Effect of COVID-19 infection on pregnant women in plateau regions.

OBJECTIVE: The present study aims to explore the effect of COVID-19 infection on pregnant women in plateau regions. STUDY DESIGN: Data from 381 pregnant women infected with COVID-19 who underwent prenatal examination or treatment at Women and Children's Hospital of Tibet Autonomous Region between January 2020 and December 2022 and 314 pregnant women not infected with COVID-19 were retrospectively collected. METHODS: The study participants were divided into an infected and non-infected group according to whether they were infected with COVID-19. Basic information (ethnicity, age, body mass index and gestational age [GA]), vaccination status, intensive care unit (ICU) admission and delivery outcomes were compared. Binary logistic regression was used to analyse the influencing factors of ICU admission. RESULTS: The results revealed significant differences in the GA, vaccination rate, blood pressure, partial pressure of oxygen, white blood cell (WBC) count, ICU admission rate, preeclampsia rate, forearm presentation rate, thrombocytopenia rate, syphilis infection rate and placental abruption rate between the two groups (P < 0.05). A univariate analysis showed that COVID-19 infection, hepatitis B virus infection, the WBC count and hypoproteinaemia were risk factors for ICU admission. The results of the multivariate analysis of the ICU admission of pregnant women showed that COVID-19 infection (odds ratio [OR] = 4.271, 95 % confidence interval [CI]: 3.572-5.820, P < 0.05) was a risk factor for ICU admission and the WBC count (OR = 0.935, 95 % CI: 0.874-0.947, P < 0.05) was a protective factor for ICU admission. CONCLUSION: Pregnant women are vulnerable to the adverse consequences of COVID-19 infection, and public health measures such as vaccination are needed to protect this population subgroup.

Association of clopidogrel resistance and ABCD-GENE score with long-term clinical prognosis in patients with ischemic stroke or TIA.

BACKGROUND: Clopidogrel resistance (CR) is associated with adverse clinical outcomes in acute ischemic stroke or transient ischemic attack (TIA) patients. However, whether CR affects the long-term clinical prognosis remains to be clarified. The ABCD-GENE score is a novel risk model that identifies CR in cardiovascular disease patients; its diagnostic ability and application in ischemic stroke or TIA remain to be studied. This study aimed to investigate the diagnostic ability of the ABCD-GENE score for CR and analyze the relationship between CR and long-term clinical prognosis in patients with ischemic stroke or TIA. METHODS: From January 2018 to January 2021, 251 ischemic stroke or TIA patients who were treated with clopidogrel for more than three months after onset and maintained the medication until the follow-up time were enrolled, and platelet reactivity was detected by thromboelastography. CYP2C19 gene analysis was performed. Adverse clinical outcomes were recorded from 3months after onset. The median follow-up time was 878days. RESULTS: The prevalence of CR was 33.9%. The proportion of CYP2C19 loss-of-function carriers was 62.2%. The ABCD-GENE score≥10 was independently associated with CR (OR=1.82, 95% CI: 1.02-3.24, P=0.041), and the C-statistic value of the score (as a binary and integer variable) on CR was 0.58 and 0.63, respectively. The risk of long-term adverse clinical outcomes was not significantly different between CR and clopidogrel sensitive groups (12.94% vs. 11.44%, HR=1.22, 95% CI: 0.57-2.62, P=0.603). A similar result was observed between ABCD-GENE score≥10 and ABCD-GENE score<10 groups (10.38% vs. 12.64%, HR=1.19, 95% CI: 0.55-2.60, P=0.666). CONCLUSIONS: In ischemic stroke or TIA patients, the ABCD-GENE score could identify the risk of CR. CR was not associated with long-term adverse clinical outcomes.

[Correlation and predictive value analysis of iliac artery calcification score and restenosis of lower extremity arteries after drug-coated balloon combined with stent implantation in patients with lower extremity atherosclerotic occlusive disease].

