[Relationship between valve ablation and bladder function in children with posterior urethral valves disorder]

This study is to investigate the effect of valve ablation on bladder function in patients with posterior urethral valves. The clinical data of patients with posterior urethral valves who received urodynamic examination before and after valve ablation were retrospectively analyzed.The bladder compliance improved during urine storage after operation, and the maximum detrusor pressure decreased during micturition. The postoperative urinary system ultrasound showed that the residual urine volume of the group with significantly improved upper urinary tract hydrocephalus was significantly less than that of the group with no improvement. The bladder compliance was significantly higher than that of the group with no improvement, and the maximum urine flow rate was significantly higher than that of the group with no improvement (all P<0.05). Valve ablation has limited effect on improving bladder function in patients with PUV. Valve incision can help improve the maximum bladder volume, residual urine volume and maximum urinary flow rate. It has a certain effect on bladder compliance and maximum detrusor pressure.

[A prospective cohort study on socioeconomic status and risk of all-cause mortality among patients with type 2 diabetes based on latent class analysis]

Objective: To investigate the relationship between socioeconomic status (SES) and all-cause mortality in patients with type 2 diabetes. Methods: A total of 17 553 patients with type 2 diabetes were recruited under the National Basic Public Health Service Project in Changshu county, Qingjiangpu district, and Huai'an district in Huai'an city of Jiangsu province as participants. Latent class analysis was applied to classify the individuals based on five socioeconomic indicators. Then, Cox proportional hazards regression models were used to estimate the associations of different levels of SES with all-cause mortality, and stratified analysis was performed according to age and area. Results: Among 100 529.08 person-years of the fo1low-up, the median follow-up time was 5.7 years, and 1 829 deaths occurred during the follow-up period. According to the relevant results of the latent class model, the model of the "three classes" was the best. The related population was then divided into low SES (8 256 people, 47.0%), medium SES (4 427 people, 25.2%), and high SES groups (4 870 people, 27.8%). Compared to patients with high SES, the multivariate-adjusted hazard ratio (95%CI) of all-cause mortality associated with low SES for males and females were 1.84 (1.53-2.21) and 1.41 (1.51-1.72), respectively. Stratified analysis showed that the hazard ration (95%CI) of all-cause mortality associated with low SES for males and females were 1.99 (1.12-2.95) and 2.01 (1.20-3.23), respectively, in people younger than 60 years old, and were 1.90 (1.57-2.31) and 1.40 (1.13-1.73) in people over 60 years old. The HR values (95%CI) for all-cause mortality associated with low SES for the male and females were 1.54 (1.17-2.04) and 1.27 (1.02-1.59) in the urban population with 2.11 (1.55-2.85) and 2.64 (1.17-3.35) in rural population, respectively. Conclusions: Lower SES increased the risk of all-cause mortality in type 2 diabetic patients, which is more significant in younger and rural populations.

[Characteristics and depressive symptoms among self-reported HIV infection through heterosexual transmission men who have sex with men]

Objective: To understand the characteristics and depressive status of men who have sex with men (MSM) who self-reported HIV infection through heterosexual transmission and to provide evidence for personalized management of HIV infected people. Methods: A cross-sectional survey was carried out in Shandong province from September to December in 2019. Male HIV patients aged ≥15 years who self-reported HIV infection through heterosexual transmission were selected to verify the route of infection by one-to-one interview in Ji'nan, Qingdao, Weifang and Linyi cities of Shangdong province. According to the 1∶1 ratio, local HIV patients with age difference ≤3 years who self-reported MSM were selected as controls. A questionnaire survey was conducted, including data on demographic characteristics, behavior status, CES-D and PSSS. The related factors of the depressive symptoms and characteristics were analyzed. Results: A total of 373 male HIV patients were interviewed, and 39.7%(148/373) were confirmed as MSM after reexamination. The interviewers were: aged (40.3±12.0) years old, 41.9% (62/148) married/cohabiting. 27.0% (40/148) had been tested before HIV diagnosis, 71.6% (106/148) had homosexual partners ≥2 and 55.4% (82/148) had depressive symptom. Multivariate analysis showed that the MSM without HIV testings before diagnosis, had homosexual partners ≥2 before diagnosis, had first homosexual behavior at the age >30 years old and with depressive symptoms were more likely to conceal the true infection route. The incidence of depression among MSM who self-reported HIV infection through heterosexual transmission was related to physical health status social support and occupational stability. Conclusions: Some male HIV persons self-reported as being heterosexually transmitted were really transmitted through homosexual behavior. There were high-risk behaviors such as multiple partners and intersex among this group, and with high incidence of depression. It is necessary to encourage the reexamination program during follow-up and target on psychological and behavioral interventions, continuously.

