Development of an energy spread analyzer for secondary ion mass spectrometry ion source.

The energy spread (ΔE) of an ion source is an important parameter in the production of a finely focused primary ion beam applied in secondary ion mass spectrometry (SIMS). A variable-focusing retarding field energy analyzer (RFEA) has been developed and tested with an Ar+ beam and an oxygen ion beam extracted from a 2.45 GHz microwave ion source, which is developed as a candidate ion source for SIMS applications. The simulation results show that the relative resolution ΔE/E of the designed RFEA reaches 7 × 10-5. The experimental results indicate that a focusing electrode can improve the ΔE measurement results, which is consistent with the simulation results. The ion energy distributions of the Ar+ beam and oxygen ion beam are of Gaussian distribution with the value of ΔE of 3.3 and 2.9 eV, respectively. These results indicate that the designed RFEA is reliable for measuring the ion beam energy spread. The developed RFEA is also used to study the plasma behavior in different settings, which reveals that plasma stability is critical to making a low energy spread ion beam. This paper will present the simulation, design, and test of the variable-focusing RFEA. Preliminary ion beam quality studies with this instrument will also be discussed.

A compact radio-frequency ion source for high brightness and low energy spread negative oxygen ion beam production.

A high brightness and low energy spread (∆E) ion source is essential to the production of a high-quality primary ion beam applied in secondary ion mass spectrometry (SIMS). A compact 13.56 MHz radio-frequency (RF) ion source with an external planar spiral antenna has been developed as a candidate ion source for the production of negative oxygen ion beams for SIMS application. This ion source is designed with a three-and-a-half-turn water-cooled planar antenna for RF power coupling, a multi-cusp magnetic field for effective plasma confinement, and a three-electrode extraction system. The experimental results show that more than 50 µA negative oxygen ion beams have been extracted, which consist of 56% O-, 25% O2-, and 19% O3-. The ion energy distribution of the negative oxygen ion beam exhibits a Gaussian distribution with a minimum ∆E of 6.3 eV. The brightness of the O- beam is estimated to be 82.4 A m-2 Sr-1 V-1. The simulation, design, and experimental study results of this RF ion source will be presented in this paper.

[Application of augmented reality navigation in laparoscopic and robot-assisted liver surgery].

In recent years, laparoscopic surgery and robotic surgery have been widely used, and various intraoperative image navigation systems have also developed rapidly. However, the liver itself has a complex vessel and duct system, which increase the difficulty of liver surgery. The augmented reality image navigation system combines the three-dimensional reconstructed image of the liver with the real liver anatomy, which presents the specific relationship between the tumor location and the surrounding vessels for the surgeon. Compared with other intraoperative image navigation methods, augmented reality has its unique advantages. This paper provides an overview of current advances in registration technology in augmented reality image navigation system, and focuses on its applications in liver surgery, including laparoscopic surgery and robotic surgery. Finally, the technological problems and difficulties still faced at present are summarized, and future directions worth studying in this field are proposed.

Simulation of beam extraction and space charge effect in an electromagnetic isotope separator.

Space charge effect of intense ion beam has critical influence on separation efficiency in the electromagnetic isotope separator. In this paper, a ribbon beam extraction system with slit electrodes for an electromagnetic isotope separator was designed and studied. The extracted beam currents were varied from 10 to 40 mA and the corresponding extracted beam energies were 40 keV and 100 keV respectively. The simulated output beam density distributions were used in the subsequent multi species particle transmission simulation with the space charge effect included. The separated isotope beam spot distributions at the focal plane were simulated under different space charge compensation factors and thus the optimum operation gas pressures in vacuum box were roughly estimated. For the case of high intensity and high power isotope beam collection, an isotope collector with a deceleration electrode was proposed to mitigate the effect of high power beam bombardment and the resultant temperature rising on the collector surface.

[The long-term efficacy of left cardiac sympathetic denervation in long QT syndrome].

