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 plane3-6, 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.

Constraints on Ultraheavy Dark Matter Properties from Dwarf Spheroidal Galaxies with LHAASO Observations.

In this Letter we try to search for signals generated by ultraheavy dark matter at the Large High Altitude Air Shower Observatory (LHAASO) data. We look for possible γ rays by dark matter annihilation or decay from 16 dwarf spheroidal galaxies in the field of view of the LHAASO. Dwarf spheroidal galaxies are among the most promising targets for indirect detection of dark matter that have low fluxes of astrophysical γ-ray background while having large amount of dark matter. By analyzing more than 700 days of observational data at LHAASO, no significant dark matter signal from 1 TeV to 1 EeV is detected. Accordingly we derive the most stringent constraints on the ultraheavy dark matter annihilation cross section up to EeV. The constraints on the lifetime of dark matter in decay mode are also derived.

[Analysis of the correlative factors of long-term positive nucleic acid and the characteristics of nucleic acid conversion in novel coronavirus infected patients].

To analyze the correlative factors of long-term positive nucleic acid and the characteristics of negative nucleic acid conversion in novel coronavirus infected patients.Novel coronavirus infected patients who were hospitalized in Beijing Tsinghua Changgung Hospital from December 2022 to June 2023 were retrospectively included. Patients who were positive for novel coronavirus nucleic acid for ≥30 days were selected as the long-positive group, and age-and sex-matched patients with novel coronavirus nucleic acid for <30 days were selected as the control group. The clinical data of all enrolled patients were collected. Binary logistic regression was used to analyze the influencing factors of the positive duration of nucleic acid ≥30 days. The Cox risk ratio model was used to analyze the risk factors for the prognosis of severe patients during hospitalization, and the difference in the time of nucleic acid conversion between the upper and lower respiratory tract was compared between the groups. A total of 30 patients were included in the long-positive group, including 24 males and 6 females, aged [M (Q1, Q3)] 77 (64, 86) years. Fifty-eight patients were included in the control group, including 46 males and 12 females, aged 78 (66, 86) years. Transplantation status (OR=50.32, 95%CI: 1.98-1 278.63, P=0.018), malignant tumor (OR=12.85, 95%CI: 1.65-99.88, P=0.015), CD4+T cell count (OR=0.99, 95%CI: 0.99-1.00, P=0.005) were correlative factors for positive nucleic acid≥30 days. Acute Physiology and Chronic Health Evaluation (APACHE) Ⅱ score (HR=1.12, 95%CI: 1.03-1.22, P=0.012) and nucleic acid positive time (HR=1.16, 95%CI: 1.01-1.33, P=0.031) were correlative factors for death in severe patients. The nucleic acid conversion time of the lower respiratory tract specimens in both groups was later than that of the upper respiratory tract specimens (all P<0.001). Weakened underlying immunity is a correlative factor for long-term novel coronavirus nucleic acid positivity, and long-term positive novel coronavirus nucleic acid in severe patients indicates high risk of death. The nucleic acid of the lower respiratory tract specimen turned negative later than the upper respiratory tract specimen.

[Analysis of the long-term prognosis of transjugular intrahepatic portosystemic shunt treatment for esophagogastric variceal hemorrhage concomitant with sarcopenia in cirrhotic patients].

