Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A

We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15  PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.

[Molecular mechanisms of quinolone resistance in non-typhoidal Salmonella]

By conducting retrospective analysis, this study aim to investigate the resistance mechanism of quinolones in non-typhoidal Salmonella (NTS). A total of 105 strains of NTS isolated from clinical specimens from the Fifth Affiliated Hospital of Southern Medical University from May 2020 to February 2021 were used as research objects. VITEK2 Compact automatic identification drug sensitivity analysis system and serological test were used to identify the strains. The sensitivity of the strains to ciprofloxacin, levofloxacin and nalidixic acid was detected by AGAR dilution method. The whole genome of 105 strains of NTS was sequenced. Abricate and other softwares were used to analyze drug-resistant genes, including plasmid-mediated quinolone resistance gene (PMQR) and Quinolone resistance determination region (QRDR). Serotypes and ST types were analyzed using SISTR and MLST, and phylogenetic trees were constructed. The results showed that the NTS isolated in this region were mainly ST34 Salmonella typhimurium (53.3%). The drug sensitivity results showed that the drug resistance rates of NTS to ciprofloxacin, levofloxacin and nalidixic acid were 30.4%, 1.9% and 22.0%, respectively, and the intermediate rates of ciprofloxacin and levofloxacin were 27.6% and 54.2%.A total of 46 (74.2%) of the 62 quinolone non-susceptible strains carried the PMQR gene, mainly qnrS1 (80.4%), followed by aac(6')-Ib-cr(15.2%); there were 14 NTS and 8 NTS had gyrA and parC gene mutations, respectively. The gyrA was mutations at the amino acid position 87, Asp87Tyr, Asp87Asn, Asp87Gly, and Thr57Ser mutations were detected in parC. In conclusion, this study found that NTS had relatively high resistance to quinolones, carrying qnrS1 gene mainly resulted in decreased sensitivity of NTS to ciprofloxacin and levofloxacin, and gyrA:87 mutation mainly resulted in NTS resistance to Nalidixic acid; Salmonella typhimurium in clinical isolates showed clonal transmission and required further epidemiological surveillance.

Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A

The diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°10  TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of -2.99±0.04, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of ∼3 than the prediction. A similar spectrum with an index of -2.99±0.07 is found in the outer Galaxy region, and the absolute flux for 10≲E≲60  TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.

[Effects of neonatal stimulator of interferon genes innate immune signaling pathway of HBsAg-positive mothers on non/hypo-response to hepatitis B vaccine in infants]

Objective: To explore the effects of neonatal stimulator of interferon genes (STING) innate immune signaling pathway of HBsAg-positive mothers on non/hypo-response to hepatitis B vaccine (HepB) in their infants. Methods: From November 2019 to June 2022, HBsAg-positive mothers and their infants in the Third People's Hospital of Taiyuan were recruited as the study subjects. The epidemiological and clinical data were collected by questionnaire survey and medical records review. The key molecular proteins of STING innate immune signaling pathway (STING, pIRF3) and immune cells associated with vaccine response (DC, T and B and plasma cells) in neonatal cord blood were detected by flow cytometry. Follow up was conducted for infants for 1-2 months after the full vaccination of HepB. Serum hepatitis B surface antibody (anti-HBs) was detected by chemiluminescence microparticle immunoassay. Unconditional logistic regression model, nomogram and Bayesian network model were used to evaluate the effect of STING innate immune signaling pathway on non/hypo-response to HepB and related factors in infants, and the relationship between various factors. Results: A total of 195 pairs of HBsAg-positive mothers and infants were recruited, the rate of non/hypo-response to HepB in the infants was 12.31% (24/195). High maternal HBV DNA load, low expression of neonatal STING, low expression of pIRF3 and low percentage of plasma cells were risk factors for non/hypo-response to HepB in the infants (OR=4.70, 3.46, 3.18 and 2.20, all P<0.05). The nomogram constructed by these factors had good predictive efficacy (area under curve=0.81, 95%CI: 0.63-0.83). The results of Bayesian network model showed that the infants with a high maternal HBV DNA load had a higher conditional probability of low STING expression (62.50%) and a higher conditional probability of low pIRF3 expression (58.54%). The conditional probabilities of low expression of DC, T, B and plasma cells were 53.16%, 60.20%, 68.42% and 57.14%, respectively. Conclusion: Maternal HBV DNA might inhibit STING innate immune signaling pathways in infants and immune cells associated with HepB response, resulting in non/hypo-response to HepB in infants of HBsAg-positive mothers.

A tera-electron volt afterglow from a narrow jet in an extremely bright gamma-ray burst

Some gamma-ray bursts (GRBs) have a tera-electron volt (TeV) afterglow, but the early onset of this has not been observed. We report observations with the Large High Altitude Air Shower Observatory of the bright GRB 221009A, which serendipitously occurred within the instrument field of view. More than 64,000 photons >0.2 TeV were detected within the first 3000 seconds. The TeV flux began several minutes after the GRB trigger, then rose to a peak about 10 seconds later. This was followed by a decay phase, which became more rapid ~650 seconds after the peak. We interpret the emission using a model of a relativistic jet with half-opening angle ~0.8°. This is consistent with the core of a structured jet and could explain the high isotropic energy of this GRB.

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.

[Relationship between vitamin D receptor gene polymorphisms and gestational diabetes mellitus: a case-control study]

Objective: To investigate the relationship between vitamin D receptor (VDR) gene polymorphisms and gestational diabetes mellitus (GDM) and provide evidence for the study of the mechanism of GDM. Methods: A case-control study design was used to study pregnant women who delivered in the obstetrics department of the First Hospital of Shanxi Medical University from March 1, 2012 to July 30, 2014. Of these, 334 cases were diagnosed with GDM and were matched 1∶1 by age, gestation time and residence to corresponding healthy controls. DNA genotyping was performed for the study subjects, and those with genotyping deletions >10% were excluded. Finally 323 cases and 320 controls were included in the study. Under co-dominant, dominant, recessive, and allele genetic models, unconditional logistic regression analysis on the relationship between VDR gene locus polymorphism and GDM was conducted. And software Haploview was used to analyze the relationship between haplotype and GDM. Results: At the genetic level, VDR gene was associated with the risk of developing GDM (P<0.05). After adjusting for pre-pregnancy body mass index, family history of diabetes, it was found that rs7967152 loci was associated with an increased risk of developing GDM (AC vs. AA, OR=1.58, 95%CI: 1.13-2.21; AC+CC vs. AA, OR=1.58, 95%CI: 1.15-2.18; C vs. A, OR=1.41, 95%CI: 1.10-1.82) and rs2238140 loci was associated with an increased risk of developing GDM (AA vs. GG, OR=2.24, 95%CI: 1.19-4.20; GA+AA vs. GG, OR=1.48, 95%CI: 1.07-2.03; A vs. G, OR=1.43, 95%CI: 1.11-1.83). Carrying rs2853564 locus AG genotype and AG+GG genotype (OR=1.46, 95%CI: 1.04-2.05; OR=1.45, 95%CI: 1.05-2.00) compared with carrying AA genotype and carrying rs2853566 locus AG genotype and AG+GG genotype (OR=1.43, 95%CI: 1.03-2.00; OR=1.41, 95%CI: 1.02-1.94) compared with carrying AA genotype were risk factors for GDM. Haplotype block consisting of rs1544410, rs7967152 in the VDR gene with GC haplotype was a risk factor for GDM(OR=1.50, 95%CI: 1.15-1.97). Conclusions: VDR gene rs7967152, rs2238140, rs2853564, rs2853566 locus polymorphisms and block (rs1544410, rs7967152) GC haplotype were associated with an incrased risk of developing GDM.

[The effect of maternal HBV DNA levels on HBV intrauterine transmission and fetal distress]

Aim: To identify the key risk factors of intrauterine hepatitis B virus transmission (HBV) and its effect on the placenta and fetus. Methods: 425 infants born to hepatitis B surface antigen (HBsAg)-positive pregnant women who received combined immunization with hepatitis B immunoglobulin and hepatitis B vaccine between 2009 to 2015 were prospectively enrolled in this study. The intrauterine transmission situation was assessed by dynamic monitoring of infants HBV DNA load and quantitative HBsAg. Univariate and multivariate regression analysis was used to determine the high risk factors for intrauterine transmission. Stratified analysis was used to determine the relationship between maternal HBV DNA load and fetal distress. Transmission electron microscopy was used to observe HBV Effects on placental tissue. Results: HBV intrauterine infection rate was 2.6% (11/425). Multivariate analysis result showed that the maternal HBV DNA load was an independent risk factor for intrauterine infection among infants (P=0.011). Intrauterine infection and distress rate was significantly higher in infants with with maternal HBV DNA>10⁶ IU/ml than those with HBV DNA <10⁶ IU/ml (12.2% vs. 1.8%; χ²=11.275, P=0.006), and (24.4% vs. 16.0%, χ²=3.993, P=0.046). Transmission electron microscopy showed that mitochondrial edema, endoplasmic reticulum expansion and thicker basement membrane were apparent when the maternal HBV DNA>10⁶ IU/ml than that of maternal HBV DNA<10⁶ IU/ml (960 nm vs. 214 nm, Z=-2.782, P=0.005) in the placental tissue. Conclusion: Maternal HBV DNA>10⁶ IU/ml is associated not only with intrauterine infection, but also with increased incidence of intrauterine distress and placental sub-microstructural changes, providing strong clinical and histological evidence for pregnancy avoidance and treatment in this population.