Objective: To analyze the correlation between iliac artery calcification score and restenosis of lower extremity arteries in patients with lower extremity atherosclerotic occlusive disease (LEASO) who underwent drug-coated balloon (DCB) combined with stenting, and to assess the predictive value. Methods: A total of 105 patients with LEASO at Nanjing Drum Tower Hospital, Nanjing University Medicine School, from January 2018 to June 2023 were retrospectively included, and the patients were divided into 2 groups according to whether restenosis of the original lower limb arteries had occurred during follow-up after DCB combined stent implantation: the restenosis group (n=64) and the patency group (n=41). The clinical information of the study subjects was collected through the electronic case system, and all patients underwent CTA examination of both lower limb arteries before the operation, and the calcification scores of common iliac arteries and external iliac arteries of patients' bilateral and stenotic sides were calculated according to the results of the CTA examination. The follow-up time [M (Q1, Q3)] was 9.15 (5.67, 15.60) months in the patency group and 9.20 (6.85, 19.65) months in the restenosis group. Univariate and multivariate logistic regression models were used to analyze the factors associated with restenosis after DCB combined with stent implantation in LEASO patients. The predictive value of iliac artery calcification score for postoperative restenosis was assessed using the receiver operating characteristic (ROC) curves. Results: There were 44 males and 20 females in the restenosis group, aged (73±9) years; 31 males and 10 females in the patency group, aged (73±10) years. Compared with the patency group, the restenosis group had higher neutrophil counts, platelet counts, lymphocyte counts, neutrophil-to-lymphocyte ratios (NLR), platelet-to-lymphocyte ratios (PLR), C-reactive protein, fibrinogen, stent lengths, stent numbers, common iliac artery calcification scores (bilateral and stenotic side), and external iliac artery calcification scores (bilateral and stenotic side) (all P<0.05). Multifactorial logistic regression analysis showed that higher external iliac artery calcification score on the stenotic side (OR=1.480, 95%CI: 1.130-1.939, P=0.004) was an associated factor for restenosis of the lower extremity arteries after DCB combined with stenting.ROC curve analysis showed that the cut-off value of the external iliac artery calcification score on the stenotic side was 5.5 score, the area under the curve (AUC) for predicting restenosis of lower extremity arteries after DCB combined stent implantation in LEASO patients was 0.818 (95%CI: 0.731-0.904, P<0.001), with a sensitivity of 85.4% and a specificity of 68.8%. Conclusions: An elevated calcification score of the external iliac artery on the stenotic side is a correlate of restenosis of the lower extremity arteries after DCB combined stenting in patients with LEASO. With a cut-off value of 5.5 points, its sensitivity for predicting restenosis of the lower extremity arteries after DCB combined stenting is 85.4%, and its specificity is 68.8%.

[Correlation analysis of carotid adipose tissue density and plaque stability in patients with carotid artery stenosis].

Objective: To investigate the correlation between perivascular fat density (PFD) and plaque stability in patients with carotid artery stenosis. Methods: Clinical data of 110 patients with carotid artery stenosis treated at Drum Tower Hospital, Nanjing University Medical School from January 2018 to December 2022 were retrospectively collected. Based on pathological results of carotid plaque specimens obtained from carotid endarterectomy (CEA), patients were categorized into stable plaque group (n=51) and vulnerable plaque group (n=59). All patients underwent preoperative carotid CT angiography (CTA) to measure PFD at the narrowest carotid artery. Preoperative levels of interleukin-6 (IL-6) and other hematological parameters were collected. Multivariable logistic regression analysis was used to identify factors associated with plaque stability in carotid artery stenosis patients. Area under the curve (AUC) of receiver operating characteristic (ROC) was performed to evaluate the predictive value of PFD for plaque stability. Results: The stable plaque group consisted of 43 males and 8 females with a mean age of (67.6±9.0) years, while the vulnerable plaque group comprised 48 males and 11 females with a mean age of (69.3±9.0) years. The proportions of smokers were 31.4% (16/51) and 50.8% (30/59) in the stable and vulnerable plaque groups, respectively. The proportions of patients with diabetes were 33.3% (17/51) and 52.5% (31/59), respectively. IL-6 levels were 3.46(2.67, 5.34) and 4.51(3.62, 5.51) ng/L in the stable and vulnerable groups, respectively. Mean PFD values were (-69.04±5.35) and (-63.24±6.08) HU, respectively, with maximum PFD values of (-62.90±6.98) and (-56.93±5.90) HU, respectively. The differences were statistically significant (all P<0.05). Multivariable logistic regression analysis showed that increased mean PFD (OR=1.167, 95%CI: 1.029-1.324, P=0.016) and elevated IL-6 levels (OR=1.489, 95%CI: 1.151-1.926, P=0.002) were associated with vulnerability of carotid artery plaques. ROC curve analysis results showed that a cut-off value of -65.5 HU, the AUC for predicting plaque stability based on the mean PFD was 0.756 (95%CI: 0.667-0.844, P<0.001), with sensitivity of 64.4% and specificity of 74.5%. Conclusion: Increased mean PFD at the narrowest carotid artery is associated with vulnerability of plaques in patients with carotid artery stenosis.

