[Child with sitosterolemia initially presenting with hemolytic anemia and thrombocytopenia: a case repore and literrature review]

This article focuses on a case study of sitosterolemia in a child who initially presented with hemolytic anemia and thrombocytopenia. Sitosterolemia is a rare autosomal recessive lipid metabolism disorder, difficult to diagnose due to its non-typical clinical manifestations. The 8-year-old patient was initially misdiagnosed with pyruvate kinase deficiency. Comprehensive biochemical and molecular biology analyses, including gene sequencing, eventually led to the correct diagnosis of sitosterolemia. This case highlights the complexity and diagnostic challenges of sitosterolemia, emphasizing the need for increased awareness and accurate diagnosis in patients presenting with similar symptoms.

Teneligliptin Co-Infusion Alleviates Morphine Tolerance by Inhibition of Spinal Microglial Cell Activation in Streptozotocin-Induced Diabetic Rats

Morphine (MOR) is a commonly prescribed drug for the treatment of moderate to severe diabetic neuropathic pain (DNP). However, long-term MOR treatment is limited by morphine analgesic tolerance (MAT). The activation of microglial cells and the release of glia-derived proinflammatory cytokines are known to play an important role in the development of MAT. In this study, we aimed to investigate the effects of the dipeptidyl peptidase-4 inhibitor (DPP-4i) teneligliptin (TEN) on MOR-induced microglial cell activation and MAT in DNP rats. DNP was induced in four groups of male Wistar rats through a single intraperitoneal injection of streptozotocin (STZ) (50 mg/kg, freshly dissolved in 5 mmol/L citrate buffer, pH 4.5). Sham rats were administered with the vehicle. Seven days after STZ injection, all rats were implanted with an intrathecal (i.t) catheter connected to a mini-osmotic pump, divided into five groups, and infused with the following combinations: sham + saline (1 µL/h, i.t), DNP + saline (1 µL/h, i.t), DNP + MOR (15 µg/h, i.t), DNP + TEN (2 µg/h, i.t), and DNP + MOR (15 µg/h, i.t) + TEN (2 µg/h, i.t) for 7 days at a rate of 1 μL/h. The MAT was confirmed through the measurement of mechanical paw withdrawal threshold and tail-flick tests. The mRNA expression of neuroprotective proteins nuclear factor erythroid 2-related factor (Nrf2) and heme oxygenase-1 (HO-1) in the dorsal horn was evaluated by quantitative PCR (qPCR). Microglial cell activation and mononucleate cell infiltration in the spinal cord dorsal horn were assessed by immunofluorescence assay (IFA) and Western blotting (WB). The results showed that co-infusion of TEN with MOR significantly attenuated MAT in DNP rats through the restoration of neuroprotective proteins Nrf2 and HO-1 and suppression of microglial cell activation in the dorsal horn. Though TEN at a dose of 2 μg has mild antinociceptive effects, it is highly effective in limiting MAT.

[Guidelines for diagnosis and treatment of glucocorticoid-induced osteoporosis]

Glucocorticoid-induced osteoporosis (GIOP) is a skeletal disease characterized by decreased bone strength and increased fracture risk associated with long-term glucocorticoid use. GIOP is the most common secondary osteoporosis that critically affects the quality of life of patients. Currently, the incidence of GIOP in China remains high, with insufficient awareness and lack of prevention and treatment norms. Therefore, the Chinese Rheumatology Association has established this standard based on domestic and international experience, with the aim of raising awareness of prevention and treatment among clinicians, guiding the standardized diagnosis and treatment of this disease, and improving the overall prognosis of patients with GIOP.

[Expression and significance of immune checkpoint B7-homolog 4 in endometrial cancer]

Objective: To investigate the expression of B7 homolog 4 (B7-H4) and its clinical significance in endometrial cancer. Methods: A total of 833 patients with endometrial cancer admitted to Peking Union Medical College Hospital, Chinese Academy of Medical Sciences from 2009 to 2019, were enrolled. The expression of B7-H4, mismatch repair (MMR), p53, programmed cell death ligand 1 (PD-L1) protein, and CD₈⁺ T lymphocyte density in endometrial cancer tissues were detected by the EnVision two-step method of immunohistochemical staining. First-generation sequencing (Sanger method) was used to determine molecular subtyping of endometrial cancer. The χ² test was used to compare the differences in positive expression rate of B7-H4 protein in endometrial cancer tissues with different clinicopathological features and molecular subtyping, PD-L1 protein expression, and CD₈⁺ T lymphocyte density. Survival analyses [including recurrence-free survival (RFS) and disease-specific survival (DSS)] were performed for 664 patients with follow-up time≥3 months, with a median follow-up time of 31 months (range: 4-121 months), and the Cox proportional hazards regression model was used to analyze the relevant factors affecting the prognosis of patients with endometrial cancer. Results: (1) The median age of 833 patients was 58 years (range: 25-88 years); pathological type: 595 with endometrioid carcinoma, 238 with non-endometrioid carcinoma; surgical-pathological staging: 542 cases at stage Ⅰ, 38 cases at stage Ⅱ, 173 cases at stage Ⅲ, and 45 cases at stage Ⅳ. Molecular subtyping was performed in 590 patients, including 50 with POLE mutation, 163 with mismatch repair defect (MMR-d) type, 246 with nospecific molecular change (NSMP) type, and 131 with p53 mutation subtype. (2) B7-H4 protein was expressed with brownish-yellow stainind in the cell membrane and cytoplasm of endometrial carcinoma, and the positivity rate of B7-H4 protein was 71.5% (596/833). The positivity rates of B7-H4 protein among patients with different age, surgical-pathological stage, tumor grade, pathological type, depth of muscular invasion, presence or absence of lymphovascular space invasion, and molecular subtype were significantly different (all P<0.05). The positivity rates of B7-H4 protein among patients with different PD-L1 protein expression and CD₈⁺ T lymphocyte density were not significantly different (P>0.05). The 5-year RFS (83.9%) and DSS (87.3%) of B7-H4 protein-positive patients had an increasing trend compared with the 5-year RFS (77.2%) and DSS (78.1%) of B7-H4 protein-negative patients, but there were not statistically significant differences (P=0.053, P=0.083). (3) Univariate analysis showed that the 5-year RFS and DSS of patients with different age, tumor grade, surgical-pathological stage, pathological type, depth of muscular invasion, lymphovascular space invasion, and molecular subtype were significantly different (all P<0.01). There were no significant differences in 5-year RFS (P=0.184, P=0.113) and DSS (P=0.549, P=0.247) among patients with different CD₈⁺ T lymphocyte density and PD-L1 protein expression. Further analysis according to molecular subtype, the results of CD₈⁺ T lymphocyte density and PD-L1 protein expression showed that the 5-year RFS and DSS of B7-H4 protein-positive patients were higher than those of B7-H4 protein-negative patients with NSMP subtype, low density of CD₈⁺ T lymphocyte and PD-L1 protein-negative endometrial carcinoma (all P<0.05), however, there was no significant difference in 5-year DSS between B7-H4 protein-positive patients and B7-H4 protein-negative patients with PD-L1 protein-negative endometrial cancer (P=0.060). Multivariate analysis showed that positive expression of B7-H4 protein was an independent factor for 5-year RFS (HR=0.27, 95%CI: 0.09-0.78, P=0.016) and DSS (HR=0.16, 95%CI: 0.05-0.58, P=0.005) in patients with NSMP subtype endometrial carcinoma. In patients with low-density CD₈⁺ T lymphocytes endometrial cancer, positive expression of B7-H4 protein was an independent factor for 5-year RFS (HR=0.45, 95%CI: 0.26-0.80, P=0.006), but it was not an independent factor for 5-year DSS. In patients with PD-L1 protein-negative endometrial cancer, B7-H4 protein was not an independent factor for 5-year RFS. Conclusion: B7-H4 protein expressed highly in endometrial carcinoma tissues, and its high expression is closely related to clinicopathological features, molecular subtype of p53 mutant and NSMP, and the favorable prognosis of patients with low density of CD₈⁺ T lymphocyte immunophenotype endometrial carcinoma.

