Optimising diffusion-weighted imaging of the thyroid gland using dedicated surface coil

AIM

To assess the feasibility of applying field-of-view (FOV) optimised and constrained undistorted single-shot (FOCUS) diffusion-weighted imaging (DWI) in the thyroid gland by comparing its image quality with conventional DWI (C-DWI) qualitatively and quantitatively using a dedicated surface coil exclusively designed for the thyroid gland at 3 T magnetic resonance imaging (MRI).

MATERIALS AND METHODS

In this prospective study, 32 healthy volunteers who had undergone 3 T the thyroid gland MRI with FOCUS-DWI and C-DWI were enrolled. Two independent reviewers assessed the overall image quality, artefacts, sharpness, and geometric distortion based on a five-point Likert scale. The signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and apparent diffusion coefficient (ADC) were quantified for both sequences. Interobserver agreement, qualitative scores, and quantitative parameters were compared between two sequences.

RESULTS

Agreement between the two readers was good for FOCUS-DWI (κ = 0.714-0.778) and moderate to good for C-DWI (κ = 0.525-0.672) in qualitative image quality assessment. Qualitatively, image quality (overall image quality, artefacts, sharpness, and geometric distortion) was significantly better in FOCUS-DWI than that in the C-DWI (all p<0.05); however, quantitatively, FOCUS-DWI had significantly lower SNRs (p<0.001) and CNRs (p=0.012) compared with C-DWI. The ADC value on FOCUS-DWI was significantly higher than that on C-DWI (p<0.001).

CONCLUSION

FOCUS-DWI depicted the thyroid gland with significantly better image quality qualitatively and less ghost artefacts, but had significantly lower SNR and CNR quantitatively, compared with C-DWI, suggesting that both DWI sequences have advantages and could be chosen for different purposes.

In 18F-positron emission tomography/computed tomography-guided precision radiotherapy for centrally located non-small cell lung cancer, tumor related atelectasis is a prognostic factor of survival

Purpose

Tumor related atelectasis(TRA) is an essential factor affecting survival that can cause chest pain, cough, hemoptysis, chest tightness, dyspnea, and even death. In the current study, we explored the possible impact of TRA on survival in cancer patients and the guiding significance of 18F-positron emission tomography/computed(PET/CT) in radiotherapy for patients with atelectasis tumors.

Methods

In this retrospective study, we analyzed the treatment model and survival of patients with centrally located non-small cell lung cancer(NSCLC) treated with radiotherapy at two medical centers between May 2005 and August 2019. We identified 152 eligible patients and used propensity score matching (1:1) to process the data to reduce confounding factors, data bias, and mal-distribution.

Results

We used propensity scores created well-matched groups of 57 patients overall with or without TRA. The one-year survival rate of all patients was 71.9%, and the two-year survival rate was 33.3%. Compared to the atelectasis group, the overall survival (OS) of patients in the non-atelectasis group was significantly prolonged (25 months vs. 17 months, p = 0.004), as well as in the atelectasis recovery group (28 months vs. 14 months, p = 0.008). In multivariate analysis, non-atelectasis was closely correlated with favorable OS (HR, 1.804 (−2.840); 95% CI, 1.145–2.840; p = 0.011).

Conclusion

PET/CT can accurately stage NSCLC and better guide the treatment of NSCLC complicated with atelectasis. Tumor-associated atelectasis in patients with centrally located NSCLC can lead to is a poor prognostic marker.

[IL-1β inhibitor sensitizes to olaparib in homologous recombination deficiency proficient ovarian cancer cells]

