Spatial mapping of greenhouse gases using a UAV monitoring platform over a megacity in China.

Urban environments are recognized as main anthropogenic contributors to greenhouse gas (GHG) emissions, characterized by unevenly distributed emission sources over the urban environments. However, spatial GHG distributions in urban regions are typically obtained through monitoring at only a limited number of locations, or through model studies, which can lead to incomplete insights into the heterogeneity in the spatial distribution of GHGs. To address such information gap and to evaluate the spatial representation of a planned GHG monitoring network, a custom-developed atmospheric sampler was deployed on a UAV platform in this study to map the CO2 and CH4 mixing ratios in the atmosphere over Zhengzhou in central China, a megacity of nearly 13 million people. The aerial survey was conducted along the main roads at an altitude of 150 m above ground, covering a total distance of 170 km from the city center to the suburbs. The spatial distributions of CO2 and CH4 mixing ratios in Zhengzhou exhibited distinct heterogeneities, with average mixing ratios of CO2 and CH4 at 439.2 ± 10.8 ppm and 2.12 ± 0.04 ppm, respectively. A spatial autocorrelation analysis was performed on the measured GHG mixing ratios across the city, revealing a spatial correlation range of approximately 2 km for both CO2 and CH4 in the urban area. Such a spatial autocorrelation distance suggests that the urban GHG monitoring network designed for emission inversion purposes need to have a spatial resolution of 4 km to characterize the spatial heterogeneities in the GHGs. This UAV-based measurement approach demonstrates its capability to monitor GHG mixing ratios across urban landscapes, providing valuable insights for GHG monitoring network design.

Gender-Specific Risk Factors for Asymmetric Bone Density in Adult Degenerative Lumbar Scoliosis: A Retrospective Cohort Analysis.

BACKGROUND This study aimed to evaluate the performance of Hounsfield Unit (HU) value on the vertebral bone mineral density associated with adult degenerative lumbar scoliosis (ADLS) and to compare the HU and coronal height changes of the lumbar spine on the concave and convex sides. The secondary aim was to investigate the risk factors for increased asymmetric ratio of HU (ARH) by concave-to-convex. MATERIAL AND METHODS A total of 74 patients aged ≥50 years were retrospectively reviewed. The height and the HU values of the region of interest were measured and compared. Multiple linear regression and gender-stratified analyses were performed to explore risk factors. Restricted cubic spline (RCS) was used to visually assess the dose-effect relationship between the Cobb angle and ARH. RESULTS The heights on the concave sides were significantly lower while HU values were significantly higher than that of the convex side. Cobb angle (95% CI: 0.001 to 0.009, P=0.034) was positively correlated with the increased ARH, while apex orientation to the right (95% CI: -0.152 to -0.013, P=0.022) was negatively associated. Gender-stratified analyses showed age and apex vertebrae location are 2 additional risk factors in male patients but not in female patients. Cobb angle was identified by RCS as a risk factor both in males and females and the inflection points were 15 and 17.5, respectively. CONCLUSIONS HU values on the concave side are significantly higher than on the convex side, showing the asymmetrical bone mass distribution of ADLS patients. Several gender-related risk factors for increased ARH have been identified.

Postbiotics from Saccharomyces cerevisiae fermentation stabilize microbiota in rumen liquid digesta during grain-based subacute ruminal acidosis (SARA) in lactating dairy cows.

