Chest computed tomography analysis of lung sparing morphology: differentiation of COVID-19 pneumonia from influenza pneumonia and bacterial pneumonia using the arched bridge and vacuole signs

INTRODUCTION

This study evaluated the arched bridge and vacuole signs, which constitute morphological patterns of lung sparing in coronavirus disease 2019 (COVID-19), then examined whether these signs could be used to differentiate COVID-19 pneumonia from influenza pneumonia or bacterial pneumonia.

METHODS

In total, 187 patients were included: 66 patients with COVID-19 pneumonia, 50 patients with influenza pneumonia and positive computed tomography findings, and 71 patients with bacterial pneumonia and positive computed tomography findings. Images were independently reviewed by two radiologists. The incidences of the arched bridge sign and/or vacuole sign were compared among the COVID-19 pneumonia, influenza pneumonia, and bacterial pneumonia groups.

RESULTS

The arched bridge sign was much more common among patients with COVID-19 pneumonia (42/66, 63.6%) than among patients with influenza pneumonia (4/50, 8.0%; P<0.001) or bacterial pneumonia (4/71, 5.6%; P<0.001). The vacuole sign was also much more common among patients with COVID-19 pneumonia (14/66, 21.2%) than among patients with influenza pneumonia (1/50, 2.0%; P=0.005) or bacterial pneumonia (1/71, 1.4%; P<0.001). The signs occurred together in 11 (16.7%) patients with COVID-19 pneumonia, but they did not occur together in patients with influenza pneumonia or bacterial pneumonia. The arched bridge and vacuole signs predicted COVID-19 pneumonia with respective specificities of 93.4% and 98.4%.

CONCLUSION

The arched bridge and vacuole signs are much more common in patients with COVID-19 pneumonia and can help differentiate COVID-19 pneumonia from influenza and bacterial pneumonia.

Insulin Resistance-Varying Associations of Adiposity Indices with Cerebral Perfusion in Older Adults: A Population-Based Study

OBJECTIVES

Excessive accumulation of adipose tissue may accelerate brain aging, but the underlying mechanisms are poorly understood. Several adiposity indices were proposed to assess obesity, while their linkage with brain health in older adults remained unclear. Here we aimed to examine the associations of adiposity indices with global and regional cerebral blood flow (CBF) in older adults, while considering insulin resistance.

DESIGN

This was a cross-sectional population-based study that included older adults derived from the baseline participants in the ongoing Multimodal Interventions to Delay Dementia and Disability in rural China (MIND-China) study.

SETTING AND PARTICIPANTS

The study included 103 Chinese rural-dwelling older adults (age≥60 years; 69.9% women) who underwent brain magnetic resonance imaging scans.

METHODS

We estimated eight adiposity indices based on anthropometric measures. We automatically quantified global and regional CBF using the arterial spin labeling scans. Insulin resistance was assessed using the triglyceride-glucose index and then dichotomized into high and low levels according to the median. Data were analyzed using general linear model and voxel-wise analysis.

RESULTS

Of the eight examined adiposity indices, only higher waist-to-height ratio (WHtR) and body roundness index (BRI) were associated with reduced global CBF (multivariable-adjusted β-coefficients and 95%CI: -1.76; -3.25, -0.27 and -1.77; -3.25, -0.30, respectively) and hypoperfusion in bilateral middle temporal gyri, angular gyri and superior temporal gyri, left middle cingulum and precuneus (P<0.05). There were statistical interactions of WHtR and BRI with levels of insulin resistance on CBF, such that the significant associations of higher WHtR and BRI with lower global and regional CBF existed only in people with high insulin resistance (P<0.05).

CONCLUSION

Higher WHtR and BRI are associated with cerebral hypoperfusion in older adults, especially in people with high insulin resistance. This may highlight the pathological role of visceral fat in vascular brain aging.