Objective: To investigate the long-term efficacy and safety of left cardiac sympathetic denervation(LCSD) for long QT syndrome(LQTS) patients with either recurrence on drug therapy intolerance/refusal. Methods: This study was a retrospective cohort study. The cases selected from 193 patients with LQTS who were enrolled in the Chinese Channelopathy Registry Study from November 1999 to November 2012. This study selected 28 LQTS patients with either recurrence on drug therapy intolerance/refusal and underwent LCSD surgery in the Peking University People's Hospital or Beijing Tongren Hospital. The patients were allocated into 3 groups: high-risk group(n=13, baseline QTc ≥550 ms or symptomatic in the first year of life or highly malignant genetics); intermediate-risk group(n=10, 500 ms≤baseline QTc<550 ms, symptomatic after the first year and without highly malignant genetics); low-risk group(n=5, baseline QTc<500 ms, symptomatic after the first year and without highly malignant genetics). LCSD was performed with the traditional supraclavicular approach or video assisted thoracoscopic surgery (VATS). Patients were regularly followed up until 20 years after the surgery. Data were collected before and 1 year after surgery and at the last follow-up. Patients' electrocardiograph(ECG), cardiac events and surgery-related complications were recorded. Kaplan-Meier survival analysis was used to determine the cardiac event-free survival based on different risk stratification and genotypes. Results: A total of 28 LQTS patients, aged 20.5 (15.0, 37.5) and underwent LCSD surgery, were enrolled in this study, including 23(82.1%) women. There were 11(39.3%) patients treated with traditional approach while 17(60.7%) with VATS-LCSD. There were 19(67.9%) patients had positive genetic test results, including 4 LQT1, 12 LQT2, 1 LQT1/LQT2 mixed type, and 2 Jervell-Lange-Nielsen (JLN) syndrome. The median follow-up period was 189.3(138.7, 204.9) months. The dropout rate was 10.7%(3/28) while 3 patients in the intermediate-risk group were lost to follow-up. Horner syndrome occurred in 1 patient (in the high-risk group). Sudden cardiac deaths were observed in 3 (12.0%) patients (all in the high-risk group), and 12 patients (48.0%) had syncope recurrences (2 in low-risk group, 3 in intermediate-risk group and 7 in high-risk group). A significant reduction in the mean yearly episodes of cardiac events was observed, from (3.5±3.3) before LCSD to(0.2±0.1) at one year after LCSD and (0.5±0.8) at last follow up(P<0.001). The mean QTc was shortened from (545.7±51.2)ms before the surgery to (489.0±40.1)ms at the last follow-up (P<0.001). Among the 20 patients with basic QTc ≥500 ms and completing the follow-up, the QTc intervals of 11(55.0%) patients were shortened to below 500 ms. The event free survival rates for any cardiac events after LCSD decreased sequentially in the low-, intermediate- and high-risk groups, and the difference was statistically significant (χ²=7.24, log-rank P=0.026). No difference was found in the event free survival rates among LQT1, LQT2 and undefined gene patients (χ²=5.20, log-rank P>0.05). Conclusions: LCSD surgery can reduce the incidence of cardiac events and shorten the QTc interval in patients with LQTS after the long-term follow-up. LCSD surgery is effective and safe for patients with LQTS ineffective or intolerant to drug therapy. However, high-risk patients are still at a high risk of sudden death after surgery and should be actively monitored and protected by combined therapies.

Topological modes in a laser cavity through exceptional state transfer.

Shaping the light emission characteristics of laser systems is of great importance in various areas of science and technology. In a typical lasing arrangement, the transverse spatial profile of a laser mode tends to remain self-similar throughout the entire cavity. Going beyond this paradigm, we demonstrate here how to shape a spatially evolving mode such that it faithfully settles into a pair of bi-orthogonal states at the two opposing facets of a laser cavity. This was achieved by purposely designing a structure that allows the lasing mode to encircle a non-Hermitian exceptional point while deliberately avoiding non-adiabatic jumps. The resulting state transfer reflects the unique topology of the associated Riemann surfaces associated with this singularity. Our approach provides a route to developing versatile mode-selective active devices and sheds light on the interesting topological features of exceptional points.

Effect of supplementing hydroxy selenomethionine on meat quality of yellow feather broiler.