Objective: To investigate the inhibitory effect of combined strategy of poly adenosine diphosphate ribose polymerase (PARP) inhibitor and interleukin-1β (IL-1β) inhibitor on homologous recombination deficiency (HRD)-proficient ovarian cancer cells. Methods: (1) HRD-proficient ovarian cancer cell lines OVCAR3 and CAOV3 were treated with PARP inhibitor olaparib. Screening by RNA sequencing analysis, the expression level of IL-1β was validated by enzyme-linked immunosorbent assay (ELISA) and western blot. (2) The dose-response curves of IL-1β inhibitor diacerein were evaluated by cell counting kit-8 (CCK-8) assays in OVCAR3 and CAOV3 cells. CCK-8 assays were further applied to determine the viabilities of OVCAR3 and CAOV3 cells. (3) To evaluate the synergistic effects of olaparib and IL-1β inhibitor in vivo, the transplanted ovarian cancer model was constructed. BALB/c-nude mice (n=16) were injected intraperitoneally with 1×107 OVACR3 cells labelled with luciferase (OVCAR3-Luc). Immunohistochemistry (IHC) assay was performed to determine nuclear antigen associated with cell proliferation (Ki-67) expression. (4) Blood routine tests, kidney and liver function tests were performed to analyze the toxic reaction of different drug treatments. The potential drug-induced injuries of vital organs including heart, liver, spleen, lungs and kidneys of nude mice were determined by hematoxylin-eosin (HE) staining. Results: (1) The RNA sequencing results showed that the mRNA level of IL-1β was the most significantly increased among the 25 differentially expressed genes in OVCAR3 cells treated with olaparib, compared to the negative control group. Olaparib treatment significantly promoted the secretion and expression of IL-1β protein in both OVACR3 and CAOV3 cells by ELISA [(36.2±3.5) and (49.5±3.5) pg/ml, respectively; all P<0.001] and western bolt (2.87±0.37 and 2.05±0.08, respectively; all P<0.01). (2) The half maximal inhibitory concentration (IC50) value of IL-1β inhibitor was determined as follows: 75 μmol/L for OVACR3 cells and 100 μmol/L for CAOV3 cells. The treatments were divided into four groups including control group, olaparib monotherapy group, IL-1β inhibitor monotherapy group and the combination therapy group. The cell viabilities of each group in OVCAR3 and CAOV3 were determined by CCK-8 assay. The data in each group were showed as follows for OVCAR3 and CAOV3 cells: (100.0±0.4)% and (100.0±3.5)% in control group; (63.1±6.2)% and (63.3±3.8)% in olaparib monotherapy group; (61.6±4.7)% and (63.8±3.5)% in IL-1β inhibitor monotherapy group; and (32.9±5.2)% and (30.0±1.3)% in the combination therapy group. The viability assay showed that the combined strategy exhibited a significant inhibition effect on OVACR3 and CAOV3 cells, compared to the monotherapy group and the control group (all P<0.01). (3) All mice with transplanted tumors of HRD-proficient ovarian cancer cells were randomly divided into four groups, and treated with four different treatments as mentioned above, respectively. After 4 weeks (on day 29), the vivo fluorescence imaging were determined. The results showed that the amount of fluorescence of transplanted tumors was mostly decreased in the combination therapy group [(0.5±0.4)×1010 p/s], compared to the control group [(4.2±1.0)×1010 p/s] or the groups treated with any single drug [(3.1±0.9)×1010, (2.2±0.9)×1010 p/s; all P<0.05]. Mice were then sacrificed under anesthesia, and all transplanted tumors detached and weighed for further investigation. The weight of transplanted tumors was significantly decreased in the combination therapy group [(0.09±0.03) g], compared to that in control group [(0.25±0.05) g] or groups treated with any single drug [(0.17±0.03), (0.19±0.04) g; all P<0.05]. The measurement of the expression of Ki-67 showed that it was significantly decreased in the combination therapy group (0.33±0.10), compared to that in the control group (1.00±0.20) or monotherapy groups (0.76±0.07, 0.77±0.12; all P<0.05). (4) There were no significant differences of body weights, blood routine test, renal and liver function tests among mice with different treatments (all P>0.05). Moreover, no significant injuries were observed in the vital organs among the four groups. Conclusions: The combination of olaparib and IL-1β inhibitor synergistically exhibits significant cytotoxicity in HRD-proficient ovarian cancer cells. Moreover, the blood routine and blood biochemistry results confirmed the biosafety of the combination of olaparib and IL-1β inhibitor.

[Improved Mayo Endoscopic Score has a higher value for evaluating clinical severity of ulcerative colitis]

OBJECTIVE

To assess the value of Improved Mayo Endoscopic Score (IMES) for evaluation of the clinical severity of ulcerative colitis (UC).

METHODS

We retrospectively analyzed the clinical and endoscopic data of 167 patients diagnosed with UC in Beijing Tsinghua Changgung Hospital from January, 2015 to November, 2021. The severity of endoscopic lesions was determined by Mayo Endoscopic Score (MES, 0-3 points) and the Ulcerative Colitis Endoscopic Index of Severity (UCEIS) score (0-8 points), and the scope of endoscopic lesions was evaluated based on the Montreal classification system. The IMES was established by combining the MES with the Montreal classification.

