% CI: 3.1-9.9; P = 7.3 × 10^-8 ). Meta-analysis of ten cohorts for 2891 patients together obtained an OR of 2.5 (95% CI: 1.9-3.3; P < 0.00001). Semi-quantitative analysis of lung images for each of five lobes revealed a significant difference in neither lung damage at first examination nor dynamics of the lung damage at different time-points of examinations between the smoking and nonsmoking groups. No significant differences were found either in laboratory results including D-dimer and C-reactive protein levels except different covariances for density of the immune cells lymphocyte (P = 3.8 × 10^-64 ) and neutrophil (P = 3.9 × 10^-46 ).

CONCLUSION

Tobacco smoking history increases the risk for great severity of COVID-19 but this risk is achieved unlikely by affecting the lungs.

[Investigation of 603 medical staff occupational exposure with blood-borne pathogens]

Objective: To investigate the occupational exposure with blood-borne pathogens of medical staff, and explore the protective strategy. Methods: Using cluster sampling method, 603 medical staff with occupational exposure with blood-borne pathogens were analyzed, from July 2014 to July 2018 in a tertiary hospital. Results: In total of 603 occupational exposure incidents, 70.98% (428/603) were freshmen younger than 30 years old. 48.92% (295/603) nurses. The most cases of occupational exposure were in surgery (35.16%, 212/603) . Sharp injury was the major contact manner (86.90%, 524/603) . Hands were the main contact parts (90.38%, 545/603) . Ward (53.57%, 323/603) and the operating room (22.72%, 137/603) were the high-risk place. The most dangerous actions were needle injection (34.83%, 210/603) , surgery (20.89%, 126/603) and finishing/cleaning items (19.73%, 119/603) . The main items lead to injuries were scalp needles (34.73%, 182/524) . The most exposure source was hepatitis B virus (HBV) which occupied 39.30% (237/603) . Exposure source mainly comes from medical devices containing blood (81.92%, 494/603) . To compared the groups (χ(2)=19.940, P<0.01) and titer (t=-8.592, P<0.01) of hepatitis B surface antibody (HBsAb) before and after used prophylactics, the differences were statistically significant. Conclusion: Comprehensive strategies of occupational exposure protection education, operation norms and monitoring management were effective methods to reduce the occupational exposure in the medical staff with blood-borne pathogens.

Increased expression of CXCL2 in ACPA-positive rheumatoid arthritis and its role in osteoclastogenesis

Anti-citrullinated protein/peptide antibodies (ACPA) play important roles in the pathogenesis of rheumatoid arthritis (RA). ACPA-positive (ACPA⁺ ) and ACPA-negative (ACPA^- ) RA were suggested to be different disease subsets, with distinct differences in genetic variation and clinical outcomes. The aims of the present study were to compare gene expression profiles in ACPA⁺ and ACPA^- RA, and to identify novel candidate gene signatures that might serve as therapeutic targets. Comprehensive transcriptome analysis of peripheral blood mononuclear cells (PBMCs) from ACPA⁺ and ACPA^- RA patients and healthy controls was performed via RNA sequencing. A validation cohort was used to further investigate differentially expressed genes via polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). Spearman's correlation test was used to evaluate the correlation of differentially expressed genes and the clinical and laboratory data of the patients. The role of differentially expressed genes in osteoclastogenesis was further investigated. Expression of C-X-C motif chemokine ligand 2 (CXCL2) was significantly increased in ACPA⁺ RA than in ACPA^- RA, which was validated in PBMCs and serum. CXCL2 promoted the migration of CD14⁺ monocytes and increased osteoclastogenesis in RA patients. RAW264.7 macrophages were used to investigate specific mechanisms, and the results suggested that CXCL2 stimulated osteoclastogenesis via extracellular receptor kinase (ERK) mitogen-activated protein kinase (MAPK) and nuclear factor kappa B pathways. In conclusion, CXCL2 was highly expressed in ACPA⁺ RA than in ACPA^- RA. CXCL2 promoted osteoclastogenesis and was related to bone erosion in RA, which suggests that the blockade of CXCL2 might be a novel strategy for the treatment of RA.