[Research progress on the association between prenatal exposure to air pollutants and hypospadias in the offspring].

Recent epidemiological studies have increasingly found that pregnant women who are exposed to air pollutants (for example airborne particulate matter, nitrogen oxides, ozone, and sulfur dioxide) increase the risk of various birth defects in their offspring, such as congenital heart disease, neural tube defects, cleft lip and palate, and hypospadias. Hypospadias not only impairs the sexual function of infants but also causes major social and psychological problems during their growth period, therefore, the prevention and treatment of hypospadias infant carry substantial public health importance. However, the association between prenatal exposure to air pollution and hypospadias remains controversial. The study reviews the epidemiological research progress and potential biological mechanisms of prenatal maternal exposure to air pollutants such as particulate matter, nitrogen oxides, ozone, sulfur dioxide, and the risk of hypospadias in offspring. The study also summarizes the limitations of previous research and looks forward to future research directions, to provide scientific evidence for creating a healthy living environment for pregnant women, and reducing the risk of hypospadias in offspring.

Average and statistical properties of coherent radiation from steady-state microbunching.

A promising accelerator light source mechanism called steady-state microbunching (SSMB) is being actively studied. With the combination of strong coherent radiation from microbunching and high repetition rate of a storage ring, high-average-power narrow-band radiation can be anticipated from an SSMB storage ring, with wavelengths ranging from THz to soft X-ray. Such a novel light source could provide new opportunities for accelerator photon science like high-resolution angle-resolved photoemission spectroscopy and industrial applications like extreme ultraviolet (EUV) lithography. In this paper, a theoretical and numerical study of the average and statistical properties of coherent radiation from SSMB are presented. The results show that 1 kW average-power quasi-continuous-wave EUV radiation can be obtained from an SSMB ring provided that an average current of 1 A and a microbunch train with bunch length of 3 nm can be formed at the radiator which is assumed to be an undulator. Together with the narrow-band feature, the EUV photon flux can reach 6 × 1015 photons s-1 within a 0.1 meV energy bandwidth, which is three orders of magnitude higher than that in a conventional synchrotron source and is appealing for fundamental condensed matter physics and other research. In this theoretical investigation, we have generalized the definition and derivation of the transverse form factor of an electron beam which can quantify the impact of its transverse size on coherent radiation. In particular, it has been shown that the narrow-band feature of SSMB radiation is strongly correlated with the finite transverse electron beam size. Considering the pointlike nature of electrons and quantum nature of radiation, the coherent radiation fluctuates from microbunch to microbunch, or for a single microbunch from turn to turn. Some important results concerning the statistical properties of SSMB radiation are presented, with a brief discussion on its potential applications, for example the beam diagnostics. The presented work is of value for the development of SSMB to better serve potential synchrotron radiation users. In addition, this also sheds light on understanding the radiation characteristics of free-electron lasers, coherent harmonic generation, etc.

[The prognostic value of morphological and functional parameters of cardiac magnetic resonance in patients with systemic light chain amyloidosis].