RESULTS

The IMSE showed stronger correlations with modified Truelove and Witts Disease Severity, Mayo score and partial Mayo score (r=0.712, 0.784, and 0.703, respectively) than MES (r=0.642, 0.754, and 0.604, respectively), Montreal classification (r=0.598, 0.628, and 0.603, respectively) and UCEIS (r= 0.670, 0.767, and 0.677, respectively). ROC curve analysis showed that IMES was superior to MES, Montreal and UCEIS in diagnosis of severe and moderate- to-severe UC. IMES also showed stronger correlations with the laboratory indicators including CRP (r=0.583), WBC (r=0.235), HB (r=-0.280), PLT (r=0.352), ALB (r=-0.396) and ESR (r=0.471) than MES and Montreal classification. An IMES score of 5 was of greater value than a MES score of 3, E3, and UCEIS≥6 for predicting the administration of systemic hormones, immunosuppressants, or surgery in the near future.

CONCLUSION

IMES can better reflect the clinical severity of UC and has good correlations with the laboratory indicators of the patients.

Cone beam computed tomography volumetric airway changes after orthognathic surgery: a systematic review

The aim of this systematic review was to provide a structured overview of three-dimensional airway volume changes in relation to various orthognathic surgeries. Clinical human studies performing pre- and postoperative three-dimensional airway volume assessments to investigate volumetric changes of the airway after orthognathic surgery were included. Pre-determined inclusion and exclusion criteria were applied in an extensive search of the PubMed, Embase, and Web of Science electronic databases. The cut-off date was set to January 1, 2022. Forty-one articles reporting retrospective and prospective case-control and case series studies were included. All studies were determined to be of medium quality (moderate risk of bias). The included studies were categorized by type of intervention. Pre- and postoperative volumes were extracted from the available data, and volume changes as a percentage of the preoperative levels were calculated. Isolated mandibular setback surgery generally decreased the airway volume. Isolated maxillary or mandibular advancement, bimaxillary advancement, and surgically assisted maxillary expansion generally increased the airway volume in the total airway and oropharynx, among which the effect of bimaxillary advancement surgery appeared most significant. High heterogeneity exists in the terminology and definitions of the airway and its segments. A more uniform methodology for airway volume measurement is needed to provide an insight into the impact on the airway of specific types of surgical intervention. In conclusion, airway volumes are affected after orthognathic surgery, which may be of clinical significance, especially in patients who are predisposed to obstructive sleep apnoea.

Atomic structure and Mott nature of the insulating charge density wave phase of 1T-TaS2

Using x-ray pair distribution function (PDF) analysis and computer modeling, we explore structure models for the complex charge density wave (CDW) phases of layered 1T-TaS₂that both well capture their atomic-level features and are amenable to electronic structure calculations. The models give the most probable position of constituent atoms in terms of 3D repetitive unit cells comprising a minimum number of Ta-S layers. Structure modeling results confirm the emergence of star-of-David (SD) like clusters of Ta atoms in the high-temperature incommensurate (IC) CDW phase and show that, contrary to the suggestions of recent studies, the low-temperature commensurate (C) CDW phase expands upon cooling thus reducing lattice strain. The C-CDW phase is also found to preserve the stacking sequence of Ta-S layers found in the room temperature, nearly commensurate (NC) CDW phase to a large extent. DFT based on the PDF refined model shows that bulk C-CDW 1T-TaS₂also preserves the insulating state of individual layers of SD clusters, favoring the Mott physics description of the metal-to-insulator (NC-CDW to C-CDW) phase transition in 1T-TaS₂. Our work highlights the importance of using precise crystal structure models in determining the nature of electronic phases in complex materials.

Effect of voxel size in cone-beam computed tomography on surface area measurements of dehiscences and fenestrations in the lower anterior buccal region

Objectives

This study aims to assess whether different voxel sizes in cone-beam computed tomography (CBCT) affected surface area measurements of dehiscences and fenestrations in the mandibular anterior buccal region.

Materials and methods

Nineteen dry human mandibles were scanned with a surface scanner (SS). Wax was attached to the mandibles as a soft tissue equivalent. Three-dimensional digital models were generated with a CBCT unit, with voxel sizes of 0.200 mm (VS200), 0.400 mm (VS400), and 0.600 mm (VS600). The buccal surface areas of the six anterior teeth were measured (in mm²) to evaluate areas of dehiscences and fenestrations. Differences between the CBCT and SS measurements were determined in a linear mixed model analysis.