[The peripheral blood inflammatory markers in Ménière's disease patients with and without migraine]

Objective: To investigate the peripheral blood inflammatory markers including white blood cell count (WBC), monocytes, neutrophils, lymphocytes, platelets, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), high-density lipoprotein(HDL-C), low-density lipoprotein and fibrinogen (FIB) in Ménière's disease (MD) patients with and without migraine, and to explore the relationship between the inflammatory response with MD and migraine. Methods: The general physical condition, clinical manifestations, pure-tone audiometry, and peripheral blood inflammatory markers of 92 unilateral MD patients who were hospitalized in Peking University People's Hospital for surgical treatment from January 2017 to January 2021 were continuously collected. Meanwhile, 50 healthy controls matched with age and sex were included, and their general physical conditions and peripheral blood inflammatory markers were also collected. This study consisted of two parts. First, the differences in epidemical characteristics and peripheral blood inflammatory markers between MD patients and healthy controls were compared by univariate analysis. Second, all 92 MD patients were divided into two subgroups according to whether they were accompanied by migraine. The clinical characteristics and peripheral blood inflammatory markers of MD patients with and without migraine were compared by univariate analysis. Thereafter, binary Logistic regression was used to analyze the related factors of whether MD patients were accompanied with migraine. Results: Compared with the healthy control group, the peripheral blood WBC, neutrophils and FIB of MD patients were significantly increased (all P<0.05). Compared with MD patients without migraine, MD patients with migraine had higher female prevalence, longer disease history, lower low-frequency hearing threshold, higher frequency of vertigo attacks and higher HDL-C levels (all P<0.05), meanwhile, female, frequency of vestibular attacks and HDL-C were independent related factors of whether MD patients were accompanied with migraine. Conclusion: The occurrence of MD and migraine may be related to the inflammatory response. The level of anti-inflammatory factors in the blood of MD patients with migraine are higher, suggesting that the inflammatory response status of MD patients with and without migraine is different.

[Clinical application of laparoscopic sentinel lymph node mapping in early staged cervical cancer]

Objective: To investigate the application of sentinel lymph node biopsy (SLNB) in early-staged cervical cancer by laparoscopy. Methods: It was a prospective, single-arm, single-center clinical study. Seventy-eight cases of cervical cancer patients were collected from July 2015 to December 2018 at the Fourth Hospital of Hebei Medical University. All the patients were injected with tracer into the disease-free block of cervical tissue after anesthesia by the same surgeon who learned sentinel lymph node (SLN) mapping technique in Memorial Sloan-Kettering Cancer Center, and underwent SLN mapping followed by complete pelvic lymphadenectomy. Moreover, all the dissected lymph nodes were stained with hematoxylin eosin staining (HE) pathological examination. Besides, the negative SLN on hematoxylin-eosin staining were detected by immunohistochemistry cytokeratin staining micro-metastasis. To analyze the distribution, detection rate, false negative rate the sensitivity and negative predictive value of the SLN in early-staged cervical cancer by laparoscopy, and explore the value of SLN mapping in predicting the lymph nodes metastasis in early-staged cervical cancer. Results: The overall detection rate of SLN in cervical cancer was 99% (77/78), bilateral detection rate was 87% (68/78). The average of 12.4 lymph node (LN) and 3.6 SLN were dissected for each patients each side. SLN of cervical cancer were mainly distributed in the obturator space (61.5%, 343/558), followed by external iliac (23.5%, 131/558), common iliac (7.3%, 41/558), para-uterine (3.8%, 21/558), internal iliac (2.2%, 12/558), para abdominal aorta (1.1%, 6/558), and anterior sacral lymphatic drainage area (0.7%, 4/558). Fourteen cases of LN metastasis were found among all 78 cases. There were a total of 38 positive LN, including 26 SLN metastasis and 12 none sentinel LN metastasis. Through immunohistochemical staining and pathological ultra-staging, 1 SLN was found to be isolated tumor cells (ITC), and 5 SLNs were found to be micro-metastases (MIC), accounting for 23% (6/26) of positive SLN. SLN mapping with pathological ultra-staging improved the prediction of LN metastasis in cervical cancer (2/14). Metastatic SLN mainly distributed in the obturator space (65%, 17/26), peri-uterine region (12%, 3/26), common iliac region (15%, 4/26), and external iliac region (8%, 2/26). The consistency of the diagnosis of lymph node metastasis by SLN biopsy and postoperative retroperitoneal lymph node metastasis showed that the Kappa value was 1.000 (P<0.001), indicated that the metastasis status of SLN and retroperitoneal lymph node were completely consistent. The sensitivity, specificity, accuracy, false-negative rate, and negative predictive value of SLN biopsy in the diagnosis of lymph node metastasis were 100%, 100%, 100%, 0, and 100%, respectively. Conclusions: SLN in early-staged cervical cancer patients were mainly distributed in the obturator and external iliac space, pathalogical ultra-staging of SLN could improve the prediction of LN metastasis. Intraoperative SLN mapping is safe, feasible and could predict the state of retroperitoneal LN metastasis in early-staged cervical cancer. SLNB may replace systemic pelvic lymphadenectomy.