Objective: To explore whether transjugular intrahepatic portosystemic shunt (TIPS) can improve the prognosis of esophagogastric variceal bleeding (EGVB) combined with sarcopenia in cirrhotic patients. Methods: A retrospective cohort study was performed. A total of 464 cases with cirrhotic EGVB who received standard or TIPS treatment between January 2017 and December 2019 were selected. Regular follow-up was performed for the long-term after treatment. The primary outcome was transplantation-free survival. The secondary endpoints were rebleeding and overt hepatic encephalopathy (OHE). The obtained data were statistically analyzed. The t-test and Wilcoxon rank-sum test were used to compare continuous variables between groups. The χ2 test, or Fisher's exact probability test, was used to compare categorical variables between groups. Results: The age of the included patients was 55.27±13.86 years, and 286 cases were male. There were 203 cases of combined sarcopenia and 261 cases of non-combined sarcopenia. The median follow-up period was 43 months. The two groups had no statistically significant difference in follow-up time. There was no statistically significant difference in transplant-free survival between the TIPS group and the standard treatment group in the overall cohort (HR=1.31, 95%CI: 0.97-1.78, P=0.08). The TIPS patient group with cirrhosis combined with sarcopenia had longer transplant-free survival (median survival: 47.76 vs. 52.45, χ2=4.09; HR=1.55, 95CI: 1.01~2.38, P=0.04). There was no statistically significant difference in transplant-free survival between the two kinds of treatments for patients without sarcopenia (HR=1.22, 95%CI: 0.78~1.88, P=0.39). Rebleeding time was prolonged in TIPS patients with or without sarcopenia combination (patients without combined sarcopenia: median rebleeding time: 39.48 vs. 53.61, χ2=18.68; R=2.47, 95CI: 1.67~3.65, P<0.01; patients with sarcopenia: median rebleeding time: 39.91 vs. 50.68, χ2=12.36; HR=2.20, 95CI: 1.42~3.40, P<0.01). TIPS patients had an increased 1-year OHE incidence rate compared to the standard treatment group (sarcopenia patients: 6.93% vs. 16.67%, χ2=3.87, P=0.049; patients without sarcopenia combination: 2.19% vs. 9.68%, χ2=8.85, P=0.01). There was no statistically significant difference in the long-term OHE incidence rate between the two kinds of treatment groups (P>0.05). Conclusion: TIPS can significantly prolong transplant-free survival compared to standard treatment as a secondary prevention of EGVB concomitant with sarcopenia in patients with cirrhosis. However, its advantage is not prominent for patients with cirrhosis in EGVB without sarcopenia.

Measurement of the

The ^{18}O(α,γ)^{22}Ne reaction is critical for AGB star nucleosynthesis due to its connection to the abundances of several key isotopes, such as ^{21}Ne and ^{22}Ne. However, the ambiguous resonance energy and spin-parity of the dominant 470 keV resonance leads to substantial uncertainty in the ^{18}O(α,γ)^{22}Ne reaction rate for the temperature of interest. We have measured the resonance energies and strengths of the low-energy resonances in ^{18}O(α,γ)^{22}Ne at the Jinping Underground Nuclear Astrophysics experimental facility (JUNA) with improved precision. The key 470 keV resonance energy has been measured to be E_{α}=474.0±1.1 keV, with such high precision achieved for the first time. The spin-parity of this resonance state is determined to be 1^{-}, removing discrepancies in the resonance strengths in earlier studies. The results significantly improve the precision of the ^{18}O(α,γ)^{22}Ne reaction rates by up to about 10 times compared with the previous data at typical AGB temperatures of 0.1-0.3 GK. We demonstrate that such improvement leads to precise ^{21}Ne abundance predictions, with an impact on probing the origin of meteoritic stardust SiC grains from AGB stars.

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.

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.

Deep Underground Laboratory Measurement of

The ^{13}C(α,n)^{16}O reaction is the main neutron source for the slow-neutron-capture process in asymptotic giant branch stars and for the intermediate process. Direct measurements at astrophysical energies in above-ground laboratories are hindered by the extremely small cross sections and vast cosmic-ray-induced background. We performed the first consistent direct measurement in the range of E_{c.m.}=0.24 to 1.9 MeV using the accelerators at the China Jinping Underground Laboratory and Sichuan University. Our measurement covers almost the entire intermediate process Gamow window in which the large uncertainty of the previous experiments has been reduced from 60% down to 15%, eliminates the large systematic uncertainty in the extrapolation arising from the inconsistency of existing datasets, and provides a more reliable reaction rate for the studies of the slow-neutron-capture and intermediate processes along with the first direct determination of the alpha strength for the near-threshold state.

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.

[Risk stratification and low-density lipoprotein cholesterol goal attainment rates in patients with very high-risk or extreme high-risk atherosclerotic cardiovascular diseases regarding three guidelines].