Results

The mean surface area per tooth was 88.3 ± 24.0 mm², with the SS, and 94.6 ± 26.5 (VS200), 95.1 ± 27.3 (VS400), and 96.0 ± 26.5 (VS600), with CBCT scans. Larger surface areas resulted in larger differences between CBCT and SS measurements (− 0.1 β, SE = 0.02, p < 0.001). Deviations from SS measurements were larger with VS600, compared to VS200 (1.3 β, SE = 0.05, P = 0.009). Fenestrations were undetectable with CBCT.

Conclusions

CBCT imaging magnified the surface area of dehiscences in the anterior buccal region of the mandible by 7 to 9%. The larger the voxel size, the larger the deviation from SS measurements. Fenestrations were not detectable with CBCT.

Clinical relevance

CBCT is an acceptable tool for measuring dehiscences but not fenestrations. However, CBCT overestimates the size of dehiscences, and the degree of overestimation depends on the actual dehiscence size and CBCT voxel size employed.

[Exploration of construction mode of real-world data system]

Real-world data study evidence, as an important part of evaluating the safety and effectiveness of drugs and devices, has attracted increasing attention from regulatory agencies and scholars both at home and abroad, and has become an essential source of evidence to support the development and review of drugs and devices. This paper systematically discusses the process and mode of real-world data system construction based on the preliminary practical study of real-world data according to the guidelines/technical specifications issued by regulatory agencies and academic research results. This study result provides not only reference for the generation of clinical evaluation evidence to meet the regulatory requirements for innovative drugs and devices, but also reference for researchers, sponsors and regulators to carry out real-world data studies successfully.

Erratum to "An automated controlled-release device for intravaginal hormone delivery" (JDS Commun. 1:15-20)

[This corrects the article DOI: 10.3168/jdsc.2020-18816.].

[A comparative study of artificial intelligence nasal polyp classification based on whole-slide imaging and JESREC diagnostic criteria]

Objective: To explore the types and clinical characteristics of chronic rhinosinusitis with nasal polyps (CRSwNP) based on artificial intelligence and whole-slide imaging (WSI), and to explore the consistency of the diagnostic criteria of the Japanese epidemiological survey of refractory eosinophilic chronic rhinosinusitis (JESREC) in Chinese CRSwNP patients. Methods: The data of 136 patients with CRSwNP (101 males and 35 females, aging 14 to 70 years) who underwent endoscopic sinus surgery from 2018 to 2019 in the Department of Otorhinolaryngology Head and Neck Surgery, the Third Affiliated Hospital of Sun Yat-sen University were analysed retrospectively. The preoperative clinical characteristics of patients were collected, such as visual analogue scale (VAS) of nasal symptoms, peripheral blood inflammatory cell count, total immunoglobulin E (IgE), Lund-Kennedy score and Lund-Mackay score. The proportion of inflammatory cells such as eosinophils, lymphocytes, plasma cells and neutrophils were calculated on the WSI of each patient through artificial intelligence chronic rhinosinusitis evaluation platform 2.0 (AICEP 2.0), and the specific type of nasal polyps was then obtained as eosinophilic CRSwNP (eCRSwNP) or non-eosinophilic CRSwNP (non-eCRSwNP). In addition, the JESREC diagnostic criteria was used to classify the nasal polyps, and the classification results were compared with the current gold standard for nasal polyps diagnosis (pathological diagnosis based on WSI). The accuracy, sensitivity and specificity of the diagnostic criteria of JESREC were evaluated. The data were expressed in M (Q₁, Q₃) and statistically analyzed by SPSS 17.0. Results: There was no significant difference between eCRSwNP and non-eCRSwNP in age distribution, gender, time of onset, total VAS score, Lund-Kennedy score or Lund-Mackay score. However, there was a significant difference in the ratio of nasal polyp inflammatory cells (eosinophils 40.5% (22.8%, 54.7%) vs 2.5% (1.0%, 5.3%), neutrophils 0.3% (0.1%, 0.7%) vs 1.3% (0.5%, 3.6%), lymphocytes 49.9% (39.3%, 65.9%) vs 82.0% (72.8%, 87.5%), plasma cells 5.1% (3.6%, 10.5%) vs 13.0% (7.4%, 16.3%), χ² value was 9.91, 4.66, 8.28, 5.06, respectively, all P<0.05). In addition, eCRSwNP had a significantly higher level of proportion of allergic symptoms (nasal itching and sneezing), asthma, peripheral blood eosinophil and total IgE (all P<0.05). The overall accuracy, sensitivity and specificity of the JESREC diagnostic criteria was 74.3%, 81.3% and 64.3%, respectively. Conclusions: The eCRSwNP based on artificial intelligence and WSI has significant high level of allergic symptoms, asthma, peripheral blood eosinophils and total IgE, and the percentages of inflammatory cells in nasal polyps are different from that of non-eCRSwNP. The JESREC diagnostic criteria has good consistency in our research.

