[Appropriate selection of multimodal fundus imaging approaches].

With the advancement of science and technology, fundus imaging modalities are rapidly changing and constantly being introduced, playing an important role in the diagnosis and treatment of fundus diseases, as well as in follow-up and prognostic assessment. Clinicians need to update their knowledge and concepts, rationally select a variety of imaging tests for diagnostic and therapeutic purposes, and consider the use of different test protocols in different clinical scenarios. This article summarizes the advantages and limitations of commonly used fundus imaging techniques based on the international research findings and personal clinical experience, with the aim of providing guidance and reference for the rational selection of multimodal fundus imaging approaches in clinical practice.

[Toxic retinopathy caused by veterinary antiparasitic closantel: a case report].

A 32-year-old female patient presented with bilateral vision loss for 2 months following her intake of various antiparasitic drugs, including closantel, a veterinary drug, for a self-perceived intraocular parasitic infection. Swept-source optical coherence tomography revealed diffuse hyperreflectivity between the outer nuclear layer and the retinal pigment epithelium, as well as the largely indistinguishable outer retinal layers. This case was clinically diagnosed with veterinary closantel-induced toxic retinopathy and had a poor visual prognosis after nerve nutrition and circulation improvement therapy due to the long duration of the disease.

[Fundus imaging features of purified protein derivative and T-spot positive tubercular serpiginous-like choroiditis].

Objective: To summarize the clinical and fundus imaging features of purified protein derivative and T-spot positive tubercular serpiginous-like choroiditis (PTP-SLC) patients. Methods: This retrospective study consecutively enrolled 13 PTP-SLC patients (21 eyes) in Beijing Tongren Hospital from November 2015 to November 2017. There were 8 males and 5 females with an average age of (45.2±12.1) years. Medical history and results of systemic and ophthalmological examinations, such us fundus autofluorescence photography, optical coherence tomography (OCT), fluorescein fundus angiography (FFA) and indocyanine green angiography, were evaluated. Results: Eight patients had binocular disease with an average interval time of (8.4±7.9) years. The average visual acuity of all patients was 0.3, and 4 patients had a clear history of exposure to tuberculosis. The active lesions in the PTP-SLC patients were homogeneous and creamish-yellow with unclear boundaries. Fundus autofluorescence showed an ill-defined, diffuse hyperautofluorescent zone. OCT showed punctate hyperreflexes between the choroidal stroma, destruction of the outer retinal structure with intraretinal edema and discrete vitreal hyper-reflective spots. FFA showed hypofluorescence in the active lesion at early stage and diffuse hyperfluorescence with leakage. Indocyanine green angiography showed persistent hypofluorescence. Conclusions: PTP-SLC fundus lesions are mainly manifested as homogeneous creamish-yellow lesions with unclear boundaries and high in autofluorescence. The involvement of the choroid and the outer layer of the retina can be observed on OCT. FFA can find more retinal vascular inflammatory changes. It is difficult to distinguish PTP-SLC from serpiginous choroiditis simply based on clinical and epidemiological characteristics. The pathogenic examination of tuberculosis is still the key to differential diagnosis (Chin J Ophthalmol, 2020, 56: 914-919).

[Identification of pathogens in the vitreous of patients with infectious uveitis by metagenomic sequencing].

Objective: To investigate the role of metagenomic sequencing in the diagnosis of infectious uveitis. Methods: Cross-sectional study. A total of 19 vitreous specimens of patients with suspected infectious uveitis from March 2016 to July 2018 in Beijing Tongren Hospital were collected, including 8 males and 11 females, 19 to 68 years old. There were 10 cases in the right eye, 8 cases in the left eye and 1 case in both eyes. Acute retinal necrosis was clinically diagnosed in 8 patients (9 eyes), and the diagnosis was unknown in 11 patients (11 eyes). About 1 ml of the vitreous fluid was reserved for each specimen, 800 µl for metagenomic sequencing and 200 µl for real-time fluorescence quantitative PCR verification. The TIANamp Micro DNA Kit was used to extract the sample DNA for metagenomic sequencing, and the ultrasonic fragment was broken to 200-300 bp. The BGISEQ-500 platform was used for sequencing. The data with low quality and length less than 35 bp were cleared from the sequencing data to obtain high-quality data. Through biological authentication software, the reference human genome sequence and low complexity were removed from high-quality data. The data obtained were compared with a special microorganism database regarding the percentage of microbial sequences, the number of unique sequences, coverage and sequencing depth, so as to determine positive sequencing parameters, which were classified into bacteria, viruses, fungi and parasites. Real-time fluorescence quantitative PCR was performed to validate the accuracy. Results: A variety of microorganisms were detected by metagenomic sequencing in 19 specimens, including 3 cases of varicella zoster virus, 2 cases of Candida albicans, 1 case of Propionibacterium acnes and 1 case of Haemophilus parainfluenzae. The percentage of microbial sequences was 77.93% （1 794/2 302）, 99.98% （12 843/12 845） and 98.88%（5 733/5 798）, and the number of unique sequences was 1 794, 12 843 and 57 33 in varicella zoster virus cases, respectively. The verification of varicella zoster virus by PCR was consistent with that by metagenomic sequencing. Conclusion: Metagenomic sequencing can be used as an alternative method for laboratory diagnosis of infectious uveitis. (Chin J Ophthalmol, 2020, 56: 519-523).

