[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.

Burden and distribution of monosodium urate deposition in patients with hyperuricemia and gout: a cross-sectional Chinese population-based dual-energy CT study

Background

To investigate the distribution and burden of monosodium urate (MSU) deposition in hyperuricemia and gout patients with dual-energy computed tomography (DECT).

Methods

A total of 1,936 consecutive patients from January 1, 2009, to September 15, 2017, underwent DECT examinations in Jinling Hospital. Of these, 1,294 patients were excluded due to other clinical diagnoses (n=1,041), inappropriate locations (n=82), poor-quality images (n=105), training cases (n=30) and duplicated data (n=36). Finally, 642 patients were included in this study. We retrospectively analyzed 1,127 DECT examinations in 642 consecutive patients (hyperuricemia group, n=121; gout group, n=521) and recorded the volume and number of MSU deposits. For each anatomical location, we recorded MSU deposition in the soft tissue and joint cavity. MSU deposition was analyzed and compared between groups. For normally distributed data, independent sample t-tests were used for comparison between the two groups. The independent samples nonparametric test was used to analyze nonnormally distributed data.

Results

(I) The burden of MSU deposition in the gout group {volume [0.14 (0.04-1.36)] and numbers [10.00 (5.00-19.00)]} was significantly higher than that {volume [0.08 (0.02-0.47), P=0.003] and numbers [9.50 (2.00-16.00), P=0.01]} in the hyperuricemia group. (II) The burden of MSU deposition in the knees {volume [0.24 (0.01-1.79), P=0.002] and quantity [6.00 (2.00-12.00), P=0.04]} and feet {volume [0.10 (0.04-0.66)] and number [9.00 (5.00-15.00)]} was significantly higher in the gout group than those {knees: the volume [0.03 (0.00-0.27), P=0.002] and the quantity [4.00 (0.00-9.00), P=0.04]; feet: the volume [0.07 (0.02-0.19), P=0.003)] and number [8.00 (2.25-12.00), P=0.04]} in the hyperuricemia group, respectively. (III) In the hyperuricemia group, the volume of MSU deposition was significantly higher in the soft tissues of the knee (0.022±0.042) and ankle (0.062±0.305) than in those (knee: 0.001±0.005, P=0.02; ankle: 0.027±0.234, P=0.02) in the joint cavity.

Conclusions

Although subclinical urate deposition can occur in patients with asymptomatic hyperuricemia, the burden of urate deposition is greater in patients with symptomatic gout, and the distribution is more pronounced in the foot/knee. Thus, more effective patient management and monitoring can be achieved by measuring the burden of MSU deposits in the patient's feet/knees. These data suggest that a threshold for urate crystal volume at typical sites may be required before symptomatic disease develops.

[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.

[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 (iFR_CT) 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, iFR_CT 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 iFR_CT in different sites. Bland-Altman and spearman correlation coefficient were used to analyze the consistency between iFR_CT and invasive FFR. Intraclass correlation coefficient (ICC) and spearman correlation coefficient were used to test the repeatability of iFR_CT. Results: iFR_CT 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 iFR_CT 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 iFR_CT 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 iFR_CT 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 iFR_CT and FFR. Conclusion: With the invasive FFR value as reference standard, iFR_CT had a high diagnostic performance in detecting myocardial ischemia and the best measurement site was the proximal downstream of the stenosis.

[Association of coronary perivascular fat attenuation index, the parameters of plaque and fractional flow reserve]

Objective: To explore the association of coronary perivascular fat attenuation index (FAI), the parameters of plaque and fractional flow reserve (FFR). Methods: A total of 113 patients (with 141 plaques) (78 males and 35 females, age from 40 to 83 years) with stable coronary artery disease were retrospectively collected from Jingling Hospital and Shanghai Sixth People's Hospital. All the patients underwent coronary CT angiography and invasive FFR examinations. The quantitative and qualitative parameters of plaque and vessel (such as the length and volume of plaque, the characteristics of plaque and high-risk plaque) and the FAI around the plaque were measured. The patients were divided into positive FAI group (n=46) and negative FAI group (n=66) according to the standard of whether the threshold of FAI≥ -70 HU. The quantitative indexes, including age, the length and volume of plaque, minimal lumen area (MLA) and FAI, as well as the qualitative indexed, including the characteristics of plaque, the number and characteristic of high-risk plaque and the number of patients and plaque with positive FFR were compared between the two groups. Further, logistic regression analysis was performed to analyze the correlation among myocardial ischemia, age, the length of plaque, minimal lumen area (MLA), FAI and so on. ROC curve was used for evaluating the performance of each parameter. Results: Compared to the negative FAI group, positive FAI group had lower MLA (2.00±1.33 mm² vs 4.13±2.41 mm², P<0.001). The proportion of patients and vessels with FFR<0.75 in positive FAI group were significantly higher than that in negative FAI group (21.3% vs 4.5%, P=0.006; 23.2% vs 8.2%, P=0.016). The FAI between high-risk plaque and non-high-risk plaque had no significant difference (21.2% vs 16.1%, P=0.451). FAI predicted myocardial ischemia (AUC=0.666, P=0.021) and significantly improved the prediction efficiency of complex model(0.915 vs 0.951,P=0.033). Conclusion: Lower MLA and higher incidence of myocardial ischemia were associated with patients with higher FAI. In addition, FAI has a certain prediction efficiency and can provide incremental value for the determination of myocardial ischemia.

