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.

[Progress in research of rash and fever syndrome surveillance and early warning]

Objective: To introduce the progress in research of rash and fever syndrome (RFS) surveillance and early warning both at home and abroad, and provide reference for surveillance and prevention of RFS in China. Methods: The keywords "fever" "rash" and "surveillance" and others were used for a literature retrieval by using China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform, PubMed and Web of Science. The languages of literatures were limited in Chinese and English. The key information of the literatures were collected and analyzed with Excel. Results: A total of 36 study papers (21 in Chinese and 15 in English) were included. The studies mainly focused on the pathogen surveillance of RFS (n=19). The pathogens included measles virus, varicella-zoster virus, rubella virus, enterovirus, human B19 virus, dengue virus, streptococcus group A, Salmonella typhi and Salmonella paratyphoid,human herpesvirus, mumps virus and adenovirus. Eight studies were about the surveillance in major events, such as sport game, World Expo and religious gathering, or sudden natural disasters, such as earthquake and tropical storm, during 2010-2015. Eight studies focused on case or epidemic surveillance, most of which were studies from other counties. The surveillance sites were medical institutions. RFS was diagnosed according to the International Classification of Diseases, 9th (ICD-9) and symptoms descripted in chief-complaint. Only one study in Mongolia conducted RFS epidemic prediction. The analysis methods of 36 papers included simple descriptive analysis, time-based early warning models (such as regression analysis, fixed threshold method, Hugh Hart control chart method and cumulative sum control chart method) and time series analysis method. Conclusions: In the future, RFS surveillance system should cover both known pathogens and emerging pathogens. Automatic surveillance using information capture and intelligent modelling can be applied to improve the sensitivity and specificity of RFS surveillance and early warning.

[Analysis on personal protection in occupational population at high risk for brucellosis and influencing factor in China]

Objective: To understand the current status of personal protection in occupational population at high risk for brucellosis in China and provide evidence for the evaluation of implementation of National Brucellosis Prevention and Control Plan (2016-2020). Methods: Four counties in Shanxi Province and Xinjiang Uygur Autonomous Region were selected to conduct a questionnaire survey in occupational population at high risk for brucellosis from December 2019 to July 2020 by using cross-sectional survey methods. Results: A total of 2 384 persons at high risk for brucellosis were surveyed, and the standardized utilization rate of personal protective equipment (PPE) was 20.13% (480/2 384). The utilization rate of glove, mask, rubber shoe, and work cloth were 38.26% (912/2 384), 31.80% (758/2 384), 32.01% (763/2 384) and 30.87% (736/2 384),respectively. There were significant differences in the utilization rate and standardized utilization rate of the four types of PPE among populations in different age, occupation, educational level and area groups (all P<0.001). The utilization rate and standardized utilization rate of PPE were lower in people over 60 years old, women, farmers, and those with lower educational level. The results of multivariate analysis showed that occupation and area were the influencing factors for the standardized utilization of PPE, the standardized utilization rates of PPE were higher in herdsmen and veterinarians. The standardized utilization rate of PPE in Yanggao County and Huocheng County was significantly higher than that in Zuoyun County and Hunyuan County. Conclusions: The utilization rate of the four types of PPE in occupational population at high risk for brucellosis was not high in China, and the standardized utilization rate was low, lower than the requirement in National Brucellosis Prevention and Control Plan, and there were significant differences among different areas. It is urgent to distribute PPE to occupational population at high risk for brucellosis and carry out health education about PPE utilization. Meanwhile, it is necessary to strengthen information exchange or sharing among different areas.

Expression of water-soluble nucleocapsid protein of SARS-CoV-2 and analysis of its immunogenicity

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to be a major public health concern. Nucleocapsid (N) protein is the most abundant structural protein on SARS-CoV-2 virions and induces the production of antibodies at the early stage of infection. Large-scale preparation of N protein is essential for the development of immunoassays to detect antibodies to SARS-CoV-2 and the control of virus transmission. In this study, expression of water-soluble N protein was achieved through inducing protein expression at 25°C with 0.5 mM IPTG for 12 h. Western blot and ELISA showed that recombinant N protein could be recognized by sera collected from subjects immunized with Sinovac inactivated SARS-CoV-2 vaccine. Four monoclonal antibodies namely 2B1B1, 4D3A3, 5G1F8, and 7C6F5 were produced using hybridoma technology. Titers of all four monoclonal antibodies in ELISA reached more than 1.28×10 6.0. Moreover, all monoclonal antibodies could react specifically with N protein expressed by transfection of pcDNA3.1-N into BHK-21 cells in IPMA and IFA. These results indicated that water-soluble N protein retained high immunogenicity and possessed the same epitopes as that of native N protein on virions. In addition, the preparation of water-soluble N protein and its monoclonal antibodies laid the basis for the development of immunoassays for COVID-19 detection.

[Animal study on left bundle branch current of injury and anatomic location of leads in His-purkinje conduction system pacing]

Objective: Explore the relationship between tip of the left bundle branch pacing lead and anatomic location of left bundle branch as well as the mechanism of left bundle branch current of injury. To clarify the clinical value of left bundle branch current of injury during operation. Methods: The pacing leads were implanted in the hearts of two living swines. Intraoperative electrophysiological study confirmed that the left bundle branch or only the deep left ventricular septum was captured at low output. Immediately after operation, the gross specimen of swine hearts was stained with iodine to observe the gross distribution of His-purkinje conduction system on the left ventricular endocardium and its relationship with the leads. Subsequently, the swine hearts were fixed with formalin solution, and the pacing leads were removed after the positions were marked. The swine hearts were then sectioned and stained with Masson and Goldner trichrome, and the relationship between the anatomic location of the conduction system and the tip of the lead was observed under a light microscope. Results: After iodine staining of the specimen, the His-purkinje conduction system was observed with the naked eye in a net-like distribution, and the lead tip was screwed deeply and fixed in the left bundle branch area of the left ventricular subendocardium in the ventricular septum. Masson and Goldner trichrome staining showed that left bundle branch pacing lead directly passed through the left bundle branch when there was left bundle branch potential with left bundle branch current of injury, while it was not directly contact the left bundle branch when there was left bundle branch potential without left bundle branch current of injury. Conclusion: The left bundle branch current of injury observed on intracardiac electrocardiogram during His-purkinje conduction system pacing suggests that the pacing lead directly contacted the conduction bundle or its branches, therefore, the captured threshold was relatively low. Left bundle branch current of injury can be used as an important anatomic and electrophysiological evidence of left bundle branch capture.

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.

[Research and reflection on the diversified method system of multi-stages and multi-scenarios surveillance and early warning of infectious diseases]

With the outbreak of infectious diseases, more and more attention has been paid to surveillance and early warning work. Timely and accurate monitoring data is the basis of infectious diseases prevention and control. Effective early warning methods for infectious diseases can improve the timeliness and sensitivity of early warning work. This paper briefly introduces the intelligent early warning model of infectious diseases, summarizes the emerging surveillance and early warning methods of infectious diseases, and seeks the possibility of diversified surveillance and early warning in different epidemic stages and different outbreak scenarios of infectious diseases. This paper puts forward the idea of constructing a diversified method system of infectious diseases surveillance and early warning based on multi-stages and multi-scenarios and discusses the future development trend of infectious diseases surveillance and early warning, in order to provide reference for improving the construction level of infectious diseases surveillance and early warning system in China.

