[Study on revision of standard limits for benzene in"Standards for indoor air quality（GB/T 18883-2022）"in China].

Benzene, as a major indoor pollutant, has received widespread attention. In order to better control indoor benzene pollution and protect people's health, the limit value of benzene in the"Standards for indoor air quality (GB/T 18883-2022)'' was reduced from 0.11 mg/m3 to 0.03 mg/m3. This study reviewed and discussed the relevant technical contents of the determination of benzene limit value, including the exposure status of benzene, health effects, and derivation of the limit value. It also proposed prospects for the future direction of formulating indoor air benzene standards.

Temporal Structures in Positron Spectra and Charge-Sign Effects in Galactic Cosmic Rays.

We present the precision measurements of 11 years of daily cosmic positron fluxes in the rigidity range from 1.00 to 41.9 GV based on 3.4×10^{6} positrons collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. The positron fluxes show distinctly different time variations from the electron fluxes at short and long timescales. A hysteresis between the electron fluxes and the positron fluxes is observed with a significance greater than 5σ at rigidities below 8.5 GV. On the contrary, the positron fluxes and the proton fluxes show similar time variation. Remarkably, we found that positron fluxes are modulated more than proton fluxes with a significance greater than 5σ for rigidities below 7 GV. These continuous daily positron fluxes, together with AMS daily electron, proton, and helium fluxes over an 11-year solar cycle, provide unique input to the understanding of both the charge-sign and mass dependencies of cosmic rays in the heliosphere.

Properties of Cosmic-Ray Sulfur and Determination of the Composition of Primary Cosmic-Ray Carbon, Neon, Magnesium, and Sulfur: Ten-Year Results from the Alpha Magnetic Spectrometer.

We report the properties of primary cosmic-ray sulfur (S) in the rigidity range 2.15 GV to 3.0 TV based on 0.38×10^{6} sulfur nuclei collected by the Alpha Magnetic Spectrometer experiment (AMS). We observed that above 90 GV the rigidity dependence of the S flux is identical to the rigidity dependence of Ne-Mg-Si fluxes, which is different from the rigidity dependence of the He-C-O-Fe fluxes. We found that, similar to N, Na, and Al cosmic rays, over the entire rigidity range, the traditional primary cosmic rays S, Ne, Mg, and C all have sizeable secondary components, and the S, Ne, and Mg fluxes are well described by the weighted sum of the primary silicon flux and the secondary fluorine flux, and the C flux is well described by the weighted sum of the primary oxygen flux and the secondary boron flux. The primary and secondary contributions of the traditional primary cosmic-ray fluxes of C, Ne, Mg, and S (even Z elements) are distinctly different from the primary and secondary contributions of the N, Na, and Al (odd Z elements) fluxes. The abundance ratio at the source for S/Si is 0.167±0.006, for Ne/Si is 0.833±0.025, for Mg/Si is 0.994±0.029, and for C/O is 0.836±0.025. These values are determined independent of cosmic-ray propagation.

Temporal Structures in Electron Spectra and Charge Sign Effects in Galactic Cosmic Rays.

We present the precision measurements of 11 years of daily cosmic electron fluxes in the rigidity interval from 1.00 to 41.9 GV based on 2.0×10^{8} electrons collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. The electron fluxes exhibit variations on multiple timescales. Recurrent electron flux variations with periods of 27 days, 13.5 days, and 9 days are observed. We find that the electron fluxes show distinctly different time variations from the proton fluxes. Remarkably, a hysteresis between the electron flux and the proton flux is observed with a significance of greater than 6σ at rigidities below 8.5 GV. Furthermore, significant structures in the electron-proton hysteresis are observed corresponding to sharp structures in both fluxes. This continuous daily electron data provide unique input to the understanding of the charge sign dependence of cosmic rays over an 11-year solar cycle.

[Effectiveness of a whole-process health education model among inpatients with ascites type of advanced schistosomiasis].

