Association of elevated circulating monocyte-platelet aggregates with hypercoagulability in patients with nephrotic syndrome.

BACKGROUND: Hypercoagulability emerges as a central pathological feature and clinical complication in nephrotic syndrome. Increased platelet activation and aggregability are closely related to hypercoagulability in nephrotic syndrome. Monocyte-platelet aggregates (MPAs) have been proposed to represent a robust biomarker of platelet activation. The aim of this study was to investigate levels of the circulating MPAs and MPAs with the different monocyte subsets to evaluate the association of MPAs with hypercoagulability in nephrotic syndrome. METHODS: Thirty-two patients with nephrotic syndrome were enrolled. In addition, thirty-two healthy age and sex matched adult volunteers served as healthy controls. MPAs were identified by CD14 monocytes positive for CD41a platelets. The classical (CD14 + + CD16-, CM), the intermediate (CD14 + + CD16+, IM) and the non-classical (CD14 + CD16++, NCM) monocytes, as well as subset specific MPAs, were measured by flow cytometry. RESULTS: Patients with nephrotic syndrome showed a higher percentage of circulating MPAs as compared with healthy controls (p < 0.001). The percentages of MPAs with CM, IM, and NCM were higher than those of healthy controls (p = 0.012, p < 0.001 and p < 0.001, respectively). Circulating MPAs showed correlations with hypoalbuminemia (r=-0.85; p < 0.001), hypercholesterolemia (r = 0.54; p < 0.001), fibrinogen (r = 0.70; p < 0.001) and D-dimer (r = 0.37; p = 0.003), but not with hypertriglyceridemia in nephrotic syndrome. The AUC for the prediction of hypercoagulability in nephrotic syndrome using MPAs was 0.79 (95% CI 0.68-0.90, p < 0.001). The sensitivity of MPAs in predicting hypercoagulability was 0.71, and the specificity was 0.78. CONCLUSION: Increased MPAs were correlated with hypercoagulability in nephrotic syndrome. MPAs may serve as a potential biomarker for thrombophilic or hypercoagulable state and provide novel insight into the mechanisms of anticoagulation in nephrotic syndrome.

Strategy for Clinical Setting of Co-transplantation of Mesenchymal Stem Cells and Pancreatic Islets.

Islet transplantation may be the most efficient therapeutic technique for patients with type 1 diabetes mellitus (T1DM). However, the clinical application of this method is faced with numerous limitations, including isolated islet apoptosis, recipient rejection, and graft vascular reconstruction. Mesenchymal stem cells (MSCs) possess anti-apoptotic, immunomodulatory, and angiogenic properties. Here, we review recent studies on co-culture and co-transplantation of islets with MSCs. We have summarized the methods of preparation of co-transplantation, especially the merits of co-culture, and the effects of co-transplantation. Accumulating experimental evidence shows that co-culture of islets with MSCs promotes islet survival, enhances islet secretory function, and prevascularizes islets through various pretransplant preparations. This review is expected to provide a reference for exploring the use of MSCs for clinical islet co-transplantation.

Customization of Manganese Oxide Cathodes via Precise Electrochemical Lithium-Ion Intercalation for Diverse Zinc-Ion Batteries.

Manganese oxide-based aqueous zinc-ion batteries (ZIBs) are attractive energy storage devices, owing to their good safety, low cost, and ecofriendly features. However, various critical issues, including poor conductivity, sluggish reaction kinetics, and unstable structure still restrict their further development. Oxygen defect engineering is an effective strategy to improve the electrochemical performance of manganese oxides, but challenging in the accurate regulation of oxygen defects. In this work, an effective and controllable defect engineering strategy-controllable electrochemical lithium-ion intercalation - is proposed to tackle this issue. The incorporation of lithium ions and oxygen defects can promote the conductivity, lattice spacing, and structural stability of Mn2O3 (MO), thus improving its capacity (232.7 mAh g-1), rate performance, and long-term cycling stability (99.0% capacity retention after 3000 cycles). Interestingly, the optimal ratio of intercalated lithium-ion varies at different temperature or mass-loading of MO, which provides the possibility to customize diverse ZIBs to meet different application conditions. In addition, the fabricated ZIBs present good flexibility, superior safety, and admirable adaptability under extreme temperatures (-20-100 °C). This work provides an inspiration on the structural customization of metal oxide nanomaterials for diverse ZIBs, and sheds light on the construction of future portable electronics.