Constraints on Heavy Decaying Dark Matter from 570 Days of LHAASO Observations

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 10^{5} and 10^{9}  GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

[Applying Swanson's Caring Theory to a Patient With an Initial Diagnosis of Marfan's Syndrome With Aortic Dissection]

This article describes the author's experience using Swanson Care Theory in the provision of nursing care to a 20-year-old man, an exchange student from Hong Kong, following his initial diagnosis with Marfan's syndrome. This patient required emergency aortic root replacement surgery due to type A aortic dissection. Immediately after learning of his illness, the patient was faced with making a major surgical decision. The absence of relatives and friends close by to assist him made him unable to decide whether to agree to the operation. Because of the importance of evaluating the physical and mental needs of the case, which would affect his prognosis, the author conducted a four-facet physical, psychological, social, and spiritual assessment of the patient from April 13-18, 2020. The results confirmed the presence of significant health problems, including "body image disturbance" and "anxiety". The author applied the five processes of Swanson's caring theory in caring for this patient. The process of "Knowing" and "Being with" helped, through active companionship and care, establish a trusting relationship, elucidate the client's inner thoughts on the disease, evaluate the client's needs, and accept the negative emotions. The process of "Doing for" and "Enabling" were employed to serve as a bridge for family communication to help both parties achieve consensus and to encourage effective problem-facing, provide timely assistance, promote self-adjustment, and reduce psychological shock, unease, and anxiety. Health education was implemented to increase the patient's disease and postoperative-care knowledge and promote self-care abilities to facilitate his acceptance of the current situation and active participation in treatment. Finally, the process of "Maintaining belief" was used to elicit positive feedback through actual situations. Patients with conditions similar to this patient were introduced to share their experiences and provide empathy to provide our patient with the motivation necessary to maintain positive progress. Based on this experience, it is recommended that critical caregivers strengthen their caring ability to improve their quality of care. This experience is may be referenced by clinical workers.

[Preliminary analysis of the promotion effect of laparoscopic standardized surgical treatment for gastric cancer in regional medical centers in Shanghai]

Objective: To explore the promotion effect of laparoscopic standardized surgery for gastric cancer observational in some regional medical centers in Shanghai. Methods: A retrospective cohort study was carried out. Eleven regional medical centers in Shanghai received the promotion program of laparoscopic standardized surgery for gastric cancer, which was led by Ruijin Hospital, Shanghai Jiaotong University School of Medicine (Shanghai Minimally Invasive Surgery Center) from January to December 2020. Clinicopathological data of gastric cancer patients treated at these 11 regional medical centers before and after the promotion program were collected. Inclusion criteria were as follows: patients undergoing laparoscopic distal gastrectomy or total gastrectomy; gastric cancer confirmed by pathology; without distant metastasis or peritoneal metastasis. Patients who did not undergo laparoscopic D2 radical resection, or received neoadjuvant chemotherapy before surgery, or without complete clinical data were excluded. Patients undergoing laparoscopic surgery from January to December 2019 were included in the pre-promotion group (46 cases). Patients undergoing laparoscopic surgery from January to December 2021 were included in the post-promotion group (102 cases). In addition, patients undergoing laparoscopic surgery at Ruijin Hospital from January 2021 to December were included in the control group (138 cases). The baseline data, perioperative measurements postoperative complications, and pathological results of the three groups were analyzed and compared. Results: There were no significant differences in baseline characteristics among the three groups (all P>0.05). Compared with the pre-promotion group, the operation time in post-promotion group was significantly shorter [(207.3±36.0) minutes vs. (254.2±47.1) minutes, t=7.038,P<0.001], and the number of harvested lymph node was significantly more (24.4±12.2 vs. 18.9±5.5, t=2.900, P=0.004). However, there were no significant differences in the extent of resection, time to fluid intake, and postoperative hospital stay between the two groups (all P>0.05). Compared with the control group, the operation time [(207.3±36.0) minutes vs (172.6±26.0) minutes, t=8.281, P<0.001], time to fluid intake [(6.3±3.2) days than (5.5±3.0) days, t=2.029, P=0.044], and the postoperative hospital stay [(14.3±5.6) days vs. (10.1±4.8) days, t=6.036, P<0.001] in the post- promotion group were still longer. Total gastrectomy was less common in the post-promotion group compared with the control group [18 cases (17.6%) vs. 41 cases (29.7%), χ²=7.380, P=0.007]. However, there was no significant difference in the number of harvested lymph node between the two groups (P>0.05). The morbidity of postoperative complication in the post-promotion group (9.8%, 10/102) was significantly lower than that in the pre-promotion group (23.9%, 11/46) (χ²=5.183, P=0.023), while above morbidity was not significantly different between the post-promotion group and the control group [9.8% vs. 6.5% (9/138), χ²=0.867, P=0.352]. Conclusion: After the promotion of laparoscopic standardized surgery for gastric cancer in regional medical centers, the standardization degree of surgery has been improved, and the morbidity of postoperative complication decreases. Laparoscopic standardized surgery for gastric cancer can be promoted to more regional medical centers.

[Relationship between simple renal cyst and adverse events in patients receiving thoracic endovascular aortic repair for Stanford B aortic dissection]

Objective: To explore the prognostic value of simple renal cyst (SRC) for adverse events in patients receiving thoracic endovascular aortic repair (TEVAR) for Stanford B aortic dissection (TBAD). Methods: This study is a retrospective cohort study. Consecutive patients receiving TEVAR for TBAD between January 2010 and December 2015 were enrolled in this study. The patients were divided into SRC group and non-SRC group. With sex and age ±2 years old as matching factors, SRC group and non-SRC group were matched by 1∶1. Collect and compare the differences of clinical data between the two groups. Adverse events were recorded through outpatient, telephone follow-up and in-hospital review. After adjusting for confounding factors, multivariate Cox regression was used to analyze the risk factors of aortic adverse events. Kaplan-Meier method was used to analyze the survival curve of SRC group and non-SRC group. Results: A total of 692 consecutive patients were recruited. Patients were divided into SRC group (n=235) and non-SRC group (n=457). After 1∶1 matching, there were 229 cases in SRC group and no SRC group respectively. The age of SRC group was (62.3±10.4) years old, 209 cases were male (91.3%), and the age of no SRC group was (62.0±10.2) years old, 209 cases were male (91.3%). Cox regression analysis showed that, after adjusting for confounding factors, comorbid SRC (HR=1.991, 95%CI: 1.090-3.673, P=0.025), TEVAR in the acute phase (HR=13.635, 95%CI: 5.969-31.147, P=0.001), general anesthesia (HR=2.012, 95%CI: 1.066-3.799, P=0.031) are independent factors of aortic-adverse events after TEVAR for TBAD. Kaplan-Meier analysis showed that the cumulative survival rate of SRC group was significantly lower than non-SRC group (log-rank P=0.031, 0.005). Conclusion: SRC is an independent predictor of aortic-related adverse events in patients following TEVAR for TBAD.