[Green channel construction mode and development of stroke center in China]

Stroke poses a social and economic burden worldwide.Intravenous thrombolytic therapy and endovascular interventional therapy are recommended as early as possible for patients with acute ischemic stroke in many national and international guidelines, however, their clinical applications are limited due to their strong time dependence.To date, the treatment of acute stroke in China has many problems, such as backward development of hospital treatment process and shortage of stroke professionals.Establishing a complete stroke green channel and maintaining its smooth operation contributes to the most important and effective way to promote thrombolytic therapy, which requires setting a clear target time, appropriately adjusting the hospital layout and hardware and software investment, attaching importance to team building and clear job responsibilities.Moreover, the most important task is to improve the green channel process through replacing the "serial mode" with the "parallel mode", making full use of the first aid map of stroke, bridging the gap between pre-hospital and in-hospital treatment, and popularizing stroke-related knowledge.In recent years, considerable progress has been made in the construction of stroke green channel in China.The implementation of the above-mentioned reform mode may minimize pre-hospital and in-hospital delays, expand the benefit population of stroke and thus improve the early treatment rate of acute ischemic stroke.

Genetic characterization and clinical characteristics of bovine viral diarrhea viruses in cattle herds of Heilongjiang province, China

BACKGROUND

Heilongjiang province is the main cattle-producing area in China, and molecular epidemiological studies of bovine viral diarrhea viruses (BVDV) in cattle have not been performed in the province.

AIMS

The objective of this research was to determine the genetic and clinical characteristics of BVDV in cattle.

METHODS

Fifty-three BVDV-positive clinical samples were collected from 22 cattle farms in Heilongjiang, and the 5´-untranslated region (5´-UTR) was used to carry out a phylogenetic analysis of the viruses.

RESULTS

The similarity of the 5´-UTR sequences among these BVDVs was 84.2%-100%, and the phylogenetic analysis showed that all viruses belong to the BVDV-1 species, which is classified into five subtypes: BVDV-1b (47.17%, n=25), 1c (15.09%, n=8), 1d (16.98%, n=9), 1 m (3.77%, n=2), and 1o (16.98%, n=9). The statistical results showed that the BVDV-1b subtype had a positive correlation with gastrointestinal disease (P<0.05; 95% CI: 1.19 to 3.34). There were up to three or four BVDV-1 subtypes in some dairy cattle farms, but farms with a single subtype were prevalent (5/10).

CONCLUSION

BVDV-1b is predominant in cattle herds of Heilongjiang province, China, and shows a positive correlation with gastrointestinal disease. BVDV-1o was found for the first time in Chinese cattle, which increased the complex distribution of BVDV-1 subtypes in cattle herds of China.

Inheritance of physico-chemical properties and ROS generation by carbon quantum dots derived from pyrolytically carbonized bacterial sources

Bacteria are frequently used in industrial processes and nutrient supplementation to restore a healthy human microflora, but use of live bacteria is often troublesome. Here, we hypothesize that bacterially-derived carbon-quantum-dots obtained through pyrolytic carbonization inherit physico-chemical properties from probiotic and pathogenic source-bacteria. Carbon-quantum-dots carbonized at reaction-temperatures below 200 ​°C had negligible quantum-yields, while temperatures above 220 ​°C yielded poor water-suspendability. Fourier-transform infrared-spectroscopy demonstrated preservation of amide absorption bands in carbon-quantum-dots derived at intermediate temperatures. X-ray photoelectron-spectroscopy indicated that the at%N in carbon-quantum-dots increased with increasing amounts of protein in source-bacterial surfaces. Carbonization transformed hydrocarbon-like bacterial surface compounds into heterocyclic aromatic-carbon structures, evidenced by a broad infrared absorption band (920-900 ​cm⁻¹) and the presence of carbon in C–C functionalities of carbon-quantum-dots. The chemical composition of bacterially-derived carbon-quantum-dots could be explained by the degradation temperatures of main bacterial cell surface compounds. All carbon-quantum-dots generated reactive-oxygen-species, most notably those derived from probiotic lactobacilli, carrying a high amount of surface protein. Concluding, amide functionalities in carbon-quantum-dots are inherited from surface proteins of source-bacteria, controlling reactive-oxygen-species generation. This paves the way for applications of bacterially-derived carbon-quantum-dots in which reactive-oxygen-species generation is essential, instead of hard-to-use live bacteria, such as in food supplementation or probiotic-assisted antibiotic therapy.