Objective: To investigate the features of morphological and functional parameters of cardiac magnetic resonance (CMR) in patients with systemic light chain (AL) amyloidosis, and the prognostic values of these related parameters. Methods: The data of 97 patients (including 56 males and 41 females, aged 36 to 71 years) with AL amyloidosis from April 2016 to August 2019 in the General Hospital of Eastern Theater Command were retrospectively analyzed. All patients underwent CMR examination. Those patients were divided into survival (n=76) and death groups (n=21) according to the clinical outcomes, and the differences in clinical baseline and CMR parameters between the two groups were analyzed and compared. A smooth curve fitting was used to analyze the association between morphological and functional parameters and extracellular volume (ECV), and Cox regression models were conducted to explore the association between related parameters and mortality. Results: The left ventricular global function index (LVGFI), myocardial contraction fraction (MCF) and stroke volume index (SVI) decreased with increasing ECV [ß (95%CI) was -0.566 (-0.685--0.446), -1.201 (-1.424--0.977), -0.149 (-0.293--0.004), respectively;all P<0.05]. Left ventricular mass index (LVMI), and diastolic left ventricular global peak wall thickness (LVGPWT) increased with increasing ECV [ß(95%CI) was 1.440 (1.142-1.739), 0.190 (0.147-0.233), respectively;both P<0.001]. While left ventricular ejection fraction (LVEF) began to decrease only at higher amyloid burden (ß=-0.460, 95%CI:-0.639--0.280, P<0.001). The median follow-up time was 39 months (range 2-64 months), and 21 patients died during the follow-up period. The estimated survival rates according to Kaplan-Meier curves at 1, 3, and 5 years were 92.8%, 78.7%, and 77.1%, respectively. MCF<39% (HR=10.266, 95%CI: 4.093-25.747) and LVGFI<26% (HR=9.267, 95%CI: 3.705-23.178) were independent risk factors for death in patients with AL amyloidosis after adjusting for other CMR parameters (P<0.001). Conclusion: Multiple morphologic and functional parameters of CMR vary with the increase of ECV. MCF<39% and LVGFI<26% were independent risk factors for death.

[Research progress in stent associated respiratory tract infection].

Airway stents are commonly used to treat patients with central airway obstruction, but several complications have been identified, including mucus plugging, granulation tissue, stent migration, and infection. Stent associated respiratory tract infection (SARTI) has often been neglected by the practicing clinicians. Therefore, we reviewed the available current literatures on the diagnosis and management of stent associated respiratory tract infection.

[A survey on the practice of bronchoscopy in county-level hospitals of China].

Objective: To investigate the bronchoscopy resource allocation and technology application in county-level hospitals in China. Methods: A cross-sectional survey was conducted. In 2021, 12 provinces were sampled from all provinces in China according to the regional Gross Domestic Product (GDP) and the number of counties, in which a total of 291 county-level hospitals were randomly enrolled. Two county-level hospitals which carried out bronchoscopy technology in each province were randomly sampled to investigate the status of bronchoscopy resources, technical application, decontamination and anesthesia by using questionnaires. Independent sample t test or two related sample nonparametric test were used for comparison between groups. Spearman correlation analysis was used to explore the correlation. Bilateral P<0.05 was considered statistically significant. Results: According to the sampling results, it was estimated that in the county-level hospitals, the proportion of those performing bronchoscopy was 11.4% (9.9%, 13.8%), which was significantly correlated with the population in the province (r=0.64, P=0.025) and the regional GDP (r=0.65, P=0.025).The 24 county-level hospitals interviewed were equipped with (1.6±1.0) bronchoscopes on average, and the number of hospitals with electronic bronchoscopes and fiberoptic bronchoscopes was 22 (91.7%) and 6 (25.0%), respectively. Six (25.0%) hospitals performed bronchoscopy every working day. Twelve (50.0%) hospitals had relatively permanent physicians and nurses. All operating doctors had received special training. There was a significant increase in the number of bronchoscopy cases per hospital in 2020 compared to 2019 [140(70, 335) vs. 100(29, 254), P=0.001]. All hospitals used standard cleaning and sterilization workbenches, cleaning agents and disinfectants. Surface anesthesia was available in 24 hospitals, and bronchoscopy techniques under sedation and analgesia were performed in 10 (41.7%) hospitals. Atropine was still used to prevent airway secretions in 2 (8.3%) hospitals,although not recommended by guidelines. Conclusions: There was a large gap between the current status of bronchoscopy technology in county-level hospitals and the standards of the National Health Commission, together with regional disparities. Bronchoscopist training in the standardization and the decontamination work met the requirements. In some hospitals, the use of complementary medicines was not standardized or the sedatives were not given routinely according to the guidelines. We should promote the popularization and standardization of bronchoscopy technology, and strengthen the allocation of related resources in China's county hospitals.

