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This study sought to analyze the main antibacterial active components of Lactobacillus pentosus (L. pentosus) L-36 cell-free culture supernatants (CFCS) in inhibiting the growth of Staphylococcus aureus (S. aureus), to explore its physicochemical properties and anti-bacterial mechanism. Firstly, the main antibacterial active substance in L-36 CFCS was peptides, which inferred by adjusting pH and enzyme treatment methods. Secondly, the physicochemical properties of the antibacterial active substances in L-36 CFCS were studied from heat, pH, and metal ions, respectively. It demonstrated good antibacterial activity when heated at 65 °C, 85 °C and 100 °C for 10 and 30 min, indicating that it had strong thermal stability. L-36 CFCS had antibacterial activity when the pH value was 2–6, and the antibacterial active substances became stable with the decrease in pH value. After 10 kinds of metal ions were treated, the antibacterial activity did not change significantly, indicating that it was insensitive to metal ions. Finally, scanning electron microscopy, transmission electron microscopy and fluorescence probe were used to reveal the antibacterial mechanism of S. aureus from the aspects of cell morphology and subcellular structure. The results demonstrated that L-36 CFCS could form 1.4–2.3 nm pores in the cell membrane of S. aureus, which increased the permeability of the bacterial cell membrane, resulting in the depolarization of cell membrane potential and leakage of nucleic acid protein and other cell contents. Meanwhile, a large number of ROS are produced and accumulated in the cells, causing damage to DNA, and with the increase in L-36 CFCS concentration, the effect is enhanced, and finally leads to the death of S. aureus. Our study suggests that the main antibacterial active substances of L-36 CFCS are peptides. L-36 CFCS are thermostable, active under acidic conditions, insensitive to metal ions, and exhibit antibacterial effects by damaging cell membranes, DNA and increasing ROS. Using lactic acid bacteria to inhibit S. aureus provides a theoretical basis for the discovery of new antibacterial substances, and will have great significance in the development of antibiotic substitutes, reducing bacterial resistance and ensuring animal food safety.

We study a substantially generalized version of the equation on nonlinear monomial differential equations, and obtain two-sided inequalities for the growth of entire solutions. We also study the Fermat-type differential equation with two exponential terms, and obtain almost all of the entire solutions.

Methane (CH4) is an important greenhouse as well as a chemically active gas. Accurate monitoring and understanding of its spatiotemporal distribution are crucial for effective mitigation strategies. Nowadays, satellite measurements are widely used for CH4 studies. Here, we use the CH4 products from four commonly used satellites (GOSAT, TROPOMI, ARIS, and IASI) during the period from 2018 to 2020 to investigate the spatiotemporal variations of CH4 in China. In spite of the same target (CH4) for the four satellites, differences among them exist in terms of the instrument, spectrum, and retrieval algorithm. The GOSAT and TROPOMI CH4 retrievals use shortwave infrared spectra, with a better sensitivity near the surface, while the IASI and AIRS CH4 retrievals use thermal infrared spectra, showing a good sensitivity in the mid–upper troposphere but a weak sensitivity in the lower troposphere. The GOSAT and TROPOMI observe high CH4 concentrations in the east and south and low concentrations in the west and north, which is highly related to the CH4 emissions. The IASI and AIRS show a more uniform CH4 distribution over China, which reflects the variation of CH4 at a high altitude. However, a large discrepancy is observed between the IASI and AIRS despite using a similar retrieval band, e.g., significant differences in the seasonal variations of CH4 are observed between the IASI and AIRS across several regions in China. This study highlights the CH4 differences observed by the four satellites in China, and caution must be taken when using these satellite products.

Pleckstrin-2 is a member of pleckstrin family with well-defined structural features that was first identified in 1999. Over the past 20 years, our understanding of PLEK2 biology has been limited to cell spreading. Recently, increasing evidences support that PLEK2 plays important roles in other cellular events beyond cell spreading, such as erythropoiesis, tumorigenesis and metastasis. It serves as a potential diagnostic and prognostic biomarker as well as an attractive target for the treatment of cancers. Herein, we summary the protein structure and molecular interactions of pleckstrin-2, with an emphasis on its regulatory roles in tumorigenesis.

