[Impact of COVID-19 on the treatment of sleep medicine].

The outbreak of coronavirus disease 2019 (COVID-19) has become a major threat to the global healthcare system. As an airborne disease, COVID-19 posed a great challenge to the management of sleep medicine. Given the increased risk of adverse events in obstructive sleep apnea patients infected with COVID-19, strategies have been proposed worldwide. These include standard treatment procedure, use of self-protect equipment, telemedicine services, development of machine learning and portable monitoring, and in-home sleep monitoring and titration. This review aims to introduce the impact of COVID-19 on the operation of sleep medicine landscape and provide advice on public health care emergency.

Predictors of Clinical Outcomes in Acute Appendicitis: A Retrospective Study.

INTRODUCTION: Acute appendicitis is one of the most common causes of intra-abdominal emergency surgery worldwide. This study was conducted to contribute to global databases by presenting data from our institution, which consist of multi-racial population. We aimed to evaluate the presentation, diagnosis, and management of acute appendicitis and post-operative outcome in our institution and evaluate the risks factors associated with severe complications and prolonged length of stay (LOS). MATERIALS AND METHODS: We performed a retrospective analysis using multivariate regression analysis of all patients who underwent appendectomy (2009-2014) in our institution. The primary outcomes included demographics, presentation, and perioperative management, and the secondary outcomes included risk factors associated with prolonged LOS. RESULTS: Of the 1185 patients, the mean age was 36.4 years, and 940 (79.3%) were male. Majority (98.1%) of patients were ASA (American Society of Anaesthesiologists) 1 or 2. Most of them (83.9%) were from the four racial subgroups (Chinese, Malay, Bangladeshi, and Indian). There was no racial variation in the diagnosis and presentation of disease. The mean duration of symptoms was 1.8 days. The history was commonly a localised or migratory abdominal pain associated with anorexia, nausea, vomiting, and fever. The commonest physical findings were right-sided abdominal tenderness associated with rebound and guarding. About 42.9% of the patients underwent pre-operative CT scan to establish the diagnosis of appendicitis prior to surgery, whilst 57.1% underwent surgery on clinical diagnosis and blood investigation (NWR and CRP). An open appendectomy was performed in 13.2% of the patients. The conversion rate of laparoscopic appendectomy was 4.9% (n = 50). The mean length of hospital stay was 3.6 days. On multivariate Cox regression, patients of Burmese and Thai descent were independently associated with a prolonged LOS. The postoperative morbidity was 5.5%. The 30-day readmission rate was 2.4%. There was no mortality in our study. DISCUSSION: Our study showed that pre-operative diagnosis of acute appendicitis can be made accurately by classical clinical presentation or by imaging. Independent risk factors associated with increased LOS included increased age, male gender, prolonged duration of symptoms pre-admission, fever, generalised tenderness, and prolonged operative time. The effect of race on LOS has been observed in the literature for other surgical procedures. The prolonged LOS found in Burmese and Thai patients contribute to the possibility of intrinsic racial differences in the post-surgery recovery. However, the numbers are small and therefore prone to type I error. Compared to the open approach, the use of laparoscopic appendectomy was associated with shorter LOS. This has similar outcomes to those reported in the literature. CONCLUSION: The identification of risks factors could help surgical team to predict the clinical outcomes and develop risk reduction strategy in post-operative care of these patients.

Effects of surface roughness on the time-dependent wear performance of lithium disilicate glass ceramic for dental applications.

OBJECTIVES: Purpose of the present study was to evaluate the effect of surface roughness on the time-dependent wear performance of lithium disilicate (LD) glass-ceramic. METHODS: Friction pairs (pin and disk specimens) were prepared by IPS e.max® Press lithium disilicate glass-ceramic. The lateral faces of friction pairs (N = 12) were grinded with silicon carbide papers, and 6 friction pairs were polished with a 0.25 µm diamond suspension after grinding. The friction pairs were tested for wear performance using a pin-on-disk tribometer with 10 N for 1.02 × 106 wear cycles in artificial saliva. Wear analysis of the pin and disk was performed with a 3D profilometer. The microstructure and worn surface morphology were examined with scanning electron microscopy. One-way analysis of variance and Tukey's post-hoc pairwise comparison were used to analyze the wear data. RESULTS: The two group LD friction pairs presented strong time-dependent wear performance. The polished group (GP) exhibited a high wear rate and extensive surface wear during 0-1 × 105 cycles (running-in wear stage). The wear rate, height loss and surface roughness were obviously lower than those of grinded group (GG) in running-in wear stage. However, these wear parameters were similar during the steady wear stage. The worn surface topographies of the pin and disk in GP were smoother at the same cycle before the GG entering the steady wear stage. CONCLUSION: Running-in, which means the initial stage of wear process, is a critical period to determine the final wear loss and surface degradation, when compare the wear behavior of lithium disilicate ceramic with different initial surface states. Ceramic layer with smooth contact area leads to low wear rate and short running-in wear stage.