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.

[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.

[The correlations between influenza and meteorological factors in 15 cities of northern China, 2008-2020]

Objective: To understand the influence of meteorological factors on the morbidity of influenza in northern cities of China and explore the differences in the influence of meteorological factors on the morbidity of influenza in 15 cities. Methods: The monthly reported morbidity of influenza and monthly meteorological data from 2008 to 2020 were collected in 15 provincial capital cities, including Xi 'an, Lanzhou, Xining, Yinchuan and Urumqi (5 northwestern cities), Beijing, Tianjin, Shijiazhuang, Taiyuan, Hohhot, Ji'nan, Zhengzhou (7 northern cities), Shenyang, Changchun and Harbin (3 northeastern cities). The panel data regression model was applied to conduct quantitative analyze on the influence of meteorological factors on influenza morbidity. Results: The univariate and multivariate panel regression analysis showed that after controlling the population density and other meteorological factors, for each 5 ℃ drop of monthly average temperature, the morbidity change percentage (MCP) of influenza was 11.35%, 34.04% and 25.04% in the 3 northeastern cities, 7 northern cities and 5 northwestern cities, respectively, and the best lag period months was 1, 0 and 1 month; When the monthly average relative humidity decreased by 10%, the MCP was 15.84% in 3 cities in northeastern China and 14.80% in 7 cities in northern China respectively, and the best lag period months was 2 and 1 months respectively; The MCP of 5 cities in northwestern China was 4.50% for each 10 mm reduction of monthly accumulated precipitation, and the best lag period months was 1 month; The MCPs of 3 cities in northeastern China and 5 cities in northwestern China were 4.19% and 5.97% respectively when the accumulated sunshine duration of each month decreased by 10 hours, the best lag period months was 1 month. Conclusions: In northern cities of China from 2008 to 2020, the temperature, relative humidity, precipitation and sunshine duration all had negatively impact on the morbidity of influenza, and temperature and relative humidity were the main sensitive meteorological factors. Temperature had a strong direct impact on the morbidity of influenza in 7 cities in northern China, and relative humidity had a strong lag effect on the morbidity of influenza in 3 cities in northeastern China. The duration of sunshine in 5 cities in northwestern China had a greater impact on the morbidity of influenza compared with 3 cities in northeastern China.

[Thinking about development of multi-channel surveillance and multi-dimensional early warning system of emerging respiratory communicable diseases]

The world has paid a heavy price for the pandemic of the emerging respiratory communicable disease, so more concern about communicable disease surveillance and early warning has been aroused. This paper briefly reviews the establishment of the surveillance and early warning system of respiratory communicable diseases in China, discusses its future development and introduces the novel surveillance methods and early warning models for the purpose of establishment of a multi-channel surveillance and multi-dimensional early warning system of communicable diseases in the future and the improvement of the prevention and control of emerging respiratory communicable diseases in China.

[Assessment of intensity of seasonal influenza activity in Beijing-Tianjin-Hebei region, 2019-2021]

Objective: To explore the feasibility of moving epidemic method (MEM) in the assessment of seasonal influenza (influenza) activity intensity from the perspective of urban agglomeration, assess influenza activity intensity in the Beijing-Tianjin-Hebei region from 2019 to 2021 and evaluate the reliability of surveillance data and the effectiveness of the MEM model application. Methods: The weekly reported incidence rate (IR) of influenza and the percentage of influenza-like illness (ILI%) from 2011-2021 in Beijing-Tianjin-Hebei region were collected to establish MEM models respectively. The model fitting effect and the reliability of the two data were evaluated for the purpose of establishing an optimal model to assess the influenza activity intensity in Beijing-Tianjin-Hebei region from 2019-2021. A cross-validation procedure was used to evaluate the performance of the models by calculating the Youden's index, sensitivity and specificity. Results: The MEM model fitted with weekly ILI% had a higher Youden's index compared with the model fitted with weekly IR at both Beijing-Tianjin-Hebei region level and provincial level. The MEM model based on ILI% showed that the epidemic threshold in Beijing-Tianjin-Hebei region during 2019-2020 was 4.42%, the post-epidemic threshold was 4.66%, with medium, high and very high intensity thresholds as 5.38%, 7.22% and 7.84%, respectively. The influenza season during 2019-2020 had 10 weeks (week 50 of 2019 to week 7 of 2020). The influenza season started in week 50 of 2019, and the intensity fluctuated above and below medium epidemic level for six consecutive weeks. The high intensity was observed in week 4 of 2020, the threshold of very high intensity was excessed in week 5, and the intensity gradually declined and became lower than the threshold at the end of the influenza season in week 8. The epidemic threshold was 4.29% and the post-epidemic threshold was 4.35% during 2020-2021. Influenza activity level never excessed the epidemic threshold throughout the year, and no epidemic period emerged. Conclusions: The MEM model could be applied in the assessment of influenza activity intensity in Beijing-Tianjin-Hebei region, and the use of ILI% to assess influenza activity intensity in this region was more reliable than IR data. Influenza activity intensity in Beijing-Tianjin-Hebei region was higher during 2019-2020 but significantly lower in 2020-2021.

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.

[Progress in the practice of surveillance and early warning of infectious diseases in major countries and regions]

The COVID-19 pandemic is yet another reminder that the threat of infectious disease has never really gone away. As the cornerstone of preventing and controlling infectious diseases, effective surveillance and early warning are of great significance in understanding the outbreak and epidemic of specific infectious diseases and putting forward effective prevention and control measures. Therefore, we must continue strengthening the construction of infectious disease surveillance and early warning system. We reviewed the surveillance and early warning practices of infectious diseases in major countries and regions, then discussed the development direction in the field of surveillance and early warning of infectious diseases to provide the reference for strengthening the construction and capacity of infectious disease surveillance and early warning system in China.

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.

[The impact of occupational aluminum exposure on workers' overall cognitive function and various cognitive fields]

Objective: To evaluate the effects of occupational aluminum exposure on workers' overall cognitive function and cognitive fields. Methods: From July to August 2019, using the method of cluster sampling, 101 and 117 workers were selected from the electrolytic aluminum workshop of an aluminum plant in a region and the maintenance workshop of a plant in the same region. The venous blood of the subjects was collected, the plasma was extracted, and the blood aluminum concentration was measured by ICP-MS. According to the blood aluminum concentration and type of work, 93 workers who were lower than the median blood aluminum concentration and in the maintenance workshop of a factory were divided into low aluminum exposure group, and 85 workers who were higher than the median blood aluminum concentration and in the electrolytic aluminum workshop of an aluminum factory were divided into high aluminum exposure group. The basic information of the respondents, was collected through the employee physical examination form. The overall cognitive function of workers was evaluated by Beijing Montreal Cognitive Assessment Scale (MoCA) . Multiple linear regression analysis and logistic regression analysis were used for multiple statistical analysis. Results: Compared with the low aluminum exposure group (25.42±1.808) , the total score of MoCA in the high aluminum exposure group (23.84±2.919) was significantly lower, and the scores of visual space, executive function, abstract and delayed recall were significantly lower (P<0.05) . Linear regression analysis showed that the total score of MoCA, visual space and executive function, naming and delayed recall were negatively correlated with blood aluminum concentration (β=-0.018、-0.008、-0.003、-0.008, P<0.05) .MOCA total score, visual space and executive function, attention, language, abstraction, orientation were positively correlated with educational level (β=0.853、0.310、0.216、0.171、0.412、0.122, P<0.05) . Logistic regression analysis showed that adjusting for age, smoking, drinking and education, blood aluminum was a risk factor for mild cognitive impairment (OR=1.017, P<0.05) ; Education level was the protective factor of mild cognitive impairment (OR=0.419, P<0.05) . Conclusion: Occupational aluminum exposure can affect the overall cognitive function of workers, and occupational aluminum exposure increases the risk of MCI.