This study was conducted to evaluate the effect of supplementing hydroxy selenomethionine (OH-SeMet) on performance, selenium (Se) deposition in the breast muscle, quality and oxidative stability, and expression of selenoprotein encoding genes of breast meat of the native slow-growing yellow-feathered broiler birds. A total of 375 one-day-old local yellow male birds were randomly assigned into 5 dietary treatments, supplemented with Se 0.0, 0.2, 0.4, 0.6, and 0.8 mg/kg in the form of OH-SeMet. Each treatment consisted of 5 replicates and each replicate had 15 birds, the birds were fed on basal diet containing corn and soybean meal, and the experiment lasted for 63 d. The results showed that dietary Se supplementation linearly increased (P < 0.001) Se contents in both serum and muscle, no significant changes (P > 0.05) were observed on growth performance, yield of breast, meat color, and intramuscular fat deposition of the breast muscle. Dietary Se addition improved water-holding capacity, the pH24h value, and tenderness of breast muscle, evidenced by a linear decreases of shear force (P < 0.05), accompanied by lower thiobarbituric acid reactive substances and higher glutathione reductase activity. The mRNA abundance of selenoprotein encoding genes also responded to dietary Se levels. It is concluded that, dietary supplementation with OH-SeMet improved muscular Se deposition and meat quality of the native yellow birds, with enhanced antioxidant capability and regulation in selenogenome.

[Induction of hepatocellular carcinoma in B6C3 (F1) mice chronicly exposed to trichloroethylene with enhanced acetylation of histone H2AK9ac and SET expression in the liver tissue].

Objective: To establish an animal model of trichloroethylene (TCE) -induced liver cancer following chronic exposure and to understand the changes in SET expression and histone acetylation, potentially serving as a molecular mechanism for TCE-induced hepatocarcinogenesis. Methods: B6C3 mice at 6 weeks were treated with TCE at a series of doses (500, 1000 and 2000 mg/kg) by gastric gavage, with corn oil used as the negative control and carbon tetrachloride (CCl(4)) as the positive control. The serum and liver were sampled for the determination of biochemical indexes and pathological examination after 56 weeks of chemical exposure. Western blot was used to determine the levels of SET, H2AK9ac and HDAC1 expression. Results: The overall survival rate of the mice in various groups was 90.4% (141/156) , with no statistical difference between groups (P>0.05) . Compared with the negative control, the organ coefficient for the liver in the high dose TCE group and the positive control group were significantly increased (P<0.05) . The levels of ALT, AST, LDH and BUN in the all the three TCE groups and the positive control were significantly higher than those in the negative control (P<0.01) . CREA levels in the 1000 and 2000 mg/kg TCE groups were significantly higher than those in the negative control (P<0.05) . Statistical increases in the incidence of hepatocellular carcinoma and the activities of ALT and AST in various doses of TCE-exposed mice as compared with the control were observed (P<0.01) , in a dose-dependent manner. In the 1000 and 2000 mg/kg of TCE treated mice, levels of SET and H2AK9ac were increased (P<0.05) , while HDAC1 was decreased (P<0.05) , Compared to the tissue adjacent to liver cancer, in the 1000 and 2000 mg/kg TCE groups, the levels of SET were increased (P<0.05) , while HDAC1 was decreased (P<0.05) , and H2AK9ac increased in the 2000 mg/kg group. Conclusion: The hepatocellular carcinoma mouse model induced by chronic exposure to trichloroethylene was successfully established, with enhanced SET protein expression and H2AK9ac in the hepatic tissue.

[One case successfully rescued acute poisoning caused by misadministration of large amount of glufosinate].

Objective: To report a case of acute glufosinate-ammonium poisoning cause respiratory cardiac arrest and grass amine poisoning cases of successful rescue. Methods: The clinical data of a case of acute glufosinate-ammonium poisoning admitted to a third-class a hospital in April 2018 were analyzed and summarized. Results: The patient was poisoned by oral administration of a large amount of glufosinate-ammonium. Respiratory and cardiac arrest occurred during treatment and resuscitation was successful Later, the nervous system showed impaired function, The patients were treated with complete gastrointestinal cleansing, hemoperfusion, and the protection of important organs. Conclusion: For a large number of patients with oral glufosinate-ammonium poisoning, we should pay close attention to the damage of nervous system while taking active and conventional detoxification treatment.

[Study of reactive oxygen species and adiponectin for chronic HBV infection combined with nonalcoholic fatty liver diseases].