[Clinical characteristics of patients with biopsy-proven sarcoid uveitis].

Objective: To investigate the clinical features of patients with biopsy-proven sarcoid uveitis. Methods: The clinical data of the patients with biopsy-proven sarcoid uveitis who consulted the Ophthalmic Clinic of Beijing Tongren Hospital from February 2012 to February 2020 was retrospectively reviewed and analyzed. All the patients underwent visual acuity test, slit lamp microscopy, indirect ophthalmoscopy, fundus fluorescein angiography (FFA), chest computed tomography (CT) and other auxiliary examinations. Results: A total of 9 patients (18 eyes) (6 females, 3 males) with biopsy-proven sarcoid uveitis were included in the study, with a mean age of (52.6±9.0) years. Based on the modified Scadding classification, there were 2 and 7 cases of Stage Ⅰ and Ⅱ sarcoidosis, respectively. The ocular symptoms were the initial presenting complaints in 6 patients, who had a time from onset to diagnosis of 9.0 (2.6, 20.3) months. Three patients had a history of sarcoidosis. Fever was reported in 2 patients, fatigue in 3 patients, body weight loss in 3 patients, respiratory problems in 5 patients, with bilateral ocular involvement in all the patients. Among the 18 eyes, panuveitis occurred in 10 eyes, posterior uveitis in 4 eyes, anterior uveitis in 4 eyes, mutton fat keratic precipitates (KP) in 10 eyes, granular KP or no obvious KP in 8 eyes, posterior synechia of the iris in 9 eyes, cataract in 8 eyes, inflammatory vitreous opacity in 8 eyes, macular edema in 7 eyes, epiretinal membrane in 6 eyes, retinal vasculitis in 2 eyes, glaucoma in 2 eyes, and optic disc granuloma in 2 eye. Among the 13 eyes whose peripheral ocular fundus was visible, multiple chorioretinal peripheral lesions were found in 5 eyes. Conclusions: Chest CT should be performed in the uveitis patients with older age, female gender, bilateral ocular involvement, the symptom of fever, body weight loss and respiratory problems in time to exclude the sarcoid uveitis. Sarcoid uveitis may presents with granular KP or no obvious KP, and the posterior segment of the eye ball was the most commonly involved area.

[Clinical analysis and laboratory diagnosis of three cases with infantile botulism caused by Clostridium botulinum type B].

Objective: To summarize the clinical characteristics and laboratory diagnostic methods of infant botulism caused by Clostridium botulinum type B. Methods: Clinical data of 3 infants with type B botulism who were admitted to Children's Hospital Affiliated to Capital Institute of Pediatrics from May to November 2018 were retrospectively analyzed. Botulinum toxin was detected in fecal samples or fecal enrichment solution of the patients, and Clostridium botulinum was cultured and isolated from fecal samples. Results: The age of onset of the patients (two boys and one girl) was 3, 3 and 8 months old, respectively. Two cases had the onset in May and one case had the onset in November. There were two cases with mixed feeding and one case with breast feeding. One case's family members engaged in meat processing. All of them were previously healthy. All the children presented with acute flaccid paralysis, cranial nerve involvement and difficult defecation. Two cases had secondary urinary tract infection. Electromyograms of two cases showed that action potential amplitude of the motor nerve were lower than those of their peers. After treatments including intravenous human immunoglobulin, respiratory tract management, urethral catheterization, nasal feeding, etc., three cases recovered completely 2 to 4 months later. Type B botulinum toxin was detected in the fecal diluent of one patient, and the TPGYT enrichment solution and cooked meet medium of the feces of 3 patients, respectively. Clostridium botulinum B was identified from the feces of 3 infants after culture, isolation and purification. Conclusions: Combined with typical clinical manifestations including acute flaccid paralysis, cranial nerve involvement symptoms and difficult defecation examination, infant botulism can be clinically diagnosed. The detection of fecal botulinum toxin and the culture and isolation of Clostridium botulinum are helpful for the diagnosis.