[A multicenter study to test the reliability and validity of the frailty assessment scale for elderly patients with inguinal hernia and to evaluate the value of clinical application].

Objectives: To verify the reliability and validity of the frailty assessment scale for elderly patients with inguinal hernia and to evaluate the value of its clinical application. Methods: A convenience sampling method was used to collect 129 geriatric patients who underwent inguinal hernia surgery from January 2018 to January 2023 in nine hospitals in Liaoning Province. There were 120 males and 9 females, of whom 89 patients were 60 to <75 years old, 33 patients were 75 to <85 years old and 7 patients were ≥85 years old. The 129 patients included 11 elderly patients with inguinal hernia who had recovered from preoperative infection with COVID-19. Statistical methods such as Cronbach's coefficient, Kaiser-Meyer-Olkin test, Bartlett's test, Pearson's correlation analysis, etc. were calculated to verify the reliability indexes such as feasibility, content validity, structural validity, criterion-related validity, internal consistency reliability, and re-test reliability. Taking the 5-item modified frailty index (5-mFI) as the gold standard, the area under the curve was used to analyze the ability of the two scales to predict the occurrence of postoperative acute urinary retention, postoperative delirium, poor incision healing, operative hematoma seroma, and postoperative complications. Results: The frailty assessment scale for elderly patients with inguinal hernia showed good reliability and validity (valid completion rate of 99.2%; item content validity index of 1.000, and the scale content validity index of 1.000; exploratory factor analysis extracted a total of 1 principal component, and factor loadings of each item of 0.565 to 0.873; the AUC for frailty diagnosis using 5-mFI as the gold standard of 0.795 (P<0.01) Cronbach's coefficient of 0.916, retest reliability coefficient of 0.926), it could effectively predict postoperative acute urinary retention, delirium, hematoma seroma in the operative area and total complications (AUC of 0.746, 0.870, 0.806, and 0.738, respectively; all P<0.05), and prediction efficiency was higher than that of 5-mFI (AUC of 0.694, 0.838, 0.626 and 0.641, P<0.05 for delirium only), but both scales were inaccurate in predicting poor incision healing (AUC of 0.519, P=0.913 for the frailty assessment scale and 0.455, P=0.791 for the 5-mFI). Conclusions: The frailty assessment scale for elderly patients with inguinal hernia is reliable and significantly predicts the occurrence of postoperative adverse events in elderly inguinal hernia patients. The scale can also be used for preoperative frailty assessment in elderly patients with inguinal hernia after rehabilitation from COVID-19 infection.

[Research advances on size selection and vault prediction of posterior chamber phakic intraocular lens].

Posterior chamber phakic intraocular lens (pIOL) implantation has been widely adopted for the correction of refractive errors. Among pIOLs, the Implantable Collamer Lens is the most common choice. The selection of the appropriate pIOL size and achieving the desired postoperative vault to minimize complications has consistently been a focal point in academic research. With the advancement of ophthalmic biometric measurement technology and the application of artificial intelligence in the field of medicine, numerous new technologies and methods for pIOL size selection and vault prediction have emerged in recent years. This paper provides a comprehensive review on the topic of how to choose the pIOL size and predict the vault.

Processed electroencephalography: impact of patient age and surgical position on intraoperative processed electroencephalogram monitoring of burst-suppression.