Bone fracture is associated with incident myocardial infarction in long-term follow-up.

BACKGROUND: The association between bone fracture and cardiovascular diseases is examined in this study. While basic research has established a connection between fractures and heart attacks through the linkage between bones and arteries, population studies have not provided clear evidence. The aim of the present study is to investigate the association between bone fracture and the occurrence of myocardial infarction in a natural population during long-term follow-up. METHODS: A total of 13,196 adult participants with bone fracture history at baseline from the China Health and Nutrition Survey (CHNS) prospective cohort were included in this study. Baseline investigation was performed in 1997-2009 and the outcome was followed up till 2015. Hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) were calculated using Cox proportional hazards models. RESULTS: From 1997 to 2015, a total of 329 incident myocardial infarction cases were identified. In univariate and multivariate Cox regression analysis, a history of bone fracture was associated with an increased risk of myocardial infarction incidence in the total population (for the crude model: HR = 2.56, 95% CI 1.83-3.53, P < 0.001; for the multivariate model: HR = 1.43, 95% CI 1.02-1.99, P = 0.036). In the stratified analysis, bone fracture was not associated with an increased risk of incident myocardial infarction in subjects with age < 50 years (HR = 0.71, 95% CI 0.34-1.47, P = 0.356), but significantly associated with an increased risk of incident myocardial infarction in subjects with age ≥ 50 years (HR = 1.80, 95% CI 1.23-2.63, P = 0.003). CONCLUSIONS: It is suggested by the present study that bone fracture may be associated with an increased risk of incident myocardial infarction in the elderly population during long-term follow-up.

Highly Dispersed Ni Atoms and O3 Promote Room-Temperature Catalytic Oxidation.

Transition metal oxides are promising catalysts for catalytic oxidation reactions but are hampered by low room-temperature activities. Such low activities are normally caused by sparse reactive sites and insufficient capacity for molecular oxygen (O2) activation. Here, we present a dual-stimulation strategy to tackle these two issues. Specifically, we import highly dispersed nickel (Ni) atoms onto MnO2 to enrich its oxygen vacancies (reactive sites). Then, we use molecular ozone (O3) with a lower activation energy as an oxidant instead of molecular O2. With such dual stimulations, the constructed O3-Ni/MnO2 catalytic system shows boosted room-temperature activity for toluene oxidation with a toluene conversion of up to 98%, compared with the O3-MnO2 (Ni-free) system with only 50% conversion and the inactive O2-Ni/MnO2 (O3-free) system. This leap realizes efficient room-temperature catalytic oxidation of transition metal oxides, which is constantly pursued but has always been difficult to truly achieve.

Achieving Exceptional Volumetric Desalination Capacity Using Compact MoS2 Nanolaminates.

Capacitive deionization (CDI) has emerged as a promising technology for freshwater recovery from low-salinity brackish water. It is still inapplicable in specific scenarios (e.g., households, islands, or offshore platforms) due to too low volumetric adsorption capacities. In this study, a high-density semi-metallic molybdenum disulfide (1T'-MoS2) electrode with compact architecture obtained by restacking of exfoliated nanosheets, which achieve high capacitance up to ≈277.5 F cm-3 under an ultrahigh scan rate of 1000 mV s-1 with a lower charge-transfer resistance and nearly tenfold higher electrochemical active surface area than the 2H-MoS2 electrode, is reported. Furthermore, 1T'-MoS2 electrode demonstrates exceptional volumetric desalination capacity of 65.1 mgNaCl cm-3 in CDI experiments. Ex situ X-ray diffraction (XRD) reveal that the cation storage mechanism with the dynamic expansion of 1T'-MoS2 interlayer to accommodate cations such as Na+, K+, Ca2+, and Mg2+, which in turn enhances the capacity. Theoretical analysis unveils that 1T' phase is thermodynamically preferable over 2H phase, the ion hydration and channel confinement also play critical role in enhancing ion adsorption. Overall, this work provides a new method to design compact 2D-layered nanolaminates with high-volumetric performance for CDI desalination.