Constraints on Sub-GeV Dark Matter-Electron Scattering from the CDEX-10 Experiment

We present improved germanium-based constraints on sub-GeV dark matter via dark matter-electron (χ-e) scattering using the 205.4  kg·day dataset from the CDEX-10 experiment. Using a novel calculation technique, we attain predicted χ-e scattering spectra observable in high-purity germanium detectors. In the heavy mediator scenario, our results achieve 3 orders of magnitude of improvement for m_{χ} larger than 80  MeV/c^{2} compared to previous germanium-based χ-e results. We also present the most stringent χ-e cross-section limit to date among experiments using solid-state detectors for m_{χ} larger than 90  MeV/c^{2} with heavy mediators and m_{χ} larger than 100  MeV/c^{2} with electric dipole coupling. The result proves the feasibility and demonstrates the vast potential of a new χ-e detection method with high-purity germanium detectors in ultralow radioactive background.

Exotic Dark Matter Search with the CDEX-10 Experiment at China's Jinping Underground Laboratory

A search for exotic dark matter (DM) in the sub-GeV mass range has been conducted using 205 kg day data taken from a p-type point contact germanium detector of the CDEX-10 experiment at China's Jinping underground laboratory. New low-mass dark matter searching channels, neutral current fermionic DM absorption (χ+A→ν+A) and DM-nucleus 3→2 scattering (χ+χ+A→ϕ+A), have been analyzed with an energy threshold of 160 eVee. No significant signal was found; thus new limits on the DM-nucleon interaction cross section are set for both models at the sub-GeV DM mass region. A cross section limit for the fermionic DM absorption is set to be 2.5×10^{-46}  cm^{2} (90% C.L.) at DM mass of 10  MeV/c^{2}. For the DM-nucleus 3→2 scattering scenario, limits are extended to DM mass of 5 and 14  MeV/c^{2} for the massless dark photon and bound DM final state, respectively.

[Bedside monitoring of lung perfusion by electrical impedance tomography]

As a non-invasive and radiation-free bedside imaging method, electrical impedance tomography (EIT) can perform real-time regional pulmonary ventilation evaluation and pulmonary blood flow monitoring for patients, thus realizing bedside ventilation/perfusion matching visualization, effectively guiding the pathophysiological mechanism of hypoxemia, and providing a new method for the study of pulmonary blood flow. EIT has also played a unique and irreplaceable role in COVID-19 research and treatment. At the same time, as functional imaging, the operation details and image reconstruction algorithm of this technology still need to be further optimized by more researches to provide a more robust evaluation in clinical application. In this paper, EIT pulmonary blood flow monitoring methods, operation and implementation of monitoring indicators, application and related research progress will be described.