[Distributive characteristics of HBV DNA CpG islands in HBsAg positive mothers and its relationship with intrauterine transmission]

Objective: To investigate the type, length, and CG loci of HBV DNA CpG islands in HBsAg positive maternal C genotype and its relationship with intrauterine HBV transmission, so as to provide a new perspective for the study of intrauterine transmission of HBV. Methods: From June 2011 to July 2013, HBsAg-positive mothers and their newborns who delivered in the obstetrics and gynecology department of the Third People's Hospital of Taiyuan were collected. Epidemiological data were collected through face-to-face questionnaires and electronic medical records. Serum HBV markers and serum HBV DNA were detected by electrochemiluminescence and quantitative fluorescence PCR, respectively. Intrauterine transmission of HBV was determined by positive HBsAg and/or HBV DNA in femoral venous blood before injection of HBV vaccine/Hepatitis B immunoglobulin within 24 h of birth. A total of 22 mothers and their newborns with HBV DNA load ≥10⁶ IU/ml in intrauterine transmission were selected as the intrauterine transmission group, and 22 mothers with HBV DNA load ≥10⁶ IU/ml without intrauterine transmission were chosen as the control group by random seed method. The distribution prediction of CpG islands of HBV DNA in 39 mothers with genotype C by HBV DNA sequencing was analyzed. Results: Among 39 mothers with HBV C genotype, 19 were in the intrauterine transmission group, and 20 were in the control group. The HBV DNA of 39 patients with genotype C traditional CpG island Ⅱ and Ⅲ, while the control group had traditional CpG island Ⅰ and novel CpG island Ⅳ and Ⅴ. The length of CpG island Ⅱ and Ⅲ and the number of CG loci of CpG island Ⅱ in the intrauterine transmission group differed from those in the control group (P<0.05). The CpG island Ⅱ length ≥518 bp and the number of CG loci ≥40 in the intrauterine transmission group (11/19) were significantly higher than those in the control group (2/20) (P<0.05). The length of CpG island Ⅱ and the number of CG loci in the X gene promoter region (Xp region) were higher than those in the control group (P<0.05). In the HBV intrauterine transmission group, most of maternal (12/19) HBV DNA CpG island Ⅱ completely covered the Xp region, which was significantly higher than that in the control group (5/20), and the number of HBV DNA Xp region CG loci was higher than that in the control group (P<0.05). Conclusions: The distribution of maternal C genotype HBV DNA CpG islands is related to intrauterine transmission. The length of CpG island Ⅱ and the number of CG sites may increase the risk of intrauterine transmission of HBV.

[Non/hypo-response to hepatitis B vaccination and influencing factors in HIV-infected patients in the context of different immunization schedules]

Objective: To study the non/hypo-response to hepatitis B vaccination in HIV-infected patients, identify the influencing factors and provide evidence for the development of hepatitis B prevention and control strategies and measures for special population. Methods: On the basis of the randomized controlled trial of 20 µg hepatitis B vaccine immunization at 0-1-6 month, 0-1-2-6 month and 60 µg hepatitis B vaccine immunization at 0-1-2-6 month, the HIV-infected patients who completed one-month follow-up after the full course vaccination were selected as study subjects. Quantification of antibody to hepatitis B surface antigen (anti-HBs) in serum samples was performed by using chemiluminescent microparticle immunoassay (CMIA) and demographic characteristics, disease history, HIV infection and treatment status of the study subjects were collected. Statistical analysis was conducted by χ² test, t test, unconditional logistic regression and interaction analyses. Results: The non/hypo-response rates to hepatitis B vaccination were 34.65% (35/101), 24.49% (24/98) and 10.99% (10/91) in 20 µg group at 0-1-6 month or 0-1-2-6 month and 60 µg group at 0-1-2-6 month (P<0.001), respectively. Logistic regression analysis showed that after controlling for confounding factors, the risk for non/hypo-response was 0.22 times higher in HIV-infected patients receiving 60 µg hepatitis B vaccine at 0-1-2-6 month than in patients receiving 20 µg hepatitis B vaccine at 0-1-6 month (95%CI: 0.10-0.50), the risk for non/hypo-response was higher in men than in women (OR=3.65, 95%CI: 1.88-7.07), and the risk for non/hypo-response was 2.64 times higher in those without hepatitis B vaccination history than in those with hepatitis B vaccination history (95%CI: 1.10-6.32). Moreover, there were multiplicative interactions between immunization schedule and gender (OR=2.49, 95%CI: 1.24-5.00). Conclusion: The non/hypo-response rate to hepatitis B vaccination was significantly lower in HIV-infected patients receiving 60 µg hepatitis B vaccine at 0-1-2-6 month than in those receiving 20 µg hepatitis B vaccine at 0-1-6 month and 0-1-2-6 month. Gender, vaccination schedule and history of hepatitis B vaccination were the influencing factors of the non/hypo-response to hepatitis B vaccination. There was a multiplicative interaction between vaccination schedule and gender, and men receiving 20 µg hepatitis B vaccines had a higher risk for non/hypo-response to hepatitis B vaccination.

[The 494th case: acute pancreatitis, acute acalculous cholecystitis and anaphylaxis]

A young male patient with abdominal pain and fever was diagnosed as acute hyper-triglyceridemicpancreatitis is clear. During the recovery of pancreatitis, the patient developed acute acalculous cholecystitis, as well as carbapenem-resistant Enterobacter infection and Cytomegaloviremia, and had anaphylaxis for several times after the use of antibiotics, which cannot be completely explained by drug allergy. This paper analyzes the possible causes of multiple diseases in the same patient in detail.

[Methylation of p16 gene and reduced expression of p16 protein in insulinoma associated with clinicopathological features]

Objective: To study the alterations of p16 gene and its expression in insulinoma and to correlate the findings with clinicopathological characteristics. Methods: Expression of p16 protein was detected in 72 insulinomas and 49 para-tumoral or normal pancreatic tissues by immunohistochemical staining. Genomic DNA was isolated from 32 tumor tissue and 17 paired pancreatic tissues and bisulfite-modified. Promoter methylation status of p16 gene was detected in 32 tumor tissue and 17 paired pancreatic tissues by methylation specific PCR. The findings were correlated with the clinicopathological features. Results: There were 30 males and 42 females in all 72 patients, aged (46.5±14.0) years. Loss or reduced expression of p16 protein was found in 42 of 72 insulinomas (58.3%) while loss or reduced expression of p16 was seen in only 34.7% (17/49) of para-tumoral or normal pancreatic tissues (χ²=6.52, P=0.011). Promoter methylation of p16 gene was found in 13 of 32 insulinomas (40.6%) and only 2 of 17 (11.8%) para-tumoral tissues (χ²=4.35, P=0.037). The expression of p16 protein in insulinoma was not associated with clinicopathological features such as gender, age, tumor size and tumor grade. Conclusions: Loss or reduced expression of p16 protein was found in insulinomas, and associated with p16 gene promoter methylation.

[Effect of activation of Toll-like receptor signaling pathway of peripheral blood mononuclear cell in recombinant hepatitis B surface antigen immune response]

Objective: To explore the effect and mechanism of activation of peripheral blood mononuclear cell (PBMC) Toll-like receptor (TLR3) signaling pathway in recombinant HBsAg (rHBsAg) immune response. Methods: White blood cells were collected from peripheral blood of 13 healthy donors in the preparation of blood products. PBMC was isolated and treated with Poly I:C (Poly I:C group) and PBS (control group) respectively. 48 h later, some cells were collected and the expressions of TLR3 signaling pathway proteins were detected by flow cytometry. After activating (Poly I:C group)/inactivating (control group) TLR3 signaling pathway, rHBsAg was given to both groups for 72 h, and the proportions of DC, T, B cells and their subsets in PBMC were detected by flow cytometry. Paired t-test, paired samples wilcoxon signed-rank test and canonical correlation analyses were used for statistical analysis. Results: The percentage of TLR3 protein-positive cells (19.21%) and protein expression (8 983.95), NF-κB protein expression (26 193.13), the percentage of pNF-κB protein-positive cells (13.73%) and its proportion in NF-κB (16.03%), and the percentage of pIRF3 protein-positive cells (12.64%) and its proportion in IRF3 (21.80%) in Poly I:C group were higher than those in control group (11.54%, 8 086.00, 22 340.66, 8.72%, 9.71%, 9.57%, 19.12%) (P<0.05), and the percentage of TRIF protein-positive cells (89.75%) and protein expression (304 219.54) were higher in Poly I:C group than in the control group (89.64%, 288 149.72) (P>0.05). After PBMC stimulation by rHBsAg, the proportions of mDC (2.90%), pDC (1.80%), B cell (5.31%) and plasma cell (67.71%) in Poly I:C group were significantly higher than those in the control group (1.83%, 0.81%, 4.23%, 58.82%) (P<0.05). Results of canonical correlation analysis showed that the expression of TLR3 protein was positively correlated with the proportions of plasma cells, the expression of pIRF3 protein was positively correlated with the proportions of plasma cells and mDC, and the percentage of pNF-κB protein-positive cells and the percentage of pIRF3 protein-positive cells were positively correlated with the proportion of CD4⁺T cells. Conclusions: Poly I:C can activate TLR3/TRIF/NF-κB and TLR3/TRIF/IRF3 signaling pathway, promote the function of downstream signaling molecules, and then promote the maturation of DC, induce the immune responses of CD4⁺T cell, and promote the maturation and activation of B cells and the immune response of rHBsAg.