Intercalation in 2D materials and in situ studies.

Intercalation of atoms, ions and molecules is a powerful tool for altering or tuning the properties - interlayer interactions, in-plane bonding configurations, Fermi-level energies, electronic band structures and spin-orbit coupling - of 2D materials. Intercalation can induce property changes in materials related to photonics, electronics, optoelectronics, thermoelectricity, magnetism, catalysis and energy storage, unlocking or improving the potential of 2D materials in present and future applications. In situ imaging and spectroscopy technologies are used to visualize and trace intercalation processes. These techniques provide the opportunity for deciphering important and often elusive intercalation dynamics, chemomechanics and mechanisms, such as the intercalation pathways, reversibility, uniformity and speed. In this Review, we discuss intercalation in 2D materials, beginning with a brief introduction of the intercalation strategies, then we look into the atomic and intrinsic effects of intercalation, followed by an overview of their in situ studies, and finally provide our outlook.

High blood pressure is associated with increased risk of future fracture, but not vice versa.

The association between high blood pressure and fracture showed obvious discrepancies and were mostly between hypertension with future fracture, but rarely between fracture and incident hypertension. The present study aims to investigate the associations of hypertension with future fracture, and fracture with incident hypertension. We included adult participants from the China Health and Nutrition Survey (CHNS) prospective cohort in 1997-2015 (N = 10,227), 2000-2015 (N = 10,547), 2004-2015 (N = 10,909), and 2006-2015 (N = 11,121) (baseline in 1997, 2000, 2004, 2006 respectively and outcome in 2015). Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% CIs. In the analysis of the association between hypertension and future fracture, the adjusted HRs (95% CIs) were 1.34 (0.95-1.90) in 1997-2015, 1.40 (1.04-1.88) in 2000-2015, 1.32 (0.98-1.78) in 2004-2015, and 1.38 (1.01-1.88) in 2006-2015. In the analysis of the association between fracture and incident hypertension, the adjusted HRs (95% CIs) were 1.28 (0.96-1.72) in 1997-2015, 1.18 (0.94-1.49) in 2000-2015, 1.12 (0.89-1.40) in 2004-2015, and 1.09 (0.85-1.38) in 2006-2015. The present study showed that hypertension history was associated with increased risk of future fracture, but not vice versa.

Rational Design of Cost-Effective Metal-Doped ZrO2 for Oxygen Evolution Reaction.

The design of cost-effective electrocatalysts is an open challenging for oxygen evolution reaction (OER) due to the "stable-or-active" dilemma. Zirconium dioxide (ZrO2), a versatile and low-cost material that can be stable under OER operating conditions, exhibits inherently poor OER activity from experimental observations. Herein, we doped a series of metal elements to regulate the ZrO2 catalytic activity in OER via spin-polarized density functional theory calculations with van der Waals interactions. Microkinetic modeling as a function of the OER activity descriptor (GO*-GHO*) displays that 16 metal dopants enable to enhance OER activities over a thermodynamically stable ZrO2 surface, among which Fe and Rh (in the form of single-atom dopant) reach the volcano peak (i.e. the optimal activity of OER under the potential of interest), indicating excellent OER performance. Free energy diagram calculations, density of states, and ab initio molecular dynamics simulations further showed that Fe and Rh are the effective dopants for ZrO2, leading to low OER overpotential, high conductivity, and good stability. Considering cost-effectiveness, single-atom Fe doped ZrO2 emerged as the most promising catalyst for OER. This finding offers a valuable perspective and reference for experimental researchers to design cost-effective catalysts for the industrial-scale OER production.

Power evolution prediction of bidirectional Raman amplified WDM system based on PINN.