Production of metallic ion beams by electron cyclotron resonance ion sources equipped with inductive heating ovens at the Institute of Modern Physics.

A high-temperature oven based on the inductive heating technology was developed successfully at the Institute of Modern Physics in 2019. This oven features a durable operation temperature of over 2000 °C inside the tantalum susceptor. By carefully designing the oven structure, the material compatibility issue at high temperature has been successfully solved, which enables the production and routine operation of refractory metal ions with SECRAL-II (Superconducting Electron Cyclotron Resonance ion source with Advanced design in Lanzhou No. 2). To further apply this type of oven to the room temperature ECR ion sources LECR4 and LECR5 (Lanzhou Electron Cyclotron Resonance ion source No. 4 and 5), a mini-inductive heating oven has been fabricated and tested in 2020. By directly evaporating calcium oxide, some high charge state calcium beams have been produced successfully, such as 52 euA of 40Ca16+, 30 euA of 40Ca17+, and 12 euA of 40Ca18+. The detailed design and testing results will be presented and discussed.

Influence of electron cyclotron resonance ion source parameters on high energy electrons.

In order to diagnose the electron cyclotron resonance (ECR) plasma, a high-efficiency collimation system has been developed at the Institute of Modern Physics, and the bremsstrahlung spectra in the range of 10 keV-300 keV were measured on a third generation superconducting ECR ion source, SECRAL-II, with a CdTe detector. Used as a comparative index of the mean energy of the high energy electron population, the spectral temperature, Ts, is derived through a linear fitting of the spectra in a semi-logarithmic representation. The influences of some main source parameters, such as the neutral gas pressure, extraction voltage, microwave power, and bias disk voltage, on the high energy electrons are systemically investigated.

Improved reliability of wear performance for a fluorapatite veneering porcelain by ion-exchange strengthening and toughening.

OBJECTIVES: Purpose of the present study was to explore the improvement of wear performance for a nano fluorapatite veneering porcelain by ion-exchange. METHODS: Bar and disk specimens were prepared by IPS e.max Ceram as the nano fluorapatite veneering porcelain. Ion-exchange was performed in a melted KNO3 bath at two temperatures for different time-periods. After the ion-exchange, the bars were tested for flexural strength, surface Vickers hardness and HIF toughness, the disks were tested for wear performance paired with zirconia antagonist using a pin-on-disk tribometer with 10 N for 70✕104 wear cycles in artificial saliva. Wear analysis of the porcelain and zirconia was performed with a 3D profilometer. The microstructure and worn surface morphology were examined with scanning electron microscopy. One-way analysis of variance and Tukey's post-hoc pairwise comparison were used to analyse the wear data. RESULTS: The nano fluorapatite veneering porcelain before ion-exchange presented strong time-dependent wear behavior. Furthermore, wear rate of the original porcelain exhibited a very large standard deviation in the running-in wear stage, which was correlated with highly inhomogeneous distribution of the characteristic fluorapatite crystals in the microstructure. After ion-exchange at 350 °C and 380 °C, especially after the processing at 350 °C for 128 h, the wear rates of both running-in and steady wear stages could be significantly decreased. More importantly, the standard deviation of wear rate in the running-in wear stage could be remarkably reduced after the treatment. The improved reliability of wear performance was attributed to the strengthening and toughening effects of the ion-exchange processing. CONCLUSION: For the fluorapatite veneering porcelain, the ion-exchange protocol to obtain an ion-exchange layer with less stress relaxation and a considerable depth could strengthen and toughen the porcelain; as a result, the reliability of wear performance could be remarkably improved.

