On-site in situ high-pressure ultrafast pump-probe spectroscopy instrument

We conceive and construct an on-site in situ high-pressure time-resolved ultrafast optical spectroscopy instrument that facilitates ultrafast pump-probe dynamics measurements under high pressure conditions. We integrate an ultrafast pump-probe spectroscopy system with a diamond anvil cell (DAC) system. Significantly, both the DAC and the sample are fixed within the light path without motion and rotation throughout the whole ultrafast spectroscopy experiment, including tuning and calibrating the pressure. This instrument thus avoids introducing artifacts due to sample motion or rotation, enabling precision high-pressure ultrafast pump-probe dynamics investigations. As a demonstrating example, we compare the effect of on-site in situ conditions with off-site in situ conditions on the ultrafast dynamics of Sr₂IrO₄ under 0-44.5 GPa high pressure. Our data and analysis show that conventional possible artifacts are greatly reduced by using the on-site in situ layout. Our work helps the high-pressure ultrafast science investigation develop into a promising new area, which enables the exploration of nonequilibrium excited quantum states in the high-pressure regime.

Ultrafast quasiparticle dynamics and coherent phonon in nodal line topological material LaBi

We use an ultrafast optical pump-probe spectroscopy to study quasiparticle (QP) dynamics in a topological insulator LaBi. Temperature-dependent optical measurements have been carried out, by which we observed nearly constant fast component (with a lifetime of 0.15 ps) and slow component (with a lifetime of 1.5 ps) for the whole range from 10 K to 295 K. The laser fluence dependence result shows that there is no saturation for the QP dynamics up to 3.3 mJ /cm². Moreover, an Eg mode transverse optical (TO) coherent phonon has also been observed, with a frequency of 2.8 THz. Our results provide for the first time the ultrafast dynamics information of both the QPs and coherent phonons in a nodal line topological material.

[Clinical features and laboratory data analysis of Aeromonas bacteremia with hematological diseases]

目的

分析患有血液系统疾病患者气单胞菌血流感染的临床及实验室特征，为该类患者气单胞菌感染的防治提供依据。

方法

回顾性分析中国医学科学院血液病医院2014年1月至2018年12月5年发生气单胞菌血症的血液系统疾病患者，收集患者临床感染特征、菌株耐药性、发生季节、治疗及转归情况等相关信息。

结果

共42例血液病患者发生气单胞菌血流感染，其中39例（92.9%）血流感染发生于粒细胞缺乏（粒缺）期，平均发热时间为4（1~27）d，22例（52.4%）患者症状仅为发热，6例（14.3%）伴消化道症状（腹痛、腹泻、恶心、上消化道出血），8例（19.0%）伴肺部感染，13例（31.0%）伴皮肤软组织感染。7例（16.7%）患者死亡，且均伴皮肤软组织感染。气单胞菌对碳青霉烯类抗菌药物的耐药率为68.3%~70.7%，而对头孢菌素类、喹诺酮类及氨基糖苷类抗菌药物的耐药率均小于10%。

结论

血液系统疾病合并气单胞菌血流感染主要发生在粒缺期，主要以发热为主，当伴有皮肤软组织感染时死亡率高。抗菌药物选择应依据药敏结果，避免使用碳青霉烯类抗菌药物。

[The role of abnormal mitochondrial fusion and fission in PBDE-47-induced change in mitochondrial mass in PC12 cells]

Objective: To investigate the effect of 2, 2', 4, 4'-tetrabromodiphenyl ether (PBDE-47) on the mitochondrial mass in rat adrenal pheochromocytoma (PC12) cells and the potential mechanisms. Methods: Highly differentiated PC12 cells were divided into control, 1, 10 or 20 μmol/L PBDE-47-treated groups and cultured for 24 h. Transmission electron microscopy was employed to observe the changes in mitochondrial morphology and quantity in PC12 cells. Flow cytometry was used to measure the fluorescence intensity of Nonyl Acridine Orange (NAO) , a fluorescent indicator of mitochondrial membrane cardiolipin, to reflect mitochondria mass. Western blotting was used to determine the expression levels of Mitofusion 1 (Mfn1) and Fission 1 (Fis1) proteins. To further explore the role of abnormal mitochondrial fusion and fission in PBDE-47-induced mitochondrial mass changes, PC12 cells were divided into control group, 5 μmol/L M1 treatment group, 20 μmol/L PBDE-47 treatment group and 5 μmol/L M1+20 μmol/L PBDE-47 combined treatment group and cultured for 24 h, then the fluorescence intensity of NAO and expression levels of Mfn1 and Fis1 proteins were detected. Results: The control group showed numerous mitochondria with normal morphology, while the number of mitochondria decreased after PBDE-47 treatment. Especially, the disappeared cristae, swelling and vacuoles of mitochondria and decreased fluorescence intensity of NAO (P<0.05) were observed in 10 and 20 μmol/L PBDE-47-treated groups. Meanwhile, the expression levels of Mfn1 and Fis1 proteins in the 10 and 20 μmol/L PBDE-47-treated groups were significantly decreased compared with control group (P<0.05) . However, 5 μmol/L M1 co-treatment with 20 μmol/L PBDE-47 significantly increased the levels of Mfn1 and Fis1 proteins and fluorescence intensity of NAO compared with the 20 μmol/L PBDE-47 group (P<0.05) . Conclusion: PBDE-47 can inhibit the mitochondrial fusion and fission process, thus leading to damage of mitochondria mass in PC12 cells.