We propose using physical-informed neural network (PINN) for power evolution prediction in bidirectional Raman amplified WDM systems with Rayleigh backscattering (RBS). Unlike models based on data-driven machine learning, PINN can be effectively trained without preparing a large amount of data in advance and can learn the potential rules of power evolution. Compared to previous applications of PINN in power prediction, our model considers bidirectional Raman pumping and RBS, which is more practical. We experimentally demonstrate power evolution prediction of 200 km bidirectional Raman amplified wavelength-division multiplexed (WDM) system with 47 channels and 8 pumps using PINN. The maximum prediction error of PINN compared to experimental results is only 0.38 dB, demonstrating great potential for application in power evolution prediction. The power evolution predicted by PINN shows good agreement with the results simulated by traditional numerical method, but its efficiency is more suitable for establishing models and calculating noise, providing convenience for subsequent power configuration optimization.

The application of high-throughput sequencing technology in corneal diseases.

High-throughput sequencing technology, also known as next-generation sequencing technology, can explore new biomarkers and specific gene mutations. It has a pivotal role in promoting the gene research, which can limit the detection area, lessen the time needed for sequencing. Also, it can quickly screen out the suspected pathogenic genes of patients, gain the necessary genetic data, and provide the basis for clinical diagnosis and genetic counseling. In the research of corneal diseases, through the DNA sequencing of patients' diseased cells, it can provide a deeper understanding of corneal diseases and improve the diagnosis, classification and treatment alternatives of various corneal diseases. This article will introduce the application progress of high-throughput sequencing technology in corneal diseases, which will help to understand the application of this technology in various corneal diseases.

A mini-resonant photoacoustic sensor based on a sphere-cylinder coupled acoustic resonator for high-sensitivity trace gas sensing.

This paper reports a mini-resonant photoacoustic sensor for high-sensitivity trace gas sensing. The sensor primarily contains a sphere-cylinder coupled acoustic resonator, a cylindrical buffer chamber, and a fiber-optic acoustic sensor. The acoustic field distributions of this mini-resonant photoacoustic sensor and the conventional T-type resonant photoacoustic sensor have been carefully evaluated, showing that the first-order resonance frequency of the present mini-resonant photoacoustic sensor is reduced by nearly a half compared to that of the T-type resonant photoacoustic sensor. The volume of the developed photoacoustic cavity is only about 0.8 cm3. Trace methane is selected as the target analytical gas and a detection limit of 101 parts-per-billion at 100-s integration time has been achieved, corresponding to a normalized noise equivalent absorption (NNEA) coefficient of 1.04 × 10-8 W·cm-1·Hz-1/2. The developed mini-resonant photoacoustic sensor provides potential for high-sensitivity trace gas sensing in narrow spaces.

Broadband continuous-wave differential absorption lidar for atmospheric remote sensing of water vapor.

What we believe to be a novel low-cost broadband continuous-wave water vapor differential absorption lidar (CW-DIAL) technique has been proposed and implemented by combing the Scheimpflug principle and the differential absorption method. The broadband CW-DIAL technique utilizes an 830-nm high-power multimode laser diode with 3-W output power as a tunable light source and a CMOS image sensor tilted at 45° as the detector. A retrieval algorithm dedicated for the broadband CW-DIAL technique has been developed to obtain range-resolved water vapor concentration from the DIAL signal. Atmospheric remote sensing of water vapor has been carried out on a near-horizontal water vapor path to validate the performance of the broadband CW-DIAL system. The retrieved water vapor concentration showed a good consistency with those measured by an air quality monitoring station, with a correlation coefficient of 0.9669. The fitting error of the water vapor concentration is found to be less than 10%. Numerical simulation studies have revealed that the aerosol-induced error on the water vapor concentration is below 5% with a background water vapor concentration of 5 g/m3 for most atmospheric conditions. The experimental results have successfully demonstrated the feasibility of the present broadband CW-DIAL technique for range-resolved water vapor remote sensing.