[Immunogenicity and influencing factors of hepatitis B vaccination based on different vaccination schedules among chronic kidney disease patients]

Objective: To explore the immunogenicity and influencing factors of hepatitis B vaccination based on different vaccination schedules among chronic kidney disease (CKD) patients. Methods: CKD patients who participated in randomized controlled trials in four hospitals in Shanxi province and completed three doses of 20 µg vaccination (at months 0, 1 and 6) and four doses of 20 µg or 60 µg vaccination (at months 0, 1, 2, and 6) were surveyed from May 2019 to July 2020.According to the ratio of 1∶1∶1, 273 CKD patients were divided into 3 groups randomly. Quantification of the anti-hepatitis B surface antigen-antibody (anti-HBs) in serum samples was performed using chemiluminescent microparticle immunoassay at months 1 and 6 after the entire course of the vaccinations. The positive rate, high-level positive rate, geometric mean concentration (GMC) of anti-HBs, and the influencing factors were analyzed by χ² tests, analysis of variance, unconditional logistic regression analysis. Results: A total of 273 CKD patitents were participants.The positive rates in the CKD patients with four doses of 20 µg vaccination (92.96%,66/71) or 60 µg vaccination (93.15%, 68/73) were higher than that in the CKD patients with three doses of 20 µg vaccination (81.69%, 58/71) at month one after the full course of the vaccinations (P<0.05). The GMCs of anti-HBs showed similar results (2 091.11 mIU/ml and 2 441.50 mIU/ml vs. 1 675.21 mIU/ml) (P<0.05). The positive rate was higher in the CKD patients with four doses of 60 µg vaccination (94.83%,55/58) than in those with three doses of 20 µg vaccination (78.79%,52/66) (P<0.05) at month six after the full course of the vaccinations. And the GMC of anti-HBs in the patients with four doses of 60 µg vaccination (824.28 mIU/ml) was significantly higher than those in the patients with 3 or 4 doses of 20 µg vaccination (639.74 mIU/ml and 755.53 mIU/ml) (P<0.05). After controlling the confounding factors, the positive rate in the CKD patients with four doses of 60 µg vaccination were 3.19 (95%CI: 1.02-9.96) and 5.32 (95%CI: 1.27-22.19) times higher than those in the patients with three doses of 20 µg vaccination at months 1 and 6 after the full course of the vaccinations, respectively. The positive rate in CKD patients without immune suppression or hormone therapy was 3.33 (95%CI: 1.26-8.80) and 4.78 (95%CI: 1.47-15.57) times higher than those in the patients with such therapy, respectively. Conclusions: Four doses of 20 µg or 60 µg hepatitis B vaccination could improve the immunogenicity in patients with CKD. And four doses of 60 µg vaccination might play a positive role in maintaining anti-HBs in this population. The immunogenicity in the CKD patients with immune suppression or hormone therapy was poor.

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.

[Analysis on influencing factors of HBV intrauterine transmission based on integration of decision tree model and logistic regression model]

Objective: To investigate the influencing factors of HBV intrauterine transmission and their interaction effects by integrating logistic regression model and Chi-squared automatic interaction detector (CHAID) decision tree model. Methods: A total of 689 pairs of HBsAg-positive mothers and their neonates in the obstetrics department of the Third People's Hospital of Taiyuan from 2007 to 2013 were enrolled, and the basic information of mothers and their neonates were obtained by questionnaire survey and medical record review, such as the general demographic characteristics, gestational week and delivery mode. HBV DNA and HBV serological markers of the mothers and newborns were detected by fluorescence quantitative PCR and electrochemiluminescence immunoassay respectively. The CHAID decision tree model and unconditional logistic regression analysis were used to explore the factors influencing HBV intrauterine transmission in neonates of HBsAg-positive mothers. Results: Among the 689 neonates, the incidence of HBV intrauterine transmission was 11.47% (79/689). After adjusted for confounding factors, the first and second logistic multivariate analysis showed that cesarean delivery was a protective factor for HBV intrauterine transmission (OR=0.25, 95%CI: 0.14-0.43; OR=0.27, 95%CI: 0.15-0.46); both models indicated that maternal HBeAg positivity and HBV DNA load ≥2×10⁵ IU/ml before delivery were risk factors of HBV intrauterine transmission (OR=3.89, 95%CI: 2.32-6.51; OR=3.48, 95%CI: 2.12-5.71), respectively. The CHAID decision tree model screened three significant factors influencing HBV intrauterine transmission, the most significant one was maternal HBeAg status, followed by delivery mode and maternal HBV DNA load. There were interactions between maternal HBeAg status and delivery modes, as well as delivery mode and maternal HBV DNA load before delivery. The rate of HBV intrauterine transmission in newborns of HBeAg-positive mothers by vaginal delivery increased from 19.08% to 29.37%; among HBeAg-positive mothers with HBV DNA ≥2×10⁵ IU/ml, the rate of HBV intrauterine transmission increased to 33.33% in the newborns by vaginal delivery. Conclusions: Maternal HBeAg positivity,maternal HBV DNA ≥2×10⁵ IU/ml and vaginal delivery could be risk factors for HBV intrauterine transmission in newborns. Interaction effects were found between maternal HBeAg positivity and vaginal delivery, as well as vaginal delivery and high maternal HBV DNA load. Logistic regression model and the CHAID decision tree model can be used in conjunction to identify the high-risk populations and develop preventive strategies accurately.

[Chronic radiation-induced rectal injury after adjuvant radiotherapy for pelvic malignant tumors: report based on a phase 3 randomized clinical trial]

Objective: Radiotherapy is one of the standard treatments for pelvic malignant tumors. However, researches associated with intestinal radiation injury and the quality of life (QoL) of patients receiving radiotherapy were lacking in the past. This study aims to analyze the occurrence of radiation-induced rectal injury after adjuvant radiotherapy for pelvic malignant tumors and call for more attention on this issne. Methods: A retrospectively observational study was conducted. Case data of cervical cancer patients from the database of STARS phase 3 randomized clinical trial (NCT00806117) in Sun Yat-sen University Cancer Center were analyzed. A total of 848 cervical cancer patients who received adjuvant radiation following hysterectomy and pelvic lymphadenectomy in Sun Yat-sen University Cancer Center from February 2008 to August 2015 were recruited. The pelvic radiation dosage was 1.8 Gy/day or 2.0 Gy/day, five times every week, and the total dosage was 40-50 Gy. Among 848 patients, 563 patients received radiation six weeks after surgery, of whom 282 received adjuvant radiation alone and 281 received concurrent chemoradiotherapy (weekly cisplatin); other 285 patients received sequential chemoradiotherapy (paclitaxel and cisplatin). Acute adverse events, chronic radiation damage of rectum, and QoL were collected and analyed. The digestive tract symptoms and QoL were evaluated based on EORTC QLQ-C30 questionnaires at one week after surgery (M0), during adjuvant therapy period (M1), and at 12 months and 24 months after the completion of treatments (M12 and M24), respectively. Higher scores in the functional catalog and overall quality of life indicated better quality of life, while higher scores in the symptom catalog indicated severe symptoms and worse QoL. Chronic radiation rectal injury was defined as digestive symptoms that were not improved within three months after radiotherapy. Grading standard of acute adverse events and chronic radiation rectal injury was according to the gastrointestinal part of National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0 (NCI-CTCAE Version 4.0). Results: The mean total radiation dosage of 848 patients was (47.8±4.6) Gy. During adjuvant therapy, the common symptoms of acute intestinal dysfunction were nausea (46.0%, 390/848), vomiting (33.8%, 287/848), constipation (16.3%, 138/848) and abdominal pain (10.3%, 87/848). At M12 and M24, the number of 0 QLQ-C30 questionnaires collected was 346 and 250, respectively. QLQ-C30 questionnaires showed that the scores of nausea or vomiting, appetite decrease, diarrhea, constipation, etc. were improved obviously at M12 or M24 compared with those at M0 or during M1 (all P<0.05). As the extension of the follow-up time, the score of the overall QoL of patients gradually increased [M0: 59.7 (0.0-100.0); M1: 63.1 (0.0-100.0); M12: 75.2 (0.0-100.0); M24: 94.1 (20.0-120.0); H=253.800, P<0.001]. Twelve months after the completion of treatments, the incidence of chronic radiation rectal injury was 9.8% (34/346), mainly presenting as abdominal pain, constipation, stool blood, diarrhea, mostly at level 1 to 2 toxicity (33/34, 97.1%). One patient (0.3%) developed frequent diarrhea (>8 times/d), which was level 3 toxicity. Twenty-four months after all treatments, the incidence of chronic radiation rectal injury was 9.6% (24/250), which was not decreased significantly compared to that in the previous period (χ(2)=0.008, P=0.927). The symotoms of one patient with level 3 toxicity was not relieved. Conclusions: The common symptoms of patients with pelvic maligant tumors during postoperative adjuvant radiotherapy include nausea, vomiting, constipation, abdominal pain and diarrhea. These symptoms are alleviated obviously at 12 and 24 months after adjuvant radiotherapy, and the QoL is significantly improved. However, a few patients may develop chronic radiation rectal injury which is not improved for years or even decades, and deserves attention in clinical practice.