[Perianal swabs surveillance cultures of Carbapenem-resistant Enterobacteriaceae(CRE) can be hints for CRE bloodstream infection in patients with hematological diseases]

目的

探讨血液病患者肛周皮肤拭子细菌培养检出耐碳青霉烯类肠杆菌（CRE）对CRE血流感染的预警价值，寻找CRE血流感染的危险因素。

方法

对2016年1月至2017年12月进行肛周皮肤拭子细菌培养的血液病患者分离出CRE的耐药率、患者后期CRE血流感染发生情况及危险因素进行回顾性分析。

结果

2 914例血液病患者进行了肛周皮肤拭子细菌培养，74例检出CRE，其中后期发生CRE血流感染者13例（17.6%）。共分离出CRE 87株（相同患者相同部位去重），包括肺炎克雷伯菌31株、大肠埃希菌43株、阴沟肠杆菌8株、其他肠杆菌科细菌6株。分离出CRE菌株对哌拉西林/他唑巴坦、亚胺培南、美罗培南、阿米卡星、左氧氟沙星、替加环素的耐药率分别为91.9%、74.4%、98.8%、17.6%、74.4%和8.0%。13例发生CRE血流感染患者肛周皮肤拭子与血液中分离株对碳青霉烯类、氨基糖苷类、喹诺酮类及替加环素耐药程度一致率较高。粒细胞缺乏（粒缺）、存在消化道症状、肛周感染持续时间为肛周皮肤CRE阳性患者发生CRE血流感染的独立危险因素（OR值分别为1.10、1.13和1.23，P值分别为0.029、0.005、0.016）。

结论

对血液病患者进行肛周皮肤拭子细菌培养可为后期CRE血流感染提供预警，并可为其提供抗菌药物选择参考；粒缺、伴消化道症状以及肛周感染持续时间长可作为CRE血流感染患者早期识别因素。

[Sero-epidemiological survey on hepatitis B virus in Yunnan province, between 2006 and 2014]

Objective: Through two nationwide sero-epidemiological survey programs on hepatitis B virus (HBV), hepatitis B markers in Yunnan province were compared between the findings in 2014 and in 2006. Results were used to understand the HBV epidemic status in Yunnan province and to estimate the efficiency of measures on prevention and control of the disease. Methods: People at the age of 1-29 years were sampled from 6 counties of the National Disease Surveillance sites in Yunnan province, by multi-stage random sampling method. Demographic information was collected by questionnaire, and 2-4 ml serum sample was taken to detect HBsAg, anti-HBs, anti-HBc, HBeAg and anti-HBe, by ELISA method. Results: were logged-in the database and analyzed by SPSS 17.0. Results Between the two studies, no statistically significant differences were observed on the overall HBV infection rates and the positive rates of HBsAg, HBeAg, anti-HBe, anti-HBc. Positive rate of anti-HBs in 2014 was significantly higher than that in 2006. The main two combination profiles of hepatitis B markers were through the fifth model which was positive only for anti-HBs and the sixth model which was negative for all markers in 2006, and the same in 2014. Detection rate through the fifth profile in 2014 was significantly higher than the rate in 2006, while the detection rate of the sixth profile in 2014 was significantly lower than the one in 2006. When analyzing the differences in the same age group, between the two surveys, results showed that the positive rate of anti-HBs in 2014 was significantly higher than that in 2006, in both the10-14 and the 15-19 years-old groups. Positive rate of anti-HBc in the 20-29 year-olds in 2014 was significantly lower than the one of 2006. The positive rates of HBsAg in the age groups of 1-4, 5-14 and 15-29 were 1.12%,1.61% and 1.25% respectively, in 2014. Conclusion: Prevention and control measures on HBV seemed in great progres. However, more effective prevention and control measures should be taken continually among people under the age of 15, in Yunnan province.