BACKGROUND: Subacute ruminal acidosis (SARA) is a common metabolic disorder of high yielding dairy cows, and it is associated with dysbiosis of the rumen and gut microbiome and host inflammation. This study evaluated the impact of two postbiotics from Saccharomyces cerevisiae fermentation products (SCFP) on rumen liquid associated microbiota of lactating dairy cows subjected to repeated grain-based SARA challenges. A total of 32 rumen cannulated cows were randomly assigned to 4 treatments from 4 weeks before until 12 weeks after parturition. Treatment groups included a Control diet or diets supplemented with postbiotics (SCFPa, 14 g/d Original XPC; SCFPb-1X, 19 g/d NutriTek; SCFPb-2X, 38 g/d NutriTek, Diamond V, Cedar Rapids, IA, USA). Grain-based SARA challenges were conducted during week 5 (SARA1) and week 8 (SARA2) after parturition by replacing 20% DM of the base total mixed ration (TMR) with pellets containing 50% ground barley and 50% ground wheat. Total DNA from rumen liquid samples was subjected to V3-V4 16S rRNA gene amplicon sequencing. Characteristics of rumen microbiota were compared among treatments and SARA stages. RESULTS: Both SARA challenges reduced the diversity and richness of rumen liquid microbiota, altered the overall composition (ß-diversity), and its predicted functionality including carbohydrates and amino acids metabolic pathways. The SARA challenges also reduced the number of significant associations among different taxa, number of hub taxa and their composition in the microbial co-occurrence networks. Supplementation with SCFP postbiotics, in particular SCFPb-2X, enhanced the robustness of the rumen microbiota. The SCFP supplemented cows had less fluctuation in relative abundances of community members when exposed to SARA challenges. The SCFP supplementation promoted the populations of lactate utilizing and fibrolytic bacteria, including members of Ruminococcaceae and Lachnospiraceae, and also increased the numbers of hub taxa during non-SARA and SARA stages. Supplementation with SCFPb-2X prevented the fluctuations in the abundances of hub taxa that were positively correlated with the acetate concentration, and α- and ß-diversity metrics in rumen liquid digesta. CONCLUSIONS: Induction of SARA challenges reduced microbiota richness and diversity and caused fluctuations in major bacterial phyla in rumen liquid microbiota in lactating dairy cows. Supplementation of SCFP postbiotics could attenuate adverse effects of SARA on rumen liquid microbiota.

Blister formation in acute compartment syndrome: Unraveling the underlying predictors.

Blisters are a common complication of orthopedic trauma and can cause surgery delay and increase the risk of infection. This study aims to identify risk factors for blisters in patients with acute compartment syndrome (ACS). Our study collected data from 206 ACS patients admitted to 2 hospitals between November 2013 and January 2021. Patients were divided into 2 groups: the blister group (BG) and the control group (CG), based on the presence or absence of blisters. We conducted univariate analysis, logistic regression analysis, and receiver operating characteristic (ROC) curve analysis to identify any significant differences in demographics, comorbidities, and admission laboratory test results between the 2 groups. Our study found that the incidence of blisters in ACS patients was 21.8% (45 out of 206). Univariate analysis identified several factors that were significantly associated with blister formation. Logistic regression analysis showed that patients who developed ACS in the winter or spring (P = .007, OR = 2.690, 95% CI [1.308-5.534]), patients who received a referral (the process whereby patients are transferred between medical facilities for further evaluation and treatment attempts prior to admission to our hospital) (P = .009, OR = 4.235, 95% CI [1.432-12.527]), and patients with higher PLR (P = .036, OR = 1.005, 95% CI [1.000-1.009]) were independent risk factors for blisters. Additionally, a history of drinking (P = .039, OR = 0.027, 95% CI [0.046-0.927]) was found to be a protective factor for blister formation in these patients. Moreover, ROC curve analysis showed that a PLR value of 138 was the cutoff point for predicting the development of blisters in ACS patients. Our study identified seasonal factors (refer to these months like winter or spring), referral, and patients with higher PLR as independent risk factors, and a history of drinking as a protective factor for blister formation in ACS patients. These findings allow clinicians to individualize the evaluation of blister risk and perform early targeted therapies.

Disturbances of Ruminal Microbiota and Liver Inflammation, Mediated by LPS and Histamine, in Dairy Cows Fed a High-Concentrate Diet.