Postoperative Serotonin Syndrome Following Administration of Preoperative Intrapulmonary Methylene Blue and Intraoperative Granisetron: A Case Report

BACKGROUND Methylene blue (MB), which is often used perioperatively, is a potent monoamine oxidase inhibitor that can strongly block the clearance of extracellular serotonin. Granisetron, a serotonin receptor subtype 3 (5-HT3) antagonist, is an antiemetic used to prevent or treat postoperative nausea and vomiting (PONV). Through its antagonism, granisetron can increase the extracellular serotonin concentration. Serotonin syndrome is a potentially life-threatening condition resulting from a drug reaction that affects serotonin levels. This report is of a 50-year-old woman with postoperative serotonin syndrome following co-administration of preoperative intrapulmonary methylene blue and intraoperative granisetron. CASE REPORT A 50-year-old woman with well-controlled gastroesophageal regurgitation disease presented under impression of lung cancer. She received a computed tomography (CT)-guided localization followed by video-assisted thoracic surgery under endotracheal general anesthesia. The surgery was completed uneventfully. Her postoperative course was significant for serotonin syndrome, likely triggered by co-administration of preoperative intrapulmonary MB for tumor localization and intraoperative granisetron. Other differential diagnoses were ruled out. Her management was primarily supportive, using benzodiazepine administration, and resulted in full neurologic recovery. CONCLUSIONS Intrapulmonary MB can lead to serotonin syndrome in combination with 5HT-3 antagonists when used for preoperative tumor localization. Because both MB and 5-HT3 antagonists are being widely used clinically at present, this report has highlighted that physicians, surgeons, and anesthesiologists should be aware of serotonin syndrome, its presenting features, and management, and its association with the use of methylene blue and 5-HT3 receptor antagonists, including granisetron.

Exploring Lorentz Invariance Violation from Ultrahigh-Energy γ Rays Observed by LHAASO

Recently, the LHAASO Collaboration published the detection of 12 ultrahigh-energy γ-ray sources above 100 TeV, with the highest energy photon reaching 1.4 PeV. The first detection of PeV γ rays from astrophysical sources may provide a very sensitive probe of the effect of the Lorentz invariance violation (LIV), which results in decay of high-energy γ rays in the superluminal scenario and hence a sharp cutoff of the energy spectrum. Two highest energy sources are studied in this work. No signature of the existence of the LIV is found in their energy spectra, and the lower limits on the LIV energy scale are derived. Our results show that the first-order LIV energy scale should be higher than about 10^{5} times the Planck scale M_{Pl} and that the second-order LIV scale is >10^{-3}M_{Pl}. Both limits improve by at least one order of magnitude the previous results.

[Association analysis between extracurricular physical activity and dyslipidemia among primary, middle and high school students in Guangzhou]

Objective: To investigate the prevalence of dyslipidemia, and to explore the association between extracurricular physical activity and dyslipidemia among primary, middle and high school students in Guangzhou. Methods: This cross-sectional study selected primary and middle school students in Guangzhou by the stratified cluster sampling method from March to December 2019. Physical examination and blood lipid test were performed. Information about students' basic characteristics and extracurricular physical activity was collected by questionnaire. Multivariate logistic regression analysis was used to determine the association between extracurricular physical activity and dyslipidemia in this cohort. Results: A total of 7 797 participants (mean aged (12.2±2.9) years) were included (4 194 (53.79%) boys and 3 603 (46.21%) girls]. The detection rates of high total cholesterol, high triglycerides, low high-density lipoprotein cholesterol, high low-density lipoprotein cholesterol and dyslipidemia were 12.49% (974/7 797), 6.44% (502/7 797), 6.62% (516/7 797), 11.31% (882/7 797) and 23.83% (1 858/7 797), respectively. Dyslipidemia rate was lower in the junior school students (21.39% (675/3 156)) than in primary school students (25.96% (896/3 451)) and high-school students (24.12% (287/1 190)) (P<0.001). The dyslipidemia rates of boys and girls were similar (23.15% (971/4 194) vs. 24.62% (887/3 603), P>0.05). Dyslipidemia rate was lower in students with extracurricular physical activity than in students without extracurricular physical activity (22.50% (923/4 102) vs. 25.30% (935/3 695), P<0.05). Multivariate logistic regression analysis showed that extracurricular physical activity was associated with lower risk of dyslipidemia (OR=0.88, 95%CI=0.79-0.99, P=0.033). Among all types of extracurricular physical activities, participating in extracurricular large ball game was associated with 28% lower risk among junior school students (OR=0.72, 95%CI=0.57-0.91, P=0.006). Conclusion: The prevalence of dyslipidemia is high among primary, middle and high school students in Guangzhou. Extracurricular physical activity is associated with reduced risk of dyslipidemia in this cohort.

[Preliminary clinical observation of omalizumab therapy for moderate to severe asthma]