[Effects of occupational exposure to aluminum on verbal function of workers]

Objective: To explore the effect of occupational aluminum (Al) exposure on workers' overall cognitive level and speech function. Methods: In July 2019, by using cluster sampling method, the group of 232 exposed to Al from an Al plant in Shanxi Province were selected as the exposed group, and the group of 228 not exposed to Al were selected as the control group. The blood Al concentration was determined by inductively coupled plasma mass spectrometry (ICP-MAS) . The exposed group was divided into high exposure group and low exposure group according to the median (M) concentration of Al in serum. The general cognitive function and speech function were evaluated with the Montreal Cognitive Assessment Scale (MoCA) , and the differences in the general cognitive function and speech function between the groups were compared, and non-conditional logistic regression was used to analyze the possible influencing factors of mild cognitive impairment (MCI) . Results: There were significant differences in age, working age, education and drinking status between Al exposed group and control group (P<0.05) . The total MoCA score, animal naming tese (ANT) score and category fluency repetition (CFT) score in Al exposure group were lower than control group and the differences were statistically significant (P<0.05) . The full rate of ANT was lower than that of CFT in Al exposure group (P<0.05) . The total MoCA score, ANT score and CFT score in the high exposure group were significantly lower than those in the control group (P<0.05) . The score of MoCA, ANT and CFT in high exposure group were lower than those in low exposure group between the level of serum aluminum>60 μg/L group and ≤60 μg/L group (P<0.05) . Logistic regression analysis showed that working age, serun Al concentration, ANT score, CFT score and SR score were the possible influencing factors of MCI in occupational Al exposure workers (P<0.05) . Conclusion: Occupational Al exposure can lead to impaired speech function of workers, the higher the ANT score, CFT score and SR score, the lower working age and serum Al concentration, the lower risk of MCI.

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.

[Conversion of serum anti-Schistosoma japonicum antibodies detected by immunological tests following treatment with praziquantel: a meta-analysis]

OBJECTIVE

To evaluate the conversion of serum antibodies against Schistosoma japonicum in humans and livestock detected by immunological tests following treatment with praziquantel.

METHODS

The studies pertaining to serological tests of schistosomiasis japonica published from 1991 to 2020 were retrieved in electronic databases, including Chinese National Knowledge Infrastructure, WanFang Data, PubMed and ScienceDirect. Data were extracted from included studies. The publication bias was assessed with funnel plots using the software RevMan version 5.3, and the conversion of antibodies against S. japonicum was evaluated through meta-analysis.

RESULTS

A total of 40 publications were included in the final meta-analysis, consisting of 33 Chinese publications and 7 English publications, and all immunological tests were performed with indirect hemagglutination test (IHA) and enzyme-linked immunosorbent assay (ELISA). Pooled analysis showed that the negative rates of serum anti-S. japonicum antibody were 45.36% [95% confidential interval (CI): (43.96%, 46.76%)] and 20.83% [95% CI: (19.69%, 21.97%)] detected by ELISA and IHA within 6 months post praziquantel treatment, 62.95% [95% CI: (61.59%, 64.31%)] and 55.61% [95% CI: (54.21%, 57.01%)] within 6 to 12 months after treatment and 85.92% [95% CI: (84.94%, 86.90%)] and 86.90% [95% CI: (85.95%, 87.85%)] over 12 months after treatment, respectively.

CONCLUSIONS

The negative rate of the serum anti-S. japonicum antibody by IHA and ELISA increased with the time of post-treatment with praziquantel. The overall negative rates of anti-S. japonicum antibody detected by IHA and ELISA are low within 12 months post praziquantel treatment. However, a high negative rate of anti-S. japonicum antibody is detected if there is no new contact with infested water after 12 months of praziquantel treatment.

[Pilot surveillance and evaluation of influenza-like illness based on automatic computer analysis of electronic medical record in sentinel hospital]

Objective: To compare the accuracy of influenza-like illness (ILI) surveillance by automatic computer analysis based on electronic medical records and by doctor's report. Methods: A total of 3 542 patients who presented to Yichang Central Hospital fever clinic, respiratory department or emergency department between April to October 2019 with an ICD-10 code for acute respiratory illness (J00-J22) and complete electronic medical information of ILI related syndromes were drawn as the study sample. Taking the classification of the study sample according to the ILI case definition by influenza surveillance professionals as the gold standard, draw the receiver operating characteristic (ROC) curve and calculate sensitivity, specificity, diagnostic consistency to compared the accuracy of ILI surveillance by automatic computer analysis and by doctor's report. Results: Median age of 3 542 cases was 30 (24, 38) years old; 1 179 cases (33.29%) compliance with the case definition, ILI reported by doctors was 1 306 cases (36.87%), and computer automatic identification ILI were 1 150 cases (32.47%); 1 391 (39.27%) cases were men. The results of automatic computer analysis and doctor report consistency of kappa values with gold standard judgment were 0.97 and 0.66 respectively; area under the ROC curve was 0.98 and 0.84, respectively. And the sensitivity and specificity of automatic computer analysis were higher than that of doctor's report (all P values were <0.001), the sensitivity was 96.95% and 82.27%, and the specificity was 99.70% and 85.78%, respectively. Conclusion: The automatic computer analysis based on electronic medical records can identified ILI cases with good sensitivity and specificity in ILI case surveillance.

[Progress of research regarding the influenza early warning system, based on "Big Data"]

Shortcomings have been inherited in the traditional influenza early warning system, often expressed through the scope, accuracy on prediction and real-time performance of the monitor related programs. With the new round of scientific and technological revolution and the increasingly maturity of modern information system, related technology on influenza early warning has become the focus of research in this field, based on big data analysis technology. Using the traditional influenza surveillance and early warning system as reference, this paper summarizes the progress of influenza early warning research, based on the Internet, influencing factors, time and space trends, and risk assessment etc., to summarize the trends on the advantages, shortcomings and future development of big data, used in the early warning system on influenza.