Visible imaging system with changeable field of view on the HL-2A tokamak

A new visible imaging system characterizing a flexible optical design and delivering high resolution frames is established on the HL-2A tokamak. It features a modular configuration, consisting of a front-end imaging lens, a set of bilateral telecentric relay lenses, and a camera. To avoid the effects of plasma radiation (x and gamma-rays) and magnetic field variation on the camera, it should be away from the coils. Therefore, the length of the relay lenses determines the total size of the imaging system. The main feature of this imaging system is to realize the variation of field of view (FOV) by interchanging the front-end prime lenses or by using a zoom lens directly rather than designing the optical system afresh, which lowers the cost drastically. The primary purpose of varying FOV is to enrich the versatility of this system, i.e., focusing on a narrow FOV such as gas puff imaging or a wide FOV such as the plasma cross sections. During the HL-2A experiments, this visible imaging system is used to provide high quality pictures of the plasma-wall interaction, divertor detachment, pellet injections, and so on. The frames confirmed that a strong radiation close to the X point is correlated with the completely detached inner target.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Improving coronary ultrafast Doppler angiography using fractional moving blood volume and motion-adaptive ensemble length

Coronary microperfusion assessment is a key parameter for understanding cardiac function. Currently, coronary ultrafast Doppler angiography is the only non-invasive clinical imaging technique able to assess coronary microcirculation quantitatively in humans. In this study, we propose to use fractional moving blood volume (FMBV), proportional to the red blood cell concentration, as a metric for perfusion. FMBV compares the power Doppler in a region of interest (ROI) inside the myocardium to the power Doppler of a reference area in the heart chamber, fully filled with blood. This normalization gives then relative values of the ROI blood filling. However, due to the impact of ultrasound attenuation and elevation focus on power Doppler values, the reference area and the ROI need to be at the same depth to allow this normalization. This condition is rarely satisfied in vivo due to the cardiac anatomy. Hereby, we propose to locally compensate the attenuation between the ROI and the reference, by measuring the attenuation law on a phantom. We quantified the efficiency of this approach by comparing FMBV with and without compensation on a flow phantom. Compensated FMBV was able to estimate the ground-truth FMBV with less than 5% variation. This method was then adapted to the in vivo case of myocardial perfusion imaging during heart surgery on human neonates. The translation from in vitro to in vivo required an additional clutter filtering step to ensure that blood signals could be correctly identified in the fast-moving myocardium. We applied the singular value decomposition filter on temporal sliding windows whose lengths were a function of myocardium motion. This motion-adaptive temporal sliding window approach was able to improve blood and tissue separation in terms of contrast-to-noise ratio, as compared to well-established constant-length sliding window approaches. Therefore, compensated FMBV and singular value decomposition assisted with motion-adaptive temporal sliding windows improves the quantification of blood volume in coronary ultrafast Doppler angiography.

[Epidemiological distribution of hepatitis B virus genotypes in acute hepatitis B cases in China,2015-2017]

Objective: To analyze the genotype distribution of acute hepatitis B virus in China. Methods: A total of six hundred and twenty acute Hepatitis B cases reported to China Information System for Diseases Control and Prevention from 2015 to 2017 were selected. First, the full-length HBV genome was obtained by nested PCR amplification. In addition, the HBV genotype was determined by constructing a phylogeny tree. Finally, using primarydata, HBV genotype distribution was analyzed. Results: A total of 519 (83.71%, 519/620) sequences were obtained genotype of 620 acute hepatitis B cases, including A (0.19%, 1/519), B (27.17%, 141/519), C (62.04%, 322/519), D (9.06%, 47/519), I (0.77%, 4/519) and C/D (0.77%, 4/519); B2(95.03%, 134/141) and C2 (72.67%, 234/322) were the two major subgenotypes. Genotypes were distributed differently in seven regions of China. The proportion of genotype C appeared higher in Northeast China (94.55%, 52/55), North China (93.85%, 61/65), East China (78.87%, 56/71), and South China (58.14%, 50/86). The proportion of genotype B was higher in Central China (58.07%, 36/62) and Southwest China (52.94%, 45/85), the proportion of genotype D was the highest in Northwest China (48.42%, 46/95). A total of 515 cases were classified as serotypes, including 'adr' (57.48%, 296/515), 'adw' (30.87%, 159/515), 'ayr' (0.19%, 1/515), and 'ayw' (11.46%, 59/515). Genotype B was dominated by 'adw' serotype (92.14%, 129/140), genotype C was dominated by 'adr' serotype (91.88%, 294/320),all genotype D were 'ayw' serotype. The genotype of acute hepatitis B was correlated with serotype, 'adw' was dominant in genotype B, 'adr' was dominant in genotype C and 'ayw' was dominant in genotype D.In different gender and age group, there was no statistical significance ingenotype distribution (P>0.05). Conclusions: The genotype of acute hepatitis B in China from 2015 to 2017 was mainly B, C, and D; genotype C was dominant in the Northeast China,North China, East China and South China; B and C were common in Central and Southwest China, and genotype B was dominant. Genotype D was primarily distributed in Northwest China. The genotype of acute hepatitis B was correlated with serotype, 'adw' was dominant in genotype B, 'adr' was dominant in genotype C and 'ayw' was dominant in genotype D. There was no difference in the distribution of acute hepatitis B genotypes among different genders and age groups.