[Application of near infrared fluorescence imaging in detection of residual cancer in oral squamous cell carcinoma]

Objective: Local recurrence is the main cause of treatment failure in patients with oral squamous cell carcinoma (OSCC). This study was proposed to investigate the feasibility of near infrared fluorescence (NIF) via indocyanine green (ICG) for monitoring surgical marginal in operation for OSCC patients. Methods: In 35 patients with OSCC treated surgically in the Department of Oral and Maxillofacial Surgery, Nanjing University School of Medicine, from January 2019 to June 2020, ICG (0.75 mg/kg) was administered intravenously via elbow vein at (12±1) hours before surgery, and NIF was performed intraoperatively on the surgical field and the cut edge of the surgically excised specimen, and fluorescence intensity was measured for OSCC tissue and normal oral mucosa, abnormal fluorescence signals were taken and subjected to rapid cryopathological examination. Correlation between NIF tumor boundary grading and pathological tumor boundary grading was analyzed by Spearman correlation analysis. Results: Clear ICG NIF was obtained for tumor lesions in all 35 patients, with a positive rate of 100%. The fluorescence intensity of OSCC tissue was (412.73±146.56) au, which was higher than that of normal oral mucosa tissue [(279.38±82.56) au, P<0.01]. Abnormal fluorescence signals were detected at the tumor bed and the cut edge of the surgical resection specimen in 4 patients, of which 2 cases were pathologically confirmed as cancer cell residue and 2 cases as inflammatory cell infiltration. The rate of positive detection of cut margins using ICG NIF technique in OSCC was 5.7% (2/35). Twenty of the 35 OSCC patients had grade 1, 11 of grade 2, and 4 of grade 3 tumor borders revealed by NIF of surgical resection specimens, which was positively correlated with pathological tumor border (r=0.809, P<0.001). Conclusions: ICG NIF technique can effectively detect the residual cancer cells at the incision margin, which is of great clinical value in reducing local recurrence of OSCC after surgery due to intraoperative cancer residue.

[Research advances on exosomes derived from adipose-derived mesenchymal stem cells in promoting diabetic wound healing]

Impaired healing of diabetic wounds is mainly attributed to its pathological mechanism, and refractory diabetic wounds bring heavy burdens to patients and society. Exosomes derived from stem cells possess the similar ability as stem cells in promoting tissue regeneration and more clinical advantages and are gradually playing important roles in wound healing. In recent years, researches have shown that exosomes derived from adipose-derived mesenchymal stem cells (ADSC-EXOs) can promote the healing of diabetic wounds by participating in various processes of wound healing. This article reviews the pathological mechanism leading to impaired healing of diabetic wounds, the related mechanism and the application prospect of ADSC-EXOs in promoting diabetic wound healing.

[The prevalence and associated factors of metabolic syndrome among Tibetan pastoralists in transition from nomadic to settled urban environment]

Objective: To study the prevalence and associated factors of metabolic syndrome (MS) among Tibetan pastoralists in transition from high altitude nomadic to settled urbanized environment, especially dietary factors. Methods: The community-based cross-sectional study included 920 Tibetan adults (men 419, women 501). Data were collected using questionnaires, anthropometric measurements, and biomarker tests. Questionnaires included socio-economic, lifestyle characteristics and food consumption. Principal component analysis was used to identify dietary patterns. The risk factors of MS and its components were analyzed by logistic regression model. Results: The prevalence rates of MS and its components were 32.8% (MS), 83.7% (decreased HDL-C), 62.1% (central obesity), 36.7% (elevated blood pressure), 11.8% (elevated TG), and 7.9% (elevated blood glucose), respectively. The prevalence of overweight was 31.2%, obesity 30.3%. Multivariate analysis showed smoking was associated factor for both of decreased HDL-C (OR=1.239, 95%CI: 1.025-1.496) and elevated TG (OR=1.277, 95%CI: 1.038-1.571). Alcohol drinking appeared as associated factor of elevated TG (OR=1.426, 95%CI: 1.055-1.927). However, physical activity showed as a protective factor for central obesity, decreased HDL-C, and elevated TG. With the increase of age, the adherence to the urban and western dietary patterns decreased, and that to the pastoral dietary pattern increased. By quintiles of dietary pattern scores, the urban dietary pattern was significantly associated with MS (trend test P=0.016). Conclusions: Tibetan pastoralists had high prevalence of both MS and obesity. Smoking, alcohol drinking, the transition from pastoral dietary pattern to urban dietary pattern and inadequate physical activity served as associated factors for MS and its components.

