Biogeochemical factors regulating photosynthetically dissolved organic carbon produced by phytoplankton in the Taiwan Strait.

The distribution and mechanisms of photosynthetically dissolved organic carbon (PDOC) released by marine phytoplankton are frequently neglected and inadequately understood because most studies on carbon sequestration capacity have focused on photosynthetic particulate organic carbon. In this study, percentage extracellular release (PER) and its environmental influencing factors were investigated for 10 cruises in the Taiwan Strait during 2006-2023. The results indicated that the PER increased horizontally from the nearshore to the off-shelf and vertically from the surface to the bottom within the euphotic zone. PER tends to be low in eutrophic waters such as upwellings and estuaries and high in oligotrophic waters. The study revealed that the average contribution of PDOC to total primary productivity (TPP) in the Taiwan Strait could reach 18.2 ± 11.7%, which is similar to the previously estimated global oceanic values. PDOC production satisfied approximately 25% the carbon requirements of heterotropic bacteria (HB). A detailed analysis of the PER combined with model simulations proved that the distribution of the PER in the Taiwan Strait was caused by the joint contribution of irradiance, size-fractionated phytoplankton, and nutrient stoichiometry. Our results contradict the view that the PER is a constant factor that is unaffected by TPP. However, there was a significant negative correlation between the PER and TPP. The PDOC was always lower than the bacterial carbon demand for a broad range of bacterial growth efficiencies, suggesting a weak coupling between phytoplankton exudation and bacterial metabolism. This challenges the idea that there is a well-coupled relationship between bacteria and phytoplankton present on the continental shelf. These findings indicate significant discrepancies in PDOC mechanisms and the quantitative importance of nearshore eutrophic and off-shelf oligotrophic environments. Consequently, it is unwise to use uniform PERs without differentiation under trophic conditions when reevaluating and appraising marine carbon fixation.

The impact of two dietary patterns on hyperuricemia in adults: A meta analysis of observational studies.

BACKGROUND: Hyperuricemia (HUA) is a crucial factor contributing to some chronic diseases among adults. In past observational literatures, scholars have debated the effectiveness of dietary pattern on HUA and inconsistencies exist. Given this condition, the study aimed to provide a comparative assessment of the relation between dietary pattern and HUA risk and offer implications to policy makers. METHODS: A systematic research was undertaken in PubMed, Web of Science, Cochrane, Embase, Medicine, ScienceDirect and Medline to identify observational studies examining the effect of dietary pattern on HUA, and search period was from past to January 2022. Meta analysis was applied by using the Stata version 11.0 software. RESULTS: A total of 34,583 adults from 8 observational studies, 45,525 adults from 6 observational studies were included to examine the effectiveness of "healthy" and "meat/western" dietary patterns on HUA risk respectively. The findings suggested that "healthy" dietary pattern significantly decreased the HUA risk (OR = 0.73; 95% CI: 0.61-0.88) both in Eastern countries (OR = 0.79; 95% CI: 0.64-0.98) and Western countries (OR = 0.53; 95% CI: 0.30-0.92) while the "Meat/Western" pattern increased the HUA possibilities (OR = 1.26; 95% CI: 1.17-1.37). Stratified analysis exhibited that "healthy" pattern reduced HUA risk in adults was more effective in cohort study (OR = 0.79; 95% CI: 0.72-0.86). CONCLUSIONS: This study's findings highlighted the potential benefit of healthy dietary pattern in decreasing HUA risk. Accordingly, implementing policy makers of countries should enhance to appeal adults to keep a healthy diet, offer financial support to low-income staff, or provide guidelines for adult's dietary behavior changes. TRIAL REGISTRATION NUMBER: INPLASY: INPLASY202290034.

[Clinical characteristics and pathogens of infancy lower respiratory tract infections in infants with bronchopulmonary dysplasia]. / æ”¯æ°”ç®¡è‚ºå‘è‚²ä¸è‰¯æ‚£å„¿å©´å„¿æœŸä¸‹å‘¼å¸é“æ„ŸæŸ“çš„ä¸´åºŠç‰¹å¾åŠç— åŽŸå­¦åˆ†æž.