Objective: To investigate the application value of reactive oxygen species (ROS) and adiponectin (ADPN) in the judgment of liver inflammation in chronic hepatitis B virus infection combined with nonalcoholic fatty liver disease (NAFLD). Methods: A total of 159 cases with NAFLD (21 cases), chronic hepatitis B virus infection (57 cases), and chronic hepatitis B virus infection combined with NAFLD (81 cases) were collected between June 2016 to December 2018, and the visited patients diagnosis were confirmed by histopathological examination of the liver. ROS and ADPN level retained in serum was determined by enzyme-linked immunosorbent assay. Histopathological examination of liver tissue was used as the gold standard to discuss the diagnostic value of the serum in patients with chronic hepatitis B virus infection combined with NAFLD for the occurrence of nonalcoholic steatohepatitis. One-way analysis of variance was used for the comparison among multiple groups, and LSD-t test was used for pairwise comparison between groups. Measurement data for non-normal distributions were expressed as M (P25, P75). Comparisons between groups were performed using the Mann-Whitney U or Kruskal-Wallis H test. Chi-square test was used to compare the count data between groups. Correlation analysis was performed using Spearman correlation analysis. Histopathological grouping of liver tissue was used as the gold standard, and the area under the receiver operating characteristic curve was used to evaluate the diagnostic efficacy of the regression formula. Results: (1) In patients with chronic hepatitis B virus infection combined with NAFLD, the levels of ROS in the non-hepatic steatosis group and the mild hepatic steatosis group were significantly lower than those in the moderate and severe hepatic steatosis group, while the ADPN level in the non-hepatic steatosis group was significantly higher than liver steatosis group, P < 0.05. (2) The results of correlation analysis showed that ROS was significantly correlated with NAS score, change in the degree of fatty liver and lobular inflammation (all P < 0.05).There was a significant negative correlation between ADPN and the change in the degree of fatty liver (P < 0.05). (3) Logistic regression analysis results showed that the diagnostic formula for chronic hepatitis B virus infection combined with nonalcoholic steatohepatitis was 0.02 × controlled attenuation index + 0.584 × white blood cells/10(9) + 0.587 × ROS-10.982. The area under receiver operating characteristic curve of the subject was = 0.896. The sensitivity, specificity, positive and negative predictive value were 97.1%, 71.2%, 64.2%, and 97.9%. Conclusion: ADPN and ROS have certain reference value in differentiating the change in the degree of fatty liver and inflammation in chronic hepatitis B virus infection combined with NAFLD and the diagnostic formula has higher application value in the diagnosis and exclusion of chronic hepatitis B virus infection combined with nonalcoholic steatohepatitis.

An electromagnetic separation system for the enrichment of 39Ar.

An isotope enrichment system for 39Ar has been developed at the Institute of Modern Physics, which is designed to increase the abundance of 39Ar in the incident sample gas. With intense Ar+ beams produced by a 2.45 GHz electron cyclotron resonance ion source and a high mass resolution spectrometer system, Ar isotopes are evidently separated on the target plane and selectively collected by an Al target. The separated Ar isotopes have been identified on the target plane, which is consistent with the simulations. According to the recent cross-checked results with atom trap trace analysis, a high enrichment factor of 39Ar has been successfully achieved. This paper will present the design and test results of this system.

Ion beam production with an antenna type 2.45 GHz electron cyclotron resonance ion source.

A very compact permanent magnet 2.45 GHz electron cyclotron resonance ion source has been designed and developed for various purposes. The microwave power is coupled into the plasma chamber using the coaxial antenna instead of the waveguide, the magnetic field is produced by two NdFeB permanent magnet rings, and the diameter of the source body is only 10 cm. The beam current under different conditions was measured. A maximum of 5.8 mA H+/H2 +/H3 + mixed beam could be extracted from a 5.5 mm diameter extraction aperture.

Production of O- and O2 - beams with the negative ion source at Institute of Modern Physics.

A negative oxygen ion source is under development to produce O- and O2 - beams used for a secondary ion mass spectrometer at Institute of Modern Physics (IMP), and both filament and radio frequency (RF) schemes are tested. The filament driven ion source, which was initially designed for H- production, has a 10-pole multicusp plasma chamber, two sets of virtual magnetic filters, and a 3-electrode extraction system. The RF scheme, which is improved by changing a RF back plate from the filament ion source, has an external planar spiral RF antenna behind an AlN window. The RF power system consists of a continuous wave (CW) 13.56 MHz/2 kW power supply, a capacitive automatching network and a water-cooled flat RF antenna made from a 6-mm copper tube. Oxygen and carbon dioxide gases are used to produce O- and O2 - ion beams, and ion composition is analyzed by using a Wien filter. However, the lifetime of filaments sustains from several minutes to hours before fracture occurred while the RF one can work stably with no maintenance, and the experiment results will be given on O- ion production with two different technologies using our ion source test facility.