[Preliminary study on centrifugation time of liquid plasmatrix for soft tissue regeneration]

Objective: To provide reference for clinical application of liquid plasmatrix, and to investigate the optimal centrifugation time of liquid plasmatrix prepared by horizontal centrifugation for soft tissue regeneration from the aspects of mechanical properties, biological properties, and the effect of promoting soft tissue regeneration. Methods: Venous blood was collected from 6 healthy volunteers [3 males and 3 females, aged (26±2) years, with informed consent] who volunteered to donate blood at School of Stomatology, Wuhan University from September to November 2021. The collected venous blood was centrifuged at 500 ×g for 3, 5, 8 and 12 min to obtain liquid plasmatrix. The volume, weight, solidification time, and mechanical properties of liquid plasmatrix prepared at different centrifugation time were measured and recorded (the sample size at each time point was 3). The microstructure of different groups of liquid plasmatrix clot was observed by scanning electron microscope (SEM). The rheological properties of each group of liquid plasmatrix clot were measured by rheological test. The number and concentration of cells in the whole blood group and in each liquid plasmatrix group were measured using complete blood count test. The distribution of cells in the liquid plasmatrix clots was observed by hematoxylin-eosin staining. The effect of control group (Dulbecco's modified Eagle's medium containing 20% fetal bovine serum) and liquid plasmatrix clot exudates in 3, 5, 8, 12 min group (the sample size at each time point was 3) on gingival fibroblast migration was detected by cell migration method. Finally, the effects of control group and liquid plasmatrix clot exudates on the morphology of gingival fibroblasts were observed by fluorescence microscope. Results: The volume of liquid plasmatrix in 3, 5, 8 and 12 min group were approximately (2.47±0.12), (2.67±0.12), (3.53±0.12) and (3.73±0.12) ml, respectively. The weight of liquid plasmatrix in 3, 5, 8 and 12 min group were approximately (0.35±0.01), (0.46±0.02), (0.88±0.06) and (1.03±0.01) g, respectively. The maximum tensile force of liquid plasmatrix clots in 3, 5, 8 and 12 min group were (0.55±0.03), (0.56±0.03), (1.31±0.05) and (1.38±0.02) N, respectively. SEM results showed that the fibers inside the liquid plasmatrix clot became denser with increased centrifugation time. Compared with other groups, the concentrations of leukocytes, neutrophils, monocytes and lymphocytes in 8 min group were the highest, and the distribution of cell was more even. Compared with other groups, the efficiency of stimulating gingival fibroblast migration in 8 min group was the best (1.60±0.01). Fluorescence staining test showed that the liquid plasmatrix clot exudates could make gingival fibroblasts more stretched compared with control group. Conclusions: The present study shows that liquid plasmatrix prepared by centrifugation with 500 ×g centrifugal force for 8 min has higher concentration of viable cells and the ability to promote the migration of gingival fibroblasts.

[The safety and efficacy of anlotinib in combination with stereotactic radiotherapy for the treatment of brain metastases from non-small cell lung cancer]

Objective: To investigate the efficacy and safety of anti-vascular drug anlotinib in combination with stereotactic radiosurgery (SRS) for the treatment of brain metastases from non-small cell lung cancer (NSCLC). Methods: A total of 46 patients diagnosed with NSCLC brain metastases and treated with SRS in Peking University Third Hospital were included from October 2017 to June 2019. Of these, 21 patients (33 lesions) received anlotinib combined with SRS (combined treatment group), while 25 patients (35 lesions) only received SRS (SRS-alone group). The data of combined treatment group and SRS-alone group were compared, including remission rate of intracranial hypertension, response rate (RR) of local control of intracranial lesions, incidence of radiation-induced brain necrosis and intracranial progression-free survival (iPFS). The medication and adverse reactions of anlotinib in the combined treatment group were recorded. Results: The remission rate of intracranial hypertension in the combined treatment group was 71.4% (15/21), which was significantly higher than that in the SRS-alone group [12.0% (3/25), P<0.001). However, the RR of combined treatment group and SRS-alone group was 80.9% (17/21) and 60.0% (15/25), respectively, with no statistically significant difference (P=0.289). The incidence of radiation-induced brain necrosis in the combined treatment group was 3.0% (1/33), which was significantly lower than that in the SRS-alone group [20.0% (7/35), P=0.030]. The iPFS of the combination treatment group was (13.9±2.4) months, which was significantly longer than that in the SRS-alone group [(11.4±1.8) months, P<0.001]. The medication time of anlotinib in the combined treatment group was 6 (6, 18) weeks. One patient developed grade Ⅰ hypertension and one patient developed grade Ⅰ hand-foot syndrome. The incidence of drug-related adverse reactions was 9.5% (2/21). Conclusions: Anlotinib in combination with SRS may relieve brain edema, reduce the rate of radiation-induced brain necrosis, and the rate of drug-related adverse reactions were low.