[Relationship between the pre-pregnancy BMI, gestational weight gain, and risk of preeclampsia and its subtypes]

Objective: To explore the effects of maternal pre-pregnancy body mass index (BMI) and gestational weight gain and its subtypes on the risk of preeclampsia. Methods: Pregnant women delivered in the Department of Obstetrics and Gynecology of the First Affiliated Hospital of Shanxi Medical University from March 2012 to September 2016 were selected as the research subjects. According to the inclusion and exclusion criteria, 9 274 pregnant women were included. 901 preeclampsia pregnant women were selected as the case group, and 8 373 non-preeclampsia pregnant women were selected as the control group. General demographic characteristics, pre-pregnancy weight, height, lifestyle during pregnancy, reproductive history, and disease history of pregnant women were collected, and pre-pregnancy BMI and gestational weight gain were calculated. Unconditional logistic regression was used to analyze the relationship between pre-pregnancy BMI and weight gain during pregnancy and PE and its clinical subtypes. Results: Among the 901 preeclampsia after inclusion and exclusion, 401 cases were diagnosed as early-onset PE (EOPE), 500 cases were late-onset PE (LOPE), 178 cases were Mild PE (MPE), and 723 cases were severe PE (SPE). There were statistically significant differences between PE and non-PE pregnant women in terms of maternal age, residence, parity, family history of gestational diabetes and hypertension (P<0.05). After adjusting for the above factors, the logistic regression analysis results showed that pre-pregnancy BMI<18.5 kg/m² and inadequate gestational weight gain were protective factors for PE (OR=0.74, 95%CI: 0.56-0.98; OR=0.78, 95%CI: 0.62-0.99), while pre-pregnancy BMI≥24.0 kg/m² and excessive gestational weight gain were risk factors for PE (OR=1.82, 95%CI: 1.54-2.14; OR=1.82, 95%CI: 1.54-2.15). After subtype analysis on PE, the results showed that pre-pregnancy BMI<18.5 kg/m² was a protective factor for EOPE and MPE (OR=0.52, 95%CI: 0.32-0.83; OR=0.47, 95%CI: 0.23-0.97), while pre-pregnancy BMI≥24.0 kg/m² and excessive gestational weight gain were risk factors for clinical subtypes of PE. After stratification according to pre-pregnancy BMI, excessive gestational weight gain was the risk factor for PE (OR=1.86, 95%CI: 1.51-2.30; OR=1.90, 95%CI: 1.39-2.60) in pregnant women 18.5 kg/m²≤BMI<24.0 kg/m² and ≥24.0 kg/m². Inadequate gestational weight gain (OR=0.55, 95%CI: 0.34-0.89) was a protective factor for PE in pregnant women with pre-pregnancy BMI≥24.0 kg/m². Excessive gestational weight gain (OR=4.05, 95%CI: 1.20-13.69) was a risk factor for EOPE in pregnant women with pre-pregnancy BMI<18.5 kg/m². Excessive gestational weight gain was a risk factor for the clinical subtype of PE in pregnant women 18.5 kg/m²≤BMI<24.0 kg/m² before pregnancy. Inadequate gestational weight gain was a protective factor for EOPE and MPE (OR=0.39, 95%CI: 0.19-0.80; OR=0.29, 95%CI: 0.11-0.77) in pregnant women with pre-pregnancy BMI≥24.0 kg/m². Excessive weight gain was a risk factor for EOPE, LOPE and SPE (OR=1.60, 95%CI: 1.06-2.42;OR=2.20, 95%CI: 1.44-3.37;OR=2.28, 95%CI: 1.58-3.29). Conclusions: Pre-pregnancy BMI and gestational weight gain affect the risk of preeclampsia and its clinical subtypes. In contrast, the influence of gestational weight gain on preeclampsia varies among different pre-pregnancy BMI groups. Therefore, it is recommended to pay attention to the changes in pre-pregnancy BMI and gestational weight gain simultaneously to reduce preeclampsia.

[Immunization effect and persistence of hepatitis B vaccine in HIV-infected patients with different CD4+T cell levels]

Objective: To explore the immunogenicity and persistence of hepatitis B vaccine in HIV-infected patients with different CD4⁺T cell (CD4) levels, and analyze the influence effect of CD4 levels on immunization response. Methods: A total of 182 HIV-infected patients who participated in a randomized controlled trial of 20 µg and 60 µg hepatitis B vaccination at month 0, 1, and 6 in 2014 by Guangxi Zhuang Atonomous Region CDC and Ningming county CDC were surveyed. Six months later after the first dose and 1 month, 6 months, 1 year, and 3 years later after the full course of the vaccination, 5 ml of the venous blood of the patients was collected, and the anti-HBs was detected by Chemiluminescent Microparticle Immunoassay (CMIA). On the basis of previous studies, this study focused on analyzing the immunogenicity and persistence of hepatitis B vaccine under different CD4 levels. Results: One month later after the whole course of hepatitis B vaccination, the anti-HBs geometric mean concentration (GMC), anti-HBs positive rate (≥10 mIU/ml) and strong positive rate (≥100 mIU/ml) in HIV patients with CD4 <350 cells/µl were 442.50 mIU/ml, 71.05% (27/38) and 44.74% (17/38), respectively, which were significantly lower than those HIV-infected patients with CD4 ≥350 cells/µl [583.90 mIU/ml, 92.13% (117/127) and 77.95% (99/127)] (P<0.05). After controlling the confounding factors, the probability of being anti-HBs positive induced by hepatitis B vaccine in patients with CD4 <350 cells/µl was 0.14 times higher than in those with CD4≥350 cells/µl (95%CI: 0.03-0.62), and patients with CD4 <350 cells/µl had higher risk of no response. From 6 months to 3 years after the whole course of the vaccination, the anti-HBs GMC (195.00-27.55 mIU/ml vs. 300.10-45.81 mIU/ml), the positive rate (56.67%-36.67% vs. 78.57%- 51.58%) and the strong positive rate (33.33%-6.67% vs.44.64%-15.79%) in patients with CD4 <350 cells/µl gradually declined, lower than the levels in those with CD4 ≥350 cells/µl. Conclusions: HIV-infected patients with CD4 <350 cells/µl have high risk of no response to hepatitis B vaccination and poor immune persistence. It is necessary to strengthen the anti-HBs monitoring in HIV-infected patients, with special attention to those with CD4 <350 cells/µl. When anti-HBs is negative, hepatitis B vaccine should be injected as early as possible.

[Immunity persistence of 60 μg high dose hepatitis B vaccine and influencing factors in maintained hemodialysis patients]

Objective: To compare the anti-HBs level in maintained hemodialysis patients one year after receiving 20 μg and 60 μg hepatitis B vaccination at 0, 1 and 6 months, and explore the influence factors for the immunity persistence and their interactions. Methods: Based on a randomized controlled trial of 20 μg and 60 μg hepatitis B vaccine immunization in maintained hemodialysis patients at 0, 1, and 6 months, follow up was conducted for the patients for one year after the completion of the vaccination for the quantitative detection of anti-HBs, and χ² test, t test, unconditional logistic regression and interaction analyses were used for statistical analysis. Results: One year after the vaccination, 125 and 124 patients in the 20 μg and 60 μg groups were tested for anti-HBs, respectively. The positive rate of anti-HBs in the 60 μg group (77.42%, 96/124) was significantly higher than that in the 20 μg group (65.60%, 82/125) (P<0.05). After adjusting for the confounding factors, the positive probability of anti-HBs in the 60 μg group was 1.925 times higher than that in the 20 μg group (95%CI: 1.068-3.468). Patients with hemodialysis duration ≥5 years (OR=0.523, 95%CI: 0.293-0.935) and diabetes mellitus (OR=0.376, 95%CI: 0.173-0.818) had lower positive probability of anti-HBs. Moreover, there were additive and multiplicative interactions between hemodialysis duration ≥5 years and diabetes mellitus. Conclusions: The immunity persistence after one year in 60 μg hepatitis B vaccination group was longer than that in 20 μg hepatitis B vaccination group in maintained hemodialysis patients, vaccine dose, hemodialysis duration and diabetes mellitus were the influencing factors for the immunity persistence, there were additive and multiplicative interactions between hemodialysis duration ≥5 years and diabetes mellitus.

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.