OBJECTIVE: To evaluate the effectiveness of a whole-process health education model among inpatients with ascites type of advanced schistosomiasis. METHODS: A "admission-hospitalization-discharge" whole-process health education model was created, 101 inpatients with ascites type of advanced schistosomiasis were given the whole-process health education. The scores of schistosomiasis control knowledge, attitudes towards schistosomiasis control and healthy behaviors, and awareness of schistosomiasis control knowledge, correct rate of attitudes towards schistosomiasis control and correct rate of healthy behaviors were compared among inpatients with ascites type of advanced schistosomiasis before and after implementation of the whole-process health education. RESULTS: The scores of schistosomiasis control knowledge, schistosomiasis control attitudes and healthy behaviors were all significantly higher among inpatients with ascites type of advanced schistosomiasis after implementation of the whole-process health education than before implementation (Z = -7.688, -3.576 and -4.328, all P values < 0.01). In addition, the awareness of schistosomiasis control knowledge increased from 54.3% to 82.7% (χ2 = 188.886, P < 0.01), and the correct rate of attitudes towards schistosomiasis control increased from 88.4% to 98.0% (χ2 = 22.001, P < 0.01), while the correct rate of healthy behaviors increased from 48.2% to 59.7% (χ2 = 11.767, P < 0.01). CONCLUSIONS: The whole-process health education model may remarkably improve the awareness of schistosomiasis control knowledge and promote the formation of positive attitudes towards schistosomiasis control and correct behaviors among inpatients with ascites type of advanced schistosomiasis, which is of great significance to facilitate patients' cure.

Shared genetic architecture between type 2 diabetes and COVID-19 severity.

PURPOSE: Patients with type 2 diabetes (T2D) have demonstrated a higher risk for developing more severe cases of COVID-19, but the complex genetic mechanism between them is still unknown. The aim of the present study was to untangle this relationship using genetically based approaches. METHODS: By leveraging large-scale genome-wide association study (GWAS) summary statistics of T2D and COVID-19 severity, linkage disequilibrium score regression and Mendelian randomization (MR) analyses were utilized to quantify the genetic correlations and causal relationships between the two traits. Gene-based association and enrichment analysis were further applied to identify putative functional pathways shared between T2D and COVID-19 severity. RESULTS: Significant, moderate genetic correlations were detected between T2D and COVID-19 hospitalization (rg = 0.156, SE = 0.057, p = 0.005) or severe disease (rg = 0.155, SE = 0.057, p = 0.006). MR analysis did not support evidence for a causal effect of T2D on COVID-19 hospitalization (OR 1.030, 95% CI 0.979, 1.084, p = 0.259) or severe disease (OR 0.999, 95% CI 0.934, 1.069, p = 0.982). Genes having pgene < 0.05 for both T2D and COVID-19 severe were significantly enriched for biological pathways, such as response to type I interferon, glutathione derivative metabolic process and glutathione derivative biosynthetic process. CONCLUSIONS: Our findings further confirm the comorbidity of T2D and COVID-19 severity, but a non-causal impact of T2D on severe COVID-19. Shared genetically modulated molecular mechanisms underlying the co-occurrence of the two disorders are crucial for identifying therapeutic targets.

Properties of Daily Helium Fluxes.

We present the precision measurement of 2824 daily helium fluxes in cosmic rays from May 20, 2011 to October 29, 2019 in the rigidity interval from 1.71 to 100 GV based on 7.6×10^{8} helium nuclei collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. The helium flux and the helium to proton flux ratio exhibit variations on multiple timescales. In nearly all the time intervals from 2014 to 2018, we observed recurrent helium flux variations with a period of 27 days. Shorter periods of 9 days and 13.5 days are observed in 2016. The strength of all three periodicities changes with time and rigidity. In the entire time period, we found that below ∼7 GV the helium flux exhibits larger time variations than the proton flux, and above ∼7 GV the helium to proton flux ratio is time independent. Remarkably, below 2.4 GV a hysteresis between the helium to proton flux ratio and the helium flux was observed at greater than the 7σ level. This shows that at low rigidity the modulation of the helium to proton flux ratio is different before and after the solar maximum in 2014.

[Course of disease and related epidemiological parameters of COVID-19: a prospective study based on contact tracing cohort].