Objective: To explore the differences of risk stratification of very high-risk or extreme high-risk atherosclerotic cardiovascular diseases (ASCVD) and the attainment rates of low-density lipoprotein cholesterol (LDL-C) management targets evaluated by three different criteria, and the causal attributions of these differences. Methods: Patients with ASCVD were consecutively enrolled from January 1 to December 31 in 2019, and were evaluated for very high-risk or extreme high-risk and LDL-C goal attainment rates with 2018 American guideline on the management of blood cholesterol (2018AG), 2019 China Cholesterol Education Program (CCEP) Expert Advice for the management of dyslipidemias (2019EA) and 2020 Chinese expert consensus on lipid management of very high-risk ASCVD patients(2020EC), respectively. The causal attributions of the differences in attainment rates were analyzed as well. Results: A total of 1 864 ASCVD patients were included in this study. According to 2018AG, 2019EA and 2020EC, the proportions of the patients with very high-risk or extreme high-risk were 59.4%, 90.7%, and 65.6%, respectively. The absolute LDL-C target attainment rates were 37.2%, 15.7%, and 13.7%, respectively, the differences between each two rates were statistically significant (all P<0.001). As to the differences in attainment rates between 2020EC and 2018AG, 61.5% were due to the different LDL-C goal attainment values and 38.5% were caused by the different risk stratifications, while for the differences between 2020EC and 2019EA attainment rates, different LDL-C goal attainment values were responsible for 13.2%, and different risk stratifications were responsible for 86.8% of the differences. Conclusions: There are significant differences in the proportions and LDL-C attainment rates among the three different criteria for very high-risk or extreme high-risk ASCVD. 2020EC showed a moderate proportion of patients with extreme high-risk, and had the lowest LDL-C attainment rate. The differences between 2020EC and 2018AG are mainly due to the LDL-C target values, and the differences between 2020EC and 2019EA are mainly caused by the risk stratifications.

[Testosterone levels in patients with varicocele and azoospermia].

OBJECTIVE: Androgen deficiency is common in aging males and may have unfavourable health consequences. Large-scale studies suggested low testosterone level might increse mortality and morbidity in ageing males. However, young men with low testosterone level might be neglected. Recent studies reported young men with infertility may have reduced testosterone level. To investigate the incidence of androgen deficiency in males with infertility and possible factors affecting the low testosterone level. METHODS: Between January 2011 and December 2012, 407 men with infertility caused by varicocele (VC), obstructive azoospermia (OA) and nonobstructive azoospermia (NOA) in our center were included. The number of men in each group of OA, NOA and VC was 141, 97 and 169, respectively. All the eligible patients underwent a serum testosterone assessment by a single morning blood draw (between 8:00 to noon) to test for concentration of the total testosterone. All serum samples were determined by radioimmunoassay in our andrology laboratory. Androgen deficiency was defined as having a total testosterone level less than 300 ng/dL. RESULTS: The mean age was (30.4±5.8) years. The mean testosterone level was (4.18±1.64) ng/dL (range 0.30 to 11.32 ng/dL). The overall incidence of androgen deficiency was 26.5% (108/407). The incidences of androgen deficiency in NOA, OA and VC groups were 40.2% (39/97), 19.1% (27/141) and 24.9% (42/169), respectively, which were significantly higher in the NOA than in the VC and OA groups (P < 0.001). The incidences had no difference between the VC and OA groups (P=0.229). Univariate analysis revealed the cause of infertility, FSH and the mean testis volume as possible affecting factors for androgen deficiency. However, on multivariate analysis the only cause of infertility was an independent predictor. The incidence of androgen deficiency was the highest in the NOA group [OR 0.492 (95% confidence interval 0.288-0.840)]. CONCLUSION: NOA and varicocele might be risk factors of androgen deficiency. Young men with NOA may have a higher possibility of low testosterone level. Testosterone level should be followed up after NOA and varicocele treatment. Androgen deficiency should be assessed in males with infertility in clinical practice.

[Clinicopathological features and HER2 expression of metaplastic squamous cell carcinoma of the breast].