High efficiency and collimated terahertz pulse from ultra-short intense laser and cone target

We propose a new, to the best of our knowledge, method to radiate a high-efficiency and collimated terahertz (THz) pulse from a relativistic femtosecond laser and cone target. Particle-in-cell simulations demonstrate that a THz source of 40 mJ, pointing at an angle of ∼20 ^∘, can be generated from a laser pulse of 1.9 J by using a cone target whose open angle is 10 ^∘. The peak power of the THz pulse is 10¹¹ W. This method, which manipulates the divergence angle and the energy conversion efficiency of the THz source, should promote THz science into the extra strong region with a compact laser system.

[Metagenomic data-analysis reveals enrichment of lipopolysaccharide synthesis in the gut microbiota of atrial fibrillation patients]

Objective: To investigate the functional changes of key gut microbiota (GM) that produce lipopolysaccharide (LPS) in atrial fibrillation (AF) patients and to explore their potential role in the pathogenesis of AF. Methods: This was a prospective cross-sectional study. Patients with AF admitted to Beijing Chaoyang Hospital of Capital Medical University were enrolled from March 2016 to December 2018. Subjects with matched genetic backgrounds undergoing physical examination during the same period were selected as controls. Clinical baseline data and fecal samples were collected. Bacterial DNA was extracted and metagenomic sequencing was performed by using Illumina Novaseq. Based on metagenomic data, the relative abundances of KEGG Orthology (KO), enzymatic genes and species that harbored enzymatic genes were acquired. The key features were selected via the least absolute shrinkage and selection operator (LASSO) analysis. The role of GM-derived LPS biosynthetic feature in the development of AF was assessed by receiver operating characteristic (ROC) curve, partial least squares structural equation modeling (PLS-SEM) and logistic regression analysis. Results: Fifty nonvalvular AF patients (mean age: 66.0 (57.0, 71.3), 32 males(64%)) were enrolled as AF group. Fifty individuals (mean age 55.0 (50.5, 57.5), 41 males(82%)) were recruited as controls. Compared with the controls, AF patients showed a marked difference in the GM genes underlying LPS-biosynthesis, including 20 potential LPS-synthesis KO, 7 LPS-biosynthesis enzymatic genes and 89 species that were assigned as taxa harbored nine LPS-enzymatic genes. LASSO regression analysis showed that 5 KO, 3 enzymatic genes and 9 species could be selected to construct the KO, enzyme and species scoring system. Genes enriched in AF group included 2 KO (K02851 and K00972), 3 enzymatic genes (LpxH, LpxC and LpxK) and 7 species (Intestinibacter bartlettii、Ruminococcus sp. JC304、Coprococcus catus、uncultured Eubacterium sp.、Eubacterium sp. CAG:251、Anaerostipes hadrus、Dorea longicatena). ROC curve analysis revealed the predictive capacity of differential GM-derived LPS signatures to distinguish AF patients in terms of above KO, enzymatic and species scores: area under curve (AUC)=0.957, 95%CI: 0.918-0.995, AUC=0.940, 95%CI 0.889-0.991, AUC=0.972, 95%CI 0.948-0.997. PLS-SEM showed that changes in lipopolysaccharide-producing bacteria could be involved in the pathogenesis of AF. The key KO mediated 35.17% of the total effect of key bacteria on AF. After incorporating the clinical factors of AF, the KO score was positively associated with the significantly increased risk of AF (OR<0.001, 95%CI:<0.001-0.021, P<0.001). Conclusion: Microbes involved in LPS synthesis are enriched in the gut of AF patients, accompanied with up-regulated LPS synthesis function by encoding the LPS-enzymatic biosynthesis gene.