[Effect of comprehensive health management on the prognosis of children with type â spinal muscular atrophy].

Objective: To analyze the effect of comprehensive health management on the prognosis of children with type Ⅰ spinal muscular atrophy (SMA). Methods: Eighty patients with type Ⅰ SMA (39 males and 41 females) visited-Capital Institute of Pediatrics from January 2003 to December 2017, were enrolled in this case-control study retrospectively. They were divided into the health management group and the natural history group. Main statistical parameter, including demographic indicators, survival time, 2-year survival rate and incidence of complications were compared and analyzed. Patients were evaluated every 3-6 months. All data were processed by SPSS 19.0. Differences between the two groups were compared using rank sum test or chi square test. Survival analysis was performed by using Kaplan-Meier method, and survival difference test was performed by log-rank method. Results: Among 80 SMA patients, 14 cases (7 males and 7 females) were in the health management group and 66 cases (32 males and 34 females) in the natural history group. There was no statistically significant difference in gender ratio between the two groups (χ(2)=0.01,P=0.918) . The ages of onset and death in the two groups were 2 (0-8) and 1 (0-14) month, 11 (5-17) and 6 (1-60) months, without statistically significant difference (Z=0.91, 1.19; P=0.386, 0.116) . As of the follow-up date (June 2019) , 10 patients died and 4 survived in the health management group, while 62 (93.9%) died and 4 (6.1%) survived in the natural history group (χ(2)=6.50,P=0.011) . The median survival time in the health management group was 12 months, and the 1, 2 and 3-year survival rates were 77.9%, 54.5% and 34.1%, respectively. The median survival time of the natural history group was 6 months, and the 1, 2 and 3-year survival rates were 48.5%, 15.2% and 7.6%, respectively. For the two groups, the difference in survival rates was statistically significant (χ(2)=9.11 P=0.003). The incidence rate of pneumonia combined with respiratory failure in the health management group was lower than that in the natural history group. Conclusion: Active health management can improve the survival rate of type Ⅰ SMA patients, reduce the incidence of complications, and also improve the prognosis of patients.

Multifactorial effects of hyperglycaemia, hyperinsulinemia and inflammation on bone remodelling in type 2 diabetes mellitus.

Bones undergo continuous cycles of bone remodelling that rely on the balance between bone formation and resorption. This balance allows the bone to adapt to changes in mechanical loads and repair microdamages. However, this balance is susceptible to upset in various conditions, leading to impaired bone remodelling and abnormal bones. This is usually indicated by abnormal bone mineral density (BMD), an indicator of bone strength. Despite this, patients with type 2 diabetes mellitus (T2DM) exhibit normal to high BMD, yet still suffer from an increased risk of fractures. The activity of the bone cells is also altered as indicated by the reduced levels of bone turnover markers in T2DM observed in the circulation. The underlying mechanisms behind these skeletal outcomes in patients with T2DM remain unclear. This review summarises recent findings regarding inflammatory cytokine factors associated with T2DM to understand the mechanisms involved and considers potential therapeutic interventions.

[Interventional effect of bicyclol on isoniazid-induced liver injury in rats and the expression of glucose-regulated protein 78, and growth arrest and DNA-damage-inducible gene 153].

Objective: To investigate the interventional effect of bicyclol on isoniazid-induced liver injury in rats and the expression of endoplasmic reticulum stress (ERS) protein, glucose regulatory protein 78 (GRP78), and growth arrest and DNA-damage-inducible gene 153(CHOP). Methods: Eighty Wistar rats were randomly divided into control group (8 rats) and model group (72 rats). After 10 days of intragastric administration of isoniazid, the model group rats were randomly divided into treatment group (A), natural recovery group (B), etiological persistence group (C) and etiological persistence plus treatment group (D). Sixteen rats from each group were sacrificed after 1 and 2 weeks of intervention with different methods. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected. Liver pathological morphology was observed. Apoptotic cells were detected by TUNEL assay. ERS protein expression was detected by Western blot. A t-test or randomized block analysis of variance, K-S test and Levene's test were used to analyze the normality and homogeneity of variance. Kruskal-Wallis rank sum test was used for data that did not suit the conditions of t-test and variance analysis. Results: ALT and AST were elevated in the model group, and liver pathological examination showed liver tissue damage. Apoptotic index was higher than control group (7.13% ± 1.55% vs. 0.75% ± 0.71%, Z = -3.411, P < 0.01), and the expression value of ERS protein in model group was significantly higher than control group (GRP78: 1.16 ± 0.30 vs. 0.23 ± 0.05, t = -6.008, P < 0.01; CHOP: 0.98±0.23 vs. 0.20 ± 0.10, t = -6.378, P < 0.01). Serum enzymes, apoptotic index and ERS protein expressions of rats were decreased after treatment with bicyclol, and the pathological damage was eased. Rats in natural recovery group recovered less than the treatment group. Conclusion: Isoniazid-induced liver injury is associated to ERS-related excessive apoptosis and the therapeutic effect of bicyclol on drug-induced liver injury may minimize ERS-induced apoptosis.