Objective: To investigate the clinicopathological features and HER2 expression of metaplastic squamous cell carcinoma (MSCC) of the breast. Methods: A total of 47 MSCC cases diagnosed in the Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China from January 2010 to December 2021 were reviewed. The clinical information (including the follow-up data of HER2 positive patients) and pathological features were collected and analyzed. Results: All of the patients were female. Among the 47 cases, 25 were pure squamous cell carcinoma (PSCC) and 22 were mixed metaplastic carcinoma with squamous cell component (MMSC). The median age of the patients was 54 years (range, 29-84 years). The maximum diameter of the mass ranged from 0.8 to 10.0 cm, with a mean value of 3.3 cm, 85.7% (24/28) of the cases were smaller than 5 cm, and only 4 cases were larger than or equal to 5 cm. 89.5% of the MMSC presented with a solid mass. Cystic changes were more commonly found in the PSCC group (50%, P<0.05) than the MMSC group. 36.7% (11/30) of the patients had lymph node metastasis at the time of diagnosis. The squamous cell carcinoma component in all cases showed diffuse or patchy expression of p63, p40 and CK5/6. 55.3% (26/47) of the cases showed triple-negative phenotype. Among the 7 HER2-positive patients, 6 were MMSC group, which had a significantly higher rate of HER2-positivity than that in the PSCC group (1 case). In 1 MMSC case, immunohistochemistry showed HER2 2+in the invasive ductal carcinoma component and HER2 negativity (0) in the squamous cell carcinoma component, but HER2 FISH was negative in invasive ductal carcinoma and positive in squamous cell carcinoma component. Six HER2-positive MSCC patients received anti-HER2-targeted therapy, including two patients who received neoadjuvant chemotherapy combined with anti-HER2-targeted therapy before surgery. One patient achieved pathological complete remission, while the other achieved partial remission (the residual tumors were squamous cell carcinoma components). After 9-26 months of follow-up, four patients had no disease progression, two patients developed pulmonary metastases, and one patient showed local recurrence. Conclusions: MSCC is a group of heterogeneous diseases. PSCC and MMSC may be two different entities. Most of the MSCC are triple-negative and HER2 positivity is more commonly seen in MMSC with invasive ductal carcinoma component. Some HER2-positive MSCC patients can achieve complete remission or long-term progression-free survival after receiving anti-HER2 targeted therapy, but the squamous cell carcinoma component may be less sensitive to targeted therapy than the invasive ductal carcinoma component.

From One- to Two-Magnon Excitations in the S=3/2 Magnet ß-CaCr_{2}O_{4}.

We apply neutron spectroscopy to measure the magnetic dynamics in the S=3/2 magnet ß-CaCr_{2}O_{4} (T_{N}=21 K). The low-energy fluctuations, in the ordered state, resemble large-S linear spin waves from the incommensurate ground state. However, at higher energy transfers, these semiclassical and harmonic dynamics are replaced by an energy and momentum broadened continuum of excitations. Applying kinematic constraints required for energy and momentum conservation, sum rules of neutron scattering, and comparison against exact diagonalization calculations, we show that the dynamics at high-energy transfers resemble low-S one-dimensional quantum fluctuations. ß-CaCr_{2}O_{4} represents an example of a magnet at the border between classical Néel and quantum phases, displaying dual characteristics.

New

The discrepancy between observations from γ-ray astronomy of the ^{60}Fe/^{26}Al γ-ray flux ratio and recent calculations is an unresolved puzzle in nuclear astrophysics. The stellar ß-decay rate of ^{59}Fe is one of the major nuclear uncertainties impeding us from a precise prediction. The important Gamow-Teller strengths from the low-lying states in ^{59}Fe to the ^{59}Co ground state are measured for the first time using the exclusive measurement of the ^{59}Co(t,^{3}He+γ)^{59}Fe charge-exchange reaction. The new stellar decay rate of ^{59}Fe is a factor of 3.5±1.1 larger than the currently adopted rate at T=1.2 GK. Stellar evolution calculations show that the ^{60}Fe production yield of an 18 solar mass star is decreased significantly by 40% when using the new rate. Our result eliminates one of the major nuclear uncertainties in the predicted yield of ^{60}Fe and alleviates the existing discrepancy of the ^{60}Fe/^{26}Al ratio.

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.

Controlled expression of lysis gene E by a mutant of the promoter pL of the thermo-inducible λcI857-pL system.