[In vivo and in vitro experimental studies of remote digital control endovascular robotic system in interventional angiography]

Objective: To investigate the feasibility of the remote control endovascular robotic system in interventional angiography. Method: The endovascular robotic system Heifetz™ and the matched steerable catheter Mirage™ were used to cannulate all the target vessels in the vascular model and cerebral arteries originated from the aorta of Bama mini-pigs under fluoroscopic guidance. The technical success rate, cannulation time and exposure dose were all collected and compared with the result of using conventional techniques. Result: All the target vessels were successfully cannulated.The average cannulation time for the steerable catheter into left subclavian artery, left common carotid artery, brachiocephalic artery, right common carotid artery and right subclavian artery in the vascular model was (21.3±2.8)s, (28.8±5.2)s, (17.7±2.6)s, (31.5±5.1)s and (24.2±3.7) s, respectively, while the average exposure dose was (9.3±1.2)mGy, (12.4±2.2)mGy, (7.4±1.2)mGy, (14.2±2.5)mGy and( 10.4±1.9)mGy, respectively. The endovascular robotic system completed the cerebral angiography in Bama mini-pigs successfully. The average cannulation time for left innominate artery, right innominate artery, right subclavian artery, common internal carotid trunk, left internal carotid artery and right internal carotid artery was (41.5±6.8)s, (29.1±3.7)s, (40.7±5.5)s, (40.1±5.8)s, (59.6±9.0)s and( 60.3±10.1)s, respectively, while the average exposure dose was (40.6±6.5)mGy, (36.0±5.2)mGy, (39.8±6.1)mGy, (43.9±6.7)mGy, (51.0±7.4)mGy and( 50.1±7.8)mGy, respectively. There was no significant difference between robotic and conventional group in success rate, cannulation time and exposure dose. Conclusion: The remote digital control endovascular robotic system could cannulate the target vessel in both vascular model and complete the cerebral angiography in Bama mini-pigs, which shows the feasibility of using this robotic system in endovascular intervention procedures under remote control.

In situ characterization of Cu–Co oxides for catalytic application

In situ emission and absorption FTIR methods were employed to characterize the spatially resolved structure of binary Co–Cu oxides for low-temperature oxidation of CO and propene. Co–Cu oxide catalysts were controllably synthesized by pulsed-spray evaporation chemical vapor deposition. XRD, FTIR, XPS, UV-vis and helium ion microscopy (HIM) were employed to characterize the as-prepared thin films in terms of structure, composition, optical and thermal properties as well as morphology. In situ emission FTIR spectroscopy indicates that Co₃O₄, CuCo₂O₄ and CuO are thermally stable at 650, 655 and 450 °C, respectively. The catalytic tests with absorption FTIR display that the involvement of Co–Cu oxides can initiate CO and C₃H₆ oxidation at lower temperatures. The results indicate that in situ emission and absorption FTIR are useful techniques to explore the thermal properties and catalytic performance of functional materials, allowing many potential applications in tailoring their temporally and spatially resolved structure-property relationships.

Observation of enhanced monopole strength and clustering in (12)Be

In a recent breakup-reaction experiment using a Be12 beam at 29  MeV/nucleon, the 0+ band head of the expected He4+He8 molecular rotation was clearly identified at about 10.3 MeV, from which a large monopole matrix element of 7.0±1.0  fm2 and a large cluster-decay width were determined for the first time. These findings support the picture of strong clustering in Be12, which has been a subject of intense investigations over the past decade. The results were obtained thanks to a specially arranged detection system around zero degrees, which is essential in determining the newly emphasized monopole strengths to signal the cluster formation in a nucleus.

Echocardiographic evaluation of the fetus with congenital cystic adenomatoid malformation

OBJECTIVES

The development of nonimmune hydrops is a known complication of congenital cystic adenomatoid malformation (CCAM) in the fetus. The aim of this study was to investigate the impact of CCAM on hemodynamics in the fetus and to determine whether cardiac dysfunction contributes to the development of hydrops in this patient population.

METHODS

The echocardiographic data from 41 consecutive fetuses diagnosed prenatally with CCAM were reviewed. The presence or absence of hydrops was noted in each patient. Two-dimensional ultrasonographic and Doppler data were compared between the two groups (with or without hydrops).

RESULTS

The mean gestational age for the study group at the time of imaging was 23.2 +/- 3.0 weeks. Hydrops was noted in 15 of 41 fetuses (36.5%). The fetuses that developed hydrops had a lower cardiac/thoracic ratio than those which did not develop hydrops (0.18 vs. 0.23, P = 0.001). The fetuses with hydrops also demonstrated an increase in early ventricular filling. The ratio of early ventricular filling to atrial contraction (E/A ratio) at both the tricuspid and mitral valves was significantly higher in the fetuses with hydrops (P = 0.005 and P = 0.03, respectively). Doppler interrogation of the inferior vena cava demonstrated a greater degree of reversal with atrial contraction in the hydrops group (29.7% vs. 15.1%, P = 0.003). The development of significant atrioventricular valve insufficiency was rare in the fetuses with hydrops (one of 15 cases).