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Pyrolytic carbonization of bacteria between 200°C and 220°C yields water-suspendable CQDs.

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Bacterially-derived CQDs inherit amide functionalities from bacterial cell surface proteins.

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Hydrocarbon-like bacterial surface compounds give heterocyclic aromatic-carbon structures in bacterially-derived CQDs.

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Bacterially-derived CQDs possess graphitic nitrogen.

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Zeta potentials of CQDs relate with nitrogen occurrence in CQDs.

[Combined autologous fascia transplantation with autologous fascia and fat injection into the vocal fold for sulcus vocalis]

Objective: To assess voice outcomes after surgical technique for typeⅡ and type Ⅲ sulcus vocalis. Methods: The data of 39 cases of bilateral type Ⅱ-Ⅲ sulcus vocalis were collected and analyzed retrospectively. There were 29 patients with bilateral type Ⅲ sulcus vocalis, and 10 patients with type Ⅲ on one side and typeⅡon the contralateral vocal cord. All of vocal cords were applied autologous anterior rectus sheath fascia transplant, and 68 sides of vocal cords with type Ⅲ sulcus vocalis were also applied autologous fascia and fat injection. Two male patients, whose results from transplant and injection were not satisfied, were carried out cricothyroid myotomy one year after surgery. Subjective and objective voice evaluations were performed before and after operation. Results: One patient was found mild adhesion on the middle part of vocal cords, and all the other 38 patients recovered well and there were no complications. During 5-6 weeks after surgery, breathy voice was the feather. Then vocal quality and glottal closure were gradually improved and became steady in 12 months. It showed that all the subjective and objective parameters, except for fundamental frequency, were significantly improved (P<0.05), and obvious improvement was achieved in glottal closures and mucosal waves in 35 patients. Three patients obtained no significant vocal quality improvement after transplant and injection surgery, and two male patients of them achieved improvement in mucosal waves and MPT after bilateral cricothyroid muscle amputations. One patient, who was revealed with mild adhesion, achieved a satisfied result after adhesion separation and suture. All the patients who originally had feelings of fatigue and voice discontinuity during phonation gained significant improvement postoperatively. Steady function with no complications was observed during the 36 months (up to 5 years in 20 patients) follow-up period. Conclusions: Autologous fascia transplantation combined fascia and fat injcetion can lead to excellent long-term results, and it is a good treatment option for pathologic sulcus vocalis. Cricothyroid muscle amputations can reduce the tension, and may improve vibration property of the vocal fold in patients with pathological sulcus vocalis.

Precision of orthodontic cephalometric measurements on ultra low dose-low dose CBCT reconstructed cephalograms

Objectives

To analyze differences in variation of orthodontic diagnostic measurements on lateral cephalograms reconstructed from ultra low dose-low dose (ULD-LD) cone beam computed tomography (CBCT) scans (RLC) as compared to variation of measurements on standard lateral cephalograms (SLC), and to determine if it is justifiable to replace a traditional orthodontic image set for an ULD-LD CBCT with a reconstructed lateral cephalogram.

Material and methods

ULD-LD CBCT images and SLCs were made of forty-three dry human skulls. From the ULD-LD CBCT dataset, a lateral cephalogram was reconstructed (RLC). Cephalometric landmarks (13 skeletal and 7 dental) were identified on both SLC and RLC twice in two sessions by two calibrated observers. Thirteen cephalometric variables were calculated. Variations of measurements, expressed as standard deviations of the 4 measurements on SLC and RLC, were analyzed using a paired sample t-test. Differences in the number of observations deviating ≥ 2.0 mm or degrees from the grand mean between SLC and RLC were analyzed using a McNemar test.