[Clinical manifestations and genetics analysis of collagen type â ¥-related myopathy caused by variants in COL6A3 gene].

Objective: To summarize the clinical manifestations and determine the molecular etiology for two collagen type Ⅵ-related myopathy pedigrees. Methods: Two spontaneous collagen type Ⅵ-related myopathy patients were admitted to Department of Neurology, Children's Hospital, Capital Institute of Pediatrics in October 2017. Clinical data of probands and their family members were collected and their genomic DNA was obtained for genetic testing. Next generation sequencing was performed and the variants were verified by the Sanger sequencing in the family members. Results: Target region sequencing indicated that the proband of family 1 has carried a heterozygous variant of COL6A3 gene, c.6229G>C(p.Gly2077Arg), and it was de novo variant confirmed by Sanger-sequencing in the family.The patient 1, a 2-year-three-month old boy, was admitted due to motor retardation at birth. He was defined as early severe Ullrich congenital muscular dystrophy. He never achieved independent ambulation, he had onset of symptoms was found at birth, including diffuse muscle weakness, striking distal joint hyperlaxity, proximal contractures, calcaneal protrusion, kyphosis, and hip dislocation. Serum CK level was elevated slightly and EMG showed neurogenic changes. The patient 2, a 7-year-old girl with a limp for 4 years, carried one de novo variant of COL6A3 gene,c.5169_5177del (p.Glu1724_Leu1726del). This variant results in the deletion of amino acids (1724 to 1726) in α3 chain of collagen Ⅵ, which may disturb the function of this protein.She was diagnosed as Bethlem myopathy with a mild phenotype. She had delayed motor milestones and presented with walking on tiptoe, hypotonia, and ithylordosis. The contracture of proximal joints was not very obvious. Serum CK level was normal and EMG showed myogenic changes.Muscle biopsy revealed muscular dystrophy and muscle magnetic resonance imaging of patient 2 showed vastus lateral is a "sandwich" sign. Immunofluorescence staining for COL6A3 chain in the cultured skin fibroblasts from patients 2 showed decreased deposition compared with control. Conclusions: These two patients were diagnosed as spontaneous collagen type Ⅵ-related myopathy and carried different variants of COL6A3 gene. Different in pathogenetic variants could cause different genetic features and different phenotypes. Collagen type Ⅵ- related myopathy patients have various clinical manifestations. Typical phenotypes include muscular dystrophies, proximal contractures, and distal hyperlaxity. Muscle MRI shows diffuse fatty infiltration of gluteus maximus and thigh muscle. The histological staining showed the low level expression of COL6A3 chain. The seventy of phenotype was related to the genotype.

Velocity-space sensitivity of time-of-flight neutron spectrometer at EAST in deuterium plasma.

The Time-Of-Flight Enhanced Diagnostics (TOFED) neutron spectrometer with a double-ring structure has been installed at the Experimental Advanced Superconducting Tokamak (EAST) to perform advanced neutron emission spectroscopy diagnosis for deuterium plasma. In order to reduce the random coincidence from the background neutrons and gamma-rays, TOFED was moved outside the experimental hall and placed in the newly-built nuclear diagnostics laboratory in 2017. In this paper, the instrument-specific weight functions of TOFED are derived by taking the instrument response matrix and the radial line of sight in this new layout into consideration. The results show that the instrument is predominantly sensitive to counter-passing particles in the region where time-of-flights < 69.4 ns, while events at higher time-of-flights (corresponding lower neutron energies) are mostly representative of co-passing ions. The instrument-specific weight functions express the relationship between data in a given channel of the spectrum and the velocity space region that contributes to that. The results can be applied for energetic particle physics studies at EAST, in particular to compare data from different diagnostic techniques.