Gut dysbacteriosis and intestinal disease: mechanism and treatment

The gut microbiome functions like an endocrine organ, generating bioactive metabolites, enzymes or small molecules that can impact host physiology. Gut dysbacteriosis is associated with many intestinal diseases including (but not limited to) inflammatory bowel disease, primary sclerosing cholangitis-IBD, irritable bowel syndrome, chronic constipation, osmotic diarrhoea and colorectal cancer. The potential pathogenic mechanism of gut dysbacteriosis associated with intestinal diseases includes the alteration of composition of gut microbiota as well as the gut microbiota-derived signalling molecules. The many correlations between the latter and the susceptibility for intestinal diseases has placed a spotlight on the gut microbiome as a potential novel target for therapeutics. Currently, faecal microbial transplantation, dietary interventions, use of probiotics, prebiotics and drugs are the major therapeutic tools utilized to impact dysbacteriosis and associated intestinal diseases. In this review, we systematically summarized the role of intestinal microbiome in the occurrence and development of intestinal diseases. The potential mechanism of the complex interplay between gut dysbacteriosis and intestinal diseases, and the treatment methods are also highlighted.

Role of MK2 signaling pathway mediating microglia/macrophages polarization in chronic compression injury of cervical spinal cord

BACKGROUND

The role of inflammatory factors in the chronic compression injury of cervical spinal cord has drawn more attenion recently, however, the mechanism of which is still unclear. In this study, microglia/ macrophages polarization in the inflammatory responses to the injury and its regulation by MK2 signaling pathway have been investigated.

METHODS

twy/twy mice at the age of 6-24 weeks were used in the animal model for the chronic compression of cervical spinal cord. ICR (Institute of Cancer Research) mice were used as the control group. MK2 inhibitor (PF-3644022, 30 mg/kg) was administrated intragastrically to twy/twy mice from weeks 20 to 24. The compression of cervical spinal cord was identified by CT/MRI. The cervical spinal cord between C2 and C3 of vertebral segments were investigated by Western blot and Real-time PCR. The animal behaviors were evaluated by BMS score.

RESULTS

Western blot and Real-time PCR showed that the expressions of iNOS and Arg-1 in the compressed spinal cord of twy/twy mice were significantly higher than those of the control group. After treatment with PF-3644022, the expression of Arg1 was increased while that of iNOS decreased. Realtime PCR revealed the increased expressions of inflammation related factors (such as IL-1β, NF-κB, TNF-α, MK2) and pro-apoptotic gene (Bax) except the decreased expression of anti-apoptotic gene (Bcl-2). Nevertheless, such increases were vanished after treatment of PF-3644022 except an increased expression of Bcl-2. The BMS score showed a reduced motor function of the twy/twy mice. The motor function was enhanced again with the treatment of PF-3644022.

CONCLUSIONS

Microglia/macrophages polarization may be involved in the inflammatory response to the chronic compression of cervical spinal cord. It can be regulated by the MK2 signaling pathway. Therefore, it is possible to relieve the chronic compression of cervical spinal cord by regulating microglia/macrophages polarization through MK2 signaling pathway.

[Blood pressure control and influencing factors in hypertension patients with metabolic syndrome]

Objective: To investigate the blood pressure control and its influencing factors in hypertension patients with MS. Methods: Between January 2017 and December 2018, more than 78 000 residents aged 35-75 years selected through convenient sampling were invited to participant in China Patient-Centered Evaluative Assessment of Cardiac Event Million Persons Project in Fujian province, physical and laboratory tests were conducted for them, and their basic information were recorded. A total of 5 281 hypertension patients with MS were included in the study. Results: The treatment rate of hypertension patients with MS was 55.5%, and the control rate was 7.2%. The control rate was higher in patients who were older, women, had advanced education level, had history or family history of cardiovascular disease. The results of multivariate analysis indicated that living area (urban or rural), cardiovascular history, diabetes, urine protein, BMI had impacts on both treatment and control of hypertension. Family history of cardiovascular disease, age, self-management of hypertension, dyslipidemia, waist circumference and drinking had impacts on the treatments, and gender had effects on the control. Conclusions: The treatment rate of hypertension patients with MS was unsatisfactory and the control rate was low. Intervention should be strengthened in rural area, males and young age groups, and activity of self-management group of hypertension should be conducted regularly.