The ecosystem of ruminal microbiota profoundly affects the health and milk production of dairy cows. High-concentrate diets are widely used in dairy farms and evoke a series of metabolic disorders. Several studies have reported the effects of high-concentrate diets on the ruminal microbiome, while the effect of changes in ruminal microbial flora, induced by high-concentrate diet feeding, on the liver of dairy cows has not been studied before. In this study, 12 mid-lactating Holstein Friesian cows (weight of 455 ± 28 kg; parities of 2.5 ± 0.5; starting milk yield of 31.59 ± 3.2 kg/d; DMI of 21.7 ± 1.1 kg/d; and a DIM at the start of the experiment of 135 ± 28 d) were fitted with ruminal fistulas, as well as with portal and hepatic vein catheters. All cows were randomly divided into 2 groups; then, they fed with low-concentrate diets (LC, concentrate: forage = 40:60) and high-concentrate diets (HC, concentrate: forage = 60:40) for 18 weeks. The forage sources were corn silage and alfalfa hay. After the cows of two groups were euthanized over two consecutive days, ruminal microbiota; the concentration of LPS in the rumen content; cecum content; the levels of blood and histamine in rumen fluid, blood, and the liver; the histopathological status of the rumen and cecum; and the inflammatory response of the liver were assessed in dairy cows under conditions of subacute ruminal acidosis (SARA). These conditions were caused by high-concentrate diet feeding. All data were analyzed using the independent t-test in SPSS. The results showed that high-concentrate diet feeding increased the concentration of LPS and histamine in the rumen and plasma of veins (p < 0.05). The abundance of Bacteroidetes at the phylum level, and of both Bacteroidetes and Saccharibacteria at the genus level, was decreased, while the abundance of Firmicutes at the phylum level and Oscillibacter at the genus level was increased by high-concentrate diet feeding. The decreased pH values of ruminal contents (LC = 6.02, HC = 5.90, p < 0.05) and the increased level of LPS in the rumen (LC = 4.921 × 105, HC = 7.855 × 105 EU/mL, p < 0.05) and cecum (LC = 11.960 × 105, HC = 13.115 × 105 EU/mL, p < 0.01) induced the histopathological destruction of the rumen and cecum, combined with the increased mRNA expression of IL-1ß (p < 0.05). The histamine receptor H1R and the NF-κB signaling pathway were activated in the liver samples taken from the HC group. In conclusion, the elevated concentrations of LPS and histamine in the gut may be related to changes in the ruminal microbiota. LPS and histamine induced the inflammatory response in the ruminal epithelium, cecum epithelium, and liver. However, the cause-effect mechanism needs to be proved in future research. Our study offers a novel therapeutic strategy by manipulating ruminal microbiota and metabolism to decrease LPS and histamine release and to improve the health of dairy cows.

Development and validation of models for predicting mortality in intertrochanteric fracture surgery patients with perioperative blood transfusion: a prospective multicenter cohort study.

BACKGROUND: The association between allogenic blood transfusions and all-cause mortality in surgically treated hip fracture patients with perioperative transfusion (STHFPT) remained unknown. The authors aim to introduce transfusion-related factors, new variables to develop, and validate models to predict mortality in these patients. METHODS: A prospective multicenter cohort study was conducted with STHFPT hospitalized during January 2018 and June 2021. The database was divided into training cohort and validation cohort in a ratio of 70-30% using the randomization method. All participants received a minimum of 2-year follow-up and all participants' overall and eight time-specific survival status were recorded. Prediction models were developed using multivariate logistic regression and Cox regression for variable selection. Model performance was measured by determining discrimination, calibration, overall model performance or precision, and utility. Sensitivity analyses were performed to test robustness of the results. RESULTS: A total of 7074 consecutive patients were prospectively screened and assessed for eligibility to participate. Finally, 2490 patients met our inclusion and exclusion criteria and 1743 (70%) patients were randomized to the training cohort and 747 (30%) to the validation cohort. The median duration of follow-up was 38.4 months (IQR 28.0-62.0). Our novel models highlight that preoperative transfusion is of significance for short-term mortality while mid-term outcomes are predominantly determined by severe complications, pulmonary complications, and advanced age. Our models showed high discriminative power, good calibration, and precision for mortality prediction in both training and validation cohorts, especially in short-term mortality prediction. CONCLUSIONS: The authors introduce transfusion-related factors, new variables to develop, and validate models to predict mortality with STHFPT. The models can be further tested and updated with the ultimate goal of assisting in optimizing individual transfusion strategy.

Efficacy of surgical intervention over conservative management in intertrochanteric fractures among nonagenarians and centenarians: a prospective cohort study.

BACKGROUND: Optimal treatment strategy for nonagenarians and centenarians with hip fractures (NCHF) remained unknown. The authors aimed to compare the outcomes of surgical and conservative management in NCHF. METHODS: A prospective cohort study was conducted based on CPMHF database with NCHF patients hospitalized during 2014-2020. Comorbidities were evaluated by mECM score and restricted cubic spline was utilized to visually assess the dose-effect relationship between the mECM and outcomes. Propensity score matching was performed to balance baseline characteristics between nonsurgical and surgical groups. Multivariate logistic regression, Cox proportional hazard analysis, and survival analysis were employed for unfavorable outcomes (UFO) evaluation. Competing risk of death were analyzed based on Fine and Gray's hazard model and then constructed nomogram models for predicting survival rates. Subgroup analyses were used to determine potential population heterogeneity and sensitivity analyses were performed to test robustness of the results. RESULTS: The authors found increasing trends for UFO with the increase in the mECM score, and that high mECM score (HMS, ≥3) was independently associated with a 2.42-fold (95% CI: 2.07-3.54; P =0.024) increased risk of UFO, which remained significant after considering the competing role of death and were more pronounced in nonsurgical treatment, women, no insurance, and patients with spouse (all P for interaction <0.05). Surgical intervention was identified to be significant protective factors for UFO (RR, 0.59; 95% CI: 0.46-0.75; P <0.001) and severe complications (RR, 0.63; 95% CI: 0.41-0.96; P =0.033) after propensity score matching, as well as survival (HR, 0.40, 95% CI: 0.28-0.58; P <0.001), which remained significant after considering the competing role of death and in all sensitivity analyses and were more pronounced in HMS participants ( P for interaction=0.006). Subgroup analyses revealed surgical patients with HMS had a significantly higher UFO rate (excluding death, P <0.001) while nonsurgical patients with HMS had higher mortality rate as compared to the others ( P =0.005). CONCLUSION: Surgical treatment for NCHF yields better outcomes compared to conservative treatment.