Overview of high intensity ion source development in the past 20 years at IMP.

Ion source development over the last 20 years at the IMP is reviewed. For versatile purposes, several types of ion sources have been involved in the research and development work at the IMP, i.e., the highly charged ECR (Electron Cyclotron Resonance) ion source, intense microwave ion source or the 2.45 GHz intense beam ECR ion source, and laser ion source (LIS). In the development of ECR ion sources, SECRAL (Superconducting ECR ion source with Advanced design in Lanzhou), Lanzhou ECR ion source, and Lanzhou all permanent magnet ECR ion source series have been made, which can cover the operation microwave frequency range of 10-28 GHz. The LIS with an Nd:YAG laser with a maximum output energy of 8 J in 8 ns pulse duration has been developed for very intense short pulse ion beams from solid materials such as C, Ti, Ni, Ag, and so on. Microwave ion sources have been built to produce intense pulsed or direct current beams from several mA to 100 mA for either high intensity accelerators or applications. This paper will give an overview of the high intensity ion source development at the IMP, especially on the recent progress and new results, such as the status of the fourth generation ECR ion source (first fourth generation ECR ion source), the production of recorded highly charged ion beams with SECRAL sources, key technology research studies, and so on.

A new room temperature LECR5 ion source for the SESRI project.

The Space Environment Simulation and Research Infrastructure project, which uses various ion beams as irradiated materials in life science research, is being built at the Harbin Institute of Technology. A new room temperature electron cyclotron resonance ion source, the Lanzhou Electron Cyclotron Resonance Ion Source No. 5 (LECR5), has been designed and constructed. It is an intense, highly charged, heavy ion beam injector which generates ion beams from H to Bi, typically ∼50 eµA 209Bi32+. The LECR5 is designed to operate at microwave frequencies in the range of 14.5-18 GHz. The typical magnetic parameters are designed based on those optimized for SECRAL, which operates at 18 GHz. This paper presents the LECR5 ion source, its test bench, and the preliminary beam results.

Intense carbon beams production with an all permanent magnet electron cyclotron resonance ion source for heavy ion medical machine.

LAPECR3 (Lanzhou All Permanent magnet Electron cyclotron Resonance ion source No. 3) had been developed as an ion injector of Heavy Ion Medical Machine (HIMM) accelerator facility since 2009. The first HIMM accelerator facility was built in Wuwei city in 2015, and the LAPCER3 ion source has delivered C5+ ion beam to HIMM for more than 1000 days in the past four years. In order to improve the performance of the LAPECR3 ion source for intense carbon beams production, continuous research and development work has been made. The recently developed LAPECR3 ion source together with the new low-energy beam transportation can provide better performance in terms of both beam intensity and quality. This paper will generally review the LAPECR3 ion source operation status for HIMM, and the recent improvement will be presented, especially the stable beams production of C4+ and C5+.

A new microwave coupling scheme for high intensity highly charged ion beam production by high power 24-28 GHz SECRAL ion source.

The efficiency of the microwave-plasma coupling is a key issue to enhance the performance of electron cyclotron resonance ion sources (ECRISs) in terms of higher ion beam intensity yield. The coupling properties are affected by the microwave coupling scheme, especially for the high frequency (f > 20 GHz) and high power (P > 5 kW) ECR ion sources. Based on the study of 24 GHz SECRAL ion source performances working at different launching systems, a new microwave coupling scheme, called the Vlasov launcher, is proposed, which can not only realize efficient power matching and feeding but also enhance the microwave power distribution on the ECR surface. The first promising results are presented in this article. Then, a prototype dedicated to the next generation ECRIS is described.

Production of intense uranium beams with inductive heating oven at Institute of Modern Physics.

HIAF (High Intensity heavy ion Accelerator Facility) is a new accelerator complex under construction at the Institute of Modern Physics. As the main injector of this project, the high-charge-state ECR ion source needs to provide intense uranium beams, such as 700 eµA of U35+. This requires the performance of metal ovens to be further improved so that the crucible can operate at an ultrahigh temperature for a long time without damage in a high magnetic field (>3 T). In order to meet these requirements, an inductive oven with special thermal shielding and support has been developed in the past two years. The off-line test result has shown that this oven can reach up to 2000 °C with ∼1.2 kW of heating power. After ∼5 days of continuous running on the SECRAL-II platform, the tantalum crucible survived. In this contribution, we will discuss the structure of this inductive oven and analyze the test results as well.