[Senile eye disease screening program in downtown Wenzhou: intraocular pressure].

Objective: To investigate the distribution and related factors of intraocular pressure (IOP) in the screened population aged over 50 years in Wenzhou. Methods: This study included 31 170 community residents aged 50 years or older in Wenzhou undergoing screening from March 2014 to January 2016. Participants underwent a complete ocular examination, including visual acuity, eye-ground photography, slit lamp and standardized measurement of IOP by non-contact tonometry. Subjects who had undergone ocular operation or laser peripheral iridectomy, had glaucoma, corneal or other ocular diseases that could possibly affect the IOP, had an IOP lower than 6 mmHg(1 mmHg=0.133 kPa) and visual acuity less than 0.3, or had monocular IOP values were excluded. The relationship between IOP and various parameters were analyzed. Results: A total of 20 875 subjects (6 902 males and 13 973 females) were enrolled in the current analysis, including 18 677 healthy persons and 2 125 glaucoma suspects, with an average age of (67.3±8.7) years old. The mean IOP (mean±standard deviation) of the healthy population was (13.5±3.0) mmHg (13.4±3.2) mmHg in right eyes and (13.6±3.3) mmHg in left eyes; 2.04% of the left eyes, 1.51% of the right eyes and 2.92% of either eyes of healthy population had an IOP >21 mmHg. The mean IOP in glaucoma suspects was significantly higher than that in the healthy population (P<0.001); 6.78% of the left eyes, 6.16% of the right eyes and 9.65% of either eyes of glaucoma suspects had an IOP >21 mmHg. Men had lower IOPs than women [healthy population: (12.9±3.2) mmHg versus (13.7±3.2) mmHg; P<0.05]. The linear function of IOP (Y) with age (X(1)) and the vertical cup disc ratio (X(2)) was ^Y=15.962-0.043X(1)+0.837X(2)(P<0.05) in the healthy population. Conclusion: The IOP among healthy persons aged over 50 years living in downtown Wenzhou was decreased with age but increased with the vertical cup disc ratio. The IOP in females was higher than that in males. About 3% of the healthy population had an IOP greater than 21 mmHg. (Chin J Ophthalmol, 2018, 54: 586-592).

[Analysis on the clinical and retinal imaging characteristics of autosomal recessive bestrophinopathy].

Objective: To study the clinical and imaging features of autosomal recessive bestrophinopathy (ARB). Methods: Retrospective study. The clinical and imaging data of 14 participants were analyzed in using autofluorescence (AF), fluorescein angiography (FA) and spectral-domain optical coherence tomography (SD-OCT). Ten patients were screened for mutations in BEST1 gene. Results: Retinopathy of ARB were shown as bilaterally and circularly distributed yellow subretinal deposits in the mid-peripheral and posterior retina, which was observed more clearly by AF and FA. The abnormalities were observed as hyperreflection between the sub-retinal pigment epithelium space as well as the subretinal space by SD-OCT imaging. All of the patients showed serous retinal detachment, and 4 of them were found to have intraretinal schisis. Other ocular complications include choroidal neovascularization (CNV) and angle closure glaucoma (ACG) were also found in the patients. Genetic examinations showed that the mutations are compound heterozygous in five patients, homozygous in one patient and heterozygous in only one of the rest 4 patients. Conclusions: The combination of clinical and retinal imaging data may facilitate the diagnosis of ARB. Physicians should be cautious of the vision-threatening complications of the disease. (Chin J Ophthalmol, 2018, 54: 263-269).

[A clinical and hereditary analysis of novel complex heterozygous KCNJ1 mutation in a Bartter syndrome type â ¡ patient].

Bartter syndrome (BS) is a hereditary condition transmitted as an autosomal recessive (Bartter type 1 to 4) or dominant trait (Bartter type 5). The disease associates hypokalemic alkalosis with varying degrees of hypercalciuria. Here we presented a case (BS type Ⅱ) of a 17 years old female presented with polyhydramnios, polyuria, nephrocalcinosis and hypokalemia, which was alleviated after treatment with celecoxib and vitamin D(3). DNA sequencing identified compound heterozygous KCNJ1 gene mutations, c. 931C >T (p.R311W) and c. 445-446insCCTGAACAC (p.V149Afs, 150X), with the latter a novel mutation. Her father and mother were heterozygous carriers of c. 931C >T (p.R311W) and c. 445-446insCCTGAACAC (p.V149Afs, 150X), respectively. In conclusion, this case of BS type Ⅱ is caused by a novel compound heterozygous KCNJ1 mutation. Further studies are needed to verify the effect of celecoxib in BS patients.