Objective: To analyze the course of disease and epidemiological parameters of COVID-19 and provide evidence for making prevention and control strategies. Methods: To display the distribution of course of disease of the infectors who had close contacts with COVID-19 cases from January 1 to March 15, 2020 in Guangdong Provincial, the models of Lognormal, Weibull and gamma distribution were applied. A descriptive analysis was conducted on the basic characteristics and epidemiological parameters of course of disease. Results: In total, 515 of 11 580 close contacts were infected, with an attack rate about 4.4%, including 449 confirmed cases and 66 asymptomatic cases. Lognormal distribution was fitting best for latent period, incubation period, pre-symptomatic infection period of confirmed cases and infection period of asymptomatic cases; Gamma distribution was fitting best for infectious period and clinical symptom period of confirmed cases; Weibull distribution was fitting best for latent period of asymptomatic cases. The latent period, incubation period, pre-symptomatic infection period, infectious period and clinical symptoms period of confirmed cases were 4.50 (95%CI:3.86-5.13) days, 5.12 (95%CI:4.63-5.62) days, 0.87 (95%CI:0.67-1.07) days, 11.89 (95%CI:9.81-13.98) days and 22.00 (95%CI:21.24-22.77) days, respectively. The latent period and infectious period of asymptomatic cases were 8.88 (95%CI:6.89-10.86) days and 6.18 (95%CI:1.89-10.47) days, respectively. Conclusion: The estimated course of COVID-19 and related epidemiological parameters are similar to the existing data.

Erratum: Properties of a New Group of Cosmic Nuclei: Results from the Alpha Magnetic Spectrometer on Sodium, Aluminum, and Nitrogen [Phys. Rev. Lett. 127, 021101 (2021)].

This corrects the article DOI: 10.1103/PhysRevLett.127.021101.

Properties of a New Group of Cosmic Nuclei: Results from the Alpha Magnetic Spectrometer on Sodium, Aluminum, and Nitrogen.

We report the properties of sodium (Na) and aluminum (Al) cosmic rays in the rigidity range 2.15 GV to 3.0 TV based on 0.46 million sodium and 0.51 million aluminum nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. We found that Na and Al, together with nitrogen (N), belong to a distinct cosmic ray group. In this group, we observe that, similar to the N flux, both the Na flux and Al flux are well described by the sums of a primary cosmic ray component (proportional to the silicon flux) and a secondary cosmic ray component (proportional to the fluorine flux). The fraction of the primary component increases with rigidity for the N, Na, and Al fluxes and becomes dominant at the highest rigidities. The Na/Si and Al/Si abundance ratios at the source, 0.036±0.003 for Na/Si and 0.103±0.004 for Al/Si, are determined independent of cosmic ray propagation.

Properties of Heavy Secondary Fluorine Cosmic Rays: Results from the Alpha Magnetic Spectrometer.

Precise knowledge of the charge and rigidity dependence of the secondary cosmic ray fluxes and the secondary-to-primary flux ratios is essential in the understanding of cosmic ray propagation. We report the properties of heavy secondary cosmic ray fluorine F in the rigidity R range 2.15 GV to 2.9 TV based on 0.29 million events collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. The fluorine spectrum deviates from a single power law above 200 GV. The heavier secondary-to-primary F/Si flux ratio rigidity dependence is distinctly different from the lighter B/O (or B/C) rigidity dependence. In particular, above 10 GV, the F/Si/B/O ratio can be described by a power law R^{δ} with δ=0.052±0.007. This shows that the propagation properties of heavy cosmic rays, from F to Si, are different from those of light cosmic rays, from He to O, and that the secondary cosmic rays have two classes.

Properties of Iron Primary Cosmic Rays: Results from the Alpha Magnetic Spectrometer.

We report the observation of new properties of primary iron (Fe) cosmic rays in the rigidity range 2.65 GV to 3.0 TV with 0.62×10^{6} iron nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. Above 80.5 GV the rigidity dependence of the cosmic ray Fe flux is identical to the rigidity dependence of the primary cosmic ray He, C, and O fluxes, with the Fe/O flux ratio being constant at 0.155±0.006. This shows that unexpectedly Fe and He, C, and O belong to the same class of primary cosmic rays which is different from the primary cosmic rays Ne, Mg, and Si class.

Periodicities in the Daily Proton Fluxes from 2011 to 2019 Measured by the Alpha Magnetic Spectrometer on the International Space Station from 1 to 100 GV.

We present the precision measurement of the daily proton fluxes in cosmic rays from May 20, 2011 to October 29, 2019 (a total of 2824 days or 114 Bartels rotations) in the rigidity interval from 1 to 100 GV based on 5.5×10^{9} protons collected with the Alpha Magnetic Spectrometer aboard the International Space Station. The proton fluxes exhibit variations on multiple timescales. From 2014 to 2018, we observed recurrent flux variations with a period of 27 days. Shorter periods of 9 days and 13.5 days are observed in 2016. The strength of all three periodicities changes with time and rigidity. The rigidity dependence of the 27-day periodicity is different from the rigidity dependences of 9-day and 13.5-day periods. Unexpectedly, the strength of 9-day and 13.5-day periodicities increases with increasing rigidities up to ∼10 GV and ∼20 GV, respectively. Then the strength of the periodicities decreases with increasing rigidity up to 100 GV.