[Resection of lumbar nerve sheath tumors via muscle-pedicle open-door laminoplasty approach].

Objective: To evaluate the efficacy and safety of resection of lumbar nerve sheath tumors via muscle-pedicle open-door laminoplasty approach. Methods: From March 2016 to June 2018, 6 patients (4 males and 2 females, average age (45±14) years) with lumbar spinal nerve sheath tumors received surgical treatment via muscle-pedicleopen-door laminoplasty approach in the Department of Spinal Surgery, the Affiliated Hospital of Qingdao University. The operation time, blood loss, cerebral spinal fluid (CSF) leakage, and pre- and post-operative Oswestry Disability Index (ODI) and low back and leg pain visual analogue scale (VAS) were recorded for all patients. Cobb angle of lumbar lordosis was measured on the standing lateral X-ray before and 6 months after surgery. Bone fusion was observed in computed tomography at six months after surgery. Results: Total tumor resection was achieved in all the 6 patients. The operation time was from 76 to 117 minutes (average, (102±15) minutes). The blood loss was from 160 to 280 ml (average, (256±24) ml). No CSF leakage was observed in this cohort.All patients were followed up for more than 6 months. ODI and VAS for low back and leg pain were much better at one month after operation than those before the operation(t=7.70, 8.63,11.31, all P<0.05). The Cobb angle of lumbar lordosis before operation and at six months after the operation were comparable in all six patients(t=0.70, P>0.05). Bone fusion was observed in computed tomography at six months after surgery. No bone necrosis or absorption, no lamina dislodgement or spinal stenosis was occurred. Conclusions: The muscle-pedicle open-door laminoplasty approach is proved effective and safe to incise nerve sheath tumors in the lumbar spine. Some blood supply of lamina can be kept intact to accelerate bone fusion.

Improving the wear performance of feldspathic veneering porcelain by ion-exchange strengthening.

OBJECTIVES: The present study examined the effects of Na+→K+ ion-exchange on the wear performance of feldspathic veneering porcelain. METHODS: Bar and disk specimens were prepared using IPS classic as the feldspathic veneering porcelain. After ion-exchange by immersion of the specimens in melted KNO3 at two temperatures for different time-periods, the bars were tested for flexural strength and Vickers surface hardness. The disks were paired with zirconia antagonists and tested with a pin-on-disk tribometer with 10 N for 70☓104 wear cycles in artificial saliva. Wear analysis of the porcelain and zirconia was performed using 3D profilometer and analysed with one-way analysis of variance and Tukey's post-hoc pairwise comparison procedures. Worn surfaces were examined with scanning electron microscopy. RESULTS: The feldspathic veneering porcelain exhibited strong time-dependent wear behaviour, with typical running-in and steady wear stages. Ion-exchange treatments at 380 °C and 440 °C both enhanced the mechanical properties, decreased the wear rates of running-in wear and steady wear. The wear performance of porcelain treated by ion-exchange at lower temperature (380 °C) was improved significantly, especially reducing the wear rate of the running-in stage. CONCLUSION: A thicker ion-exchange layer with less stress relaxation may be obtained by ion-exchange at lower exchange temperature for a long processing time. Such a protocol improves the wear performance of the porcelain effectively. CLINICAL SIGNIFICANCE: Restorations with veneering porcelain may fail prematurely due to excessive wear. It important to improve the wear performance of the porcelain. Ion-exchange has the potential to strengthen dental veneering porcelain. Understanding the effect of ion-exchange on the wear performance of porcelain provides insight improving the wear performance of these restorations.

[Therapeutic effect of dihydroartemisinin on pulmonary fibrosis in rats with dust].