Methane (CH 4 ) is one of the most important greenhouse gases in the atmosphere, making it worthwhile to study its temporal and vertical distributions in source areas, e.g., North China. For this purpose, a ground-based high-resolution Fourier transform infrared spectrometer (FTIR), the Bruker IFS 125HR, along with an in-situ instrument, the Picarro G2301, were deployed in Xianghe County (39.8°N,117.0°E), Hebei Province, China. Data have been recorded since June 2018. For the FTIR measurements, we used two observation modes to retrieve the mole fraction of CH 4 : the Total Carbon Column Observing Network (TCCON) method (retrieval algorithm: GGG2014), and the Network for the Detection of Atmospheric Composition Change (NDACC) method (retrieval algorithm: SFIT4). Combining FTIR with in-situ measurements, we found the temporal and vertical distributions of atmospheric CH 4 within three vertical layers (near the ground, in the troposphere, and in the stratosphere), and throughout the whole atmosphere. Regarding the diurnal variation of CH 4 near the ground, the concentration at night was higher than during the daytime. Regarding the seasonal variation, CH 4 was low in spring and high in summer, for all three vertical layers. In addition, there was a peak of CH 4 in winter near the ground, both in the troposphere and the whole atmosphere. We found that variation of CH 4 in the tropospheric column was close to that of the in-situ measurements near the ground. Furthermore, the variations of CH 4 in the stratospheric column could be influenced by vertical motions, since it was higher in summer and lower in winter.

Terahertz imaging technology has shown great potential in many fields. As the core component of terahertz imaging systems, terahertz detectors have received extensive attention. In this paper, a metasurface-based terahertz optomechanical detector is proposed, which is made of two fabrication-friendly materials: gold and silicon nitride. The optomechanical detector is essentially a thermal detector composed of metasurface absorber, bi-material micro-cantilevers and heat insulation pillars. Compared with traditional thermal terahertz detectors, the optomechanical detector employs a metasurface absorber as the terahertz radiation coupler and obtains an absorptivity higher than 90% from 3.24 to 3.98 THz, which is much higher than that of traditional terahertz detectors with absorbers made from natural materials. Furthermore, the detector is fabricated by MEMS process and its responsivity has been verified by a specifically designed optical read-out system; the measured optomechanical responsivity is 24.8 μm/μW, which agrees well with the multi-physics simulation. These results indicated that the detector can be employed as a pixel to form a terahertz focal plane array in the future, and further realize real-time terahertz imaging at room temperature.

This study sought to analyze the main antibacterial active components of Lactobacillus pentosus (L. pentosus) L-36 cell-free culture supernatants (CFCS) in inhibiting the growth of Staphylococcus aureus (S. aureus), to explore its physicochemical properties and anti-bacterial mechanism. Firstly, the main antibacterial active substance in L-36 CFCS was peptides, which inferred by adjusting pH and enzyme treatment methods. Secondly, the physicochemical properties of the antibacterial active substances in L-36 CFCS were studied from heat, pH, and metal ions, respectively. It demonstrated good antibacterial activity when heated at 65 °C, 85 °C and 100 °C for 10 and 30 min, indicating that it had strong thermal stability. L-36 CFCS had antibacterial activity when the pH value was 2–6, and the antibacterial active substances became stable with the decrease in pH value. After 10 kinds of metal ions were treated, the antibacterial activity did not change significantly, indicating that it was insensitive to metal ions. Finally, scanning electron microscopy, transmission electron microscopy and fluorescence probe were used to reveal the antibacterial mechanism of S. aureus from the aspects of cell morphology and subcellular structure. The results demonstrated that L-36 CFCS could form 1.4–2.3 nm pores in the cell membrane of S. aureus, which increased the permeability of the bacterial cell membrane, resulting in the depolarization of cell membrane potential and leakage of nucleic acid protein and other cell contents. Meanwhile, a large number of ROS are produced and accumulated in the cells, causing damage to DNA, and with the increase in L-36 CFCS concentration, the effect is enhanced, and finally leads to the death of S. aureus. Our study suggests that the main antibacterial active substances of L-36 CFCS are peptides. L-36 CFCS are thermostable, active under acidic conditions, insensitive to metal ions, and exhibit antibacterial effects by damaging cell membranes, DNA and increasing ROS. Using lactic acid bacteria to inhibit S. aureus provides a theoretical basis for the discovery of new antibacterial substances, and will have great significance in the development of antibiotic substitutes, reducing bacterial resistance and ensuring animal food safety.