Objective response of first-line chemotherapy of triple-negative breast cancer translates into survival benefit: an analysis in an independent, prospective clinical trial and a real-world setting

This study sought to assess whether the objective response (OR, including complete response and partial response) of first-line chemotherapy can predict overall survival (OS) for patients with metastatic triple-negative breast cancer (mTNBC) in both clinical trial and a real-world setting. The survival predictable parameters were assessed in two independent cohorts, the training cohort of 236 patients as part of a phase 3 trial (CBCSG006, Trial registration number NCT0128762) and the validation cohort of 360 patients from the real-world setting. Univariable and multivariable Cox proportional hazard models were applied to explore associations with progression-free survival and OS in the training cohort and then in the validation cohort. OR (OR vs non-OR, HR, 0.438, p<0.001) together with Eastern Cooperative Oncology Group (ECOG) performance status, disease-free survival, number of metastatic organ sites and platinum-based chemotherapy used as first-line chemotherapy were observed to be independent prognostic factors for progression-free survival (PFS), and OR (OR vs non-OR, HR, 0.602, p=0.002) together with ECOG score, disease-free survival, number of metastatic organ sites and previous anthracycline and/or taxane treatment were observed to be independent predictive factors for OS in the training cohort. These predictors were confirmed in the validation cohort. For OR and non-OR group, median OS was 23.72 and 13.83 months in the training cohort (HR, 0.637, p=0.002), and 21.95 and 13.80 months in the validation cohort (HR, 0.608, p<0.001), respectively. By adding OR in the OS predictors, the concordance index (C-index) improved from 0.622 to 0.645 in the training cohort and 0.653 to 0.675 in the validation cohort. PFS and OS of mTNBC can be predicted by OR status with any regimen of first-line chemotherapy in an independent prospective clinical trial and a real-world setting. Therefore, TNBC, not like other subtypes of breast cancer, may be in need of combination chemotherapy or intense chemotherapy to achieve a high response rate for survival.

[Epidemiological characteristics of fatal cases of hand, foot, and mouth disease in children under 5 years old in China, 2008-2018]

Objective: To understand the epidemiological characteristics and risk factors of fatal cases of hand, foot, and mouth disease (HFMD) in children under 5 years old in China from 2008 to 2018, and provide evidence for the development of targeted prevention and control measures and reduction of the incidence of fatal HFMD cases. Methods: The incidence data of reported HFMD cases in China during 2008-2018 were collected from the National Notifiable Disease Surveillance Reporting System of China for the analyses on the demographic characteristics, spatial distribution, diagnosis or reporting and pathogen spectrum of the HFMD cases. Then the risk factors causing deaths were analyzed by using logistic regression model. Results: From 2008 to 2018, a total of 3 646 fatal cases of HFMD in children under 5 years old were reported in China. There were more fatal HFMD cases in boys than in girls (1.82∶1), the death mainly occurred in age group 0 to 2 years (87.71%). Adjusted mortality rate of HFMD in children under 5 years old in China declined from 0.87 per 100 000 in 2010 to 0.11 per 100 000 in 2018 (APC=-23.20%). In the 2 523 laboratory-confirmed deaths, 2 323 (92.07%) were EV-A71 infections, but the constituents of CV-A16 and other enterovirus infections increased. The interval from onset to diagnosis M=2(P(25)-P(75):2-4)d. The interval from onset to death M=3(P(25)-P(75):2-4)d. Age between 0 and 1 years, EV-A71 infection, longer interval between onset and diagnosis, and living in rural area were the risk factors causing fatal HFMD cases. Conclusions: The number of the fatal cases, the rate of mortality and case fatality HFMD in China had shown downward trends since 2010. EV-A71 is still the main pathogen causing fatal cases, but we should pay more attention to gene pattern of the other enteroviruses except EV-A71 and CV-A16. To reduce the risk of the fatal cases we should strengthen the health education about the immunization of EV-A71 inactivated vaccines and reduce the interval from onset to diagnosis in young children in western provinces and rural areas.

[Analysis on duplicated reporting of brucellosis in China, 2005-2017]

Objective: To analyze the current status of duplicated reporting of brucellosis in China during 2005-2017, to understand the impact of duplicated reporting on the incidence of brucellosis, analyze the possible causes of duplicated reporting, and put forward propose solutions to further improve the brucellosis surveillance data quality. Methods: Data were from brucellosis case reporting cards in National Notifiable Disease Report System (NNDRS), Excel 2010 software was used to establish the database, the duplicated reporting was identified by using Spark DataFrame aggregation analysis in Python 3.2. Results: During 2005-2017, a total of 499 577 cases of brucellosis were reported, but the duplicated reporting rate was 75.76/10 000 (3 785/499 577). The duplicated reporting rate in same year was 37.21/10 000 (1 859/499 577), the duplicated reporting rate in other year was 39.87/10 000 (1 992/499 577) and the overall duplicated reporting rate increased year by year. The duplicated reporting rate in same institution was 33.59% (1 271/3 785) and the duplicated reporting rate by other institutions was 66.41% (2 514/3 785). Hospitals had the highest number of duplicated reporting (2 757), and community healthcare centers had the highest of duplicated reporting rate (281.27/10 000) (123/4 373). The reported incidence of brucellosis was 2.926 4/100 000 in 2017, the corrected incidence was 2.844 8/100 000 after removing the duplicated reporting, which was the maximum decrease from 2005 to 2017, the corrected incidence decreased by 2.79%. From 2005 to 2017, the average reported incidence of brucellosis in Xinjiang Uygur autonomous region was 14.712 0/100 000, and the corrected incidence was 14.060 0/100 000 after removing the duplicate reporting, with a decrease by 4.43%, the biggest decline in China. The average reported incidence of brucellosis in Ningxia Hui autonomous region was 13.987 1/100 000, and the corrected incidence of brucellosis was 13.662 2/100 000, with a decrease of 2.32%, ranking second in China. The reasons for duplicated reporting of brucellosis included repeated medical care seeking in same or different medical institutions in same year or other year, including the repeated medical care seeking in other areas. Conclusions: During 2005-2017, the number of duplicated reporting of brucellosis cases was on the rise in China. Hospital and community health service centers had highest case number and rate of duplicate reporting respectively, the duplicated reporting was mainly caused by re-reporting by other institutions or in other years. The duplicated reporting of brucellosis had greatly affected the accuracy of surveillance data of brucellosis in some provinces, such as Xinjiang and Ningxia. It is recommended to further strengthen brucellosis reporting management, improve data quality of NNDRS.

[Effect of Dendrobium nobile Lindl. alkaloids on myocardial lipid metabolism during cardiopulmonary bypass ischemia-reperfusion in dogs]