Objective: To observe the effectiveness, safety and management of omalizumab therapy for moderate to severe asthma in real-world clinical practice in China. Methods: This retrospective analysis involved 79 patients with moderate to severe asthma who received omalizumab therapy for at least 4 months in the First Affiliated Hospital of Guangzhou Medical University from March 2018 to April 2020. All participants were between 14 to 76 years old(median 50 years),including 30 males and 49 females. Data regarding the patients' clinical manifestations, eosinophil count, fractional exhaled nitric oxide (FeNO), lung function, oral corticosteroid dosage, and adverse reactions were collected before and after treatment. Paired t-test or non-parametric paired Wilcoxon analysis was used for pairwise comparison, Mann Whitney analysis for inter-group comparison, and Chi square test or Fisher test for inter-group comparison of count data. Results: The following changes were noted after 4 months of omalizumab thearpy. The patients' Asthma Control Test (ACT) scores increased from 17.0 (13.0-19.0) to 20.0 (18.0-24.0) points (P<0.001). The frequency of acute exacerbations(AE) decreased from 1.0 (0-1.0) to 0 (0-1.0) episodes every 4 months (P<0.001). The variation rate of the peak expiratory flow (PEF) decreased from 16.5 (13.8-27.3)% to 10.4 (6.0-16.2)% (P<0.001). The percent predicted value of PEF (PEFpred%) increased from 71.7 (51.4-91.6)% to 87.5 (65.2-105.5)% (P<0.001). The percent predicted value of the forced expiratory volume in 1 second(FEV₁%pred) increased from 73.6 (53.9-90.8)% to 80.6 (68.7-91.8)% (P=0.007). The maintenance dose of oral corticosteroids (OCS) decreased from 12.0 (10.0-20.0) to 5.0 (0-17.5) mg/day (P=0.001). After 4 months of treatment, the response rate of the 79 patients with asthma was 74.7%. The response rate of patients with allergic asthma (77.3%) was higher than that of patients with non-allergic asthma (25.0%) (P=0.019). Among 5 patients who completed 1 year of treatment, the ACT score, frequency of AE, PEFpred%, variation rate of PEF and OCS maintenance dose were still improved after 1 year of treatment. Adverse reactions occurred in 3 patients (3.8%), for a total of 3 (0.6%) times. Stratified analysis showed that after 4 months of treatment, the improvement in the ACT score and the decrease in the PEF variation rate among patients who reached the recommended treatment dose (full dose) [3.0 (1.0-8.0) points, 6.5 (3.5-15.8) %] were significantly higher than those among patients who did not reach the recommended treatment dose (insufficient dose) [1.0 (-0.3-3.0) points, 2.9 (1.5-5.0) %] (P<0.05). Additionally, the treatment response rate in patients with a sufficient dose (80.0%) was higher than that in patients with an insufficient dose (50.0%) (P=0.019).The main factors associated with stopping treatment within 1 year despite a response to omalizumab was economic burden (70.3%), followed by satisfactory improvement by self-evaluation (21.9%) and less improvement in symptoms than expected (7.8%). Conclusion: Omalizumab was an effective treatment for moderate to severe allergic asthma with few adverse effects. The response rate was higher when the recommended injection dose was achieved. Financial difficulty was the main reason for stopping treatment within 1 year despite a good therapeutic response.

Peta-electron volt gamma-ray emission from the Crab Nebula

The Crab Nebula is a bright source of gamma rays powered by the Crab Pulsar's rotational energy through the formation and termination of a relativistic electron-positron wind. We report the detection of gamma rays from this source with energies from 5 × 10^-4 to 1.1 peta-electron volts with a spectrum showing gradual steepening over three energy decades. The ultrahigh-energy photons imply the presence of a peta-electron volt electron accelerator (a pevatron) in the nebula, with an acceleration rate exceeding 15% of the theoretical limit. We constrain the pevatron's size between 0.025 and 0.1 parsecs and the magnetic field to ≈110 microgauss. The production rate of peta-electron volt electrons, 2.5 × 10³⁶ ergs per second, constitutes 0.5% of the pulsar spin-down luminosity, although we cannot exclude a contribution of peta-electron volt protons to the production of the highest-energy gamma rays.

Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E>25  TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160  TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.

Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 10¹⁵ electronvolts) indicates the existence of the so-called PeVatrons-cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays¹. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. ²). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane^3-6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.

[Effect of long non-coding RNA MBNL1-AS1 expression on prognosis of acute myeloid leukemia patients]

Objective: To explore the prognosis effect of the expression of long-chain non-coding RNA (lncRNA) MBNL1-AS1 on acute myeloid leukemia (AML) patients. Methods: One hundred and twenty-five AML patients of the Cancer Genome Atlas (TCGA) from November 2001 to March 2010 were involved, including 70 patients who received chemotherapy only and other 55 patients treated with allogeneic hematopoietic stem cell transplantation (allo-HSCT) in addition to chemotherapy. According to the median expression of lncRNA MBNL1-AS1, patients of chemotherapy group were divided into high expression sub-group(n=35) and low expression sub-group (n=35), and patients of allo-HSCT group were also divided into high expression sub-group (n=28) and low expression sub-group (n=27) for prognosis analysis. Clinical characteristics at diagnosis, including peripheral white blood cell counts (WBC), blast percentages in peripheral blood and bone marrow (BM), French-American-British (FAB) subtypes and the frequencies of common genetic mutations in AML were described. The event-free survival (EFS) rate and overall survival (OS) rate of patients in different groups were analyzed, and the influence of the clinical characteristics of patients on the prognosis of AML was analyzed by COX multivariate analysis. Results: In the chemotherapy group, patients with low lncRNA-MBNL1-AS1 expression had significantly lower EFS and OS (60.0%, 8.6%) than patients with high lncRNA-MBNL1-AS1 expression (68.6%, 34.3%) (χ²=7.817, 10.880, all P<0.01). However, in the alloHSCT group, no significant differences were observed in EFS and OS of patients between high and low expression groups of lncRNA-MBNL1-AS1 (all P>0.05). COX multivariate analysis confirmed that age≥60 years old (EFS: HR (95%CI): 6.934 (1.918-25.075),P=0.003;OS: HR (95%CI): 4.119 (1.812-9.364), P=0.001), and low expression of lncRNA MBNL1-AS1 (EFS: HR (95%CI): 0.354 (0.126-0.941), P=0.038; OS: HR (95%CI): 0.424 (0.231-0.778), P=0.006)were independent risk factors for EFS and OS in the chemotherapy group. Conclusion: The long-chain non-coding RNA MBNL1-AS1 is related to the prognosis of AML, and its low expression is an independent poor prognostic factor in AML patients.

[Consistency between bioelectrical impedance analysis and dual-energy X-ray absorptiometry for body composition measurement in children aged 7-17 years]

Objective: To evaluate the consistency between bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA) in the measurement of body composition in children and adolescents aged 7-17 years. Methods: Fat-free mass (FFM) and fat mass (FM) were measured by both BIA and DXA in 1 431 children. The consistency between the methods was evaluated by intra-class correlation coefficients (ICCs) and Bland-Altman analysis. Logarithmic transformation of both measurements was performed before Bland-Altman analysis. Results: The ICCs for FFM were 0.986 and 0.974 and ICCs for FM were 0.854 and 0.926 in boys and girls respectively. In boys, the mean ratio of FFMs by BIA and DXA was 1.04, with limits of Agreement (LoA) of 0.95-1.14, and in girls, the mean ratio of FFMs by BIA and DXA was 1.02, with the LoA of 0.90-1.15. The LoA of FFM became narrower with age in both boys and girls. Both boys and girls had the wide LoAs for FM (0.40-1.27 and 0.48-1.48, respectively). Additionally, the LoA ranges for FFM and FM narrowed with the increase of BMI level in both boys and girls. Conclusion: For all children, BIA showed good consistency with DXA for FFM, whereas significant errors occurred in FM measurement. The consistency between BIA and DXA was better for obese children than for underweight or normal-weight children.

Effect of peak power enhancement of ferrite phase shifter from full-height to increased-height rectangular waveguide

In order to enhance the high-power performance of the ferrite phase shifter (PS), a method of increasing waveguide height is proposed and experimentally demonstrated. Dual-toroid geometry is utilized as a high-power structure. Two configurations of X-band PSs with full-height (FH) and increased-height (IH) waveguides are designed and fabricated while keeping other parameters consistent. Comparative analysis based on simulation and high-power experiments is conducted. The simulation results agree well with experiments. Compared with the FHPS, the IHPS can enhance the peak-power-capacity from 90 kW to 140 kW while maintaining almost the same insertion loss of 0.5 dB with a slight increase in differential phase shift from 360° to 380°.