[The clinical manifestations and imaging characteristics of acute syphilitic posterior placoid chorioretinitis].

Objective: To investigate the clinical manifestations and imaging characteristics of acute syphilitic posterior placoid chorioretinitis (ASPPC). Methods: Retrospective study of 10 patients diagnosed ASPPC in the Department of Ophthalmology, Beijing Tongren Hospital from 2011 to 2016, including 6 males (10 eyes involved) and 4 females (8 eyes involved) with an age of (43.4±11.6) years (range, 26-60 years). Their clinical manifestations and imaging characteristics were summarized. Results: All 10 ASPPC patients complained about the reduction of visual acuity, and the majority of them had both eyes involved. The initial visual acuity ranged from finger count to 0.8, with an average of 0.4 and a median visual acuity of 0.3. The intraocular pressure was in the normal range. The inflammation of anterior chamber occurred in only one patient (1/10). The lesions were located at the posterior pole as shown on fundus photographs. There are six placoid lesions, four yellowish massive lesions and seven mixed lesions (placoid and yellowish massive lesions). Partial or whole disappearance, abnormality and opacity of the ellipsoid layer, retinal pigment epithelial (RPE) nodules, and cells in the vitreous body were observed by optical coherence tomography. There were partial detachment between the neuronal retina and RPE layer with fine-sand like hypereflective dots. The lesion size and morphology on autofluorescence (AF), fundus fluorescence angiography (FFA) and indocyanine green angiography (ICG) were almost consistent with those on fundus photography. The lesions were hyperautofluorescent in a placoid or massive shape. The lesions on FFA showed slight hyperfluorescence with unclear edges from the venous phase, and the fluorescence increased with the time and leaked in the late phase. Vascular walls showed blood staining in the late phase. The lesions on ICG showed hypofluorescence with hyperfluorescence and hypofluorescence dots like fine needles in the middle and late phases. Conclusion: ASPPC mainly occurs among the young adults without gender difference. The characteristic is the contradiction between sever clinical symptoms and slight signs on the fundus. The lesion area shown on fundus photography, FFA, ICG and AF is consistent, as well as injuries of the ellipsoid layer, RPE nodules and cells in the vitreous body. The above manifestations and imaging characteristics of ASPPC are significant for the diagnosis and differential diagnosis. (Chin J Ophthalmol, 2017, 53:352-357).

Dynamic intracellular tracking nanoparticles via pH-evoked "off-on" fluorescence.

Dynamic tracking of nanoparticles in cells faces a big challenge due to fluorescence quenching. Here, the pH-switchable probe spiropyran (SP) was introduced into poly(ethylene glycol) (PEG) via atom transfer radical polymerization (ATRP) to construct expected "off-on" fluorescent nanoparticles. Strong red fluorescence was emitted to efficiently track nanoparticles in cells due to the isomerization of spiropyran to merocyanine in the endosome or lysosome.

Response function of single crystal synthetic diamond detectors to 1-4 MeV neutrons for spectroscopy of D plasmas.

A Single-crystal Diamond (SD) detector prototype was installed at Joint European Torus (JET) in 2013 and the achieved results have shown its spectroscopic capability of measuring 2.5 MeV neutrons from deuterium plasmas. This paper presents measurements of the SD response function to monoenergetic neutrons, which is a key point for the development of a neutron spectrometer based on SDs and compares them with Monte Carlo simulations. The analysis procedure allows for a good reconstruction of the experimental results. The good pulse height energy resolution (equivalent FWHM of 80 keV at 2.5 MeV), gain stability, insensitivity to magnetic field, and compact size make SDs attractive as compact neutron spectrometers of high flux deuterium plasmas, such as for instance those needed for the ITER neutron camera.

Neutron emission spectroscopy of DT plasmas at enhanced energy resolution with diamond detectors.

This work presents measurements done at the Peking University Van de Graaff neutron source of the response of single crystal synthetic diamond (SD) detectors to quasi-monoenergetic neutrons of 14-20 MeV. The results show an energy resolution of 1% for incoming 20 MeV neutrons, which, together with 1% detection efficiency, opens up to new prospects for fast ion physics studies in high performance nuclear fusion devices such as SD neutron spectrometry of deuterium-tritium plasmas heated by neutral beam injection.