Establishment and pathophysiological evaluation of a novel model of acute compartment syndrome in rats.

BACKGROUND: Researches have used intra-compartmental infusion and ballon tourniquest to create high intra-compartmental pressure in animal models of Acute Compartment Syndrome (ACS). However, due to the large differences in the modeling methods and the evaluation criteria of ACS, further researches of its pathophysiology and pathogenesis are hindered. Currently, there is no ideal animal model for ACS and this study aimed to establish a reproducible, clinically relevant animal model. METHODS: Blunt trauma and fracture were caused by the free falling of weights (0.5 kg, 1 kg, 2 kg) from a height of 40 cm onto the lower legs of rats, and the application of pressures of 100 mmHg, 200 mmHg, 300 mmHg and 400 mmHg to the lower limbs of rats using a modified pressurizing device for 6 h. The intra-compartmental pressure (ICP) and the pressure change (ΔP) of rats with single and combined injury were continuously recorded, and the pathophysiology of the rats was assessed based on serum biochemistry, histological and hemodynamic changes. RESULTS: The ΔP caused by single injury method of different weights falling onto the lower leg did not meet the diagnosis criteria for ACS (< 30 mmHg). On the other hand, a combined injury method of a falling weight of 1.0 kg and the use of a pressurizing device with pressure of 300 mmHg or 400 mmHg for 6 h resulted in the desired ACS diagnosis criteria with a ΔP value of less than 30 mmHg. The serum analytes, histological damage score, and fibrosis level of the combined injury group were significantly increased compared with control group, while the blood flow was significantly decreased compared with control group. CONCLUSION: We successfully established a new preclinical ACS-like rat model, by the compression of the lower leg of rats with 300 mmHg pressure for 6 h and blunt trauma by 1.0 kg weight falling.

Evaluation of microbiological epidemiology and clinical characteristics of maternal bloodstream infection: a 10 years retrospective study.

Objective: Although the incidence of bloodstream infection (BSI) during pregnancy is relatively low, it can lead to unfavorable outcomes. The aim of our study was to analyze the clinical and microbiological characteristics of maternal bacteremia and to assess maternal and fetal outcomes. Methods: Our study was a retrospective study conducted in a tertiary women and children's hospital in Guangzhou, China, from 2013 to 2022. Data were extracted from medical records and the laboratory information system. The participants were divided into groups, and the difference between the groups was analyzed. Results: The incidence of maternal BSI during the 10 years study period was 10.2 cases/10,000 maternities, with a peak found from 2014 to 2016. Escherichia coli (48%) was the predominant causative pathogen, followed by Streptococcus agalactiae (13%). Gestational diabetes mellitus (GDM) (15%) was the most common underlying condition among maternal BSI episodes. Urinary tract (13%) and genital tract (28%) were the predominant source of BSI. About 14% of neonates were infected, and BSI was the most common type of infection. E. coli was the predominant pathogen in mother-neonate pairs with concurrent BSI. Premature rupture of membranes (PROM, OR:4.68) and preterm birth (OR:3.98) were the risk factors predicting neonatal infection. More than 85% of the E. coli were resistant to ampicillin (AMP) and 50% of the E. coli were extended-spectrum ß-lactamase (ESBL)-producing bacteria. Conclusion: Maternal BSI is a rare event, but continuous monitoring on the aspects of pathogen composition, antimicrobial resistance characteristics, and risk factors for adverse outcomes remains necessary to further reduce poor outcomes and mitigate bacterial resistance.