AIMS: To identify a lambda promoter pL mutant that could extend the thermal stability of the thermo-inducible λcI857-pR/pL system and to evaluate the effects of the modified system for the controlled expression of lysis gene E during the production of bacterial ghosts (BGs). METHODS AND RESULTS: The promoter pL mutant was identified by random mutagenesis and site-directed mutagenesis. The results showed that a T â†’ 35C mutation in the pL promoter was responsible for the phenotype alteration. Under the same induction conditions, the lysis rates of the modified lytic system on Escherichia coli and Salmonella enteritidis were significantly lower than that of the control, while the lysis rates of Escherichia coli with the thermo-inducible lytic system were significantly higher than that of S. enteritidis with the corresponding plasmid (P < 0·05). CONCLUSIONS: Increasing the heat stability of the thermo-inducible lytic systems decreased lysis efficiency during the production of BGs. There exist differences in the lysis efficiency of thermo-inducible lytic systems between different bacterial strains. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings enrich current knowledge about modifications to thermo-inducible systems and provide a reference for the application of these modified systems for the production of BGs and controlled gene expression in bacteria.

[Effects of LINC00839 targeting miR-3666 on proliferation, migration and invasion of hepatocellular carcinoma cells].

Objective: To investigate the effects of lncRNA LINC00839 on the proliferation, migration and invasion of hepatocellular carcinoma cells and its mechanism. Methods: Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of LINC00839 and miR-3666 in hepatocellular carcinoma tissues and adjacent tissues. Pearson correlation was used to analyze the correlation between LINC00839 and miR-3666 expression in liver cancer tissues. Hepatocellular carcinoma cells MHCC97H were cultured in vitro and divided into si-NC group, si-LINC00839 group, miR-NC group, miR-3666 group, si-LINC00839+ anti-miR-NC group, and si-LINC00839+ anti-miR-3666 group. Methylthiazoletrazolium (MTT) method and clone formation experiment were used to detect cell proliferation. Transwell array was used to detect the cell migration and invasion. Western blot was used to detect the protein expressions of p21, E-cadherin and MMP-2. The double luciferase reporter gene experiment was used to verify the regulatory relationship between LINC00839 and miR-3666. Results: Compared with adjacent tissues, the expression level of LINC00839 in hepatocellular carcinoma tissues increased (2.82±0.27 vs. 0.96±0.10, P<0.001), but the expression level of miR-3666 decreased (0.23±0.02 vs. 1.01±0.10, P<0.001). The expression levels of LINC00839 and miR-3666 in liver cancer tissue were negatively correlated (r=-0.658, P<0.001). The survival rate of MHCC97H cells in the si-LINC00839 group [(53.91±5.41)% vs. (100.53±10.22)%], the number of clones formed (92.0±8.0 vs. 164.0±14.3), the number of migration (131.0±12.7 vs. 247.0±22.4), the number of invasion (66.0±6.4 vs. 120.0±11.6) and the protein level of MMP-2 (0.20±0.02 vs. 0.67±0.06) were lower than those in the si-NC group (P<0.001). However, the protein levels of p21 (0.76±0.07 vs. 0.25±0.02) and E-cadherin (0.78±0.08 vs. 0.14±0.01) were higher than those in the si-NC group (P<0.001). LINC00839 targeted and negatively regulated the expression of miR-3666. The survival rate of MHCC97-H cells in the miR-3666 group [(47.93±4.86)% vs. (100.11±10.21)%], the number of clone formation (78.0±7.7 vs. 166.0±15.9), the number of migration (117.0±12.1 vs. 250.0±25.0), the number of invasion (57.0±5.7 vs. 121.0±12.3) and the protein level of MMP-2 (0.16±0.01 vs. 0.69±0.07) were lower than those in the miR-NC group (all P<0.001). However, the protein levels of p21 (0.83±0.08 vs. 0.24±0.02) and E-cadherin (0.87±0.09 vs. 0.13±0.01)were higher than those in the miR-NC group (all P<0.001). The survival rate of MHCC97-H cells in the si-LINC00839+ anti-miR-3666 group [(89.94±9.05)% vs. (54.12±5.39)%], the number of clones (143.0±13.8 vs. 94.0±9.4), the number of migration (208.0±19.8 vs. 129.0±12.6), the number of invasion (108.0±10.1 vs. 65.0±6.4) and the protein level of MMP-2 (0.31±0.03 vs 0.66±0.06) were higher than those in the si-LINC00839+ anti-miR-NC group (P<0.001). However, the protein levels of p21 (0.31±0.03 vs. 0.74±0.07) and E-cadherin (0.28±0.03 vs. 0.80±0.08) were lower than those int the si-LINC00839+ anti-miR-NC group (P<0.001). Conclusion: Inhibition of LINC00839 expression may inhibit the proliferation, migration and invasion of hepatocellular carcinoma cells by targeting up-regulation of miR-3666 expression.

