Synergistic Engineering of Energy Band Alignment and Interfacial Electric Field Distribution over Bi-bismuth-Based Hetero-nanofibers for Boosting Visible-Light-Driven Photocatalytic Ammonia Synthesis and Antibiotic Removal.

Synergistic engineering of energy band alignment and interfacial electric field distribution is essential for photocatalyst design but is still challenging because of the limitation on refined regulation in the nanoscale. This study addresses the issue by employing surface modification and thermal-induced phase transformation in Bi2MoO6/BixOyIz hetero-nanofiber frameworks. The energy band alignment switches from a type-II interface to a Z-scheme contact with stronger redox potentials and inhibited electron traps, and the optimized built-in electric field distribution could be reached based on experimental and theoretical investigations. The engineered hetero-nanofibers exhibit outstanding visible-light-driven photocatalytic nitrogen reduction activity (605 µmol/g/h) and tetracycline hydrochloride removal rate (81.5% within 30 min), ranking them among the top-performing bismuth series materials. Furthermore, the photocatalysts show promise in activating advanced oxidants for efficient organic pollutant degradation. Moreover, the Bi2MoO6/Bi5O7I hetero-nanofibers possess good recycling stability owing to their three-dimensional network structure. This research offers valuable insights into heterojunction design for environmental remediation and industrial applications.

Biomechanical effects of muscle loading on early healing of femoral stem fractures: a combined musculoskeletal dynamics and finite element approach.

Femoral stem fractures (FST) are often accompanied by muscle injuries, however, what muscle injuries affect fracture healing and to what extent is unknown. The purpose of this study was to analyze the extent to which different muscles affect FST healing through a combined musculoskeletal dynamics and finite element approach. Modeling the lower extremity musculoskeletal system for 12 different muscle comprehensives. Muscle and joint reaction forces on the femur were calculated and these data were used as boundary conditions input to the FSTs model to predict the degree of muscle influence on fracture healing. Finally, we will investigate the extent to which muscle influences FST healing during knee flexion. Muscle and joint forces are highly dependent on joint motion and have a significant biomechanical influence on interfragmentary strain (IFS) healing. The psoas major (PM), gastrocnemius lateralis (GL) and gastrocnemius medialis (GM) muscles play a major role in standing, with GM > PM > GL, whereas the gluteus medius posterior (GMP), vastus intermedius (VI), vastus medialis (VM), vastus lateralis superior (VLS), and adductor magnus distalis (AMD) muscles play a major role in knee flexion, with VLS > VM > VI > AMD > GMP. Mechanical stimulus-controlled healing can be facilitated when the knee joint is flexed less than 20°. Different muscles exert varying degrees of influence on the healing of fractures. Therefore, comprehending the impact of particular muscles on fracture site tissue FST healing can aid orthopedic surgeons in formulating improved surgical and rehabilitation strategies.

Mineral crude drug mirabilite (Mangxiao) inhibits the occurrence of colorectal cancer by regulating the Lactobacillus-bile acid-intestinal farnesoid X receptor axis based on multiomics integration analysis.

Mineral crude drug has revolutionized the treatment landscape in precision oncology niche that leads to the improvement in therapeutic efficiency on various tumor subtypes. Mangxiao (MX), a mineral crude drug in traditional Chinese medicine, has been used for treating gastrointestinal diseases for thousands of years. However, the action mechanisms are still ambiguous. Here, we attempt to explore inhibitory roles and associated pharmacological mechanisms of MX upon colorectal cancer (CRC) in APCMin/+ male mice by integrating metabolomics, 16S rDNA sequencing analyses, and metagenomic-based microbiota analysis. We found that MX can significantly inhibit the occurrence of CRC through the regulation of the dysregulated gut microbe metabolism. Furthermore, the correlation analysis of metabolomes and 16S rDNA revealed that MX could restore the disorders of gut microbes by specifically enriching the abundance of Lactobacilli to improve bile acid metabolism, which further activated the farnesoid X receptor (FXR) in CRC mice, then the improvement of gut dysbiosis could inhibit the development of CRC. Collectively, our effort confirmed MX has the capacity to intervene the development of CRC and further discovered that it targets Lactobacillus-bile acid-intestinal FXR axis, which can be regarded as a candidate medicine for future drug discovery and development against CRC.