P5609Outcomes of chimney technique for aortic arch diseases: a single-center experience with 226 cases

Objective

The aim of the present study is to report our single-center experience with chimney technique for aortic arch diseases and the early- and mid-term outcomes in these patients.

Methods

From August 2012 to October 2017, 226 patients (mean age 54±12 years; 197 men) with aortic arch diseases underwent thoracic endovascular aortic repair combined with chimney stents. Pathologies included type B aortic dissection (n=185), aortic arch aneurysm/descending thoracic aortic aneurysm (n=13), aortic arch pseudoaneurysm (n=10), penetrating aortic ulcer (n=7), intramural hematoma (n=7), and aortic rupture (n=4).

Results

The aortic stent-grafts were deployed in zone 0 (n=22), zone 1 (n=13), and zone 2 (n=191). A total of 230 chimney stents were deployed (innominate artery, n=21; right common carotid artery, n=1; left common carotid artery, n=13; left subclavian artery, n=195). The technical success rate was 84% (189/226) and immediate type Ia endoleak occurred in 37 (16%) patients. In the early-term, four patients died, of which from aortic rupture (n=1), ventricular fibrillation (n=1) or major stroke (n=2). Four major strokes occurred (two patients died and two recovered), but no reintervention was recorded. Spinal cord ischemia developed in three patients. The mean duration of follow-up was 22±16 months. Late type Ia endoleaks were recorded in two patients. Chimney stent occlusions were recorded in six patients. During follow-up, five patients died, of which from aortic rupture (n=3), cerebral hemorrhage (n=1) or rectal cancer (n=1). Two major strokes occurred (one patient died and one recovered) and reintervention performed in one case.

Conclusion

The chimney technique for aortic arch diseases is safe and feasible. And long-term follow-up observation is needed.

[Role and mechanism of lipopolysaccharide induced exosome in the pathogenesis of acute lung injury]

Objective: To explore the effect and mechanism of exosome derived from lipopolysaccharide (LPS)-induced mouse macrophage (RAW264.7) on acute lung injury. Methods: RAW264.7 were cultured in vitro and divided into 2 groups: control group and LPS-induced group. The exosomes were extracted from the two groups of cell supernatant by ultracentrifugation and classified into 2 groups: C-EXO group and LPS-EXO group. In vivo, random allocation was used to averagely divide the eighteen male C57BL/6 mice into 3 groups: control group, EXO-control group and EXO-LPS group. All mice were sacrificed after 12 h. The lung tissue was used for HE staining to assess the degree of acute lung injury as well as immunohistochemical staining for interleukin (IL) -1β and tumor necrosis factor (TNF)-α. The tissue protein expression levels of IL-1β, TNF-α, β-catenin, E-cadhein, ZO-1 and Occludin were measured by Western blot. In vitro, alveolar type Ⅱ epithelial cells (MLE-12) were cultured and divided into 3 groups: C-control group, EXO-control-induced group and EXO-LPS-induced group. The tissue protein expression levels of IL-1β, TNF-α, and Occludin were measured by Western blot after 12 h. Results: The two samples of C-EXO group and LPS-EXO group was proved to be exosomes. Under a light microscope, the lung tissue of EXO-LPS group showed inflammatory cell infiltration, hemorrhage, interstitial and alveolar edema, and the thickness of alveolar septum. The tissue protein levels of IL-1β and TNF-α in EXO-LPS group were obviously higher than the control group, EXO-control group (1.331±0.203 and 0.274±0.018, 0.892±0.074; 0.800±0.096 and 0.596±0.025, 0.441±0.061; all P<0.05). While the tissue protein levels of Occludin showed the opposite phenomenon (0.251±0.021 and 0.862±0.029, 0.453±0.013; all P<0.05). In vitro, Compared with the C-control group and the EXO-control-induced group, the expression levels of IL-1β and TNF-α increased significantly in the EXO-LPS-induced group (0.900±0.033 and 0.320±0.030, 0.661±0.028; 0.739±0.045 and 0.151±0.024, 0.360±0.037; all P<0.05). whereas the protein levels of Occludin expression were reversed in MLE-12 (0.585±0.082 and 0.941±0.090, 0.732±0.083; all P<0.05). Conclusion: Exosomes derived from LPS-induced RAW264.7 can induced the acute lung injury by affecting barrier function, which probably is related to the low degree of Occludin in alveolar type Ⅱ epithelial cells.

[Characteristics of pulmonary vascular remodeling in rat model of pulmonary hypertension in left heart disease]

Objective: To investigate pulmonary vascular remodeling in rat model of pulmonary hypertension in left heart disease (PH-LHD). Methods: A total of 66 male minor Sprague-Dawley (SD) rats were randomly divided into control group (n=6), sham operation group (n=6) and model group (n=54). The rats in the control group entered the experimental procedure immediately without any treatment, and the rats in the sham operation group entered the experimental procedure 64 days after sham operation, and the rats in model group entered the experimental procedure (6 rats each) on day 1, day 3, day 5, day 8, day 15, day 22, day 36, day 50 and day 64 respectively after supracoronary aortic banding successfully. The lung tissue was fixed and cut and made into pathological sections to observe the characteristics of pulmonary vascular remodeling. Results: Medial thickening was mainly observed in pulmonary arterioles with diameter <100 μm [(11.17±1.03)%]. Additionally, medial thickening was seen in pulmonary arterioles with diameter 50-100 μm and 20-50 μm from day 15 [(12.73±1.15)%] and day 50 [(14.53±1.53)%], respectively. Medial muscularize of pulmonary arterioles were mainly observed in arterioles with diameter 20-50 μm, and deteriorated with time. Reduced pulmonary arteriole lumen size were observed with diameter 20-50 μm since day 50 (P<0.05). Conclusion: Pulmonary arteries with diameter >100 μm have little effect on the reconstruction of pulmonary vessels in PH-LHD rat model. However, arterioles with diameter 20-50 μm and 50-100 μm are the most important vessels involved in the formation of pulmonary hypertension, especially 20-50 μm.

[Feasibility and safety of paclitaxel-eluting balloon for the treatment of de novo coronary lesions]

Objective: To evaluate the safety and feasibility of treating de novo coronary lesions with paclitaxel-eluting balloon. Methods: This is a retrospective study, which enrolled 76 patients with 80 de novo coronary lesions treated with paclitaxel-eluting balloons(<30% residual stenosis and there was no blood flow limited dissection after pretreatment) from April 2015 to November 2016 in Guangdong general hospital. The data of basic characteristics,procedures,devices and follow-up information were retrieved and analyzed. The primary endpoint was the composite of cardiac death, recurrent myocardial infarction and target lesion revascularization. Results: (1)The age was (63.3±10.3) years. There were 68.4%(52/76) acute coronary syndrome patients, prevalence of type 2 diabetes was 36.8%(28/76), and 64.5%(49/76)patients with at least one high bleeding risk. (2)The lesion length was (17.4±7.6)mm, and the stenosis was (88.1±8.2)%.The reference vessel diameter≥2.75 mm accounted for 51.2% (41/80), and bifurcation stenosis accounted for 67.5%(54/80). (3)53.7%(43/80) lesions were pretreated with scoring balloon to optimize plaque modification. The paclitaxel-eluting balloon length and diameter were (22.3±5.5)mm and (2.74±0.52)mm.The residual stenosis was (12.3±10.3)%. Procedural success was 88.8%(71/80).Bail-out stenting rate was 5.0%(4/80). (4)The median follow-up duration was 12(6, 25) months. Primary endpoint occurred in 3 cases (3.9%), including 2 cardiac deaths(1 patient died of recurrent myocardial infarction, and 1 patient died of acute heart failure induced by severe mitral insufficiency), and one patient receivedtarget lesion revascularization. Conclusion: In case of no more than 30% residual stenosis and no blood flow limited dissection after lesion pretreatment,it is safe and feasible to treat de novo coronary lesionsusing paclitaxel-eluting balloon.