A comparative study was carried out to explore carbon monoxide total columnar amount (CO TC) in background and polluted atmosphere, including the stations of ZSS (Zvenigorod), ZOTTO (Central Siberia), Peterhof, Beijing, and Moscow, during 1998–2014, on the basis of ground- and satellite-based spectroscopic measurements. Interannual variations of CO TC in different regions of Eurasia were obtained from ground-based spectroscopic observations, combined with satellite data from the sensors MOPITT (2001–14), AIRS (2003–14), and IASI MetOp-A (2010–13). A decreasing trend in CO TC (1998–2014) was found at the urban site of Beijing, where CO TC decreased by 1.14%±0.87% yr −1 . Meanwhile, at the Moscow site, CO TC decreased remarkably by 3.73%±0.39% yr −1 . In the background regions (ZSS, ZOTTO, Peterhof), the reduction was 0.9%–1.7% yr −1 during the same period. Based on the AIRSv6 satellite data for the period 2003–14, a slight decrease (0.4%–0.6% yr −1 ) of CO TC was detected over the midlatitudes of Eurasia, while a reduction of 0.9%–1.2% yr −1 was found in Southeast Asia. The degree of correlation between the CO TC derived from satellite products (MOPITTv6 Joint, AIRSv6 and IASI MetOp-A) and ground-based measurements was calculated, revealing significant correlation in unpolluted regions. While in polluted areas, IASI MetOp-A and AIRSv6 data underestimated CO TC by a factor of 1.5–2.8. On average, the correlation coefficient between ground- and satellite-based data increased significantly for cases with PBL heights greater than 500 m.

Unverified β-lactam allergy labels (BALs) pose a considerable barrier to optimal antimicrobial treatment and represent a growing public health concern. However, no comprehensive meta-analysis has been conducted to explore the associations between BALs and clinical outcomes. We aimed to evaluate existing evidence on the clinical outcomes associated with BALs to determine their global burden. In this systematic review and meta-analysis, we searched PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL), and Embase from Jan 1, 2000, to Nov 30, 2024. We included observational and interventional studies that compared clinical outcomes related to the presence or absence of a BAL (as reported or documented in any clinical record), irrespective of patient age or clinical setting. The outcomes assessed included the incidence of surgical site infections, the incidence of infections or colonisation due to multidrug-resistant organisms (MDROs) or Clostridioides difficile, mortality, and length of hospital stay. Pooled estimates were calculated using random-effects models, with subgroup analyses conducted by region, country income level, type of BAL, hospital setting, sample size, age group, and quality of evidence. Publication bias was assessed using Begg's funnel plots and Egger's regression test. This study is registered with PROSPERO (CRD42023484030). 63 studies were included in this systematic review, of which 60 (95%) were from high-income countries. Studies were done in the Americas (41 [65%]), Europe (15 [24%]), and the Western Pacific region (seven [11%]). Seven studies were of moderate quality and none were classified as low quality. No significant publication bias was detected for most outcomes, except for length of hospital stay (p=0·0062). Overall, BALs were associated with increased rates of surgical site infection (OR 1·60, 95% CI 1·27–2·01; p<0·0001; I2=70·3%), rates of infection or colonisation with both MDROs (1·42, 1·22–1·64; p<0·0001; I2=84·4%) and C difficile (1·26, 1·16–1·37; p<0·0001; I2=56·4%), and length of hospital stay (standardised mean difference 0·06 days, 95% CI 0·05–0·08; p<0·0001; I2=86·1%). BALs were also associated with death at or after 180 days but not with overall, in-hospital, or 30-day mortality. BALs are associated with an array of adverse health outcomes, especially surgical site infection and infection or colonisation with MDROs and C difficile. Although BALs were associated with longer hospital stays, the observed difference was unlikely to be clinically relevant. The heterogeneity and methodological limitations of the included studies could limit the robustness of some of our conclusions. However, these findings underscore the need to develop and evaluate public health initiatives to curb inaccurate allergy labelling, thereby reducing unnecessary avoidance of first-line β-lactam antibiotics. National Natural Science Foundation of China.