[The prevalence, influencing factors and prognosis of abnormal serum potassium levels in patients with chronic kidney disease].

Objective: To estimate the prevalence of hyperkalemia and hypokalemia in patients with chronic kidney disease (CKD), analyze the influencing factors and explore the impact on disease prognosis. Methods: A total of 3 190 patients with CKD stage 1-4 from 39 tertiary clinical centers in China between November 2011 and December 2016 were recruited. The baseline characteristics of the patients were collected through face-to-face questionnaire investigation, physical examination and laboratory test. Meanwhile, the data of patient's end-stage renal disease, cardiovascular disease events and deaths were obtained up to December 2017 through active monitoring. The patients were categorized into three groups based on their baseline level of serum potassium (hypokalemia:<3.5 mmol/L, normal range: 3.5-<5.0 mmol/L, hyperkalemia: ≥5 mmol/L). Multi-nominal logistic regression was employed to evaluate the association between clinical characteristics and the presence of hyperkalemia or hypokalemia. The competing risk-based subdistribution Cox proportional hazards regression was used to assess the association between baseline level of serum potassium and various outcomes. Results: The mean age of the patients was (50±14) years, with a male rate of 57.6% (1 839/3 190) and a majority of glomerulonephritis (59.7%, 1 668/2 792). Patients with CKD stage 3-4 accounted for 70.8% (2 260/3 190), and the mean level of serum potassium was (4.4±0.7) mmol/L. The prevalence of hypokalemia and hyperkalemia was 3.7% (n=118) and 17.6% (n=561), respectively. In the multivariable adjusted analysis, presence of history of cardiovascular disease (OR=0.33, 95%CI: 0.13-0.83, P=0.019) and estimated glomerular filtration rate (OR=0.95, 95%CI: 0.91-0.98, P=0.001) were inversely associated with hypokalemia, while use of thiazide or loop diuretic (OR=2.06, 95%CI: 1.51-2.81, P<0.001) and estimated glomerular filtration rate (OR=1.13, 95%CI: 1.12-1.16, P<0.001) were positively associated with hyperkalemia. After adjusting for relevant cardiovascular and renal risk factors, the result only showed a significant association between hypokalemia and risk of all-cause mortality (HR=2.12, 95%CI: 1.06-4.24, P=0.034). Conclusions: Hypokalemia and hyperkalemia were not rare in patients with CKD in China, with the latter more prevalent. Hypokalemia was independently associated with the risk of death.

[Effect of serum potassium level on renal function progression in stage â ¢-â ¤ chronic kidney disease patients without dialysis].

Objective: To investigate the effect of serum potassium level and hyperkalemia on the renal function decline in chronic kidney disease (CKD) patients. Methods: The clinical data at baseline and follow-up in stage Ⅲ-Ⅴ CKD patients without dialysis who were followed up for more than one year in Tianjin First Central Hospital from May 2015 to June 2019 and Teikyo University School of Medicine from January 2008 to July 2013 were retrospectively collected. All patients were divided into stable group (337 cases), slow progression group (337 cases) and rapid progression group (338 cases) according to the tertile of estimated glomerular filtration rate (eGFR) slope (the annual average percentage of eGFR decline). Multivariate logistic regression analysis models were used to evaluate the correlations of baseline serum potassium or time-averaged serum potassium level with CKD rapid progression. Results: Three hundred and forty-three cases from Tianjin First Central Hospital and 669 cases from Teikyo University School of Medicine were included in the study, and 635 cases (62.7%) were male. The average age was (61±14) years old and the average eGFR decline slope was 4.0%/year. The levels of baseline serum potassium and time-averaged serum potassium of patients in the slow progression group [(4.47±0.52) and (4.51±0.43) mmo/L] and rapid progression group [(4.62±0.62) and (4.76±0.48) mmo/L] were higher than those in the stable group [(4.37±0.49) and (4.38±0.37) mmo/L] (both P<0.05). Meanwhile, 24.6% (83/338) of the patients in the rapid progression group had hyperkalemia at baseline (serum potassium ≥5.0 mmol/L) and 34.9% (118/338) of the patients had time-averaged serum potassium ≥5.0 mmol/L, which were higher than those in the stable group [10.7% (36/337) and 6.5% (22/337)] (both P<0.001). Multivariate logistic regression analysis showed that compared with the stable group, baseline serum potassium (OR=1.843, 95%CI: 1.051-3.234) and time-averaged serum potassium (OR=2.495, 95%CI: 1.040-5.987) were correlated with the rapid progression of CKD. Time-averaged serum potassium ≥5.0 mmol/L was the independent influencing factor for rapid progression of CKD. Conclusions: During the follow-up period, the average level of serum potassium in stage Ⅲ-Ⅴ CKD patients should be controlled under 5.0 mmol/L, which may reduce the risk of rapid decline of renal function.