Objective: To explore the effects and mechanisms of Dendrobium nobile Lindl. alkaloids (DNLA) on myocardial lipid metabolism during ischemia-reperfusion in dogs undergoing cardiopulmonary bypass (CPB). Methods: Twenty-four healthy hybrid dogs, half male and half female, were randomly divided into sham group, model group, solvent control group and treatment group (DNLA, 6 mg/kg) (n=6), all of which were established with CPB. Except for the sham group, the aorta of the other groups was occluded for 60 min and then reopened. The uptake rate of free fatty acids, the concentration of long-chain acyl coenzyme A (LCACoA), mRNA and protein expression of fatty acid translocase enzyme/CD36 (FAT/CD36) in myocardial tissue and the cardiac function indexes were measured at 4 time points: before cardiopulmonary bypass (T1), 15 min (T2), 60 min (T3), and 90 min (T4) after reperfusion in each group. Results: Before CPB, there were no statistically significant differences in the uptake rate of free fatty acids, the concentration of LCACoA and mRNA expression of FAT/CD36 in myocardial tissue in each group (P>0.05). After the opening of the aorta, the above indexes in model group [(35.8±4.7)%, (8.55±1.51) nmol/g, 3.23±0.68] and treatment group [(27.4±2.7)%, (6.10±1.38) nmol/g, 2.20±0.56] were higher than those in sham group [(19.6±3.9)%, (4.16±0.81)nmol/g, 1.19±0.52], which were the highest at T2, and then gradually decreased (all P<0.05). Compared with the model group, the increase of above indicators in the treatment group was significantly lower at T2 (all P<0.05). Before CPB, there was no statistically significant differences in cardiac function indexes [left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP) and±dp/dtmax] among the groups (P>0.05). After the aorta was opened, the above indexes in model group [(76.5±9.1) mmHg, (31.1±2.9) mmHg, (1.2±0.4) mmHg/ms, (-0.9±0.1) mmHg/ms] and treatment group [(92.9±8.7) mmHg, (25.3±3.6) mmHg, (1.8±0.4) mmHg/ms, (-1.3±0.1) mmHg/ms] were lower than those in sham group [(165.5±12.9) mmHg, (6.5±0.5) mmHg, (3.3±0.6) mmHg/ms, (-2.9±0.3) mmHg/ms] (all P<0.05), but the impairment degree of cardiac function indicators in treatment group was significantly lower than that those in model group (all P<0.05). Conclusion: During CPB in dogs, DNLA can inhibit the abnormal expression of FAT/CD36, decrease the uptake of free fatty acids, and reduce the abnormal accumulation of LCACoA in myocardium,thereby alleviating the myocardial injury after ischemia-reperfusion.

[Comparison of short-term and long-term efficacy between robot-assisted and thoracoscopy-laparoscopy-assisted radical esophageal cancer surgery]

Objective: To explore the safety and short-term and long-term efficacy of robot-assisted radical esophageal cancer surgery. Methods: A prospective randomized controlled trial was conducted. Patients who were preoperatively diagnosed as stage 0-IIIB esophageal squamous cell carcinoma and suitable for minimally invasive surgery in our hospital from January 1, 2014 to June 30, 2018 were prospectively enrolled. Those of age ≥75 years having received preoperative neoadjuvant therapy, contradicted to anesthesia or operation due to severe complications, with history of thoracotomy or laparotomy, with concurrent malignant tumors, without complete informations or refusing to participate in this study were excluded. Participants were randomly divided into the thoracoscopy-laparoscopy group and the robot group using a random number table in ratio of 1:1. Preoperative clinicopathological data, surgical data and postoperative outcomes were recorded. The patients were followed up mainly by telephone. Follow-up endpoint was recurrence of esophageal cancer and death. Kaplan-Meier method was used to estimate survival rate. The survival difference between the two groups was analyzed using the log-rank test. Results: According to above criteria, a total of 192 esophageal cancer patients were enrolled finally, including 144 males and 48 females with mean age of (61.9±8.6) years. The robot group had 94 cases, including 72 males and 22 females with mean age of (61.3±8.2) years, and the thoracoscopy-laparoscopy group had 98 cases, including 72 males and 26 females with mean age of (62.4±9.1) years. There were no significant differences in baseline data between the two groups (all P>0.05). Operation was abandoned in one case in each group due to extensive pleural cavity metastasis and one case in each group was converted to thoracotomy. The success rate of operation was 97.9% (92/94) in the robot group and 98.0% (96/98) in the thoracoscopy-laparoscopy group (χ(2)=0.002, P=0.996). The number of lymph nodes dissected in the robot group was significantly higher than that in the thoracoscopy-laparoscopy group (29.2±12.5 vs. 22.8±13.3, t=3.433, P=0.001), while there were no significant differences in operative time, intraoperative blood loss, R0 resection rate, postoperative 30-day mortality, postoperative hospital stay, ICU stay, time to withdrawal of chest drainage tube, ICU readmission, and postoperative morbidity of complications between the two groups (all P>0.05). The median follow-up time was 21 (3 to 57) months. During the follow-up, 3 cases and 4 cases were lost, and 2 cases and 3 cases died of other diseases in the robot group and in the thoracoscopy-laparoscopy group respectively. Recurrence occurred in 39 cases during follow-up, including 14 recurrences in the robotic group with 1- and 3-year recurrence-free survival rates of 92.4% and 87.6% respectively and the median recurrence time of 15 (9 to 42) months. There were 25 recurrences in the thoracoscopy-laparoscopy group with 1- and 3-year recurrence-free survival rates of 81.7% and 67.9% respectively and the median recurrence time of 9 (3 to 42) months. There was significant difference in recurrence-free survival between the two groups (χ(2)=4.193, P=0.041). Conclusions: The robotic surgical system has good oncology effect and surgical safety in the radical operation of esophageal cancer, which deserves further research and promotion.

[Epidemiological characteristics of leptospirosis in Sichuan province, 2004-2018]

Objective: To explore the epidemiological characteristics of leptospirosis in Sichuan province from 2004 to 2018, and provide evidence for the prevention and control of leptospirosis. Methods: The descriptive epidemiology analysis was conducted based on the epidemic data of leptospirosis collected from the national notifiable infectious disease reporting information system (NNIDRIS) and sentinel surveillance system in 11 areas in Sichuan from 2004 to 2018. The ArcGIS 10.2 software was used for mapping. The SaTScan 9.1.1 software was used to analyze spatiotemporal scanning and characteristics of temporal-spatial clusters of leptospirosis. Results: A total of 2 834 cases of leptospirosis, including 41 deaths, were reported in Sichuan from 2004 to 2018, and the reported morbidity rate was 0.23/100 000 and the mortality rate was 0.003/100 000. It revealed that leptospirosis had an overall downward fluctuated trend. The incidence of leptospirosis had obvious seasonality, mainly from the last ten-day of August to the end of September, 1-2 weeks later after rice harvesting time. The reported cases were mainly males, the male to female ratio of the cases was 2.05∶1. The incidence was higher in age group 50-65 years. The majority of reported cases were farmers, accounting for 82.75% (2 345/2 834), followed by students, accounting for 12.74% (361/2 834). However, rare cases in students had been reported since 2011. In recent years, the high-incidence areas were alternating between Mabian, Muchuan counties along the Yangtze River and Yilong county located in the Jialing River basin. According to the spatial-temporal descriptive analyses by SaTScan, there were two clustering areas in the province where most cases occurred (P<0.001). The average density of field rats in 11 sentinel surveillance areas was 5.44%(14 351/263 767), and the predominant field rats included Anourosorexsquamipes (69.07%), Apodemusagrarius (12.73%). Whatmore, the density of the Apodemusagrarius ranged from 4.60% to 0.19%, showing downward trend with the lowest level in 2018. The annual culture rate of Leptospira from rat kidney samples declined. During 2007-2018, the average positive rate of Leptospira antibodies in healthy people was 24.52%(3 271/13 339), and the predominant serogroup was Icterohaemorrhagiae. There was no replacement of Leptospira serogroup in recent years. Conclusions: The incidence of leptospirosis in Sichuan was extremely low during 2004-2018, and the incidence peak of leptospirosis occurred in rice harvesting period. The cases were mainly old farmers, and the high-risk areas were constantly alternating between the Yangtzi River and the Jialing River basin. Both the density and the carriage rate of Leptospira of Apodemusagrarius were low, and the predominant serogroup was Icterohaemorrhagiae. The average positive rate of leptospira antibodies in healthy people was very low.