CONCLUSIONS

Cystic adenomatoid malformation can result in significant cardiac compression in the fetus. This alters hemodynamics and may result in hydrops on the basis of elevated central venous pressure.

The single ventricle heart in the fetus: accuracy of prenatal diagnosis and outcome

OBJECTIVES

The purpose of this study was to determine the diagnostic accuracy of fetal echocardiography in evaluating anatomic details of the single ventricle heart and the outcome of fetuses diagnosed with this anomaly.

STUDY DESIGN

This is a retrospective study of 57 fetuses in which the results of fetal echocardiography were compared with the diagnoses at postnatal echocardiography, and postnatal surgical outcome was reviewed.

RESULTS

Diagnostic accuracy was present in predicting morphology of the predominant ventricle, visceral situs, presence of pulmonary or aortic outflow tract obstruction, and presence of obstructed pulmonary venous outflow (sensitivity 100%). However, the ability to predict for a ductal dependent pulmonary circulation was poor (sensitivity 63%). Errors were made in the fetal assessment of ventricular size and viability such that in three cases, postnatal plans were altered toward a two-ventricular intervention. Of the 57 fetuses, intervention was elected in 37 (75%). Termination or nonintervention was elected in 14, and and 6 died before intervention. Of those operated on, 71% are presently alive after various stages of intervention.

CONCLUSIONS

Accurate diagnosis of the fetal single ventricle heart is possible, and outcome is improving. Caution must be used in judging ventricular size and in predicting ductal dependent pulmonary circulation.

Quantitative assessment of myocardial tissue velocities in normal children with Doppler tissue imaging

Assessment of myocardial tissue velocities in children in feasible with DTI. We have described normal velocity values for left ventricular motion in children during systole and diastole, at the mitral annulus, and at the posterior wall. The pattern of mitral annular motion in diastole mimics that of mitral blood inflow, whereas the pattern of posterior wall motion differs and may provide for a new form of assessment of diastolic function. Further investigation of myocardial velocities in states of volume and pressure overload, as seen in various forms of congenital heart disease, is warranted.

Fetal middle cerebral artery blood flow velocities in pregnancies complicated by intrauterine growth restriction and extreme abnormality in umbilical artery Doppler velocity

If they are not delivered in a timely fashion, pregnancies complicated by severe intrauterine growth restriction (IUGR) can lead to fetal loss. Conventional fetal well-being tests, including ultrasound measurement of fetal growth rate, biophysical profile, nonstress test, and contraction stress test are used to manage these pregnancies. Some fetuses delivered based on abnormal fetal well-being tests show long-term sequelae. A better understanding of the malfunction of the placenta and its effect on the fetus is desperately required for better management of these cases. We are reporting our experience of 6 such pregnancies followed by fetal middle cerebral artery (MCA) blood flow velocity measurements. There was significant decrease in MCA flow velocities in all of these fetuses compared to normal population (p < 0.05). Reverting to normal values occurred prior to the appearance of abnormal conventional tests, on average 4 days earlier. In other words, normalization of MCA flow velocities was a harbinger of fetal jeopardy. Although our observation includes a small number of patients, there is a potential for use of MCA blood flow velocity measurement to aid us in understanding and managing fetuses with IUGR. This needs to be evaluated in a larger study.

Diastolic function of the fetal heart during second and third trimester: a prospective longitudinal Doppler-echocardiographic study

To generate normal charts of fetal cardiac inflow velocities and to assess physiologic changes of ventricular diastolic function, velocity waveforms of tricuspid and mitral valves were studied longitudinally in 49 fetuses in 4 week intervals from 14 weeks gestation to term. Doppler tracings were analyzed for: peak early (E) and peak late (A) inflow velocities, time velocity integral (TVI) of total inflow and A-wave velocity waveforms and heart rate corrected isovolemic relaxation time. E- and A-velocity as well as total- and A-wave-TVI of both valves increased significantly with gestational age (P < 0.001). Heart rate and A/E ratio decreased significantly with gestational age (P < 0.001). The ratio of A-wave TVI to total TVI of both valves and heart rate corrected isovolemic relaxation time (IVR) was constant suggesting unchanged diastolic function. This study provides normal charts for fetal cardiac inflow velocities. After 14 weeks of gestation all inflow velocities and their respective TVI's increased linearly in the growing fetal heart. There was evidence that diastolic function did not change. Area ratios and IVR should be used to determine changes in ventricular diastolic function, rather than velocity ratios.