Best Determined Position of Vents Based on Jet Cooling Model

In some data centers, cold air is required to act on the cabinet to achieve cooling requirements, and the mixing of cold air and hot air reduces the utilization efficiency of cold air. In order to solve this problem, a jet cooling model is established to solve the optimal position of the outlet through the movement of cold air

A review of air filtration technologies for sustainable and healthy building ventilation

Urbanization increased population density in cities and consequently leads to severe indoor air pollution. As a result of these trends, the issue of sustainable and healthy indoor environment has received increasing attention. Various air filtration techniques have been adopted to optimize indoor air quality. Air filtration technique can remove air pollutants and effectively alleviate the deterioration of indoor air quality. This paper presents a comprehensive review on the synergistic effect of different air purification technologies, air filtration theory, materials and standards. It evaluated different air filtration technologies by considering factors such as air quality improvement, filtering performance, energy and economic behaviour, thermal comfort and acoustic impact. Current research development of air filtration technologies along with their advantages, limitations and challenges are discussed. This paper aims to drive the future of air filtration technology research and development in achieving sustainable and healthy building ventilation

Inhibition of IRAK 1/4 alleviates colitis by inhibiting TLR4/ NF-κB pathway and protecting the intestinal barrier

Interleukin-1 receptor-associated kinase 1/4 (IRAK1/4) is the main kinase of the Toll-like receptor (TLR)-mediated pathway, considered a new target for treating inflammatory diseases. Studies showed a significant correlation between TLRs and inflammatory responses in ulcerative colitis (UC). Therefore, in this study, after inducing experimental colitis in mice with 3% dextran sulfate sodium (DSS), different concentrations of IRAK1/4 inhibitors were administered intraperitoneally. Then, the disease activity index was assessed, including the degree of pathological damage, by HE staining. Subsequently, while western blotting detected the TLR4/NF-κB pathway and intestinal barrier protein expression (Zonula-1, Occludin, Claudin-1, JAM-A), real-time polymerase chain reaction (RT-PCR) detected the mRNA expression levels of IRAK1/4 and mucin1/2. Furthermore, the expression levels of Zonula-1 and occludin were detected by immunofluorescence, including the plasma FITC-dextran 4000 concentration, to evaluate intestinal barrier permeability. However, ELISA measured the expression of inflammatory factors to reflect intestinal inflammation in mice. Investigations showed that the IRAK 1/4 inhibitor significantly reduced clinical symptoms and pathological DSS-induced colitis damage in mice and then inhibited the cytoplasmic and nuclear translocation of NF-κB p65, including the phosphorylation of IκBα and reduction in downstream inflammatory factor production. Therefore, we established that the IRAK1/4 inhibitor effectively improves colitis induced by DSS, partly by inhibiting the TLR4/NF-κB pathway, reducing inflammation, and maintaining the integrity of the colonic barrier

Experimental investigations of polymer hollow fibre heat exchangers for building heat recovery application

Due to low cost, light weight and corrosion resistant features, polymer heat exchangers have been extensively studied by researchers with the aim to replace metallic heat exchangers in a wide range of applications. Although the thermal conductivity of polymer material is generally lower than the metallic counterparts, the large specific surface area provided by the polymer hollow fibre heat exchanger (PHFHE) offers the same or even better heat transfer performance with smaller volume and lighter weight compared with the metallic shell-and-tube heat exchangers. This paper presents the construction and experimental investigations of polypropylene based polymer hollow fibre heat exchangers in the form of shell-and-tube. The measured overall heat transfer coefficients of such PHFHEs are in the range of 258–1675 W/m2K for water to water application. The effects of various parameters on the overall heat transfer coefficient including flow rates and numbers of fibres, the effectiveness of heat exchanger, the number of heat transfer unit (NTU), and the height of transfer unit (HTU) are also discussed in this paper. The results indicate that the PHFHEs could offer a conductance per unit volume of 4 × 106 W/m3K, which is 2–8 times higher than the conventional metal heat exchangers. This superior thermal performance together with its low cost, corrosive resistant and light weight features make PHFHEs potentially very good substitutes for metallic heat recovery system for building application

The Effects of Hydrogen Peroxide on the Circadian Rhythms of Microcystis aeruginosa