[Relationship between C genotype HBV mutation and intrauterine transmission]

Objective: To analyze the virus genome mutation of mothers with C genotype HBV and explore its relationship with HBV intrauterine transmission. Methods: A total of 399 mothers carrying HBV and their newborns hospitalized in the obstetrics department of the Third People's Hospital of Taiyuan from 2011 to 2013 were selected. Necessary information about mothers and children was obtained through a questionnaire survey and medical records. HBV DNA and HBV serological markers were detected by quantitative fluorescence PCR and electrochemiluminescence. Within 24 hours after birth and before active/passive immunization, those with positive HBsAg and/or HBV DNA in femoral venous blood were determined as HBV intrauterine transmission. According to the requirements of cloning and sequencing, mothers' HBV DNA load should be ≥10⁶ IU/ml. Among 54 cases of HBV intrauterine transmission, 22 pairs of mothers and their newborns meeting the requirements of cloning and sequencing were used as the intrauterine transmission group. The same number of mothers and their newborns without intrauterine transmission was selected as the random seed method's control group. After PCR amplification of HBV DNA, gene cloning, and sequencing, the gene mutation analysis of mothers with C genotype HBV was performed. Results: Among the 44 samples, 39 (88.63%, 39/44) were genotype C, 2 were genotype B, and 3 were mixed genotype B, and C. A total of 406 clone beads from 42 mothers with C genotype HBV were analyzed for gene mutation, including 204 in the intrauterine transmission group and 202 in the control group. The base substitution mutation rate of PreS1, S, C, and P regions in the HBV intrauterine transmission group were significantly lower than those in the control group (χ² ranged from 8.67 to 40.73, P<0.05). The mutation rate of base deletion in PreC and X regions in the HBV intrauterine transmission group was lower than that in the control group (χ² values were 17.82 and 34.78, P<0.001). Two clones in the X region had 31 bp insertion mutations between nt1644 and nt1645, and two clones had 27 bp insertion mutations between nt1649 and nt1650, all of which took place in the control group. Conclusions: The base substitution mutations in the PreS1, S, C, and P segments of the HBV genome in mothers with C genotype HBV were associated with the occurrence of intrauterine transmission of HBV. Deletion mutations in the PreC region, insertion and deletion mutations in the X region may reduce intrauterine transmission risk.

[Incidence and influencing factors of AIDS-related and non-AIDS-related deaths after receiving antiretroviral therapy among HIV-positive individuals in Dehong Dai and Jingpo Autonomous Prefecture, 2010-2019]

Objective: To explore the changing trends and influencing factors of AIDS-related and non-AIDS-related deaths after receiving antiretroviral therapy (ART) among HIV-positive individuals in Dehong Dai Jingpo autonomous prefecture (Dehong) from 2010 to 2019. Methods: Based on the Chinese National treatment database, HIV patients who initiated ART from 2010 to 2019 were included in the analysis. The cumulative incidence function was used to estimate the cumulative incidence of AIDS-related death and non-AIDS-related death, respectively. The Fine-Grey model was used to compare the differences between AIDS-related and non-AIDS-related deaths and analyze its influencing factors. Results: A total of 7 068 HIV-positive individuals were included, of which 388 were AIDS-related deaths and 570 were non-AIDS-related deaths. The cumulative mortality rate at years 1, 2, 3, 4, 5, 7 and 9 after receiving ART were 2.27%, 3.46%, 4.47%, 5.03%, 5.84%, 6.61%, 7.40% for AIDS-related deaths, and 1.63%, 3.11%, 4.68%, 6.02%, 7.42%, 10.49%, 12.75% for non-AIDS-related deaths, respectively. In the Fine-Grey model, older age at ART initiation, male, unmarried, injection drug use as the transmission route, lower baseline BMI, lower baseline CD4⁺ T cell counts, baseline FIB-4 score >3.25, and baseline anemia were risk factors for AIDS-related death. In contrast, age at ART initiation ≥45 years, male, Dai, and Jingpo minority ethnicities, unmarried, injection drug use as the transmission route, lower baseline BMI, baseline FIB-4 score >3.25, baseline eGFR <60 ml·min^-1·1.73 m^-2, and baseline anemia were risk factors for non-AIDS-related deaths. Conclusions: The cumulative mortality rate was low among HIV-positive individuals after receiving ART in Dehong during 2010-2019. The mortality of non-AIDS-related deaths was higher than that of AIDS-related deaths. There were also differences in the factors influencing AIDS-related and non-AIDS-related deaths and interventions should be intensified to target the influencing factors for non-AIDS-related deaths.

[Related factors and interaction on hepatitis C virus infection in patients receiving methadone maintenance treatment in Taiyuan]

Objective: To explore the prevalence of hepatitis C virus (HCV) infection, influence factors and interaction on HCV infection in patients receiving methadone maintenance treatment (MMT) in Taiyuan. Methods: Between April-June 2019, three MMT clinics in Taiyuan were selected to conduct a face-to-face questionnaire survey among MMT patients to collect the information about their socio-demographic characteristics, drug use, MMT, sexual behavior and health status. Software EpiData 3.1 was used for real-time double entry to establish the database. Software SAS 9.4 was used to analyze the data, and χ² test was used for univariate analysis and logistic regression model was used for multivariate and interaction analyses. Results: A total of 903 subjects were surveyed among MMT patients, the male to female ratio of was 7.21∶1(743∶103), and the rate of HCV infection was 12.53% (106/846). After adjusting for the confounding factors, being women (OR=1.936, 95%CI: 1.023-3.662), having sex with drug users (OR=2.073, 95%CI: 1.110-3.871) and injection drug use (OR=7.737, 95%CI: 4.614-12.973) might be the risk factors for HCV infection in patients receiving MMT. The results showed that there were multiplicative interactions among women, having sex with drug user and injection drug use on HCV infection. Conclusions: Being women, having sex with drug user and injection drug use were associated with higher risk for HCV infection in patients receiving MMT in Taiyuan. There were multiplication interactions between being women and having sex with drug user, being female and injection drug use, and having sex with drug use and injection drug use on HCV infection.

[Folic acid supplementation before and during pregnancy and the risk of preeclampsia]

Objective: To investigate the relationship between folic acid supplementation and the risk of preeclampsia (PE). Methods: A total of 9 048 pregnant women were selected from the First Hospital of Shanxi Medical University in Taiyuan from March 2012 to September 2016. Among them, 882 pregnant women with PE were divided into case group, and 8 166 pregnant women without PE were divided into control group. Information on demographic characteristics, folic acid supplementation, maternal complications, and other factors were collected by face-to-face interviews after child birth in the hospital. Unconditional logistic regression analyses were used to investigate the relationship between folic acid supplementation and the risk of PE and the effects of pre-pregnancy BMI on the relationship of folic acid supplementation with the risk of PE. Results: Compared with nonusers, folic acid supplement users had reduced risk of PE (OR=0.79, 95%CI: 0.64-0.96). Folic acid supplementation before and during pregnancy were negatively related with the risk of PE (OR=0.63, 95%CI: 0.49-0.81). Pregnant women who used folic acid tablets only or used both folic acid tablets and multivitamin containing folic acid had reduced risk of PE (OR=0.81, 95%CI: 0.66-0.99; OR=0.64, 95%CI: 0.49-0.85). No significant relationship was observed in the multivitamin group. Supplemental folic acid doses of <400, 400, and >400 μg/d were related with reduced risk of PE (OR=0.62, 95%CI: 0.42-0.91; OR=0.81, 95%CI: 0.66-0.99; OR=0.68, 95%CI: 0.49-0.94). After stratified by pre-pregnancy BMI, pregnant women who used folic acid supplementation, those with pre-pregnancy BMI<24.0 kg/m(2) had reduced risk of PE (OR=0.75, 95%CI: 0.59-0.96). However, no significant relationship was observed in women with pre-pregnancy BMI≥24.0 kg/m(2). Conclusions: Folic acid supplementation before and during pregnancy were related with reduced risk of PE. Pre-pregnancy BMI might affect the relationship between folic acid supplementation and the risk of PE. Appropriate folic acid supplementation should be recommend for women with different pre-pregnancy BMI.

[Relationship between mutations of HBV basal core promoter region in HBsAg-positive mothers and intrauterine transmission]

Objective: To analyze the relationship between maternal mutations in basal core promoter region of hepatitis B virus (HBV) genotype C and intrauterine transmission. Methods: We collected information on general demographic characteristics and process of delivery among 399 pairs of consecutive HBsAg-positive mothers and their neonates, from the Third People's Hospital of Taiyuan in Shanxi province, China. Fluorescence quantitative polymerase chain reaction (FQ-PCR) and Electro-chemiluminescence immuno-assay (ECLIA) kits were used to detect both maternal and neonatal HBV DNA and serological markers in the peripheral blood. From 113 mothers with HBV DNA load ≥10(6) IU/ml, we selected 22 mothers whose neonates were with intrauterine transmission and randomly selected the same number of mothers whose neonates were without intrauterine transmission, as controls. The whole-length HBV DNA were extracted, amplified, cloned, sequenced and genotyped. Finally, a total of 39 mothers with genotype C of HBV were selected for mutation analysis. Results: Thirty-nine cases of genotype C (88.63%) were finally included in the study, with 19 cases in the intrauterine transmission group and 20 cases as controls. Rates of A1762T/G1764A double mutations were significantly different between the intrauterine transmission group and the control group (7.53% vs. 27.72%, P<0.001). Results from the multivariate analysis showed that the A1762T/G1764A double mutations had reduced the risk of intrauterine transmission (aOR=0.065, 95%CI: 0.006-0.746, P=0.028). Maternal A1762T/G1764A double mutations appeared to be possibly associated with neonatal HBeAg (P=0.050). Conclusion: A1762T/G1764A double mutations of HBV DNA from the genotype C of those HBsAg-positive mothers could reduced the risk of HBV intrauterine transmission during pregnancy.