[Radiation dose and image quality of noncontrast chest CT in domestic and imported main stream manufacturers]

Objective: To compare the radiation dose and image quality of noncontrast chest CT and detection of ground-glass opacity pulmonary nodules (GGN) in domestic 128-slice spiral CT with the other CT scanners from three main stream manufacturers. Methods: From May 8, 2018 to October 31, 2018, noncontrast chest CT images from Neusoft 128-slice CT (75 males, 25 females, (42±16) years), dual-source 64-slice CT (53 males, 47 females, (50±16) years) and dual-source 128-slice CT scanners(69 males, 31 females, (62±17) years), Toshiba 128-slice CT (51 males, 49 females, (58±13) years) and GE 128-slice CT scanner (55 males, 45 females, (60±10) years) were collected in Eastern Theater Command and Tianjin People's Hospital. Radiation dose and image quality were evaluated.GGN detected both in Neusoft CT and dual-source CT scanners were used to analyze the displaying ability of lesions. Results: The noise in lung window of Neusoft CT ((37.8±4.9) HU) was higher than that of other mainstream CT scanners, and the noise in mediastinal window ((8.4±1.9) HU) was lower than that of GE 128-slice CT ((9.8±3.2) HU), but higher than that of dual-source CT and Toshiba 128-slice CT ((6.9±3.5)HU) (P<0.05). The absolute value of lung SNR in Neusoft CT was lower than that of other mainstream CT scanners, and the SNR in aorta (4.6±1.3) was lower than those of dual-source CT and Toshiba 128-slice CT(6.8±2.2) (P<0.05), but was not statistically significant compared with GE 128-slice CT (5.0±1.7). The mean CT value of upper lung ((-863±31) HU) at Neusoft CT was higher than 128-row dual-source CT ((-869±35) HU), and the mean CT value of aorta ((37±7) HU) was lower than that of Toshiba 128-slice CT((42±7) HU) and GE 128-slice CT ((45±9) HU) (P<0.05), while the mean CT values of the remaining lung and aorta were not statistically significant (P>0.05). The two readers had good to excellent consistency for image quality in five scanners (the highest kappa value=0.984). The delineation ability of Neusoft CT for GGN boundary was lower than that of dual-source CT (P<0.05), but had similar abilities to display the solid components, lobulation, burring, vacuoles, vascular bundle sign and pleural depression sign of GGN (all P>0.05). Radiation dose of Neusoft CT was lower than Toshiba 128-slice CT, but higher than dual-source 64-sliceCT and GE 128-slice CT scanners (P<0.05). Conclusions: With lower radiation dose than Toshiba 128-slice CT, Neusoft CT chest examination can meet the requirements of clinical diagnosis, but higher radiation dose and the lower image quality than dual-source CT and GE 128-slice CT shown in this study indicate further improvement is needed in terms of software and hardware.

S-shaped non-paraxial corrections to general astigmatic beams

Non-paraxial perturbation wave equations are solved for general astigmatic Gaussian beams for the first time, to the best of our knowledge, in the angular spectrum representation by taking into account generic boundary conditions. Expressions for second-order corrections are derived and exemplified with an optical cavity made of two cylindrical mirrors. Non-paraxial corrections can lead, depending on the choice of boundary conditions, to a transverse S-shaped beam mode, which has been qualitatively been observed in a highly divergent non-planar four-mirror cavity.