We previously reported that processed EEG underestimated the amount of burst suppression compared to off-line visual analysis. We performed a follow-up study to evaluate the reasons for the discordance. Forty-five patients were monitored intraoperatively with processed EEG. A computer algorithm was used to convert the SedLine® (machine)-generated burst suppression ratio into a raw duration of burst suppression. The reference standard was a precise off-line measurement by two neurologists. We measured other potential variables that may affect machine accuracy such as age, surgery position, and EEG artifacts. Overall, the median duration of bust suppression for all study subjects was 15.4 min (Inter-quartile Range [IQR] = 1.0-20.1) for the machine vs. 16.1 min (IQR = 0.3-19.7) for the neurologists' assessment; the 95% limits of agreement fall within - 4.86 to 5.04 s for individual 30-s epochs. EEG artifacts did not affect the concordance between the two methods. For patients in prone surgical position, the machine estimates had significantly lower overall sensitivity (0.86 vs. 0.97; p = 0.038) and significantly wider limits of agreement ([- 4.24, 3.82] seconds vs. [- 1.36, 1.13] seconds, p = 0.001) than patients in supine position. Machine readings for younger patients (age < 65 years) had higher sensitivity (0.96 vs 0.92; p = 0.021) and specificity (0.99 vs 0.88; p = 0.007) for older patients. The duration of burst suppression estimated by the machine generally had good agreement compared with neurologists' estimation using a more precise off-line measurement. Factors that affected the concordance included patient age and position during surgery, but not EEG artifacts.

[Novel study and applications of CT angiography derived fractional flow reserve in China].

CT angiography derived fractional flow reserve (CT-FFR) has been an important tool for evaluating functional significance of coronary stenosis since 2011, promoting coronary CT angiography (CCTA) from the era of traditional anatomical evaluation to a new era of functional evaluation,playing a key role in guiding clinical decisions and prognostic evaluation of coronary artery disease. This review focuses on the innovative research and contributions of Chinese scholars' in CT-FFR filed, including homemade techniques, extending clinical applications and generalization of CT-FFR.

[Temporal trend of antibiotic use among primary school children in Shanghai, 2017-2020].

To investigate the temporal trend of antibiotic use among children in Shanghai from 2017 to 2020. The stratified cluster sampling method was used to establish a dynamic cohort of healthy children based on primary schools in Changning District, Shanghai. In the cohort, there were 282 children from 2017, 287 children from 2018, 294 from 2019 and 301 from 2020. A total of 700 children aged 7-11 years were included in the study. The basic information and antibiotic use of children were investigated by questionnaire every year, and their height and weight were measured at the same time. Chi-square test was used to analyze the difference of antibiotic use rate in each year and generalized estimation equation was used to analyze the temporal trend of antibiotic use. The results showed that the use rates of all antibiotics, cephalosporins, azithromycin and other antibiotics (including penicillin, lincomycin, quinolones, etc.) of children between 2017 and 2020 were 15.6%, 10.5%, 2.7%, and 2.4%, respectively. In 2017, 2018, 2019, and 2020, there were significant differences for the use rates of total antibiotics and other antibiotics in children (P=0.033, P=0.040), and there were no significant differences for the use rates of cephalosporins and azithromycin (P=0.274, P=0.455). After adjusting for children's basic characteristics, the generalized estimation equation showed that the annual use rate of all antibiotics, cephalosporins, and other antibiotics decreased over time.

[Emphasis on the prevention and treatment of hepatic vascular diseases].

Portal hypertension, as a common and complex hepatic vascular disease, is a key pathophysiological link in many events of acute cirrhosis decompensation and the progression of multiple organ failure. The most effective measure to reduce portal hypertension is a transjugular intrahepatic portosystemic shunt (TIPS). Maintaining liver function, reducing complications, and improving patients' quality of life and survival time are positively impacted by early TIPS insertion. Patients with cirrhosis have a risk of portal vein thrombosis (PVT) that is 1 000 times higher than that of the normal population. Hepatic sinusoidal obstruction syndrome has a severe clinical course and a high mortality risk. The primary treatment approaches for PVT and HSOS are anticoagulation and TIPS. The innovative magnetic anastomosis vascular technique significantly shortens the anhepatic time and restores normal liver function in patients following liver transplantation.

CNN-based qualitative detection of bone mineral density via diagnostic CT slices for osteoporosis screening.