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.

A novel high power X-band ferrite phase shifter

A novel high power X-band ferrite phase shifter (PS) employing the structure of several waveguides connected in parallel is proposed. Each of the waveguides is a phase shift unit utilizing a dual-toroid structure. First, the phase shift unit is designed, manufactured, and tested. The results indicate that the power capacity reaches 115 kW. At this power, the maximum magnetic field strength of ferrite is 7.9 kA/m, beyond which the nonlinear effect of ferrite will occur. On this basis, the PS that consists of four units connected in parallel is designed. According to the threshold of ferrite, the power capacity of the PS can theoretically reach 430 kW. Limited by the maximum output power of the microwave source, the preliminary high-power test results demonstrate that the PS can operate properly at 270 kW. The PS exhibits an insertion loss of 0.82 dB and a maximum differential phase shift of approximately 300° at 9.3 GHz. The return loss of the PS is more than 16 dB from 9.0 to 9.5 GHz.

[The spontaneous herniation of temporomandibular joint into external auditory canal: diagnosis of otoscopy, CT and MRI]

OBJECTIVE

To summarize the otoscopy, CT and MRI features of spontaneous herniation of the temporomandibular joint(TMJ) into the external auditory canal(EAC) through the persistence Huschke's foramen(PHF).

METHODS

The otoscopy, CT and MRI images of three cases with the herniation of the TMJ into the EAC through the PHF were analyzed retrospectively.

RESULTS

Otoscopy revealed the masses located in the antero-inferior aspect of the bony EAC, and the mass displayed an alternative of forward and backward motion during opening and closing of the mouth.CT of the temporal bone showed a bony defect and a consecutive soft mass in the antero-inferior wall of the bony EAC. The margin of the bony defects were well-defined in all cases, the bone adjacent to PHF was pressed and partially wrapped around the soft mass as 'holding ball' in two cases, partly peripheral pseudo bony shell of the soft mass were showed in two cases. The soft mass in EAC appeared equal attenuated with the soft tissue of TMJ, and on enhanced CT scans showed no enhancement of the soft mass. On MRI scans, the imaging displayed a bony defect in the antero-inferior wall of the EAC with a soft mass which was formed by the capsule of the TMJ, and the mass showed iso-signal to the capsule of the TMJ on all sequences, and there was no enhancement after contrast administration.

CONCLUSION

The otoscopy, CT and MRI features of the spontaneous herniation of the TMJ into the EAC through the PHF is special, and the above examinations are valuable for diagnosis of the disease.

Compact high-power microwave divider and combiner

A novel, compact, TM01-TE10 mode power divider and a novel, compact, four-way TE10-TM01 mode power combiner were theoretically designed and experimentally tested as a proof of principle. The theoretical and experimental S parameters are consistent with each other. High-power experiments show that their power capacities are no less than 1.5 GW and 3 GW, respectively. The devices have the merits of high power capacities and low insertion losses.

Association between IL2/IL21 and SH2B3 polymorphisms and risk of celiac disease: a meta-analysis

Celiac disease (CD) is a common autoimmune disorder characterized by heightened immunological response to ingested gluten. Certain gene polymorphisms of IL2/IL21 (rs6822844 and rs6840978) and SH2B3 (rs3184504) may influence susceptibility to CD, although the effects remain unclear. We performed a meta-analysis of the associations between rs6822844, rs6840978, and rs3184504 polymorphisms and CD risk. PubMed, EMBASE, and the China National Knowledge Infrastructure were searched. ORs and 95%CIs of each single nucleotide polymorphism (SNP) were estimated using the fixed-effect model if I(2) < 50% in the test of heterogeneity; otherwise, the random-effect model was used. Our meta-analysis included 12,986 CD cases and 28,733 controls from 16 independent samples, and the analysis of each SNP contained a subset of the total. We found that the minor allele T of both rs6822844 (T vs G, OR = 0.72, 95%CI = 0.67-0.78, P < 0.001) and rs6840978 (T vs C, OR = 0.76, 95%CI = 0.71-0.83, P < 0.001) in IL2/IL21 significantly decreased the risk of CD. However, the minor allele A of rs3184504 (A vs G, OR = 1.18, 95%CI = 1.12-1.24, P < 0.001) in SH2B3 significantly increased CD susceptibility. The estimated lambda values were 0.49, 0.50, and 0.53 for rs6822844, rs6840978, and rs3184504, respectively, suggesting that a co-dominant model of genotype effect was most appropriate for the three SNPs. Our results support associations between the three SNPs and CD and provide a strong argument for further research.

Association of TLR2 and TLR4 non-missense single nucleotide polymorphisms with type 2 diabetes risk in a southern Chinese population: a case-control study

Toll-like receptors (TLRs), the triggers of the innate and adaptive immune responses, are involved in the pathogenesis of type 2 diabetes mellitus (T2DM). Several studies have investigated the effects of genetic polymorphisms in TLR4 and TLR2, but they have yielded limited results. We investigated whether non-missense genetic polymorphisms in the regulatory regions of TLR4 and TLR2 were related to T2DM in a southern Chinese population. Single nucleotide polymorphisms (SNPs) in TLR4 (rs1927911, rs11536889, rs1927907, rs1927906, rs1927914, rs7873784, and rs2149356) and TLR2 (rs1898830, rs3804099, rs4696480, and rs3804100) were genotyped in 552 T2DM and 552 unrelated age- and gender-matched controls by SNaPShot Multiplex assay. Genotypes GG (OR = 0.09, 95%CI = 0.01- 0.83, P = 0.03) and CG (OR = 0.08, 95%CI = 0.01-0.74, P = 0.03) of the 3'-untranslated region (UTR) SNP rs7873784 in TLR4, and genotype AG (OR = 0.67, 95%CI = 0.46-0.97, P = 0.04) and allele G (OR = 0.88, 95%CI = 0.79-0.97, P = 0.01) of the intron SNP rs1898830 in TLR2 were identified as protective against the development of T2DM in southern Chinese people. In contrast, a meta-analysis of rs1927911 and rs1927914 showed no association. Haplotypes AGTT (OR = 0.34, 95%CI = 0.15-0.77, P = 0.01) and AATT (OR = 1.20, 95%CI = 1.01- 1.44, P = 0.05) in TLR2 were significantly associated with susceptibility to T2DM. Our results suggest that the effects of non-missense polymorphisms located in the regulatory regions of TLR4 and TLR2 should not be neglected in T2DM association analysis.