High finesse pulsed optical cavity locking by tilt-locking technique

We report the Tilt-Locking (TL) technique applied to lock a laser in pulsed regime to a 28,000 high finesse Fabry-Perot cavity. Preliminary experimental results show that TL technique is comparable with the well-known Pound-Drever-Hall technique. This study is the first to implement the TL technique to lock a pulsed laser to a high-finesse optical cavity. Very high and stable coupling is obtained. The coupling rate is ~80%, and locking can last for more than 1 h. Furthermore, while previously published papers have focused on near field case, in this study we will give the error signal shape simulation for the far field case. We will show that for different types of error sources, the split photodiode transverse position can be carefully adjusted to obtain a symmetrical error signal. Our experimental results are consistent with the simulations.

A simple scheme for injection and extraction in compact rings

There has been great interest in building compact synchrotrons for various applications, for example, inverse Compton scattering X-ray sources. However, the beam injection and extraction in compact rings require careful design for the lack of space. In this paper, we propose a simple combined injection-extraction scheme exploiting the fringe field of existing dipole magnets instead of additional septum magnets. This scheme is illustrated by using the 4.8 m ring proposed for Tsinghua Thomson scattering X-ray source as an example. Particle tracking is applied to demonstrate the validity of this scheme.

Phase-space dynamics of ionization injection in plasma-based accelerators

The evolution of beam phase space in ionization injection into plasma wakefields is studied using theory and particle-in-cell simulations. The injection process involves both longitudinal and transverse phase mixing, leading initially to a rapid emittance growth followed by oscillation, decay, and a slow growth to saturation. An analytic theory for this evolution is presented and verified through particle-in-cell simulations. This theory includes the effects of injection distance (time), acceleration distance, wakefield structure, and nonlinear space charge forces, and it also shows how ultralow emittance beams can be produced using ionization injection methods.

Generating high-brightness electron beams via ionization injection by transverse colliding lasers in a plasma-wakefield accelerator

The production of ultrabright electron bunches using ionization injection triggered by two transversely colliding laser pulses inside a beam-driven plasma wake is examined via three-dimensional particle-in-cell simulations. The relatively low intensity lasers are polarized along the wake axis and overlap with the wake for a very short time. The result is that the residual momentum of the ionized electrons in the transverse plane of the wake is reduced, and the injection is localized along the propagation axis of the wake. This minimizes both the initial thermal emittance and the emittance growth due to transverse phase mixing. Simulations show that ultrashort (~8 fs) high-current (0.4 kA) electron bunches with a normalized emittance of 8.5 and 6 nm in the two planes, respectively, and a brightness of 1.7×10(19) A rad(-2) m(-2) can be obtained for realistic parameters.

Generating ultrabroadband terahertz radiation based on the under-compression mode of velocity bunching

We propose and analyze a scheme to generate enhanced ultrabroadband terahertz (THz) radiation through coherent transition radiation emitted by ultrashort electron beams based on a 10.5 m beamline at Tsinghua University. The proposed scheme involves the initial compression of the electron beam with a few hundred pC charges using a velocity bunching scheme (i.e., RF compression) in an under-compression mode instead of the usual critical-compression mode in order to maintain a positive energy chirp at the exit of the traveling wave accelerator. After a long drift segment, the particles in the tail catch up with the bunch head. More than 80% of the particles are distributed in a spike with an rms length less than 20 fs. Such beams correspond to an ultrabroadband coherent transition radiation (CTR) spectrum of 0.1 THz to 25 THz, with the single-pulse THz radiation energy of up to 50 μJ. The principle of CTR and under-compression mode of velocity bunching are introduced in this paper. And the ASTRA simulation parameters and the stability of the system are also discussed.

Effectiveness of a community-based multifaceted fall-prevention intervention in active and independent older Chinese adults

Objective:

To evaluate the effectiveness of an 18-month multifaceted intervention designed to reduce the incidence of falls in community-living older adults in China.

Methods:

A population-based community trial evaluated by before-and-after cross-sectional surveys. Four residential communities were randomised to either a multifaceted intervention or a control condition. Baseline information was collected from a sample of older adults in each community. A 1-year annual fall rate was calculated after an 18-month comprehensive intervention.

Results:

After intervention, 7.19% of the intervention community sample reported falls, compared with 17.86% of the control community sample (p<0.000). The annual fall rate decreased by 10.52% in the intervention communities, whereas the difference in control communities was not statistically significant.

Conclusions:

Multifaceted interventions in community settings may be useful in preventing falls among older people, and can be applied in similar settings in China.