[Investigation of human brucellosis cases in newly affected counties in Sichuan province, 2015-2017]

Objective: To understand the discovery of human brucellosis cases in new affected counties in Sichuan province, 2015-2017, and provide evidences for prevention and control of human brucellosis. Methods: The incidence data and outbreak data of human brucellosis in Sichuan were collected from Chinese Infectious Disease Surveillance Reporting System, and face to face interview, telephone interview and on-line survey were conducted to collect the case information, such as epidemiological characteristics, medical care seeking. Results: The incidence of human brucellosis in Sichuan has increased obviously since 2013, and 103 counties reported human brucellosis cases for the first time. A total of 23 cases of human brucellosis were investigated, and the common symptoms of the cases was fever, accounting for 91.30% (21/23). The cases mainly sought medical care in hospitals under county-level for the first time, accounting for 73.91% (17/23), and the misdiagnosis rate was 91.30% at the first diagnosis (21/23). The median interval between onset and diagnosis was 52 days, and the longest one was 142 days. Only 4.35% (1/23) cases knew human brucellosis, and when they contacted with suspected livestock, the use rate of protective clothing was 30.43% (7/23), the use rate of gloves was 8.70% (2/23), the use rate of mask was 4.35% (1/23), and the rate of washing hands with disinfectant after contact with livestock was 4.35% (1/23). Goat was suspected to be the infection source of all the cases, and 34.75% (8/23) of the cases were from Gansu, Qinghai and other provinces. The overall awareness rate of human brucellosis in the doctors was 34.58% (102/295), and the training rate was 58.31% (172/295). Only 33.33% (11/33) of the hospitals could perform laboratory diagnosis of human brucellosis and 34.78% (8/23) of county CDCs could carry out laboratory test of human brucellosis. Conclusions: The prevention and control of human brucellosis is facing challenge in Sichuan. The misdiagnosis rate was very high in newly affected counties, and the diagnosis were delayed obviously. The awareness of human brucellosis was low in the cases, and their awareness of self-protection was poor. The awareness rate about human brucellosis in doctors was low and they need more training; the capacity of brucellosis laboratory diagnosis in hospitals and CDCs at county-level should be improved.

[Analysis of epidemiological characteristics of report cases of rotavirus diarrhea in children under 5 years old in China, 2005-2018]

Objective: To analyze the epidemiological characteristics of rotavirus in children under 5 years old in China (excluding China Hong Kong, Macau and Taiwan data, the same below) from 2005 to 2018. Method: Data on other infectious diarrhea in the country from 2005 to 2018 were downloaded from the National Notifiable Disease Report System was to build a database for report cases of rotavirus diarrhea in children under 5 years of age, and descriptive epidemiological methods were used to analyze the data. Result: In 2005-2018, a total of 820 588 cases of rotavirus infection in children under 5 years old were reported nationwide, with male 500 944 cases, and with an average annual incidence of 63.7/100 000. The reported incidence showed a fluctuating upward trend increased from 8.4/100 000 to 178.1/100 000. The number of reporting provinces increased from 17 to 30. The reported incidence showed a peak of season from November to following February. The reported cases of rotavirus diarrhea in children under 5 months of age was 13.1%(107 845 cases), and the high-incidence age ranged from 6 months to 2 years old, accounting for 70.3% (576 874 cases), with a peak of 11-13 months (163 947 cases). The top three provinces (cities) reporting the incidence rate were Zhejiang (535.2/100 000), Guangdong (334.3/100 000) and Beijing (317.3/100 000), the provinces with the low reported case rates were Shanxi (0.9/100 000), Heilongjiang (1.6/100 000) and Liaoning (2.5/100 000), but there was no case reported in Tibet; The report cases of south region (745 526 cases) were 9.9 times north region (74 935 cases).The cases of rotavirus infection and other diarrhea pathogens were detected simultaneously accounted for 1.8% (15 030 cases) and mainly were positive for rotavirus and adenovirus (90.1%, 13 544 cases). Conclusion: The rate of rotavirus infection in children has increased rapidly since the age of 6 months, and 84.4% of the reported cases were infants before the age of 2 years.

[Diagnostic value of nucleic acid detection in schistosomiasis japonica: a meta-analysis]

OBJECTIVE

To quantitatively evaluate the diagnostic value of variable-temperature and isothermal nucleic acid amplification techniques in the detection of schistosomiasis japonica using a meta-analysis.

METHODS

The publications pertaining to the nucleic acid detection of schistosomiasis japonica were searched in electronic databases, including Chinese National Knowledge Infrastructure (CNKI), Wanfang Data, PubMed and ScienceDirect, and the compilations and proceedings of schistosomiasis were manually searched. In addition, the citations of publications associated with the nucleic acid detection of schistosomiasis japonica were traced using a document tracing method. The retrieved literatures were screened according to the inclusion and exclusion criteria, and data were extracted from the included literatures. The quality of the included literatures was assessed using the software RevMan version 5.3, and a meta-analysis was performed using the software MetaDiSc version 1.4.

RESULTS

A total of 19 publications covering 24 groups of studies were enrolled, including 5 Chinese publications and 14 English publications. There were 17 groups of studies reporting the comparison between the variable-temperature nucleic acid amplification technique and the golden standard, and 7 groups of studies showing the comparison between the isothermal nucleic acid amplification technique and the golden standard. Assessment of the literature quality indicated a minor overall bias of the included literatures, and the Deek funnel plot showed a possible publication bias in the documents reports variable-temperature nucleic acid amplification techniques. There was a heterogeneity caused by non-threshold effect among the studies associated with the variable-temperature amplification technique, and the random effects model was therefore used to combine the effects. The pooled sensitivity and specificity of the variable-temperature amplification technique were 0.81 (0.79 to 0.83) and 0.73 (0.71 to 0.74) for the diagnosis of schistosomiasis japonica, and area under the SROC curve was 0.944 3. There was no heterogeneity among the studies associated with the isothermal amplification technique, and the fixed effects model was therefore used to combine the effects. The pooled sensitivity and specificity of the isothermal amplification technique were 0.96 (0.94 to 0.98) and 0.95 (0.94 to 0.97) for the diagnosis of schistosomiasis japonica, and area under the SROC curve was 0.989 9.

CONCLUSIONS

Both variable-temperature and isothermal nucleic acid amplification techniques have a high efficiency for the diagnosis of schistosomiasis japonica, and the isothermal amplification technique shows a relatively higher accuracy than the variable-temperature amplification technique.