Effects of 2-dodecyl-6-methoxycyclohexa-2,5-diene-l ,4-dione on resisting hepatic fibrosis induced by CC14 in rats and its mechanisms via TGF-pi/Smads signaling pathway / 中国药理学通报

Aim To investigate the effects of 2-dode-cyl-6-methoxycyclohexa-2 , 5-diene-l, 4-dione ( DM-DD) on resisting hepatic fibrosis induced by carbon tetrachloride ( CC14 ) in rats and the underlying mechanisms , with a specific focus on the TGF-pi/Smads signaling pathway. Methods The hepatic fibrosis model was replicated using 50% CC14. Various parameters, including levels of aspartate transferase ( AST) , ala-nine transferase ( ALT ) , albumin/globulin ( A/G ) , total protein (TP) , total bilirubin (T-BIL) , hyaluron-ic acid ( HA ) , laminin ( LN ) , collagen type Ж ( Col Ж) , and collagen type IV(ColIV) in the blood, were measured. Liver tissue lesions and fiber formation were observed using HE and Masson staining. The expression levels of a smooth muscle actin (a-SMA) , collagen type I ( Col I ) , transformed growth factor (TGF-pi), Smad2, and Smad7 proteins were assessed using immunohistochemistry. a-SMA, Coll, TGF-pi, and Smad7 mRNA levels in liver tissue were measured by RT-PCR. Additionally, the expression levels of TGF-pi, Smad4, and Smad7 proteins in liver tissue were determined by Western blot. Results In comparison to the normal control group, the model group exhibited significantly elevated levels of AST, ALT, TP, T-BIL, HA, LN, Col Ш and Col IV in serum. But A/G level notably decreased. Successful modeling was confirmed by the presence of extensive fiber formations observed through HE and Massonstaining in liver tissue. The DMDD administration group demonstrated a notable decrease levels of AST, ALT, TP, T-BIL, HA, LN, Col III, and CollV, but A/G was significantly elevated when compared to the model group. Furthermore, a-SMA, Coll, TGF-f31, Smad2 and Smad4 mRNA and protein levels in the DMDD administration group were significantly reduced, while Smad7 significantly declined. HE and Masson staining results reflected a marked reduction in fibrous hyper-plasia. Conclusion DMDD exhibits a protective effect against CCl4-induced hepatic fibrosis, and its mechanism appears to be associated with the TGF-fJl/ Smads signaling pathway.

214.7 Tbit/s S, C, and L-band transmission over 50†km SSMF based on silicon photonic integrated transceivers.

We experimentally demonstrate a 214.7 Tbit/s generalized mutual information (GMI) estimated throughput by ultra-wideband wavelength division multiplexing (WDM) transmission in standard single-mode fiber (SSMF). With 50-GHz grid, 396 transmission channels are used to deliver 49 GBaud probabilistically constellation-shaped (PCS) 256 quadrature amplitude modulation (QAM) and PCS-64QAM signals. Silicon photonic integrated transceiver is employed to complete electro-optic and optic-electro conversion of the modulated signals. S, C, and L-band rare-earth-doped amplifiers enable the 19.8 THz bandwidth WDM transmission without the assistance of distributed Raman amplification. The measured data rate shows great potential for Silicon photonic devices deployed in ultra-wideband WDM transmission.

Predicting ventilator-associated pneumonia in elderly patients requiring mechanical ventilation through the detection in tracheal aspirates.