[Characteristics of methadone maintenance treatment clinic patients and influencing factors for HBsAg positivity based on Bayesian network model]

Objective: To understand the characteristics and explore the influencing factors of HBsAg positivity in methadone maintenance treatment (MMT) clinic patients. Methods: A face to face interview and medical record review were conducted in 1 040 patients at three MMT clinics in Guangxi from September to November in 2014. The questionnaire information included general demographic characteristics, drug use history, MMT status, sexual behaviors, and health status, etc. Blood samples were collected from the patients at the same time for the detections of the level of HBsAg, anti-HBs and anti-HCV. By using χ(2) test, unconditional logistic regression model and Bayesian network model the influencing factors for HBsAg positivity in MMT clinic patients and the complex network relationship among these factors were explored. Results: A total of 1 031 MMT clinic patients were surveyed, the HBsAg positive rate was 11.35% (117/1 031). The anti-HCV positive rate was 71.77% (740/1 031), among the anti-HCV positive patients, the HBsAg positive rate was 10.27% (76/740). After adjusting for the confounding factors, anti-HBs positive persons might not be HBsAg positive (OR=0.05, 95%CI: 0.03-0.09), and anti-HCV positive persons might not be HBsAg positive too (OR=0.30, 95%CI: 0.17-0.52) compared with anti-HBs negative and anti-HCV negative persons, respectively. The persons with family history of hepatitis B virus infection were more likely to be HBsAg positive compared those with no such family history (OR=5.30, 95%CI: 2.68-10.52). Bayesian network model analysis results showed that family history of hepatitis B virus infection and anti-HBs were directly related with HBsAg positivity. Anti-HCV, intravenous drug use in the past three months and other drug using during treatment were indirectly related with HBsAg positivity. Conclusions: Anti-HBs, family history of hepatitis B virus infection, anti-HCV, intravenous drug use in past three months and other drug use during treatment were related with the HBsAg positivity in MMT clinic patients. So, it is necessary to enhance health education, improve health awareness and decrease high risk behaviors to reduce the rate of HBV infection.

Effects of post-hatch brooding temperature on performance of starter and growing Pekin ducks

An experiment was conducted to investigate the effects of post-hatch brooding temperature on the growth performance of starter Pekin ducks from hatch to 14 D of age and the subsequent growth performance and carcass trait of growing ducks from 15 to 42 D of age. A total of 360 one-day-old male White Pekin ducks were allocated randomly to 6 environment-controlled chambers with ambient temperature set at 26, 28, 30, 32, 34, and 36°C from hatch to 7 D of age, respectively, and then decreased gradually to 26°C at 14 D of age. At 14 D of age, all ducks from all chambers were transferred to a duck barn with ambient temperature maintaining from 26 to 22°C and these birds continued to be raised from 14 to 42 D of age. At 14 D of age, body weight, weight gain, and feed intake decreased linearly or quadratically as initial brooding temperature increased (P < 0.05) and these performance traits were reduced when initial brooding temperature increased to 36°C (P < 0.05). There was no difference in growth performance between ducks fed at brooding temperature regimen starting at 26, 28, 30, and 32°C (P > 0.05). According to broken-line regression, the upper critical temperatures of the initial brooding temperature during the starter period for body weight, weight gain, and feed intake were 31.3, 31.3, and 31.1°C, respectively. On the other hand, the growing ducks brooded initially at 26 or 36°C had lower body weight, weight gain, and feed intake as compared to other birds brooded starting from 28 to 34°C (P < 0.05), but the initial brooding temperature had no effects on carcass traits (P > 0.05). It was concluded that the upper critical temperature of the initial brooding temperature for starter Pekin ducks was 31.3°C and too low initial brooding temperature could lead to growth depression during the subsequent growing period.

[Association between maternal dietary intake and the incidence of babies with small for gestational age]

Objective: To investigate the relations between dietary intake during pregnancy and the incidence of their babies with small for gestational age (SGA). Methods: Data on demographics, dietary intake of protein, fat, and carbohydrates of the pregnant mothers during the first, second and third trimester, were collected. Information related to birth weight and gestational age of the infants were also gathered. A total of 8 102 women, who delivered their babies at the First Affiliated Hospital of Shanxi Medical University from March 2012 to September 2016, were enrolled in this project. Among them, 961 mothers had infants with SGA but the other 7 141 of them having normal infants. Unconditional logistic regression model was used to analyze the effect of dietary nutrient intake on SGA the first, second and third trimester. Results: We found that low dietary intake of protein during the first trimester and following trimesters during pregnancy were positively associated with higher risk of SGA (OR=1.534, 95%CI: 1.217-1.934; OR=1.268, 95%CI: 1.005-1.599; OR=1.310, 95%CI: 1.036-1.655). When adjusting for maternal pre-pregnancy BMI, we found that when mothers were with a pre-pregnancy BMI less than 18.5 or with low maternal intake of protein during the first trimester, positive association with higher risk of SGA (OR=1.872, 95%CI: 1.033-3.395; OR=1.754, 95%CI: 1.125-2.734), was noticed. However, for mothers with a pre-pregnancy BMI between 18.5 and 24.0 or with low protein intake during the first trimester, significant association with higher risk of SGA (OR=1.465, 95%CI: 1.089-1.972) was found. Conclusions: Through our observation, maternal dietary intake during pregnancy seemed to be associated with the risk of SGA but the effects of dietary intake were different, according to the BMI of pre-pregnancy population. Early pregnancy appeares as the key period for dietary intake which may influence the SGA.

[The 470th case: recurrent vomiting]

Patients with cyclic vomiting syndrome usually have comorbid psychological disorders, the trigger and aggravating factors of gastrointestinal symptoms. It may decrease the quality of life and the response to the conventional therapies, bring the patients to seek medical care frequently and perform unnecessary examinations, result in the waste of medical resources. We reported a 20-year-old woman with complaint of recurrent vomiting since infant, and less response to symptomatic and supportive treatment. Her vomiting relieved with antidepressant after consultation with gastroenterological specialist and psychologist. Physicians should pay more attention to recognize the comorbid psychological disorders in patients with functional gastrointestinal disorders (FGIDs), including cyclic vomiting syndrome. It is important to refer the patients with refractory symptoms to the psychologists for further professional evaluation and antidepressants.

Effects of vitamin A on growth performance and tissue retinol of starter White Pekin ducks

A dose-response experiment with 8 supplemental vitamin A levels (0, 500, 1,000, 1,500, 2,500, 3,500, 7,000, and 14,000 IU/kg) were conducted to examine the effects of vitamin A on growth performance and tissue retinol of starter White Pekin ducks. A total of 512 one-day-old male Pekin ducks were randomly divided into 8 treatments and each treatment contained 8 replicate pens of 8 ducks. All these ducks were reared in raised wire-floor pens from hatch to 21 D of age. At 21 D of age, growth performance and retinol concentration in plasma and liver were measured. Among all ducks, the birds fed basal diet with no supplemental vitamin A had the lowest weight gain, feed intake, and plasma and liver retinol (P < 0.05). As supplemental vitamin A increased, weight gain and feed intake increased quadratically (P < 0.05) and plasma and liver retinol increased linearly or quadratically (P < 0.05). The weight gain and plasma retinol showed broken-line response to increasing supplemental vitamin A (P < 0.05). According to broken-line regression, the minimum supplemental vitamin A requirements for weight gain and plasma retinol were 2606 and 4371 IU/kg, respectively. It was concluded that vitamin A deficiency could lead to a reduction in growth performance and tissue retinol retention and plasma or liver retinol was available biomarker to assess duck vitamin A status.

[Detection of axillary nerve multisegment motor nerve conduction using magnetic stimulation]

Objective: To establish a method for detecting multi-segmental motor nerve conduction of axillary nerve using magnetic stimulation technique, and to preliminarily discuss its clinical application value. Methods: From April 2017 to February 2018, 80 healthy volunteers, 40 male and 40 female, were included and divided into five groups according to age and gender (groupⅠwere <35 years old; groupⅡwere 35-44 years old; group Ⅲ were 45-54 years old; groups Ⅳ were 55-64 years old; groups Ⅴ aged 65-74). Axillary nerve recording electrodes were placed in the deltoid muscle belly, reference electrode was placed in the deltoid muscle check point. Using the magnetic stimulation coil, stimulation was released at spots which were, respectively, 2 fingers from the lateral side of subscapular fossa, 2 fingers from the lateral side of infraclavicular fossae, and Erb's point. The latency, amplitude, detection distance (stimulation to recording electrode) were recorded at each spot, and the height and arm length were also measured. Results: The detection rate of axillary nerve waveform in healthy volunteers was 97.2%. There were no statistically significant differences in latency and amplitude in the different sides, gender (P>0.05).The latency corresponding to different detection distances was compared, and the difference was statistically significant (P<0.05).Height and arm length in different age groups were significantly increased in groupsⅠ, Ⅱ and Ⅲ compared with groups Ⅳ and Ⅴ, with statistical significance (P<0.05). When compared among different age groups, the latency and amplitude of group Ⅳand Ⅴ (more than 55 years old and over) were significantly prolonged and decreased, with statistically significant differences (P<0.05). Conclusions: The method of detecting multi-segmental magnetic stimulation of axillary nerve is stable and the result is reliable, which makes the evaluation of the proximal nerve of upper limbs be possible. However, the biological effects of age on nerve conduction should be carefully considered.