Properties of Neon, Magnesium, and Silicon Primary Cosmic Rays Results from the Alpha Magnetic Spectrometer.

We report the observation of new properties of primary cosmic rays, neon (Ne), magnesium (Mg), and silicon (Si), measured in the rigidity range 2.15 GV to 3.0 TV with 1.8×10^{6} Ne, 2.2×10^{6} Mg, and 1.6×10^{6} Si nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. The Ne and Mg spectra have identical rigidity dependence above 3.65 GV. The three spectra have identical rigidity dependence above 86.5 GV, deviate from a single power law above 200 GV, and harden in an identical way. Unexpectedly, above 86.5 GV the rigidity dependence of primary cosmic rays Ne, Mg, and Si spectra is different from the rigidity dependence of primary cosmic rays He, C, and O. This shows that the Ne, Mg, and Si and He, C, and O are two different classes of primary cosmic rays.

MicroRNA-140's inhibition on the cell migration and invasion of non-small cell lung cancer by down-regulating Smad3 expression.

OBJECTIVE: To investigate the effect of miR-140 on migration and invasion of non-small cell lung cancer (NSCLC) A549 cell and its regulatory mechanism. MATERIALS AND METHODS: The NSCLC cell lines A549, H1650, NCI-H838, and normal lung epithelial cells BEAS-2B were purchased, and the expression of miR-140 and Smad3 in cells was detected by RT-PCR. MiR-140-inhibitor, miR-140-mimincs, miR-NC, sh-Smad3, Si-Smad3, and NC were transfected into A549 cells. Quantitative Real Time-Polymerase Chain Reaction (QRT-PCR) was used to detect the expression of miR-140 and Smad3. Transwell and cell scratch assay were used to detect cell invasion and migration. Dual-Luciferase report assay was used to study the relationship between mir-140 and Smad3. RESULTS: MiR-140 was lowly expressed and Smad3 was highly expressed in NSCLC cells. Cell researches showed that the overexpression of miR-140 can inhibit cell invasion and migration. The downregulation of Smad3 expression inhibits cell invasion and migration. Dual-Luciferase reporter assay showed that miR-140 is a Smad3 targeting site. CONCLUSIONS: MiR-140 can inhibit the invasion and migration of NSCLC cells by regulating Smad3, and it is expected to become a potential clinical target.

[Amplitude of low-frequency fluctuations of resting-state functional MRI in colorectal cancer patients with depression].

Objective: To investigate the alterations of the cerebral resting-state spontaneous neural activity in colorectal cancer patients with depressive symptoms. Methods: Thirty-three colorectal cancer patients (patient group) with depression and 43 healthy subjects (control group) underwent the resting state functional magnetic resonance imaging (rs-fMRI). The amplitude of low-frequency fluctuations (ALFF) and fractional ALFF (fALFF) were calculated. Two independent samples t test were used to compare the ALFF and fALFF values between two groups by DPABI software, and then correlation analysis was performed between ALFF and fALFF with statistical significance and Patient Health Questionnaire (PHQ-9) scores and Generalized Anxiety Disorder (GAD-7) scores. Results: Compared with the control group, the patient group showed significantly lower ALFF and fALFF values in the bilateral precuneus, calcarine gyrus, lingual gyrus, left cuneus, superior, middle, inferior occipital gyrus and right fusiform gyrus (t=-5.730, P<0.05; t=-4.872, P<0.05). There were no significant correlations between the ALFF and fALFF values in these regions and PHQ-9 or GAD-7 scores (P>0.05). Conclusion: Spontaneous decrease of neural activity in occipital and parietal lobes exists in colorectal cancer patients with depression at resting-sate, which may be a potential neurobiological marker.

Properties of Cosmic Helium Isotopes Measured by the Alpha Magnetic Spectrometer.