OBJECTIVES: To study the clinical characteristics and pathogen features of infants with bronchopulmonary dysplasia (BPD) who were readmitted during infancy due to lower respiratory tract infections. METHODS: A retrospective analysis was conducted on 128 preterm infants with BPD who were admitted for lower respiratory tract infections in Qingdao Women and Children's Hospital from January 2020 to December 2022. An equal number of non-BPD preterm infants admitted during the same period were selected as controls. General information, clinical characteristics, lung function parameters, and respiratory pathogen results were compared between the two groups. RESULTS: Compared with the non-BPD group, the BPD group had a lower gestational age and birth weight, were more likely to experience shortness of breath, wheezing, and cyanosis, and had a longer duration of wheezing relief (P<0.05). Compared with the non-BPD group, the BPD group had lower lung function parameters, including tidal volume per kilogram of body weight, ratio of time to peak tidal expiratory flow to total expiratory time, ratio of volume at peak tidal expiratory flow to expiratory tidal volume, tidal expiratory flow at 25%, 50%, and 75% of tidal volume, and increased respiratory rate (P<0.05). The detection rates of gram-negative bacteria, such as Klebsiella pneumoniae and Acinetobacter baumannii, were higher in the BPD group than in the non-BPD group (P<0.05). CONCLUSIONS: Infants with BPD who develop infancy lower respiratory tract infections require closer attention to the clinical characteristics such as shortness of breath, wheezing, and cyanosis. Lung function is characterized by obstructive changes and small airway dysfunction. Gram-negative bacteria, including Klebsiella pneumoniae and Acinetobacter baumannii, are more likely to be detected as respiratory pathogens.

Process of overburden failure in steeply inclined multi-seam mining: insights from physical modelling.

Ground surface damage caused by steeply inclined coal seam mining is widely distributed in China, but there is little research on the failure process and movement mechanism of strata induced by steeply inclined multi-seam mining. In this paper, a physical model test is carried out to study the failure process and movement mechanism of overburden in steeply inclined multi-seam stepwise mining. The results show that at the initial stage, the main failure of the rock mass is the small-scale collapse at the initial cut and the roof (stability stage of the rock mass). After the roof is exposed over a certain range, the rock mass in the downhill direction slips into the goaf and gradually destroys the interburdens of the goaf, similar to the displacement effect of dominoes (severe failure stage of the rock mass). When the structure of the goaf fails, the overburden subsides, causing extensive damage to the ground surface. The surface damage directly above the goaf is mainly caused by serious subsidence deformation, while the surface damage in the downhill direction is dominated by cracks.

[Effect of peroxisome proliferator-activated receptor-gamma on proliferation of airway smooth muscle cells in mice with asthma].

OBJECTIVE: To investigate the effects of peroxisome proliferator-activated receptor-gamma (PPARγ) agonist rosiglitazone on the expression of cyclin D1 in lung tissue, and the proliferation of airway smooth muscle cells (ASMCs) in mice with bronchial asthma. METHODS: Thirty clean BALB/c mice were randomly divided into control group (n = 10), asthma group (n = 10), and rosiglitazone treatment group (n = 10). A mouse model of asthma was established by ovalbumin (OVA) sensitization and challenge. The treatment group received rosiglitazone (5 mg/kg) by gavage 1 hour before each challenge and the control group received saline instead of OVA sensitization and challenge. Leukocytes and eosinophils in bronchoalveolar lavage fluid (BALF) were counted under a microscope. Airway structural changes were observed by hematoxylin-eosin staining. Protein and mRNA expression levels of cyclin D1 were measured by immunohistochemical staining and RT-PCR. Perimeter of the basement membrane (Pbm), total bronchial wall area (WAt), airway smooth muscle area (WAm), and number of nuclei in ASMCs (N) were determined using image analysis software, and WAt/Pbm, WAm/Pbm, and N/Pbm were calculated. RESULTS: Compared with the control group, the asthma group showed significant increases in the total number of leukocytes and percentage of eosinophils in BALF, as well as in the mRNA and protein expression of cyclin D1, but changes in these indices were significantly reduced in the rosiglitazone treatment group (P < 0.05). In addition, compared with the control group, the asthma group had significantly increased WAt/Pbm, WAm/Pbm, and N/Pbm, but rosiglitazone significantly decreased these ratios (P < 0.05). CONCLISONS: Rosiglitazone may delay the process of airway remodeling by inhibiting the proliferation of ASMCs, so it can be used for preventing and treating chronic asthma.