[Analysis of the potential role of SET in chromium-induced malignant transformation cells based on quantitative proteomics].

Objective: To investigate alteration of proteins profile in malignant transformation bronchial epithelial cells(16HBE-T) induced by hexavalent chromium[(Cr(VI))] and analyze the expression level of SET protein, then to provide some new insights for the carcinogenesis mechanism of Cr(VI). Methods: Total protein was extracted from 16HBE cells and was alkylated and desalinated before digested into peptides. The products were labeled with Tandem Mass Tag (TMT) and identified using LC-ESI-MS/MS. Results: A total of 3 517 proteins were found, expression differences greater than 1.5 or less 0.67 times were to found have 185 and 201 proteins, respectively. Gene enrichment analysis revealed that differential proteins were mainly involved in autophagy, DNA damage repair, RNA processing and other biological processes. Western blot results showed the expression level of SET was significantly increased while downregulated in histone H3K18/27 acetylation and p53 protein. Conclusion: Proteins involved in multiple biological processes altered in 16HBE-T cells and regulation mode of SET inhibiting histone H3K18/27 acetylation regulating transcriptional activity of p53 may paly an important role in Cr(VI)-association carcinogenesis.

Effect of ulinastatin on myocardial ischemia reperfusion injury through ERK signaling pathway.

OBJECTIVE: To study the effect of ulinastatin (UTI) on myocardial ischemia-reperfusion injury (MIRI) through the extracellular signal-regulated kinase (ERK) signaling pathway. MATERIALS AND METHODS: A total of 24 Sprague-Dawley rats were randomly divided into sham group (n=8), I/R group (n=8), and UTI group (n=8), and the rat model of MIRI was established. The changes in the content of serum biochemical indexes, including superoxide dismutase (SOD) and malondialdehyde (MDA), were detected using the kits, and the changes in the expressions of serum inflammatory factors, including interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), were detected using the quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) kits. Moreover, the ERK phosphorylation level in myocardial tissues was detected using the immunofluorescence method, and the ERK phosphorylation level and cleaved caspase-3 expression were detected via qRT-PCR and Western blotting. RESULTS: Compared with those in sham group, the serum SOD content significantly declined, while the MDA content was significantly increased in I/R group, and they were significantly improved in UTI group (p<0.01). The results of detection using qRT-PCR and ELISA kits revealed that the inflammatory factors (IL-6 and TNF-α) in UTI group were significantly improved (p<0.01). The immunofluorescence results showed that the ERK phosphorylation level in myocardial tissues was significantly increased in UTI group. The results of qRT-PCR and Western blotting manifested that both ERK phosphorylation level and cleaved caspase-3 expression were significantly improved in UTI group (p<0.01). CONCLUSIONS: UTI can play a protective role in MIRI through up-regulating the ERK signaling pathway.

Application of Nonlinear Optical Microscopic Imaging Technology for Quality Assessment of Donor Kidneys.

BACKGROUND: Nonlinear optical microscopic (NLOM) imaging technique shows its high resolution imaging features in histocytology. The purpose of this study was to investigate NLOM imaging technique as a useful tool for a donor kidney quality assessment. MATERIALS AND METHODS: Eighty-three pretransplant kidney biopsies from adult donors were analyzed retrospectively. Each specimen was paraffin-embedded and sectioned into 2 consecutive 5-µm thick sections. One section was stained with Masson trichrome, and the other was left unstained for NLOM imaging using second harmonic generation combined with two-photon excited fluorescence (SHG/TPEF). The pretransplant kidney quality was assessed by an experienced pathologist using the Remuzzi scoring system, which characterizes renal tissue morphology into 4 aspects: tubular atrophy, interstitial fibrosis, glomerulosclerosis, and vascular injury. The K coefficient was used to measure the consistency of the Remuzzi scores between conventional Masson trichrome stained images and SHG/TPEF images. RESULTS: NLOM imaging technology can capture high-resolution tissue images from unstained renal tissue, is easy to operate, and shortens time-consuming histological processing procedures. No significant differences (P > .05) were found between the Remuzzi scores of the SHG/TPEF images and the Masson trichrome stained images. The high κ coefficients (0.804-0.895) showed a good consistency between these 2 techniques. CONCLUSION: The NLOM technique is suitable for renal tissue imaging and could potentially be used for routine pretransplant kidney evaluation in clinical settings.