OBJECTIVE: In this study, we evaluated the clinical utility of tracheal aspirates α-amylase (AM), pepsin, and lipid-laden macrophage index (LLMI) in the early diagnosis of ventilator-associated pneumonia (VAP) in elderly patients on mechanical ventilation. METHODS: Within 96 hours of tracheal intubation, tracheal aspirate specimens were collected from elderly patients on mechanical ventilation; AM, pepsin, and LLMI were detected, and we analyzed the potential of each index individually and in combination in diagnosing VAP. RESULTS: Patients with VAP had significantly higher levels of AM, pepsin, and LLMI compared to those without VAP (P < 0.001), and there was a positive correlation between the number of pre-intubation risk factors of aspiration and the detection value of each index in patients with VAP (P < 0.001). The area under a receiver operating characteristic (ROC) curve (AUC) of AM, pepsin, and LLMI in diagnosis of VAP were 0.821 (95% CI:0.713-0.904), 0.802 (95% CI:0.693-0.892), and 0.621 (95% CI:0.583-0.824), the sensitivities were 0.8815, 0.7632, and 0.6973, the specificities were 0.8495, 0.8602, and 0.6291, and the cutoff values were 4,321.5 U/L, 126.61 ng/ml, and 173.5, respectively. The AUC for the combination of indexes in diagnosing VAP was 0.905 (95% CI:0.812-0.934), and the sensitivity and specificity were 0.9211 and 0.9332, respectively. In the tracheal aspirate specimens, the detection rate of AM ≥ cutoff was the highest, while it was the lowest for LLMI (P < 0.001). The detection rates of AM ≥ cutoff and pepsin ≥ cutoff were higher within 48 hours after intubation than within 48-96 hours after intubation (P < 0.001). In contrast, the detection rate of LLMI ≥ cutoff was higher within 48-96 hours after intubation than within 48 hours after intubation (P < 0.001). The risk factors for VAP identified using logistic multivariate analysis included pre-intubation aspiration risk factors (≥3), MDR bacteria growth in tracheal aspirates, and tracheal aspirate AM ≥ 4,321.5 U/L, pepsin ≥ 126.61 ng/ml, and LLMI ≥ 173.5. CONCLUSION: The detection of AM, pepsin, and LLMI in tracheal aspirates has promising clinical utility as an early warning biomarker of VAP in elderly patients undergoing mechanical ventilation.

Highly sensitive trace gas detection based on a miniaturized 3D-printed Y-type resonant photoacoustic cell.

We report, what we believe to be, a novel miniaturized 3D-printed Y-type resonant photoacoustic cell (YRPAC) consisting of a frustum of cone-type buffer chamber and a cylindrical resonant chamber. The volume of the designed YRPAC is about 7.0 cm3, which is only about a half of the T-resonant photoacoustic cell (TRPAC). The finite element simulation of the sound field distribution of the TRPAC and YRPAC based on COMSOL shows that the photoacoustic signal is enhanced with the shape of the buffer chamber changing from the traditional cylinder to a frustum of cone. The photoacoustic spectroscopy (PAS) system, utilizing the YRPAC and TRPAC as the photoacoustic reaction units, a 1653.7 nm distributed feedback (DFB) laser as the excitation light source, a cantilever beam acoustic sensor as the acoustic sensing unit, and a high-speed spectrometer as the demodulation unit, has been successfully developed for high-sensitivity trace CH4 sensing. When the CH4 concentration is 1000 ppm, the 2f signal of YRPAC in the first-order resonance mode is 2.3 nm, which is 1.7 times higher than the 2f signal amplitude of TRPAC. The detection sensitivity and minimum detection limit for the PAS system are 2.29 pm/ppm and 52.8 parts per billion (ppb) at 100 s of averaging time. The reported YRPAC has higher sensitivity, smaller size, and faster response time compared to the conventional TRPAC, which can provide a new solution for PAS development.

Exploring genetic influences on adverse outcome pathways using heuristic simulation and graph data science.

Adverse outcome pathways provide a powerful tool for understanding the biological signaling cascades that lead to disease outcomes following toxicity. The framework outlines downstream responses known as key events, culminating in a clinically significant adverse outcome as a final result of the toxic exposure. Here we use the AOP framework combined with artificial intelligence methods to gain novel insights into genetic mechanisms that underlie toxicity-mediated adverse health outcomes. Specifically, we focus on liver cancer as a case study with diverse underlying mechanisms that are clinically significant. Our approach uses two complementary AI techniques: Generative modeling via automated machine learning and genetic algorithms, and graph machine learning. We used data from the US Environmental Protection Agency's Adverse Outcome Pathway Database (AOP-DB; aopdb.epa.gov) and the UK Biobank's genetic data repository. We use the AOP-DB to extract disease-specific AOPs and build graph neural networks used in our final analyses. We use the UK Biobank to retrieve real-world genotype and phenotype data, where genotypes are based on single nucleotide polymorphism data extracted from the AOP-DB, and phenotypes are case/control cohorts for the disease of interest (liver cancer) corresponding to those adverse outcome pathways. We also use propensity score matching to appropriately sample based on important covariates (demographics, comorbidities, and social deprivation indices) and to balance the case and control populations in our machine language training/testing datasets. Finally, we describe a novel putative risk factor for LC that depends on genetic variation in both the aryl-hydrocarbon receptor (AHR) and ATP binding cassette subfamily B member 11 (ABCB11) genes.