The features extracted from diagnostic computed tomography (CT) slices were used to qualitatively detect bone mineral density (BMD) through neural network models, and the evaluation results indicated that it may be a promising approach to perform osteoporosis screening in clinical practice. INTRODUCTION: The purpose of this study is to design a novelty diagnostic method for osteoporosis screening by using the convolutional neural network (CNN), which can be incorporated into the procedure of routine CT diagnostic in medical examination thereby improving the osteoporosis diagnosis and reducing the patient burden. METHODS: The proposed CNN-based method mainly comprises two functional modules to perform qualitative detection of BMD by analyzing the diagnostic 2D CT slice. The first functional module aims to locate and segment the ROI of diagnostic 2D CT slice, called Mark-Segmentation-Network (MS-Net). The second functional module is used to determine the category of BMD by the features of ROI, called BMD-Classification-Network (BMDC-Net). The diagnostic 2D CT slice of pedicle level in lumbar vertebrae (L1) was selected from 3D CT image in our experiments firstly. Then, the trained MS-Net can get the mark image of input original 2D CT slice, thereby obtain the segmentation image. Finally, the trained BMDC-Net can obtain the probability value of normal bone mass, low bone mass, and osteoporosis by inputting the segmentation image. On the basis of network results, the radiologists can provide preliminary qualitative diagnosis results of BMD. RESULTS: Training of the network was performed on diagnostic 2D CT slices of 150 patients. The network was tested on 63 patients. Each patient corresponds to a 2D CT slice. The proposed MS-Net has an excellent segmentation precision on the shape preservation of different lumbar vertebra. The dice index (DI), pixel accuracy (PA), and intersection over union (IOU) of segmentation results are greater than 0.8. The proposed BMDC-Net achieved an accuracy of 76.65% and an area under the receiver operating characteristic curve of 0.9167. CONCLUSIONS: This study proposed a novel method for qualitative detection of BMD via diagnostic CT slices and it has great potential in clinical applications for osteoporosis screening. The method can potentially reduce the manual burden to radiologists and diagnostic cost to patients.

Effect modification of the association between diurnal temperature range and hospitalisations for ischaemic stroke by temperature in Hefei, China.

OBJECTIVES: Diurnal temperature range (DTR) is an important indicator of global climate change. Many epidemiological studies have reported the associations between high DTR and human health. This study investigated the association between DTR and hospitalisations for ischaemic stroke in Hefei, China. STUDY DESIGN: This is an ecological study. METHODS: Data of daily hospital admissions for ischaemic stroke and meteorological variables from 1 January 2009 to 31 December 2017 were collected in Hefei, China. A generalised additive model combined with distributed lag non-linear model was used to quantify the effects of DTR on ischaemic stroke. The interactive effect between DTR and temperature was explored with a non-parametric bivariate response surface model. RESULTS: High DTR was associated with hospitalisations for ischaemic stroke. The adverse effect of extremely high DTR (99th percentile [17.1 °C]) occurred after 8 days (relative risk [RR] = 1.021, 95% confidence interval [CI] = 1.002, 1.041) and the maximum effect appeared after 12 days (RR = 1.029, 95% CI = 1.011, 1.046). The overall trend of the effect of DTR on ischaemic stroke was decreasing. In addition, there was a significant interactive effect of high DTR and low temperature on ischaemic stroke. CONCLUSIONS: This study suggests that the impact of high DTR should be considered when formulating targeted measures to prevent ischaemic stroke, especially for those days with high DTR and low mean temperature.

[To promote actively clinical application of advanced cardiovascular CT imaging].

In recent years, cardiovascular imaging has become an important tool to evaluate cardiovascular diseases, which can provide anatomical and function information in multidimensional ways, and is expected to have a positive impact on the diagnosis and treatment of cardiovascular diseases. This editorial briefly describes the current status of advanced cardiovascular CT imaging in cardiovascular diseases on diagnosis, treatment, decision-making and prognostic evaluation, including CT-derived flow fractional reserve, CT perfusion, pericoronary adipose tissue and application of artificial intelligence, in order to promote the clinical transformation of these technologies.

[Effect of measurement sites on coronary computed tomography angiography-derived instantaneous wave-free ratio in the diagnosis of coronary stenosis ischemia].