[Comparison of intraocular pressure reduction in eyes with different intraocular tamponades after pars plana vitrectomy by 20% mannitol]

Objective: To investigate the efficacy of 20% mannitol in reducing intraocular pressure (IOP) in eyes with different intraocular tamponades after pars plana vitrectomy (PPV). Methods: Retrospective case-control study. Sixty-eight patients were administered with 20% mannitol and IOP was noted at regular intervals after simple PPV with ocular hypertension, including 24 males (26 eyes) and 44 females (46 eyes), aged (45.6±19.3) years. These cases were divided into three groups according to different tamponades: silicon-oil tamponade, 23 eyes; gas tamponade, 30 eyes; balanced salt solution (BSS), 19 eyes. The data were analyzed using the t test, variance and q test. Results: There was a significant decrease in IOP in all patients after using 20% mannitol. The IOP in the group of silicon-oil decreased from (33.25±2.56) mmHg (1 mmHg=0.133 kPa) to (23.21±1.85) mmHg, with a maximum decrease of 30.10%; the reduction in the group of C(3)F(8) was from (33.25±2.84) mmHg to (12.15±1.12) mmHg, with a maximum decrease of 33.44%. The IOP of the two groups dropped to a minimum both at 75 minutes. In the group of BSS, the IOP decreased from (32.95±2.33) mmHg to (17.50±1.35) mmHg, and the maximum extent of the decrease was 45.82% at 45 minutes. The difference in the IOP among the three groups at 20 min, 30 min, 45 min and 60 min was statistically significant (F=34.02, 112.68, 122.07, 34.83, all P=0.00). There were significant differences between the BSS group and the silicone-oil group (q=6.44, 13.04, 15.00, 17.11, all P=0.00), and between the BSS group and the C(3)F(8) group (q=7.68, 12.56, 12.93, 13.61, all P=0.00). Conclusion: In eyes with different intraocular tamponades, 20% mannitol was useful for short-term IOP reduction after vitrectomy, especially in those with BSS within one hour. But after 75 minutes, there was no statistically significant difference between groups. (Chin J Ophthalmol, 2019, 55:289-293).

[Related factors and interaction on HIV/HCV co-infection of patients access to methadone maintenance treatment]

Objective: To estimate the prevalence of HIV/HCV co-infection and explore the influence factors and their interaction on HIV/HCV co-infection of patient's access to methadone maintenance treatment (MMT). Methods: A face to face interviews were conducted among 750 patients at two MMT clinics in Guangxi Zhuang Autonomous Region. The questionnaires information included demographic characteristics, HIV and HCV infection status, history of drug abuse, urine test for morphine, high risk sex behaviors, needle sharing, dropped out etc. Methods of χ(2) test one-way, multivariate logistic regression and interactions were used to analyze the related factors of HIV/HCV co-infection. Results: The study subjects included 750 participants, 18.31% (127/691) of patients were co-infected with HIV and HCV. The HIV/HCV co-infection rate in patients who shared needles with others or dropped out of treatment was 35.84% (81/226) and 19.88% (64/322) respectively, which were higher than those who have never shared needles or dropped out (9.89%, 46/465 and 17.07%, 63/369). Logistic regression analysis results showed that after adjusted for confounding factors, patients who shared needles (OR=4.50, 95%CI: 2.72-7.43) and dropped out of treatment (OR=1.71, 95%CI: 1.04-2.80) were more likely to be infected with HIV/HCV. Interaction analysis showed that sharing needles and dropping out of treatment exist additive effect on co-infection of HIV and HCV (RERI=4.21, AP=0.44, SI=1.95). Conclusions: Needle sharing and dropping out of treatment are associated with HIV/HCV co-infection. Health education, psychological counseling and other measures should be taken to reduce needle sharing and dropping out of MMT.

[Assessment of renal function with intravoxel incoherent motion and diffusion tensor imaging in type 2 diabetic patients]

Objective: To evaluate the application value of intravoxel incoherent motion (IVIM) and diffusion tensor imaging (DTI) in detecting early-stage diabetic nephropathy and to assess the damage of ralated renal function. Methods: A total of 52 patients with type 2 diabetes diagnosed in Zhongda Hospital were collected from April 2016 to May 2017 and were assigned to DM group (diabetes without nephropathy, n=32) and DN group (diabetes with nephropathy, n=20) according to detection of microalbuminuria, a cohort of healthy recipients were included as control group (n=27) in the meantime. All of the subjects underwent IVIM and DTI examination. The cortical and medullary parameters[IVIM: perfusion fraction f, tissue diffusivity D, pseudodiffuvisity D(*;) DTI: fractional anisotropy FA, apparent diffusion coefficient ADC, principal diffusivities (λ1, λ2, λ3)]were obtained respectively and were compared among groups. The relationship between MRI related parameters and estimated glomerular filtration rate (eGFR) were statistically investigated; and diagnostic performance of IVIM and DTI in discriminating DM and DN group was evaluated by receiver operating characteristic analysis. Results: The cortical and medullary f, D values in DN group were lower than those in DM group and control group (F=17.32, 15.69, 6.71, 10.94, all P<0.05). D values of all subjects showed positive correlations with eGFR (cortex r=0.518, medulla r=0.538, both P<0.05). The diagnostic efficiency of cortical f values to discriminate diabetes and diabetic nephropathy was 0.817, the cut-off value was 0.205. The medullary FA value in DM group was lower than that in control group ((0.371±0.051 vs 0.423±0.043, t=4.188, P<0.05); and the medullary FA value in DN group (0.315±0.062) was lower than that in control and DM group (F=25.08, P<0.05). The medullary λ3 values in DM group and DN group were all significantly higher than that in control group (F=7.86, P<0.05). The diagnostic efficiency of medullary FA values to discriminate diabetes and diabetic nephropathy was 0.763, the cut-off value was 0.344. Conclusion: IVIM and DTI can reflect the abnormal perfusion and diffusion during early-stage diabetic nephropathy and have the potential value to assess the damage of ralated renal function.

[The colonoscopic characteristics of colorectal endometriosis: a single-centered retrospective study]

Objective: To reinforce the awareness of colorectal endometriosis (EM) in colonoscopy examination. Methods: Patients diagnosed as colorectal EM at Peking Union Medical College Hospital between February 2002 and February 2017 were enrolled in this study. The clinical characteristics and endoscopic features of EM lesions were summarized and compared between pathologically positive group and negative group. Results: A total of 34 cases were included with average age of (38.3±8.9) years old. All EM lesions located within rectum and sigmoid colon. The endoscopic lesions manifested as protrusion in 21 cases (61.8%) and protrusion-depression in 13 cases (38.2%), local stenosis in 8 cases (23.5%); erosive surface in 33 cases (97.1%) with local spontaneous hemorrhage in 4 cases (11.8%); nodal surface in 23 cases (67.6%), and lymphangiectasis base in 9 cases (26.4%). Endoscopic biopsy specimens were obtained in all cases with average 3 (2, 4) pieces. Positive results were found only in 4 patients (11.8%) with 3 endometriosis and one (endometrial) adenosarcoma. Compared with negative group, spontaneous hemorrhage was more frequent in positive group (2/4 vs. 2/30, P=0.013). Mean biopsy sample number was significantly larger in positive group (5 vs. 3, P=0.004). Conclusions: Colorectal endometriosis is mostly located within rectosigmoid region. Endoscopic features mainly include protrusion or protrusion-depression lesions with erosive and nodular surface, or local stenosis. Spontaneous hemorrhage under colonoscopy yields higher positive rate for biopsy, thus increasing biopsy sample numbers may improve pathology results.

Facilitating the measurement of circulatory hydrogen sulfide with fluorescence probe-coated microplates

OBJECTIVE

The hydrogen sulfide (H₂S) role in pathogenesis of various diseases were wildly addressed in recent decade. The circulatory (plasma or serum) and biological fluid H₂S measurement is still an enormous issues due to the technical limitation. This paper aimed to develop a novel measurement method based on fluorescence probe.

METHODS

Firstly, 20 μL ethanol was used to dissolve 100 pmol fluorescence probe, then added in a 96-well plate. An equal volume of ethanol was also added to the blank well of the plate. The plate was placed in a dark room for about 1 h until the fluorescence probe was evenly coated in the 96-well microplate and dried. The plate was frozen at -20 °C for later use. Secondly, the plasma or serum sample was added with saturated ammonium sulfate buffer (pH 7.8) and then centrifuged to remove the proteins. The equal volume supernatant liquid was added to the probe-coated well and the probe-uncoated well. The plate was incubated in a dark environment at 37 °C for 2 h. Finally, after incubation, the fluorescence density was acquired at Λ_Ex/Λ_Em 340/445 nm in a microplate reader. The differences of the fluorescence density values between the probe-coated well and probe-uncoated well were counted and H₂S concentration of plasma/serum was calculated by standard curve with NaHS.