A numerical study of spin torque oscillators based on IMA/PMA bilayer nano-pillars

In this paper, the magnetization dynamics of bilayer structured nano-pillars containing a fixed layer with perpendicular magnetic anisotropy (PMA) and a free layer with in-plane magnetic anisotropy (IMA) are studied using the micro-magnetic simulation method. Unlike typical sandwich-structured spin-torque nano-pillar oscillators (STNOs), the proposed structure does not contain any nonmagnetic spacer layer. It is found that a stable oscillation with a significant amplitude can be established fast after driving out the vortex core by an in-plane magnetic pulse field. The oscillation frequency and amplitude can be easily manipulated by adjusting the side-length of the nanopillar, the thickness and saturation magnetization of the IMA layer, and an applied magnetic field along z axis. In an array with an adequate inter-pillar distance, the mutual interaction between the nano-pillars will lead the oscillations to be phase-locked, resulting in a considerable enhancement of total amplitude. As it is easy to fabricate these kinds of bi-layer nano-pillars and assemble them in arrays, they may have widespread applications in STNOs.

Detecting the presence of bacterial RNA by polymerase chain reaction in low volumes of preoperatively aspirated synovial fluid from prosthetic joint infections

Aims

Preoperative diagnosis is important for revision surgery after prosthetic joint infection (PJI). The purpose of our study was to determine whether reverse transcription-quantitative polymerase chain reaction (RT-qPCR), which is used to detect bacterial ribosomal RNA (rRNA) preoperatively, can reveal PJI in low volumes of aspirated fluid.

Methods

We acquired joint fluid samples (JFSs) by preoperative aspiration from patients who were suspected of having a PJI and failed arthroplasty; patients with preoperative JFS volumes less than 5 ml were enrolled. RNA-based polymerase chain reaction (PCR) and bacterial culture were performed, and diagnostic efficiency was compared between the two methods.According to established Musculoskeletal Infection Society (MSIS) criteria, 21 of the 33 included patients were diagnosed with PJI.

Results

RNA-based PCR exhibited 57.1% sensitivity, 91.7% specificity, 69.7% accuracy, 92.3% positive predictive value, and 55.0% negative predictive value. The corresponding values for culture were 28.6%, 83.3%, 48.5%, 75.0%, and 40.0%, respectively. A significantly higher sensitivity was thus obtained with the PCR method versus the culture method.

Conclusion

In situations in which only a small JFS volume can be acquired, RNA-based PCR analysis increases the utility of preoperative puncture for patients who require revision surgery due to suspected PJI.

Cite this article:Bone Joint Res. 2020;9(5):219–224.

THU0048 THE FUNCTION CHANGES OF SNPS IN THE P2X7 RECEPTOR BY ALA348TO THR, GLU496TO ALA AND ARG307TO GLN IN THP-1 CELLS WITH HIGH URIC ACID

Background:

Previous studies[1] have shown that ATP acts on the sputum receptor P2X ligand-gated ion channel 7 (P2X7R) as a second signal to induce gouty arthritis.

Objectives:

In this study, the functional changes of three SNP genotypes, Ala348 to Thr, Glu 496 to Ala and Arg307 to Gln, in P2X7R were analyzed with high uric acid.

Methods:

After transfection of HEK-293T cells by lentivirus, observing the uptake ability of HEK-293T cells to ethidium bromide. The effect of three different mutants on the P2X7 receptor was thus observed on the P2X7 channel. In addition, THP-1 cells were also transfected, stable expression of a THP-1 cell line that has been transfected with a wild-type or different mutants and thus established. Then three types were set up separately, and each type was randomized into three groups: MSU(labeled M), MSU+ATP (labeled MA), and unstimulated control group (labeled C).Detection of IL-1β protein expression level in serum by ELISA and NLRP3, ASC and Caspase-1 mRNA levels in transfected THP-1 cells by qRT-PCR.

Results:

1.These three variants have different effects on the uptake function of ATP-induced ethidium+bromide in transfection of HEK-293T cells by lentivirus. Ala348to Thr increased P2X7-dependent ethidium+bromide uptake (145% of wild-type P2X7response, P<0.001). In contrast, Absent or very reduced P2X7function was found in Glu496to Ala and Arg307to Gln subjects, appeared to abolish P2X7-dependent dye uptake (38% and 32% of wild-type P2X7responses, P<0.001,), who were compared with wild-type.