Theoretical and experimental investigation of the molecular depolarization ratio for broadband polarization lidar techniques.

The molecular depolarization ratio (MDR) is of great significance for polarization lidar techniques in terms of validating the measurement accuracy, etc. However, previous studies mainly focused on cases with narrowband laser linewidths, and the transmittance of the Cabannes line in the receiver has been assumed constant. In this work, the narrowband theoretical model of MDR has been re-examined by taking the transmittance of the Cabannes line into account. A large relative deviation of beyond 200% has been found if the wavelength-shift reaches up to 0.5 nm for a receiving bandwidth of 0.5 nm at 532 nm, which is much larger than the case without considering the transmittance of the Cabannes line, i.e., only 15%, reported in previous studies. Besides, a broadband theoretical model has been proposed to evaluate the MDR for polarization lidar using high-power multimode laser diodes as light sources. Simulation studies have revealed that the MDR is highly related to the laser linewidth, the receiving bandwidth, as well as the wavelength-shift between the laser wavelength and the center wavelength of the receiver. The MDR at 520 nm calculated by the broadband theoretical model is about 21% larger than the value evaluated without considering the laser linewidth, when the receiving bandwidth is equivalent to the laser linewidth (e.g., 2 nm). Validation measurements, employing a 520-nm imaging-based polarization lidar with a 3.4-nm laser linewidth and a 10-nm receiving bandwidth, illustrated that the volume depolarization ratio in a clean atmospheric region (0.129±0.0025) was highly consistent with the theoretical MDR (0.132). The good agreement between theoretical and experimental results demonstrated a high measurement accuracy of the imaging-based polarization lidar and excellent feasibility of the broadband theoretical model.

The abundance and diversity of antibiotic resistance genes in layer chicken ceca is associated with farm enviroment.

Industrialized layer chicken feedlots harbor complex environmental microbial communities that affect the enrichment and exchange of gut bacteria and antibiotic resistance genes (ARGs). However, the contribution of different environmental sources to the gut ARGs of layer chickens is not clear. Here, layer chicken gut and environmental samples (air, water, feed, cage, feather, maternal hen feces, uropygial glands) were collected during the early 3 month period before the laying of eggs, and the source and characteristics of the gut microorganisms and ARGs were analyzed by performing 16S rRNA and metagenomic sequencing. The results showed that the abundances of Bacteroidetes and Actinobacteria in cecum of layer chickens gradually increased, while that of Proteobacteria decreased with age, and the number and relative abundance of ARGs decreased significantly with age. On day 5, 57% of the layer chicken cecal ARGs were from feather samples, and 30% were from cage samples. Subsequently, the contribution of cage ARGs became progressively more prominent over time. At days 30 and 57, the contribution of cage ARGs to the chick cecal ARGs reached 63.3 and 69.5%, respectively. The bacterial community composition (especially the abundances of Klebsiella pneumoniae and Escherichia coli) was the major factor impacting the ARG profile. K. pneumoniae and E. coli were mainly transmitted from feathers to the layer chicken cecum, and the contribution rates were 32 and 3.4%, respectively. In addition, we observed the transmission of ARG-carrying bacteria (Bacteroides fragilis) from the cage to the gut, with a contribution rate of 11.5%. It is noteworthy that B. fragilis is an opportunistic pathogen that may cause diarrhea in laying hens. These results can provide reference data for the healthy breeding of layer chickens and the prevention and control of ARG pollution.