Precision measurements by the Alpha Magnetic Spectrometer (AMS) on the International Space Station of ^{3}He and ^{4}He fluxes are presented. The measurements are based on 100 million ^{4}He nuclei in the rigidity range from 2.1 to 21 GV and 18 million ^{3}He from 1.9 to 15 GV collected from May 2011 to November 2017. We observed that the ^{3}He and ^{4}He fluxes exhibit nearly identical variations with time. The relative magnitude of the variations decreases with increasing rigidity. The rigidity dependence of the ^{3}He/^{4}He flux ratio is measured for the first time. Below 4 GV, the ^{3}He/^{4}He flux ratio was found to have a significant long-term time dependence. Above 4 GV, the ^{3}He/^{4}He flux ratio was found to be time independent, and its rigidity dependence is well described by a single power law ∝R^{Δ} with Δ=-0.294±0.004. Unexpectedly, this value is in agreement with the B/O and B/C spectral indices at high energies.

[Pelvic floor function of 5 143 women in early postpartum stage and analysis on the effect factors].

Objective: To describe the situation of early stage of pelvic floor function and investigate the effect factors in postpartum women. Methods: A retrospective survey was conducted, and women who did regular examination and gave birth in Peking University People's Hospital and had an annual pelvic floor examination at 6-12 weeks after delivery from Sep. 2012 to Dec. 2017 were interviewed. General information and pelvic floor electrical physiological indexes were collected and analyzed. Results: Totally 5 143 puerpera were included in the study. The normal strength of type Ⅰ muscle was 52.40% (2 695/5 143) and the normal strength of type Ⅱ muscle was 52.69% (2 710/5 143). The abnormal degree of fatigue of type Ⅰ muscle was 55.84% (2 872/5 143) and the abnormal degree of fatigue of typeⅡmuscle was 27.34% (1 406/5 143). Pelvic floor dynamic pressure was (93±37) cmH(2)O (1 cmH(2)O=0.098 kPa). The incidence of stress urinary incontinence (SUI) was 23.49% (1 208/5 143) after delivery and it was as high as 57.58% (95/165) for women who had family history of pelvic floor dysfunction. Family history of pelvic floor dysfunction was the risk factor of the fatigue index of type Ⅰ and type Ⅱ muscle (P<0.05). The incidence of SUI was associated with vaginal delivery and age (≥30 years old) and family history of pelvic floor dysfunction (P<0.01). Conclusions: Pelvic floor electrical physiological indicators are reduced in about half of women in early postpartum stage. Age (≥30 years old) and vaginal delivery and family history of pelvic floor dysfunction are the risk factors.

Towards Understanding the Origin of Cosmic-Ray Electrons.

Precision results on cosmic-ray electrons are presented in the energy range from 0.5 GeV to 1.4 TeV based on 28.1×10^{6} electrons collected by the Alpha Magnetic Spectrometer on the International Space Station. In the entire energy range the electron and positron spectra have distinctly different magnitudes and energy dependences. The electron flux exhibits a significant excess starting from 42.1_{-5.2}^{+5.4} GeV compared to the lower energy trends, but the nature of this excess is different from the positron flux excess above 25.2±1.8 GeV. Contrary to the positron flux, which has an exponential energy cutoff of 810_{-180}^{+310} GeV, at the 5σ level the electron flux does not have an energy cutoff below 1.9 TeV. In the entire energy range the electron flux is well described by the sum of two power law components. The different behavior of the cosmic-ray electrons and positrons measured by the Alpha Magnetic Spectrometer is clear evidence that most high energy electrons originate from different sources than high energy positrons.

Towards Understanding the Origin of Cosmic-Ray Positrons.

Precision measurements of cosmic ray positrons are presented up to 1 TeV based on 1.9 million positrons collected by the Alpha Magnetic Spectrometer on the International Space Station. The positron flux exhibits complex energy dependence. Its distinctive properties are (a) a significant excess starting from 25.2±1.8 GeV compared to the lower-energy, power-law trend, (b) a sharp dropoff above 284_{-64}^{+91} GeV, (c) in the entire energy range the positron flux is well described by the sum of a term associated with the positrons produced in the collision of cosmic rays, which dominates at low energies, and a new source term of positrons, which dominates at high energies, and (d) a finite energy cutoff of the source term of E_{s}=810_{-180}^{+310} GeV is established with a significance of more than 4σ. These experimental data on cosmic ray positrons show that, at high energies, they predominantly originate either from dark matter annihilation or from other astrophysical sources.