Objective: To observe the therapeutic effect of dihydroartemisinin on pulmonary fibrosis in rats exposed to dust, and compare the therapeutic effects of dihydroartemisinin and tetrandrine. Methods: Sixty male Sprague-Dawley rats were randomly divided into control group, model group, treatment group 1 and treatment group 2, with 15 rats in each group. The model group and the treatment group were stained with disposable non-exposure silica tracheal instillation method. The drug was administered on the second day after the dust was applied. The treatment group was given with dihydroartemisinin 75 mg/kg, the treatment group was given tetrahexine 22 mg/kg, model group and control group were intragastrically administered with 1 ml of normal saline per 100 g of body mass. The drug was administered for 6 days per week for 28 days. Rats were sacrificed on the 7th, 14th and 28th day after dusting, and the lung tissues of rats were taken, detection of rat lung coefficient, ELISA was used to detect transforming growth factor-1(TGF-1)and Smad 2/3 in rat lung tissues, type I collagen (Col-I) expression level, pathological changes of rat lung tissue, immunohistochemical observation of rat lung tissue TGF-1 and Col-I protein expression. Statistial analysis was proformed with SPSS 19.0. The mean cornparis between graups wad perfomed using a completely randonized one-way (ANOVA). Results: The expressions of TGF-1, Smad 2/3 and Col-I in the lung tissue of the treatment group were significantly lower than those in the model group (P< 0.05), but the difference between the treatment group 1 and the treatment group 2 Not statistically significant (P>0.05). The results of immunohistochemistry showed that the TGF-1 and Col-I proteins in the interstitial of the model group showed strong positive expression. The expression of TGF-1 and Col-I protein in the lung interstitial of the treated group was weaker than that of the model group. Conclusion: Dihydroartemisinin can down-regulate the level of inflammatory cytokines in rat lung tissue. It is possible to inhibit pulmonary fibrosis by intervening in the TGF-ß1/Smad 2/3 signaling pathway, but the therapeutic effect between DHA and tetrandrine is not significantly different in a short time.

Oral administration of Bifidobacterium bifidum TMC3115 to neonatal mice may alleviate IgE-mediated allergic risk in adulthood.

This study aimed to demonstrate whether exposure to bifidobacteria during early life influences immunity and alleviates the risk of immunoglobulin E (IgE)-mediated allergies in adulthood. BALB/c neonatal mice (n=54) were administered with a lyophilised cell preparation of Bifidobacterium bifidum TMC3115 (TMC3115) for 3 weeks. Following the intervention, the mice were immunised with intraperitoneal ovalbumin (OVA). The morphology and function of the intestinal epithelium were determined using histopathological examinations. Intestinal microbiota was detected using quantitative PCR and characterised using next-generation sequencing of 16S rRNA genes from faecal DNA. Caecal short-chain fatty acids (SCFAs) were measured using gas chromatography-mass spectrometry. Serum levels of tumour necrosis factor (TNF)-α, interleukin (IL)-6, IL-10, and immunoglobulin E (IgE) and the percentage of splenic CD4+ T cells were examined using enzyme-linked immunosorbent assay and flow cytometry, respectively. TMC3115 did not significantly affect body weight, and cause any severe systemic inflammation or other clinical symptoms among the neonatal or adult mice, although the crypt depths and Muc2-positive cells in some intestinal segments of neonatal mice were significantly lower than control. Oral TMC3115 administration significantly increased faecal microbial diversity, relative abundance of Bacteroidetes and caecal SCFAs production in neonatal mice. Following the intervention, neonatal mice treated with TMC3115 exhibited less increase in serum IgE levels induced by OVA in adults and significantly higher TNF-α and IL-10 levels than in control. Our findings indicate that the oral administration of bifidobacteria, particularly certain strains, such as TMC3115, during early life could alleviate the risk of IgE-mediated allergies in adult host animals. Modifications of intestinal microbiota, SCFAs metabolism and anti-inflammatory cytokine IL-10 production by bifidobacteria may at least in part be a key mechanism underlying the effect of bifidobacteria on the IgE-mediated immune sensitivity of hosts to attacks by allergens at both neonatal and adult stages.

Superconducting ECR ion source: From 24-28 GHz SECRAL to 45 GHz fourth generation ECR.