Environmental and DNA repair risk factors for breast cancer in South China

PURPOSE

The incidence of breast cancer (BC) in China has been rapidly increasing. We hypothesize that China-specific risk factors, both life-style and inherent ones, contribute to the problem.

METHOD

We have conducted an epidemiology and functional DNA repair investigation to identify risk factors for the development of BC in Shantou, China.

RESULTS

Our survey of 372 patients and 419 matched normal controls confirmed the significant risk from many universal factors: high BMI, low education level, low fruit intake and sedate lifestyle. Significant risk factors can be organized into endogenous ones (low education and cooking with lard instead of vegetable oil) and externally-introduced ones (sedate life-style and cigarette smoking). We also found highly significant risk from passive exposure to cigarette smoke. Using the Challenge-Comet assay and blood samples from 57 patients who did not inherit the tumor suppressor BRCA gene mutations and 62 matched normal controls; we showed that reduced functional DNA repair capacity was a significant risk factor. In addition, the reduced repair capacity was associated with lymph node metastasis, and with tumors that had negative ER receptor and over-expression of Her-2.

CONCLUSION

Our study indicates that combined externally-introduced and endogenous life-style factors were involved with the increased incidence of BC in China. We also showed, for the first time, that inherent deficiency in DNA repair function was a significant risk factor for BC. The inherent deficiency can interact with other risk factors to significantly increase risk for BC. In addition, the reduced repair capacity was associated with certain clinical features that are indicative of poor prognosis. In this context, it is possible to integrate DNA repair capacity knowledge in promoting prevention of BC and in enhancing personalized therapeutic protocols.

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.

Antibiotic prophylaxis for dental procedures: is it necessary?

INTRODUCTION

Guidelines regarding the prevention of infective endocarditis have recently been published by the British Society for Antimicrobial Chemotherapy in 2006, the American Heart Association (AHA) in 2007 and the National Institute for Health and Clinical Excellence (NICE), UK, in 2008. These are contradictory, even though all are from developed countries. It is not known whether they are suitable for developing countries such as South Africa, nor is it known whether they are followed by general dental practitioners.

AIMS AND OBJECTIVES

To conduct a survey amongst dental practitioners in South Africa to determine knowledge of the more recent AHA and NICE guidelines and the practices followed in antibiotic prophylaxis.

METHOD

E-mails were sent to dentists registered with SADA requesting their participation in an internet-based survey.

RESULTS

The limited response rate necessitated the pooling of the data, but it was felt they would be valuable if some trends emerged. Most (88%) of the 105 respondents were aware of the AHA guidelines, but only 55% knew of the NICE guidelines. However, few actually followed the recommendations and few correctly prescribed for patients allergic to penicillin. The large number of cases of rheumatic fever in this country implies that the AHA and NICE guidelines may not be appropriate.

CONCLUSION

Despite the low sample size, the trends shown are of real concern. There is clearly a need for local guidelines, and once these are established, there is an urgent need to inform all dental practitioners of the appropriate prescription of prophylaxis for patients.

A multiscale model for bioimpedance dispersion of liver tissue

Radio-frequency ablation (RFA) has been used in liver surgery to minimize blood loss during tissue division. However, the current RFA tissue division method lacks an effective way of determining the stoppage of blood flow. There is limitation on the current state-of-the-art laser Doppler flow sensor due to its small sensing area. A new technique was proposed to use bioimpedance for blood flow sensing. This paper discusses a new geometrical multiscale model of the liver bioimpedance incorporating blood flow impedance. This model establishes correlation between the physical tissue structure and bioimpedance measurement. The basic Debye structure within a multilevel framework is used in the model to account for bioimpedance dispersion. This dispersion is often explained by the Cole-Cole model that includes a constant phase element without physical explanation. Our model is able to account for reduced blood flow in its output with changes in permittivity in gamma dispersion that is mainly due to the polarization of water molecules. This study demonstrates the potential of a multiscale model in determining the stoppage of blood flow during surgery.

Detection of novel SNPs and mapping of the fatness QTL on pig chromosome 7q1.1-1.4 region

Many QTLs for fatness traits have been mapped on pig chromosome 7q1.1-1.4 in various pig resource populations. Eight novel markers, including seven SNPs and one insertion or deletion within BTNL1, COL21A1, PPARD, GLP1R, MDFI, GNMT, ABCC10, and PLA2G7 genes, as well as two previously reported SNPs in SLC39A7 and HMGA1 genes, were genotyped in Large White and Meishan pig breeds. Except for two SNPs in HMGA1 and ABCC10 genes, allele frequencies of the other eight markers are highly significant different between Chinese indigenous Meishan breeds and Large White pig breeds. Eight polymorphic sites were then used for linkage and QTL mapping to refine the fatness QTL in a Large White × Meishan F(2) resource population. Five chromosome-wise significant QTLs were detected, of which the QTLs for leaf fat weight, backfat thickness at 6-7th rib and rump, and mean backfat thickness were narrowed to the interval between PPARD and GLP1R genes and the QTL for backfat thickness at thorax-waist between GNMT and PLA2G7 genes on SSC7p1.1-q1.4.

Clinical implication of intra-amniotic sludge on ultrasound in patients with cervical cerclage

OBJECTIVE

The aim of this study was to determine whether intra-amniotic (IA) sludge, a sonographic finding of hyperechoic matter in the amniotic fluid close to the internal cervical os, is associated with preterm delivery in patients with cervical cerclage.

METHODS

A retrospective cohort study of patients who had undergone McDonald cerclage between January 1997 and December 2004 was conducted. Transvaginal ultrasound examinations had been performed at 14-28 weeks of gestation, and the ultrasound images were assessed by three reviewers (blinded to patient outcome) to determine the presence or absence of IA sludge. The primary outcome studied was the gestational age at delivery.

RESULTS

A total of 177 patients who had undergone cervical cerclage, and for whom adequate records were available, were identified. Sixty had sonographic evidence of IA sludge (Group 1) and 117 had absence of IA sludge (Group 2). There was no significant difference in the mean gestational age at delivery between the two groups (36.4 ± 4.0 vs. 36.8 ± 2.9 weeks, P = 0.53), and no statistical difference in the rate of preterm delivery at < 28 (6.7% vs. 1.7%, P = 0.18), < 30 (6.7% vs. 3.4%, P = 0.45), < 32 (8.3% vs. 6.8%, P = 0.77) or < 36 (16.7% vs. 19.7%, P = 0.69) weeks of gestation.

CONCLUSION

Intra-amniotic sludge on ultrasound is not associated with an increased risk of preterm delivery in patients with cervical cerclage.

Postischemia myocardial injury in coronary artery bypass patients (PP6)

PURPOSE

To investigate the reperfusion injury of the myocardium in patients undergoing elective coronary artery bypass surgery (CABG) with cardiopulmonary bypass (CPB), we monitored the blood levels of troponin I (TNI), white blood cells, oxygen radicals, malondialdehyde, and myeloperoxidase seeking to define the relationship between the CABG-induced systemic inflammation and myocardial injury.