RESULTS

The method had high sensitivity (from 0.3 to 100 μmol/L) and specificity for measuring H₂S as compared with other biologically relevant reactive sulfur species and sulfur-containing amino acid. Serum H₂S concentrations were assayed in 188 health volunteers using this method [(12.1±3.5) μmol/L, 95%CI: 4.6-19.8 μmol/L], and the frequency distribution showed a normal tendency(one-sample Kolmogorov-Smirnov test, P>0.1). The serum H₂S concentrations in 30 hypertension patients were decreased compared with 22 age- and gender-matched health individuals (paired-samples t test, t=9.937, P<0.001). There were no differences of H₂S concentration in serum [(19.66±2.32) μmol/L] or plasma [(18.67±2.07) μmol/L], between the samples acquired from artery [(19.34±0.51) μmol/L] or vein [(18.99±0.50) μmol/L] of male Wistar rats (repeated measurement of ANOVA, P=0.38). One week frozen samples did not affect the detection. The values of the repeated measurement did not differ (two-way ANOVA, P>0.05).

CONCLUSION

The present method is easily performed with high sensitivity, specificity and repeatability for circulatory H₂S. It is also quick and may apply for large samples.

[The efficacy of cyclosporine A as salvage therapy for severe active ulcerative colitis refractory to glucocorticoid]

Objective: To clarify the efficacy and safety of cyclosporine A (CsA) as salvage therapy in patients with severe active ulcerative colitis (UC) and refractory to steroids. Methods: A total of 24 severe active UC patients refractory to steroids and hospitalized from 2006 to 2012, were retrospectively enrolled.Data including demographic features, clinical manifestations, laboratory tests and medications were collected. Results: CsA was effective in 15(62.5%) patients, who did not receive colectomy during 12-week administration. This regimen was tolerable in most patients.Twelve (50.0%) patients reported 16 adverse events, but only one patient withdrew CsA due to intolerance.The rates of adverse events in initial intravenous CsA including 4 mg·kg(-1)·d(-1,) 3 mg·kg(-1)·d(-1) and 2 mg·kg(-1)·d(-1) were 2/2, 9/17 and 1/5 respectively.Responders had higher white blood cell count compared with non-responders (P= 0.045). Conclusions: CsA could be an effective alternative regimen to colectomy in severe active UC patients who are refractory to steroids.

[Characteristics of HBV transmission in families with HBsAg-positive fathers and familial clustering of HBV infection]

OBJECTIVE

To investigate the characteristics of hepatitis B virus (HBV) transmission among family members in families with familial clustering of HBV infection and poor outcomes, as well as the prevalence and distribution characteristics of HBsAg in offspring with different parental HBsAg status.

METHODS

The general information of each member in families with poor outcomes were collected from 2007 to 2010, and serological test was performed to analyze the prevalence and distribution of HBsAg in family members. The chi-square test or Fisher's exact test was used to analyze and compare the sex of offspring and the prevalence of HBsAg in them in 266 nuclear families with different paternal and maternal HBsAg status.

RESULTS

The positive rates of HBsAg in parents, siblings, children, and spouses of the probands were 20%, 88.2%, 76.8%, and 9.5%, respectively. The nuclear families with HBsAg-positive fathers and HBsAg-negative mothers had a significantly increased proportion of male offspring (male/female ratio = 2.02) compared with those with HBsAg-positive mothers and HBsAg-negative fathers (1.22) or those with HBsAg-negative fathers and mothers (0.96). In addition, in the nuclear families with HBsAg-positive fathers and HBsAg-negative mothers, the male offspring had a significantly higher HBsAg positive rate than female offspring (37.4% vs 13.8%), while in those with HBsAg-positive mothers and HBsAg-negative fathers or those with HBsAg-negative fathers and mothers, HBsAg positive rate showed no significant difference between male and female offspring.

CONCLUSION

In families with familial clustering of HBV infection and poor outcomes, mother-to-child transmission is still the major route of HBV transmission, but father-to-child transmission also plays a role in HBV transmission in this special population. Positive HBsAg in fathers is associated with the increased proportion of male offspring, and father-to-son transmission of HBV is higher than father-to-daughter transmission.

[A retrospective case-control study of immunoglobulin G4-related disease combined with malignancy]

IgG₄-related disease (IgG₄-RD) has been proved to be associated with malignancy.The incidence and risk factors of malignancy development in IgG₄-RD were not clear. Nine IgG₄-RD patients with malignancies and 27 IgG₄-RD control cases were analyzed for risk factors and clinical features. The incidence of malignancy in IgG₄-RD was 3.3%, higher than age-controlled general population. Smoking history was significantly more common in patients with malignancies than in the control group (9/9 vs 16/27, P<0.05). A total of 6/9 malignancies occurred within the first year after the diagnosis of IgG₄-RD. Colorectal, biliary and thyroid cancers were the leading types. Smoking history is a risk factor for IgG₄-RD associated malignancy. Careful vigilance to monitor malignancy needs to be paid during follow-up.

Rapid and sensitive LC-MS/MS method for the determination of auraptene in rat plasma and its application in a pharmacokinetic and bioavailability study in rats

A simple, sensitive and specific liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of auraptene, a constituent isolated from Fructus aurantii with potential to combat Alzheimer's disease, in rat plasma. Rat plasma samples were pretreated by protein precipitation with methanol. The analytes were separated by a Waters Sun Fire C18 column (50 mm x 2 mm, 5 μm) and eluted with 1:1000 methanol and formic acid/water (v/v) mobile phase with a flow rate of 0.5 mL/min. Multiple reaction monitoring was used to monitor the transition of the deprotonated auraptene molecule with an m/z of 299.3 [M+H](+), to the product ion with an m/z of 162.9 [M+H](+). Progesterone, with an m/z of 315.2→ 96.9 was used as an internal standard. The limits of detection and of quantification of auraptene in the rat plasma were 1 and 5 ng/mL, respectively. The method was linear in the concentration range of 20- 2000 ng/mL with coefficient correlation of 0.9956. After auraptene (100 mg/kg, p.o.) administration, the maximum plasma concentration and the time taken to reach maximum concentration were 1719.5 ± 384.3 g/mL and 108.0 ± 25.3 min, respectively. The elimination half-life was 108.0 ± 25.3 for auraptene (100 mg/kg, p.o.) and 3.0 ± 0 min for auraptene (2 mg/kg, i.v.). The oral bioavailability was about 8.5%.

Cardiac progenitor cell-derived exosomes prevent cardiomyocytes apoptosis through exosomal miR-21 by targeting PDCD4

Cardiac progenitor cells derived from adult heart have emerged as one of the most promising stem cell types for cardiac protection and repair. Exosomes are known to mediate cell–cell communication by transporting cell-derived proteins and nucleic acids, including various microRNAs (miRNAs). Here we investigated the cardiac progenitor cell (CPC)-derived exosomal miRNAs on protecting myocardium under oxidative stress. Sca1⁺CPCs-derived exosomes were purified from conditional medium, and identified by nanoparticle trafficking analysis (NTA), transmission electron microscopy and western blotting using CD63, CD9 and Alix as markers. Exosomes production was measured by NTA, the result showed that oxidative stress-induced CPCs secrete more exosomes compared with normal condition. Although six apoptosis-related miRNAs could be detected in two different treatment-derived exosomes, only miR-21 was significantly upregulated in oxidative stress-induced exosomes compared with normal exosomes. The same oxidative stress could cause low miR-21 and high cleaved caspase-3 expression in H9C2 cardiac cells. But the cleaved caspase-3 was significantly decreased when miR-21 was overexpressed by transfecting miR-21 mimic. Furthermore, miR-21 mimic or inhibitor transfection and luciferase activity assay confirmed that programmed cell death 4 (PDCD4) was a target gene of miR-21, and miR-21/PDCD4 axis has an important role in anti-apoptotic effect of H9C2 cell. Western blotting and Annexin V/PI results demonstrated that exosomes pre-treated H9C2 exhibited increased miR-21 whereas decreased PDCD4, and had more resistant potential to the apoptosis induced by the oxidative stress, compared with non-treated cells. These findings revealed that CPC-derived exosomal miR-21 had an inhibiting role in the apoptosis pathway through downregulating PDCD4. Restored miR-21/PDCD4 pathway using CPC-derived exosomes could protect myocardial cells against oxidative stress-related apoptosis. Therefore, exosomes could be used as a new therapeutic vehicle for ischemic cardiac disease.

Capability of GaN based micro-light emitting diodes operated at an injection level of kA/cm²

Different size InGaN/GaN based micro-LEDs (μLEDs) are fabricated. An extremely high injection level above 16 kA/cm2 is achieved for 10 μm-diameter LED. The lateral current density and carrier distributions of the μLEDs are simulated by APSYS software. Streak camera time resolved photoluminescence (TRPL) results show clear evidence that the band-gap renormalization (BGR) effect is weakened by strain relaxation in smaller size μLEDs. BGR affects the relaxation of free carriers on the conduction band bottom in multiple quantum wells (MQWs), and then indirectly affects the recombination rate of carriers. An energy band model based on BGR effect is made to explain the high-injection-level phenomenon for μLEDs.