[Comparative study on metagenomics of esophageal flora in elderly and middle-aged esophageal squamous cell carcinoma patients].

Objective: To explore the flora characteristics and differences of esophageal tissues between elderly esophageal squamous cell carcinoma (ESCC) patients and young and middle-aged ESCC patients, so as to assist in studying the potential biomarkers of elderly ESCC patients. Methods: In this study, a retrospective study was adopted. 72 ESCC patients diagnosed in Taihe Hospital, Shiyan City, Hubei Province from July 2018 to July 2019 were selected, including 49 patients in the elderly group (≥ 60 years old, 40 males and 9 females), 23 patients in the young and middle-aged group (<60 years old, 21 males and 2 females). In the same period, 20 healthy persons without abnormal gastroscopy in endoscopy center were selected as the control group (aged 35-78 years old, median age 57 years old, 16 males and 4 females). The genomic DNA was extracted from the affected esophageal tissues of patients with ESCC and the middle esophageal samples of the control group. The V4 hypervariable region of bacterial 16SrRNA gene sequence was amplified. Illumina HiSeq sequencing technology was adopted. The flora characteristics of elderly, young and middle-aged ESCC patients was compared and analyzed. QIIME and Rstudio software were used to analyze the sequence data, and nonparametric Kruskal-Wallis test or Wilcoxon rank sum test were used for statistical methods. Results: Shannon index [5.17 (4.53, 5.95) vs. 4.79 (3.74, 5.97)], Simpson index [0.94 (0.91, 0.96) vs. 0.92 (0.83, 0.96)] and Chao1 index [343.55 (259.76, 570.59) vs. 329.16 (268.88, 648.00)] were similar in flora of two groups, and there was no significant difference (Z=-0.791, -1.057, -0.380, all P>0.05). There was no significant difference in ß-diversity between the elderly group and the young and middle-aged group (PC1=19.14%, PC2=6.95%, PPC1=0.67, PPC2=0.42). At the phyla level, the top 5 phyla in abundance were as follows: Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria and Fusobacteria in the young and middle-aged group, while the top 5 phyla in abundance were as follows: Firmicutes, Bacteroidetes, Proteobacteria, Fusobacteria and Actinobacteria in the elderly group; the significant difference between the two groups was Fusobacteria (Q=0.596, P<0.05). At the genus level, the top 5 genera in the young and middle-aged group in abundance were as follows: Prevotella, Bacteroides, Streptococcus, Selenomonas and Veillonella. In the elderly group, Prevotella, Bacteroides, Streptococcus, Selenomonas and Haemophilus were the top 5 in abundance, and there were significant difference in Fusobacterium between the two groups (Q=0.938, P<0.05). PICRUSt function prediction showed that the abundance of Aminoacyl.tRNA.biosynthesis, Nucleotide.excision.repair, RNA.polymerase, Ribosome, Clavulanic.acid.biosynthesis, Photosynthesis and Photosynthesis. proteins in the elderly group were lower than those in the young and middle-aged group (all Q=0.734, P<0.05). Conclusion: There is no significant difference in α-diversity and ß-diversity between elderly ESCC patients and young and middle-aged patients, but the abundance of Fusobacterium flora increased.