MATERIALS AND METHODS

We selected 10 patients undergoing primary CABG with CPB at moderate hypothermia and cardioplegic arrest concomitant with intermittent warm blood cardioplegia. We compared all data with their own baseline values to study the reperfusion injury. After release of the aortic clamp, blood was drawn from the coronary sinus, via a catheter placed through the right atrium. We measured plasma levels of inflammatory mediators, such as malondialdehyde, myeloperoxidase, oxygen radicals, and the myocardium injury parameter of TNI.

RESULTS

Patients showed no difference concerning aortic clamp time. TNI increased significantly at 1, 15, and 30 minutes after the onset of reperfusion. Blood levels of white blood cells, oxygen radicals, malondialdehyde, and myeloperoxidase also increased significantly with reperfusion time.

CONCLUSIONS

Reperfusion of ischemic myocardium induced increased TNI, which may be related to the systemic inflammatory responses induced by ischemia and reperfusion of the myocardium among patients undergoing elective coronary bypass surgery.

Strontium borate glass: potential biomaterial for bone regeneration

Boron plays important roles in many life processes including embryogenesis, bone growth and maintenance, immune function and psychomotor skills. Thus, the delivery of boron by the degradation of borate glass is of special interest in biomedical applications. However, the cytotoxicity of borate glass which arises with the rapid release of boron has to be carefully considered. In this study, it was found that the incorporation of strontium into borate glass can not only moderate the rapid release of boron, but also induce the adhesion of osteoblast-like cells, SaOS-2, thus significantly increasing the cyto-compatibility of borate glass. The formation of multilayers of apatite with porous structure indicates that complete degradation is optimistic, and the spread of SaOS-2 covered by apatite to form a sandwich structure may induce bone-like tissue formation at earlier stages. Therefore, such novel strontium-incorporated borosilicate may act as a new generation of biomaterial for bone regeneration, which not only renders boron as a nutritious element for bone health, but also delivers strontium to stimulate formation of new bones.

Two Taiwanese siblings with dyschromatosis universalis hereditaria

Two Taiwanese siblings presented with clinical and histological findings of dyschromatosis universalis hereditaria, which is an uncommon hereditary skin disease. A 26-year-old Taiwanese man had developed diffuse hyperpigmentation with hypopigmented spots over his whole body from the age of 4 years. His 34-year-old brother had also developed a similar skin pigmentary defect from about the same age. Histological examination of the hyperpigmented lesions found an increase in melanin in the basal layer, pigmentary incontinence, and some melanophages in the upper dermis but no increase in the number of melanocytes. The unique clinical, histological, and genetic features of this condition are outlined.

Silver structure environments in ion-exchanged silicate glasses studied by X-ray absorption fine structure

X-ray absorption fine structure (XAFS) technique was used to analyze structural geometry of Ag atoms introduced into soda-lime silicate glass and soda aluminosilicate glass by ion-exchange method. The results show that Ag+ ion in soda aluminosilicate glass takes a coordination number of 1.6 with a Ag-O distance of 2.20 A when the ion-exchange ratio x is smaller than 0.47 and of 2.28 A when x is larger than 0.47. The introduced Ag+ ions are stabilized at the non-bridge oxygen (NBO) sites when x is lower than 0.47. The Na+ ions in AlO4 (O4 represents the bridging oxygen) sites are exchanged by Ag+ ions after all Na+ in NBO sites are replaced. The disorder of Ag-O coordination increases gradually with increasing x from 0.24 to 0.47 in soda aluminosilicate glass and increases dramatically when x is larger than 0.47. Ag+ ions takes a coordination number of 1.6 in the ion-exchanged soda-lime silicate glass and of 1.3 after subsequently thermal treatment with the same Ag-O distance of 2.14 A. Debye-Waller factor (DWF) of Ag-O coordination in soda aluminosilicate glass is higher than that in soda-lime silicate glass. Small Ag cluster has a reduced interatomic distance and a larger DWF. Ag nanoparticle in sample Ag-7 is in a state of tensile stress.

Post-translational modification of delta antigen of hepatitis D virus

The hepatitis delta virus (HDV) genome has only one open reading frame, which encodes the viral small delta antigen. After RNA editing, the same open reading frame is extended 19 amino acids at the carboxyl terminus and encodes the large delta antigen. These two viral proteins escort the HDV genome through different cellular compartments for the complicated phases of replication, transcription and, eventually, the formation of progeny virions. To orchestrate these events, the delta antigens have to take distinct cues to traffic to the right compartments and make correct molecular contacts. In eukaryotes, post-translational modification (PTM) is a major mechanism of dictating the multiple functions of a single protein. Multiple PTMs, including phosphorylation, isoprenylation, acetylation, and methylation, have been identified on hepatitis delta antigens. In this chapter we review these PTMs and discuss their functions in regulating and coordinating the life cycle of HDV.

Prediction of n-octanol/water partition coefficients for polychlorinated dibenzo-p-dioxins using a general regression neural network

A general regression neural network was used for the first time to study quantitative structure and property relationships of organic pollutants to correlate and predict n-octanol/water partition coefficients of polychlorinated dibenzo- p -dioxins from their topological molecular descriptors. In total, 42 polychlorinated dibenzo- p -dioxins and dibenzo- p -dioxins were available for this study-42 polychlorinated dibenzo- p -dioxins and dibenzo- p -dioxins in the training data set and 41 polychlorinated dibenzo- p -dioxins in the test data set. Partial least squares regression, back propagation network and general regression neural network models were trained using the training data set, and the accuracy of the models obtained were examined by the use of leave-one-out cross-validation. For prediction of the n-octanol/water partition coefficient, the best method is the general regression neural network. With the test data set, the correlation coefficient, root mean square error and mean absolute relative error for the general regression neural network model are 0.9276, 0.22 and 2.79%, respectively. For describing the structure of polychlorinated dibenzo- p -dioxins, the topological molecular descriptors outperform the mobile order and disorder thermodynamic method.

The nucleolar phosphoprotein B23 interacts with hepatitis delta antigens and modulates the hepatitis delta virus RNA replication

Hepatitis delta virus (HDV) encodes two isoforms of delta antigens (HDAgs). The small form of HDAg is required for HDV RNA replication, while the large form of HDAg inhibits the viral replication and is required for virion assembly. In this study, we found that the expression of B23, a nucleolar phosphoprotein involved in disparate functions including nuclear transport, cellular proliferation, and ribosome biogenesis, is up-regulated by these two HDAgs. Using in vivo and in vitro experimental approaches, we have demonstrated that both isoforms of HDAg can interact with B23 and their interaction domains were identified as the NH(2)-terminal fragment of each molecule encompassing the nuclear localization signal but not the coiled-coil region of HDAg. Sucrose gradient centrifugation analysis indicated that the majority of small HDAg, but a lesser amount of the large HDAg, co-sedimented with B23 and nucleolin in the large nuclear complex. Transient transfection experiments also indicated that introducing exogenous full-length B23, but not a mutated B23 defective in HDAg binding, enhanced HDV RNA replication. All together, our results reveal that HDAg has two distinct effects on nucleolar B23, up-regulation of its gene expression and the complex formation, which in turn regulates HDV RNA replication. Therefore, this work demonstrates the important role of nucleolar protein in regulating the HDV RNA replication through the complex formation with the key positive regulator being small HDAg.