[Morphological parameters of the posterior pole in a high myopia population aged over 40 years: a 10-year follow-up study]

Objective To study the long-term changes of the morphological parameters of the posterior pole in highly myopic patients over 40 years old in Chinese natural population. Methods A population-based follow-up study. The study included 71 patients (27 males, 44 females; 110 eyes) with high myopia who completed the Beijing Eye Study in 2001 and 2011 and had assessable color fundus photographs. The age of the patients in 2011 was 56.2±9.5 years old. According to the definition of pathological myopia by the meta-analysis of the Pathological Myopia Research Group, the fundus photos in 2001 were interpreted, and 110 eyes were divided into groups of simple high myopia (79 eyes) and pathological myopia (31 eyes). The morphological parameters during the 2 follow-up visits in 2001 and 2011 were measured in the color fundus photos, including optic disc tilt ratio, optic disc rotation degree, β zone area, disc-fovea distance, disc-outer β zone border distance, fovea-outer β zone border distance, and vertical distance between temporal arterial arcades, and compared in all the subjects, patients with simple high myopia and patients with pathological myopia. Correlations between the 10-year changes of these parameters and other parameters were analyzed using multiple linear regression analysis. Results In all subjects, the incidence of optic disc tilt and rotation was 41.1% (44/107) and 63.3% (68/107), respectively. The optic disc tilt ratio in 2001 and 2011 was 1.34±0.31 and 1.34±0.33, respectively. The optic disc rotation degree was 30.4±26.3° and 30.0±25.3 in 2001 and 2011, respectively. The differences in optic disc tilt ratio (Z=-0.317, P>0.05) and optic disc rotation degree (t=0.159, P>0.05) were not statistically significant. The β zone area [1.34 (0.45,3.73)mm², Z=-7.295, P<0.05], disc-fovea distance [(5.18±0.54)mm, t=-3.523, P<0.05], and disc-outer β zone border distance [1.55 (0.24,2.16)mm, Z=-6.825, P<0.05] in 2011 were significantly increased compared to those in 2001 [1.05 (0.23,1.88)mm², 5.08±0.43, 1.39 (0.77,1.93)mm]. There was no statistically significant difference in the vertical distance between temporal arterial arcades (Z=-1.858, P>0.05). The fovea-outer β zone border distance in the simple high myopia group in 2011 was significantly shorter than that in 2001 (Z=-3.221, P<0.05), while there was no significant change in this parameter in the pathological myopia group (t=0.655, P<0.05). In multivariate analysis, larger β zone area was significantly correlated with longer corneal curvature (r=0.462, P<0.05) and longer axial length (P<0.05). Longer disc-fovea distance was significantly correlated with lower best corrected visual acuity (r=0.348, P<0.05) and longer axial length (P<0.05). Similarly, longer disc-outer β zone border distance was related to lower best corrected visual acuity (r=0.538, P<0.05) and longer axial length (P<0.05). In addition, the progression of myopic maculopathy (Z=-3.425, P<0.05) and the progression from simple high myopia to pathological myopia (Z=-2.911, P<0.05) were both related to enlargement of the β zone. Conclusion For patients with high myopia aged over 40 years, the optic disc morphology is relatively stable, while the disc-fovea distance and β zone area will continue to increase with the progression of myopia. This may be due to the elongation of axial length. Enlargement of the β zone may be a predictor for the progression of myopic maculopathy. (Chin J Ophthalmol, 2021, 57:908-915).