[Platelet derived growth factor-BB regulates phenotype transformation of pulmonary artery smooth muscle cells via SIRT3 affecting glycolytic pathway]

Objective: To investigate whether platelet-derived growth factor-BB (PDGF-BB) can regulate phenotypic transformation of pulmonary artery smooth muscle cells (PASMCs) via SIRT3 affecting glycolytic pathway. Methods: The PASMCs were isolated from Sprague Dawley rats. PASMCs were divided into 3 groups by using 2-deoxyglucose (2-DG), an inhibitor of the glycolytic pathway: normal control group, PDGF-BB group(30 ng/ml) and PDGF-BB (30 ng/ml)+2-DG (10 mmol/L) group. In lentivirus-mediated overexpression assay, cells were divided into control group, PDGF-BB group(30 ng/ml), PDGF-BB+deacetylase sirtuin-3 (SIRT3) overexpression group and PDGF-BB+empty vector group. The expression levels of phenotype related index such as α-smooth muscle actin (α-SMA), smooth muscle myosin heavy chain (SM-MHC), calponin, vimentin were detected by qRT-PCR and Western blot. Meanwhile, the expression of α-SMA was detected by cellular immunofluorescence staining. EDU staining was used to detect the proliferation of PASMCs. The expression of SIRT3 was detected by Western blot. The expressions of glucose transporter 1 and aerobic glycolytic enzymes were detected by qRT-PCR and Western blot in lentivirus-mediated overexpression assay. Results: (1) PDGF-BB affects PASMCs phenotypic transformation through glycolytic pathway: compared with normal control group, PDGF-BB significantly decreased the expressions of contractile phenotype markers such as α-SMA, SM-MHC, calponin mRNA and protein (all P<0.05), but it increased the expressions of the synthetic phenotype marker vimentin mRNA and protein (both P<0.05). Cellular immunofluorescence assay showed that PDGF-BB significantly decreased the number of α-SMA positive cells, while 2-DG reversed the process. (2) PDGF-BB promoted cell proliferation through glycolytic pathway: the proliferation of PASMCs was significantly higher in PDGF-BB group than in control group (P<0.05), and which could be significantly reduced by 2-DG (P<0.05). (3) PDGF-BB inhibited the expression of SIRT3 protein in PASMCs: the expression of SIRT3 protein in PDGF-BB group was lower than that in control group (P<0.05). (4) PDGF-BB affected glycolytic pathway through SIRT3:compared with the control group, PDGF-BB significantly increased the expression levels of glucose transporter 1 (Glut1), hexokinase 2 (HK2) and 6-phosphfructo-2-kinase 3 (PFKFB3) mRNA (all P<0.05), which was reserved by over-expression of SIRT3. There were no significant difference in mRNA expression levels between PDGF-BB group and PDGF-BB+empty vector group (P>0.05).Compared with the control group, PDGF-BB significantly increased the expression levels of Glut1, HK2 and PFKFB3 protein(all P<0.05), which was reserved by over-expression of SIRT3. There were no significant differences in protein expression levels between PDGF-BB group and PDGF-BB+empty vector group (all P>0.05). Conclusion: PDGF-BB regulates phenotypic transformation of PASMCs via SIRT3 affecting glycolytic pathway.

Biomarker assessment of the CBCSG006 trial: a randomized phase III trial of cisplatin plus gemcitabine compared with paclitaxel plus gemcitabine as first-line therapy for patients with metastatic triple-negative breast cancer

Background

CBCSG006 trial reported the superior efficacy of cisplatin plus gemcitabine (GP) regimen than paclitaxel plus gemcitabine (GT) regimen as first-line treatment of metastatic triple-negative breast cancer (mTNBC). This study focused on the updated survival data and the explorations of potential biomarkers for efficacy.

Patients and methods

Germ-line mutations of homologous recombination (HR) panel, BRCA1/2 included, were evaluated in 55.9% (132/236) patients. PD-L1 expression was evaluated in 48.3% (114/236) patients. A nonparametric sliding-window subpopulation treatment effect pattern plot (STEPP) methodology was used to analyze the absolute survival benefits. All statistical tests were two-sided.

Results

Median progression-free survival (PFS) was 7.73 [95% confidence interval (CI) 6.46-9.00] months for GP arm and 6.07 (95% CI 5.32-6.83) months for GT arm (P = 0.005). No significant difference in overall survival (OS) was observed. There was significant interaction between HR status and treatment for PFS and status of HR deficient significantly correlated with higher objective response rate (ORR) and longer PFS in GP arm than in GT arm (71.9% versus 38.7%, P = 0.008; 10.37 versus 4.30 months, P = 0.011). There was no significant interaction between germ-line BRCA1/2 (gBRCA1/2) status and treatment for PFS. Patients with gBRCA1/2 mutation had numerically higher ORR and prolonged PFS in GP arm than in GT arm (83.3% versus 37.5%, P = 0.086; 8.90 versus 3.20 months, P = 0.459). There was no significant interaction between PD-L1 status and treatment for PFS, and no significant differences in ORR, PFS or OS between two arms regardless of PD-L1 status. In STEPP analysis, patients with lower composite risks had more absolute benefits in PFS than those with higher composite risks.

Conclusions

GP regimen has superior efficacy than GT regimen as first-line chemotherapy for mTNBC patients. Germ-line mutations of BRCA1/2 and HR panel are possible biomarkers for better performance of cisplatin-based regimens. A composite risk model was developed to guide patient selection for GP treatment in TNBC patients.

Trial registration

ClinicalTrials.gov, NCT01287624.

[Current situation and related policies on the implementation and promotion of influenza vaccination among health care workers]

Health care workers have higher risk of influenza infection because of their occupational exposure to infected patients. Infection of the health care workers may not only result in the increasing risk of the nosocomial infection and family transmission, but also disrupt the health services due to absence from work. Health care workers were recommended as a priority group of influenza vaccinationin more than 40 countries and regions in the world. In recent years, domestic surveys show that the influenza vaccine coverage among health care workers was low. This paper outlines the current status and related policies of influenza vaccination among health care workers in China and global. Additionally, we analyzed and discussed the proper immunization strategy of influenza vaccine for medical staff in China.

[The mortality burden of influenza in China: a systematic review]

Objective: To systematically review the mortality burden study of influenza in mainland China. Method: "influenza", "flu", "H1N1", "pandemic", "mortality", "death", "fatality", "burden", "China" and "Chinese" were used as keywords, and a systematic literature search was conducted to identify articles in three English databases (PubMed, Web of Science and Embase) and three Chinese database (CNKI, WanFang and VIP) during 1990-2018 (excluding Hong Kong, Macao and Taiwan). The language of literature was restricted to Chinese and English. The inclusion criteria were human-oriented researches with method based on population, and research indexes included mortality and excess mortality. The exclusion criteria were non-primary research materials, predictive research and research on the burden of avian influenza related deaths. A total of 17 literatures were included, and the basic information to descriptive characteristics, methodology of modeling and the corresponding results were extracted. Results: All the 17 studies adopted indirect statistical models, with 14 of which adopted the regression model, and all the research index was excess mortality. All causes (16 studies), respiratory and circulatory diseases (14 studies) and pneumonia and influenza (10 studies) were the main causes of death associated with influenza. Influenza associated mortality burden in the elderly was higher, with the lowest excess mortality rates of all causes, respiratory and circulatory diseases, pneumonia and influenza being 49.57, 30.80 and 0.69 per 100 000 people, and the highest rates being 228.16, 170.20 and 30.35 per 100 000 people, respectively. In the non-elderly, the corresponding lowest rates were -0.27, -0.08 and 0.04 per 100 000 people respectively, and the highest rates were 3.63, 2.6 and 0.91 per 100 000 people, respectively. The influenza-related excess mortality was higher in the north, with a minimum of 7.8 per 100 000 and a maximum of 18.0 per 100 000, and slightly lower in the south, with a minimum of 6.11 per 100 000 and a maximum of 18.7 per 100 000. There were also differences in deaths caused by different influenza virus subtypes, with influenza A(H3N2) and influenza B virus possibly posing a heavier mortality burden. Conclusions: Studies on influenza mortality burden is mainly based on indirect model and urban level in China. The mortality burden of influenza in the elderly, the northern and subtype A(H3N2) and B were more severe.