2.Compared the IL-1β levels of the three variants with the wide-type and empty virus in THP-1 cells, the Ala348to Thr mutation significantly up-regulated the serum levels of IL-1β compared with the wide-type and empty virus in group MA with high uric acid (P=0.0007;P=0.013, respectively). Moreover, similar results have also been shown in IL-1β mRNA expressions (P=0.0334; P=0.0307, respectively). The Glu496to Ala and Arg307to Gln mutations down-regulated the serum levels of IL-1β compared with the wide-type in group MA (P=0.0189;P=0.0164, respectively).

3.NLRP3 mRNA was significantly increased in the Ala348to Thr mutation compared with the wide-type and empty virus in group MA (p =0.0003;P=0.0001, respectively). However, NLRP3 mRNA was significantly reduced in the Glu496to Ala and Arg307to Gln mutations compared with the wide-type in group MA (p =0.0294;P=0.0279, respectively).

4.Wild-type was signifcantly higher than empty virus in the ASC gene expression in group MA(P=0.0022). Morever, the Ala348to Thr mutation was higher than empty virus while Arg307to Gln mutation was lower than that in group MA (P=0.0138;P=0.0283, respectively).

5.Unlike NLRP3 gene expression, the data showed that the expression of caspase-1 mRNA in group C, M and MA all with no statistical significance, respectively (P>0.05).

Conclusion:

Our data revealed that Ala348to Thr up-regulate the functional status of P2X7R and Glu496to Ala and Gln460to Arg down-regulate the functional status of P2X7R, which resulted in a significant increase or decrease in IL-1β and NLRP3 expression levels with high uric acid.

References:

[1]Tao JH, Zhang Y, Li XP, et al. P2X7R: a potential key regulator of acute gouty arthritis[J].Semin Arthritis Rheum, 2013,43(3):376–380.

Disclosure of Interests:

None declared

Abstracts of published randomised controlled trials in Endodontics: Reporting quality and spin

AIMS

To assess the reporting quality of recently published randomised controlled trial (RCT) abstracts in Endodontics, to investigate factors associated with reporting quality, and to evaluate the existence and characteristics of spin. Spin refers to reporting strategies that distort study results and misguide readers.

METHODOLOGY

The PubMed database was searched to identify abstracts of RCTs in the field of Endodontics published during 2017 to 2018. Two authors assessed the reporting quality of each included abstract using the original 16-item CONSORT for Abstracts checklist, with the overall quality score (OQS, range: 0 to 16) being the primary outcome measure. For each individual item, a score of '1' was given if it was described adequately, and '0' if the description was inadequate. Linear regression analyses were conducted to identify factors associated with reporting quality. For the evaluation of spin, two authors selected parallel-group RCTs with a nonsignificant primary outcome from the included abstracts, and evaluated independently the existence and characteristics of spin among these abstracts.

RESULTS

A total of 162 abstracts were included for assessment of reporting, for which the mean OQS was 3.97 (SD, 1.30; 95 % CI, 3.77 to 4.17). According to multivariable analysis, origin from Europe (P=0.001) and reporting of the exact P value (P=0.020) were significantly associated with better reporting. Forty abstracts with statistically nonsignificant results for their primary outcome were included for spin evaluation, among which 34 (85.0%) had at least one type of spin. Thirty-two abstracts (94.1%) had spin in their conclusions section, and six abstracts (17.6%) had spin in the results section.

CONCLUSIONS

The reporting quality of RCT abstracts in Endodontics needs to be improved. The occurrence rate of spin in the sample of abstracts of RCTs in the field of Endodontics was high. Relevant stakeholders are recommended to be familiar with the CONSORT for Abstracts guideline and develop active strategies to ensure its implementation.

Use of the Veggie Meter® as a tool to objectively approximate fruit and vegetable intake among youth for evaluation of preschool and school-based interventions

BACKGROUND

Reflection spectroscopy is an emerging, non-invasive objective measure used to approximate fruit and vegetable intake. The present study aimed to use a reflection spectroscopy device (the Veggie Meter®, Longevity Link Corporation, Salt Lake City, UT, USA) to assess skin carotenoid status in preschool, middle- and high-school students and to examine associations between skin carotenoids and self-reported dietary intake.