Strength-fracture toughness synergy strategy in ostrich tibia's compact bone: Hierarchical and gradient

Ostriches are the fastest bipeds in the world, but their tibias are very thin. How the thin tibia can withstand the huge momentum impacts of the heavy body during running? The present work revealed that the combination of hierarchical and gradient design strategies was the main reason for their high strength and fracture toughness. The microstructure of ostrich's tibias compact bone was self-assembled into the 6-level hierarchical structure from the hydroxyapatite (HAP) crystals, collagen fiber (sub-nano), mineralized collagen fiber (nano-), mineralized collagen fiber bundle (sub-micro), lamellae (micro-) and osteon (macro-scales). The most distinctive design in the ostrich compact bone was that the HAP crystals were embedded in collagen fibers as well as wrapped in the outer layer of mineral collagen fibers (MCFs) in the form of HAP nanocrystals, thus achieving a high degree of soft and hard combination from the nanoscale. The bending strength was gradient-structure dependent and up to 787.2 ± 40.5 MPa, 4 times that of a human's compact bone. The fracture toughness (K_Jc) is 5.8 ± 0.1 MPa m^1/2. Several toughening mechanisms, such as crack deflection/twist, bridging, HAP fibers pulling-out, and fracture of the MCF bundles were found in the compact bone.

[Analysis of serum immunoglobulin level in children with Burkitt lymphoma]

Objective: To summarize changes of serum immunoglobulin levels before and after chemotherapy in children with Burkitt lymphoma (BL), so as to investigate the effects of chemotherapy and rituximab on serum immunoglobulin levels in children with BL. Methods: Clinical data of 223 children with newly diagnosed Burkitt lymphoma at Beijing Children's Hospital from January 2009 to April 2017 were analyzed retrospectively. They were treated according to the modified LMB 89 regimen and some of them received combined rituximab therapy during the chemotherapy. The serum immunoglobulin (IgA, IgM, IgG) before chemotherapy, at the time of discontinuing chemotherapy, as well as 6, 12, 24, 36 months after chemotherapy were collected. Changes of serum IgA, IgM and IgG with time among different treatment groups were compared using repeated measures ANOVA. Results: According to risk group, 223 children were devided into group B（n=53）and group C（n=170）. Before chemotherapy, 109 cases (48.9%) were combined with hypogammaglobulinemia. The serum IgA, IgM, and IgG levels of all the patients were (0.9±0.7), 1.2 (0.5, 1.3) and (7.2±2.9) g/L before chemotherapy, (0.5±0.4), 0.2 (0.1, 0.3) and (6.3±2.3) g/L at the time of discontinuing chemotherapy (t=13.63, Z=-11.99, t=4.57, all P<0.05). There were statistical difference in IgA, IgM levels of group B and IgA, IgM, IgG levels of group C before chemotherapy and at the time of discontinuing chemotherapy (t=8.86, Z=-6.28, t=11.19, Z=-10.15, t=4.50, all P<0.05). The differences of serum IgA and IgG levels at the time after chemotherapy among patients treated with chemotherapy alone and those treated with chemotherapy combined rituximab in group B and C were significant (F=5.38, P=0.002 and F=4.22, P=0.007). Conclusions: Approximately half of children with BL have already existed hypogammaglobulinemia at initial diagnosis prior to the start of treatment. The modified LMB 89 regimen have significant effect on humoral immunity of children with BL. In the process of immune reconstruction after chemotherapy, rituximab has more significant effect on serum IgA and IgG levels in BL patients.