[Prevention and treatment of hyperkalemia in chronic kidney disease]

Hyperkalemia is a common electrolyte disorder in patients with chronic kidney disease, and can be life-threatening in severe cases. It is an emergency that every clinician should recognize and master. This paper briefly describes the risk of hyperkalemia in order to pay more attention to hyperkalemia, summarizes the strategies for the treatment of hyperkalemia and reviews different treatment methods, so as to provide ideas for the treatment of hyperkalemia and improve the prognosis of patients.

Hydrogen solution in high-entropy alloys

High-entropy alloys (HEAs) have been reported to have superior ability in hydrogen (H) storage and strong resistance to H embrittlement. These exceptional properties are directly related to the H solution in the HEAs. However, the diversity of atomic environments in the HEAs complicate the calculation of the H solution energy. With regard to this, we clarified an origin causing the variety of solution energy from the viewpoint of chemical and elastic interactions of H with the host atoms. Combining the semi-empirical atom potential and first-principles calculations regarding H in FeCrCoNi, NbMoTaW, and FeCuCrMnMo, we found that the elastic interaction presents a visibly linear relationship with the volume expansion caused by H insertion. By contrast, the chemical interaction shows a non-linear relationship with the volume of the interstitial polyhedron. A universal model was then established to generalize the solution energy of H. This model can expeditiously assess the H distribution and provide insight into evolution of the microstructure in HEAs.

[Progress in research of avian influenza virus and human monoclonal antibody and vaccines against H7N9 virus]

Avian influenza virus (AIV) is a kind of zoonotic virus which can cause acute respiratory infectious diseases. Since the report of the world's first human infection case of avian influenza A (H7N9) virus in China in 2013, close attention has been paid to the virus. AIV spreads widely around the world, and human infection with different types of AIV continues to occur, causing huge economic losses. At present, there are no specific treatment and drugs against the disease, and vaccination is considered as the most promising and effective method to control the human infection with AIV. So far, there are many kinds of veterinary and human vaccines for H7N9 AIV, among which four types of human H7N9 AIV vaccines have entered the clinical trial stage, including virus-like particles vaccine, attenuated live vaccine, inactivated vaccine and DNA vaccine, which have shown good safety and immunogenicity. However, the true efficacies of the AIV vaccines remain unknown because no human vaccines are currently available in the market. In addition, although the existing influenza vaccine has good safety and immunogenicity in the human population, there is no cross-antibody response to H7N9 AIV. This paper summarizes the research progress of AIV etiology and epidemiology, the occupational exposure population investigation, the infection prevention and control strategies, and H7N9 AIV vaccine and H7N9 AIV anthropogenic monoclonal antibody, and discuss the remained problems, challenges and future trends in the research of AVI to improve the understanding of the disease and the prevention and control of global spread of AIV.

[Effects of eye exercises on axial eye elongation in junior students]

Objective: To evaluate the association between the eye exercises and one-year axial eye elongation in grade 7 students in Beijing. Methods: Sampling was performed using a multistage random cluster approach, and 1 443 students of grade 7 were selected from 9 middle schools in 6 districts for the baseline survey. Data were collected by questionnaires and axial length measurement. Multiple linear regression analysis was used to evaluate the association between eye exercises and excessive axial eye elongation. Results: Among 1 197 (82.95%) students with complete information, the median (Q_R) age was 12.00 (1.00) years old, girls accounted for 44.28%, and the median (Q_R) axial eye elongation was 0.22 (0.18) mm. In the multiple linear regression analysis, the frequency of eye exercises was significantly correlated with excessive axial eye elongation in boys (β=-0.135, 95%CI:-0.253--0.018) but not in girls (β=-0.075, 95%CI:-0.207- 0.058) after adjusting for sex, age, body height, the number of myopic parents, time spent outdoors and time spent on reading and writing outside class; while the seriousness of eye exercises was not significantly associated with axial eye elongation in boys (β=-0.028, 95%CI: -0.114-0.058) and girls (β=-0.035, 95%CI: -0.134-0.064). Conclusion: The increased frequency of eye exercises is beneficial to control the axial eye elongation in boys in Beijing.