Objective: To explore the influence of measurement sites on the diagnostic performance of coronary computed tomography angiography (CCTA) -derived instantaneous wave-free ratio (iFRCT) for coronary stenosis ischemia. Methods: A total of 44 patients, including 27 males and 17 females aged from 44 to 83 (59±90) years, who underwent coronary computed tomography angiography (CCTA) and invasive fractional flow reserve (FFR) in the Department of Radiology, Eastern Theater Command General Hospital from February 2009 to May 2018 were retrospectively collected. Based on CCTA images, iFRCT values at different locations (stenosis, proximal downstream of stenosis, 2 cm downstream of stenosis, 3 cm downstream of stenosis, and 4 cm downstream of stenosis) were calculated through fluid mechanics simulation. With invasive FFR≤0.80 as the reference standard, receiver operating characteristic (ROC) was used to analyze and evaluate the diagnostic performance of iFRCT in different sites. Bland-Altman and spearman correlation coefficient were used to analyze the consistency between iFRCT and invasive FFR. Intraclass correlation coefficient (ICC) and spearman correlation coefficient were used to test the repeatability of iFRCT. Results: iFRCT values at the proximal downstream of the stenosis (approximately 1 cm downstream of the stenosis) was superior to other measurement sites in the diagnosis of coronary ischemic specific stenosis. The threshold, area under the curve, sensitivity, specificity and accuracy of iFRCT at the stenosis were 0.91, 0.87 (95%CI:0.76~0.96), 82% (95%CI:48%~97%), 76% (95%CI:57%~88%) and 77% (95%CI: 63%~87%), respectively. Bland-Altman analysis showed that the mean differences between iFRCT and FFR at the proximal downstream of the stenosis was 0.07 (95%LoA: 0.06~0.09) and Spearman correlation coefficient was 0.53 (P<0.001). At the proximal downstream of the stenosis, the intraobserver ICC of iFRCT was 0.92 (95%CI: 0.85 ~0.95), the correlation coefficient was 0.85 (P<0.001); the interobserver ICC was 0.84 (95%CI: 0.60~0.94), correlation coefficient was 0.75 (P<0.001), demonstrating good repeatability between iFRCT and FFR. Conclusion: With the invasive FFR value as reference standard, iFRCT had a high diagnostic performance in detecting myocardial ischemia and the best measurement site was the proximal downstream of the stenosis.

[Effects of remote ischemic preconditioning on contrast-induced acute kidney injury after percutaneous coronary intervention in patients with chronic total occlusion].

Objective: To investigate the effect of remote ischemic preconditioning (RIPC) on contrast-induced acute kidney injury (CI-AKI) in patients with chronic total occlusion (CTO) after percutaneous coronary intervention (PCI). Methods: A total of 282 patients undergoing PCI at Zhongda Hospital Affiliated to Southeast University between June 2017 and January 2019 were prospectively enrolled. The patients were randomly divided into RIPC group (n=142) and control group (n=140). CI-AKI was defined as an increase in level of cystatin C (CysC)≥10% above baseline at 24 h after contrast administration. Baseline characteristics and the incidence of CI-AKI were compared between the two groups. The multivariate logistic regression analysis was further used to analyze the independent risk factors of CI-AKI. Results: There were no significant differences in age, gender, smoking, hypertension, diabetes, stroke and old myocardial infarction, coronary artery bypass graft surgery, previous PCI history and laboratory test indicators, target vessel and pathological characteristics of CTO lesions, contrast agent dosage, J-CTO (Multicenter CTO Registry in Japan) score, SYNTAX (Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery) score, PCI success rate and stent number between the two groups (P>0.05). The incidence of CI-AKI was significantly lower (18.3% vs 29.3%, P=0.036) in RIPC group than that of control group. Multivariate logistic analysis found that creatinine [odds ratio (OR)=1.018,95%CI: 1.006-1.030, P=0.003], CysC (OR=5.200, 95%CI:2.714-9.963, P<0.001),contrast agent dosage (OR=1.013,95%CI: 1.007-1.019, P<0.001) and J-CTO score (OR=1.834, 95%CI: 1.145-2.939, P=0.012) were independent risk factors of CI-AKI. However, RIPC was an independent protective factor of CI-AKI (OR=0.391, 95%CI: 0.199-0.765, P=0.006). Conclusion: RIPC before contrast agent administration prevents CI-AKI in CTO patients undergoing PCI.