Background: The cyanobacterium Microcystis aeruginosa is one of the principal bloom-forming cyanobacteria present in a wide range of freshwater ecosystems. M. aeruginosa produces cyanotoxins, which can harm human and animal health. Many metabolic pathways in M. aeruginosa, including photosynthesis and microcystin synthesis, are controlled by its circadian rhythms. However, whether xenobiotics affect the cyanobacterial circadian system and change its growth, physiology and biochemistry is unknown. We used real-time PCR to study the effect of hydrogen peroxide (H2O2) on the expression of clock genes and some circadian genes in M. aeruginosa during the light/dark (LD) cycle. Results: The results revealed that H 2O 2 changes the expression patterns of clock genes (kaiA, kaiB, kaiC and sasA) and significantly decreases the transcript levels of kaiB, kaiC and sasA. H2O2 treatment also decreased the transcription of circadian genes, such as photosynthesis-related genes (psaB, psbD1 and rbcL) and microcystin-related genes (mcyA, mcyD and mcyH), and changed their circadian expression patterns. Moreover, the physiological functions of M. aeruginosa, including its growth and microcystin synthesis, were greatly influenced by H 2O 2 treatment during LD. These results indicate that changes in the cyanobacterial circadian system can affect its physiological and metabolic pathways. Conclusion: Our findings show that a xenobiotic can change the circadian expression patterns of its clock genes t

Characterization of Non-heading Mutation in Heading Chinese Cabbage (Brassica rapa L. ssp. pekinensis)

Heading is a key agronomic trait of Chinese cabbage. A non-heading mutant with flat growth of heading leaves (fg-1) was isolated from an EMS-induced mutant population of the heading Chinese cabbage inbred line A03. In fg-1 mutant plants, the heading leaves are flat similar to rosette leaves. The epidermal cells on the adaxial surface of these leaves are significantly smaller, while those on the abaxial surface are much larger than in A03 plants. The segregation of the heading phenotype in the F2 and BC1 population suggests that the mutant trait is controlled by a pair of recessive alleles. Phytohormone analysis at the early heading stage showed significant decreases in IAA, ABA, JA and SA, with increases in methyl IAA and trans-Zeatin levels, suggesting they may coordinate leaf adaxial-abaxial polarity, development and morphology in fg-1. RNA-sequencing analysis at the early heading stage showed a decrease in expression levels of several auxin transport (BrAUX1, BrLAXs, and BrPINs) and responsive genes. Transcript levels of important ABA responsive genes, including BrABF3, were up-regulated in mid-leaf sections suggesting that both auxin and ABA signaling pathways play important roles in regulating leaf heading. In addition, a significant reduction in BrIAMT1 transcripts in fg-1 might contribute to leaf epinastic growth. The expression profiles of 19 genes with known roles in leaf polarity were significantly different in fg-1 leaves compared to wild type, suggesting that these genes might also regulate leaf heading in Chinese cabbage. In conclusion, leaf heading in Chinese cabbage is controlled through a complex network of hormone signaling and abaxial-adaxial patterning pathways. These findings increase our understanding of the molecular basis of head formation in Chinese cabbage

Government expenditure and economic growth in China : a time series perspective

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Development and validation of a prediction model for the early occurrence of acute kidney injury in patients with acute pancreatitis

AbstractBackground Acute pancreatitis (AP) is associated with a high incidence of acute kidney injury (AKI). This study aimed to develop a nomogram for predicting the early onset of AKI in AP patients admitted to the intensive care unit.Method Clinical data for 799 patients diagnosed with AP were extracted from the Medical Information Mart for Intensive Care IV database. Eligible AP patients were randomly divided into training and validation cohorts. The independent prognostic factors for the early development of AKI in AP patients were determined using the all-subsets regression method and multivariate logistic regression. A nomogram was constructed for predicting the early occurrence of AKI in AP patients. The performance of the nomogram was evaluated based on the area under the receiver operating characteristic curve (AUC), calibration curves and decision curve analysis (DCA).Results Seven independent prognostic factors were identified as predictive factors for early onset AKI in AP patients. The AUC of the nomogram in the training and validation cohorts were 0.795 (95% CI, 0.758–0.832) and 0.772 (95% CI, 0.711–0.832), respectively. The AUC of the nomogram was higher compared with that of the BISAP, Ranson, APACHE II scores. Further, the calibration curve revealed that the predicted outcome was in agreement with the actual observations. Finally, the DCA curves showed that the nomogram had a good clinical applicability value.Conclusion The constructed nomogram showed a good predictive ability for the early occurrence of AKI in AP patients