The development of superconducting ECR source with higher magnetic fields and higher microwave frequency is the most straight forward path to achieve higher beam intensity and higher charge state performance. SECRAL, a superconducting third generation ECR ion source, is designed for 24-28 GHz microwave frequency operation with an innovative magnet configuration of sextupole coils located outside the three solenoids. SECRAL at 24 GHz has already produced a number of record beam intensities, such as 40Ar12+ 1.4 emA, 129Xe26+ 1.1 emA, 129Xe30+ 0.36 emA, and 209Bi31+ 0.68 emA. SECRAL-II, an upgraded version of SECRAL, was built successfully in less than 3 years and has recently been commissioned at full power of a 28 GHz gyrotron and three-frequency heating (28 + 45 + 18 GHz). New record beam intensities for highly charged ion production have been achieved, such as 620 eµA 40Ar16+, 15 eµA 40Ar18+, 146 eµA 86Kr28+, 0.5 eµA 86Kr33+, 53 eµA 129Xe38+, and 17 eµA 129Xe42+. Recent beam test results at SECRAL and SECRAL II have demonstrated that the production of more intense highly charged heavy ion beams needs higher microwave power and higher frequency, as the scaling law predicted. A 45 GHz superconducting ECR ion source FECR (a first fourth generation ECR ion source) is being built at IMP. FECR will be the world's first Nb3Sn superconducting-magnet-based ECR ion source with 6.5 T axial mirror field, 3.5 T sextupole field on the plasma chamber inner wall, and 20 kW at a 45 GHz microwave coupling system. This paper will focus on SECRAL performance studies at 24-28 GHz and technical design of 45 GHz FECR, which demonstrates a technical path for highly charged ion beam production from 24 to 28 GHz SECRAL to 45 GHz FECR.

Reevaluation of Two Quantitative Trait Loci for Type II Resistance to Fusarium Head Blight in Wheat Germplasm PI 672538.

Fusarium head blight (FHB), mainly caused by Fusarium graminearum, is a destructive disease in wheat. A population consisting of 229 F2 and F2:3 plants derived from the cross PI 672538 × L661 was used to evaluate the reactions to FHB. The FHB resistance data distribution in the F2 population indicates that some quantitative trait loci (QTLs) were controlling the FHB resistance in PI 672538. We further detected two major QTLs (Qfhs-2B, Qfhs-3B) from analysis of the resistance data and the PCR-amplified results using WinQTLCart 2.5 software. Qfhs-2B, flanked by Xbarc55-2B and Xbarc1155-2B, explained more than 11.6% of the phenotypic variation of the percentage of diseased spikelets (PDS), and Qfhs-3B, flanked by Xwmc54-3B and Xgwm566-3B, explained more than 10% of the PDS phenotypic variation in the F2:3 population. In addition, Qfhs-3B was different from Fhb1 in terms of the pedigree, inheritance, resistance response, chromosomal location, and marker diagnosis. We also detected QTLs for other disease resistance indices, including the percentage of damaged kernels and 1,000-grain weight, in similar chromosomal regions. Therefore, the FHB resistance of PI 672538 was mainly controlled by two major QTLs, mapped on 2B (FhbL693a) and 3B (FhbL693b). PI 672538 could be a useful germplasm for improving wheat FHB resistance.

Advancement of highly charged ion beam production by superconducting ECR ion source SECRAL (invited).

At Institute of Modern Physics (IMP), Chinese Academy of Sciences (CAS), the superconducting Electron Cyclotron Resonance (ECR) ion source SECRAL (Superconducting ECR ion source with Advanced design in Lanzhou) has been put into operation for about 10 years now. It has been the main working horse to deliver intense highly charged heavy ion beams for the accelerators. Since its first plasma at 18 GHz, R&D work towards more intense highly charged ion beam production as well as the beam quality investigation has never been stopped. When SECRAL was upgraded to its typical operation frequency 24 GHz, it had already showed its promising capacity of very intense highly charged ion beam production. And it has also provided the strong experimental support for the so called scaling laws of microwave frequency effect. However, compared to the microwave power heating efficiency at 18 GHz, 24 GHz microwave heating does not show the ω(2) scale at the same power level, which indicates that microwave power coupling at gyrotron frequency needs better understanding. In this paper, after a review of the operation status of SECRAL with regard to the beam availability and stability, the recent study of the extracted ion beam transverse coupling issues will be discussed, and the test results of the both TE01 and HE11 modes will be presented. A general comparison of the performance working with the two injection modes will be given, and a preliminary analysis will be introduced. The latest results of the production of very intense highly charged ion beams, such as 1.42 emA Ar(12+), 0.92 emA Xe(27+), and so on, will be presented.