Results

Mean SDs for 7 out of 13 variables were significantly smaller for SLCs than those for RLCs, but differences were small. For 9 out of 13 variables, there was no significant difference between SLC and RLC for the number of measurements outside the range of 2 mm or degrees.

Conclusions

Based on the lower radiation dose and the small differences in variation in cephalometric measurements on reconstructed LC compared to standard dose LC, ULD-LD CBCT with reconstructed LC should be considered for orthodontic diagnostic purposes.

Clinical relevance

ULD-LD CBCT with reconstructed LC should be considered for orthodontic purposes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-021-04127-9.

Study of the Structure and Properties of ZnS Utilized in a Fluorescence Biosensor

ZnS materials have been widely used in fluorescence biosensors to characterize different types of stem cells due to their excellent fluorescence effect. In this study, ZnS was prepared by vulcanizing nano-Zn particles synthesized using a DC arc plasma. The composition and structure of the ZnS materials were studied by X-ray diffraction (XRD), and their functional group information and optical properties were investigated by using IR spectrophotometry and UV-vis spectrophotometry. It has been found that the synthesized materials consist of Zn, cubic ZnS, and hexagonal ZnS according to the vulcanization parameters. Crystalline ZnS was gradually transformed from a cubic to a hexagonal structure, and the cycling properties first increase, then decrease with increasing sulfurization temperature. There is an optimal curing temperature giving the best cycling performance and specific capacity: the material sulfurized thereat mainly consists of cubic β-ZnS phase with a small quantity of Zn and hexagonal α-ZnS. The cubic phase ZnS has better conductivity than hexagonal ZnS, as evinced by electrochemical impedance spectroscopy (EIS). The ZnS (as prepared) shows board absorption, which can be used in fluorescence biosensors in cell imaging systems.

[Characteristics and clinical significance of wideband tympanometry of otitis media with effusion in young children]

Objective: To study the characteristics of wideband tympanometry(WBT) and its application value in the diagnosis of otitis media with effusion(OME) in young children. Methods: We compared wideband acoustic energy absorbance(EA) under peak pressure in young children with OME(190 ears) and healthy control subjects(121 ears) from Ninth People's Hospital of Shanghai Jiaotong University School of Medicine between January 2018 and June 2020. Both groups were divided into three groups, 1-6 months, 7-36 months and 37-72 months. SPSS 20.0 statistical software was used to analyze and compare the EA parameters between OME children of different months and the control group. Receiver operating characteristic (ROC)curve was used to analyze the diagnostic value of WBT in young children with OME. Results: There were significant differences in EA among three OME groups from 500 Hz to 2 000 Hz(P<0.05).Compared with the control groups, EA of 1-6 m OME group decreased significantly below 4 000 Hz(P<0.05), EA of 7-36 m OME group decreased significantly at 545-1 600 Hz(P<0.05), EA of 37-72 m OME group decreased significantly above 545 Hz(P<0.05).ROC curve indicated that EA at 1 000 Hz had the greatest diagnostic value (AUC was 0.890), followed by 1 500 Hz and the range of 500-2 000 Hz (AUC was 0.883 and 0.881, respectively).EA at 1 000 Hz with a cutoff value of 0.55 had the best diagnostic sensitivity of 90.8%, which was higher than conventional tympanometry (85.8%). The maximum AUC (0.932) could be obtained by combining EA, peak pressure and admittance amplitude of 226 Hz tympanometry as predictors. Conclusions: EA is significantly decreased in young children with OME. Compared with the conventional single frequency tympanometry, WBT is more accurate in the diagnosis of OME in young children, and the prediction accuracy would be better if combined with 226 Hz tympanometry.

[Real-world data studies of medical products in the context of special healthcare policy: study designs and key considerations]

Boao Lecheng International Medical Tourism Pilot Area is the only administrative area in China where the pilot application of real-world data is performed. Based on the special healthcare policy in Boao Lecheng, conducting real-world data study to provide real-world evidence for the clinical evaluations and approvals of innovated medical products has become an important field that supports the reform of China's evaluation and approval system of medical products. Trustworthy real-world evidence needs to rely on both high-quality real-world data and reasonable and rigorous study designs. Based on the real-world data research guidelines and specifications issued by relevant academic research and regulatory authorities both at home and abroad, combined with the special policy environment of Boao Lecheng and previous practice experience, this paper summarizes the study designs of real world data in Boao Lecheng and discusses the key considerations of different study design in the context of special healthcare policies in Boao Lecheng in order to provide reference for the further study of real-world data.