METHODS

In Autumn 2018, we used the Veggie Meter® to assess skin carotenoids and age-appropriate validated dietary assessment measures to approximate fruit and vegetable (FV) intake. Preschool participants completed a previously validated pictorial liking tool using an iPad (Apple Inc., Cupertino, CA, USA). Middle-school participants completed selected questions from the validated School Physical Activity and Nutrition (SPAN) (Michael & Susan Dell Center for Healthy Living, University of Texas, Austin, TX, USA) questionnaire regarding frequency of their FV and beverage intake on the previous day, with additional questions about physical activity. High-school participants' FV intake was assessed using the Fruit and Vegetable Screener (National Cancer Institute, Bethesda, MD, USA). Spearman correlation coefficients were used to determine bivariate associations between measures of dietary intake and Veggie Meter®-assessed skin carotenoid levels.

RESULTS

Mean (SD) Veggie Meter® readings were 266 (82.9), 219 (68.1) and 216 (67.2) among preschool, middle- and high-school students. There was an inverse association between soda intake and Veggie Meter® readings (r = -0.22, P = 0.03) among middle-school students; and a positive association between daily fruit intake and Veggie Meter® readings (r = 0.25, P = 0.06) among high-school students.

CONCLUSIONS

The Veggie Meter® comprises a promising evaluation tool for preschool and school-based nutrition interventions.

An electromagnetic separation system for the enrichment of 39Ar

An isotope enrichment system for ³⁹Ar has been developed at the Institute of Modern Physics, which is designed to increase the abundance of ³⁹Ar in the incident sample gas. With intense Ar⁺ beams produced by a 2.45 GHz electron cyclotron resonance ion source and a high mass resolution spectrometer system, Ar isotopes are evidently separated on the target plane and selectively collected by an Al target. The separated Ar isotopes have been identified on the target plane, which is consistent with the simulations. According to the recent cross-checked results with atom trap trace analysis, a high enrichment factor of ³⁹Ar has been successfully achieved. This paper will present the design and test results of this system.

Overview of high intensity ion source development in the past 20 years at IMP

Ion source development over the last 20 years at the IMP is reviewed. For versatile purposes, several types of ion sources have been involved in the research and development work at the IMP, i.e., the highly charged ECR (Electron Cyclotron Resonance) ion source, intense microwave ion source or the 2.45 GHz intense beam ECR ion source, and laser ion source (LIS). In the development of ECR ion sources, SECRAL (Superconducting ECR ion source with Advanced design in Lanzhou), Lanzhou ECR ion source, and Lanzhou all permanent magnet ECR ion source series have been made, which can cover the operation microwave frequency range of 10-28 GHz. The LIS with an Nd:YAG laser with a maximum output energy of 8 J in 8 ns pulse duration has been developed for very intense short pulse ion beams from solid materials such as C, Ti, Ni, Ag, and so on. Microwave ion sources have been built to produce intense pulsed or direct current beams from several mA to 100 mA for either high intensity accelerators or applications. This paper will give an overview of the high intensity ion source development at the IMP, especially on the recent progress and new results, such as the status of the fourth generation ECR ion source (first fourth generation ECR ion source), the production of recorded highly charged ion beams with SECRAL sources, key technology research studies, and so on.

A new room temperature LECR5 ion source for the SESRI project

The Space Environment Simulation and Research Infrastructure project, which uses various ion beams as irradiated materials in life science research, is being built at the Harbin Institute of Technology. A new room temperature electron cyclotron resonance ion source, the Lanzhou Electron Cyclotron Resonance Ion Source No. 5 (LECR5), has been designed and constructed. It is an intense, highly charged, heavy ion beam injector which generates ion beams from H to Bi, typically ∼50 eμA ²⁰⁹Bi³²⁺. The LECR5 is designed to operate at microwave frequencies in the range of 14.5-18 GHz. The typical magnetic parameters are designed based on those optimized for SECRAL, which operates at 18 GHz. This paper presents the LECR5 ion source, its test bench, and the preliminary beam results.