[Surveillance data on notifiable infectious diseases among students aged 6-22 years in China, 2011-2016]

Objective: To analyze the epidemiological characteristics of notifiable infectious diseases among Chinese students from 2011 to 2016 and to provide reference for the effective prevention and control programs on infectious disease among students. Methods: Both morbidity and mortality of notifiable infectious diseases among Chinese students aged 6-22 years from 2011 to 2016 were analyzed, with main characteristics of the disease described. Results: During 2011 to 2016, morbidities of Categories A, B and C infectious diseases among the Chinese students aged 6-22 years showed a decreasing trend, from 248.24/100 000 in 2012 to 158.57/100 000 in 2016. Mortality rates of Category A, B and C infectious diseases had also decreased from 0.12/100 000 in 2011 to 0.07/100 000 in 2016. The average morbidity of the top four diseases from Category A and B infectious diseases appeared as: tuberculosis (16.24/100 000), scarlet fever (9.39/100 000), hepatitis B (7.69/100 000) and bacillary and amebic dysentery (7.15/100 000). The average rates of mortality on the top four diseases appeared as: rabies (0.044 8/100 000), HIV/AIDS (0.027 7/100 000), tuberculosis (0.008 0/100 000) and Japanese encephalitis (0.005 9/100 000). The average rates of morbidity on the top four diseases appeared as: mumps (75.81/100 000), hand-foot-mouth disease (28.55/100 000), other infectious diarrhea (22.41/100 000) and influenza (15.67/100 000) in the Category C. Reported death cases were from hand-foot-mouth disease (11 cases), influenza (9 cases), mumps (1 case) and rubella (1 case). The prevalence rates varied among different student populations, with higher HIV/AIDS, hepatitis B and tuberculosis rates among college and senior high school students, while higher mumps, influenza and hand-foot-mouth disease rates among primary school and junior high school students. Conclusions: Both morbidity and mortality of notifiable infectious diseases among Chinese students aged 6-22 years had decreased significantly in 2011-2016. However, the major infectious diseases had become new challenges among students. HIV/AIDS had become a key infectious disease among college students and the relatively high prevalence of tuberculosis was seen in college and high school students.

[The prevalence and related factors of HBV infection among adults in Mianyang]

Objective: To analyze the prevalence and related factors of HBV infection among people aged 18 years old and above in Mianyang city. Methods: A total of 260 950 residents, living in Mianyang city more than 6 months, aging 18 years old and above were employed by multi-stage random sampling method from November 2014 to September 2015. Questionnaire survey was conducted on participants using a self-designed questionnaire, including general demographic characteristics, family history of Hepatitis B, history of Hepatitis B vaccination and history of present illness, etc. 5ml blood was collected from all participants, and the blood samples were detected for HBsAg by enzyme-linked immunosorbent assay (ELISA). The multivariate unconditional logistic regression was performed to identify the related factors of positive HBsAg. Results: Among the 260 950 subjects, 113 184 were males (43.37%), 147 766 were females (56.63%), and the average age was (47.68±17.36) years old. The positive rate of HBsAg was 6.10%(15 822 cases). Subjects who were 25-34 years old (OR=1.23), 35-44 years old (OR=1.26), 45-54 years old (OR=1.23), and 55-64 years old (OR=1.34) were more likely to be HBsAg positive,65 years and older (OR=0.88) were less likely to be, compared with subjects aging 18-24 years old; males were more likely to be HBsAg positive compared with females (OR=1.35); people living in Fucheng district were more likely to be HBsAg positive compared with who living in Jiangyou district(OR=1.91); married people were more likely to be HBsAg positive compared with unmarried ones (OR=1.36); medical staff were less likely to be HBsAg positive compared with non-medical staff (OR=0.61); subjects with a surgery history were more likely to HBsAg positive compared with who without (OR=1.13); subjects with trauma history were more likely to HBsAg positive compared with who without (OR=1.13); people with history of Hepatitis B were more likely to HBsAg positive compared with who without (OR=4.21); people with Hepatitis B vaccination history were less likely to be HBsAg positive compared with who without (OR=0.48); all the P values above were less than 0.05. Conclusion: The positive rate of HBsAg among adults in Mianyang city was very high, and we should pay more attention to people aging between 25 and 64 years old, male, medical staff, with surgery history, trauma history, and a family history of Hepatitis B and Hepatitis B vaccination history.

Perspectives on novel vaccine development

Vaccination is a common routine for prevention and control of human and animal diseases by inducing antibody responses and cell-mediated immunity in the body. Through vaccinations, smallpox and some other diseases have been eradicated in the past few years. The use of a patho- gen itself or a subunit domain of a protein antigen as immunogens lays the basis for traditional vaccine development. But there are more and more newly emerged pathogens which have expe- rienced antigenic drift or shift under antibody selective pressures, rendering vaccine-induced im- munity ineffective. In addition, vaccine development has been hampered due to problems includ- ing difficulties in isolation and culture of certain pathogens and the antibody-dependent enhancement of viral infection (ADE). How to induce strong antibody responses, especially neu- tralizing antibody responses, and robust cell-mediated immune responses is tricky. Here we re- view the progress in vaccine development from traditional vaccine design to reverse vaccinology and structural vaccinology and present with some helpful perspectives on developing novel vaccines.

[Investigation of human brucellosis diagnosis and report quality in medical institutions in key areas of Shanxi province]

Objective: To evaluate the accuracy of human brucellosis diagnosis and reporting in medical institutions in Shanxi province, and understand the performance of clinical doctors to diagnose human brucellosis according to diagnostic criteria. Methods: Field investigation was conducted in 6 medical institutions in the key areas of human brucellosis in Shanxi province. The diagnosis data of the reported brucellosis cases in 2015 were collected and reviewed retrospectively for the evaluation of the diagnosis accuracy with systematic sampling method. The database was established with Excel 2010 and the descriptive analysis and statistical test were conducted with software R 3.3.2. Results: The diagnosis consistent rate of the 377 brucellosis cases reviewed was 70.8% (267/377), the diagnosis consistent rates in medical institutions at city-level and country-level were 77.0% (127/165) and 66.0% (140/212) respectively, the differences had significance (χ(2)=5.4, P=0.02). Among the reviewed cases, the diagnosis consistent rate of laboratory diagnosis and clinical diagnosis were 87.1% (256/294) and 13.3% (11/83) respectively, and the differences had significance (χ(2)=170.7, P<0.001). Among the 21 investigated clinical doctors, the numbers of the doctors who correctly diagnosed the suspected cases, probable cases and lab-confirmed cases were only 3, 0 and 8 respectively. All of the clinical doctors knew that it is necessary to report the brucellosis cases within 24 hours after diagnosis. Conclusion: The accuracy of human brucellosis diagnosis in key areas of human brucellosis in Shanxi was low, and the performance of the clinical doctors to diagnose human brucellosis according to diagnostic and case classification criteria was unsatisfied.