Prediction of potential mechanisms of rhubarb therapy for colorectal cancer based on network pharmacological analysis and molecular docking.

The objective of this study was to investigate the potential targets and mechanism of Rheum palmatum L in the treatment of colorectal cancer based on the network pharmacology and molecular docking, which could provide the theoretical basis for clinical applications. The potential components were screened using TCMSP database and articles. The gene targets of colorectal cancer were screened through the Genecards database and Online Mendelian Inheritance in Man database. Then, the common targets of components and colorectal cancer were used to construct the network diagram of active components and targets in Cytoscape 3.7.0. The protein-protein interaction (PPI) diagram was generated using String database, and the targets were further analyzed by gene ontology and Kyoto Encyclopedia of Genes and Genomes. Molecular docking between gene targets and active components was analyzed via AutoDock, and visualized through PyMol. Among this study, main targets might be TP53, EGF, MYC, CASP3, JUN, PTGS2, HSP90AA1, MMP9, ESR1, PPARG. And 10 key elements might associate with them, such as aloe-emodin, beta-sitosterol, gallic acid, eupatin, emodin, physcion, cis-resveratrol, rhein, crysophanol, catechin. The treatment process was found to involve nitrogen metabolism, p53 signaling pathway, and various cancer related pathway, as well as the AGE-RAGE signaling pathway, estrogen signaling pathway, interleukin-17 signaling pathway and thyroid hormone signaling pathway. The molecular docking was verified the combination between key components and their respective target proteins. Network pharmacological analysis demonstrated that R palmatum was could regulated p53, AGE-RAGE, interleukin-17 and related signaling pathway in colorectal cancer, which might provide a scientific basis of mechanism.

Comparison of Computed Tomography and Clinical Features Between Patients Infected with the SARS-CoV-2 Omicron Variant and the Original Strain.

Purpose: To investigate potential differences in clinical and computed tomography (CT) features between patients with the SARS-CoV-2 Omicron variant and the original strain. Patients and Methods: This retrospective study included 69 hospitalized patients infected with Omicron variant from November to December 2022, and 96 hospitalized patients infected with the original strain from February to March 2020 in Chongqing, China. The clinical features, CT manifestations, degrees of lung involvement in different stages on CT, and imaging changes after the reverse-transcription polymerase chain reaction (RT-PCR) results turned negative were compared between the two groups. Results: For clinical features, patients with Omicron were predominantly old people and females, without manifestation of any clinical symptoms, who had low serum levels of C-reactive protein and procalcitonin. Shorter interval from symptoms onset to initial CT scan was observed in Omicron patients compared to patients with the original strain (all P < 0.05). For CT features, patients with Omicron were more likely to present with round-like opacities and tree-in-bud pattern (all P < 0.05), but less likely to exhibit a diffuse distribution, patchy and linear opacities, as well as vascular enlargement pattern (all P < 0.05). The Omicron group was more susceptible to exhibiting lower CT involvement scores in each stage (all P < 0.05) and imaging progression after the RT-PCR results turned negative (P < 0.001). Conclusion: Patients infected with the Omicron variant exhibited less severe changes on chest CT compared to those infected with the original strain. Furthermore, imaging progression under low viral load conditions was more common in patients with Omicron than in those with the original strain.

Carboxylic Acid-Enabled Vinylene Transfer Reaction by Co(III) Catalyst: Scope and Applications to the Five-Step Total Synthesis of Protoberberine Alkaloids Containing Free Hydroxyl Group without Protection.

A Co(III)-catalyzed vinylene transfer reaction enabled by carboxylic acid is presented. This redox-neutral transformation tolerates various functional groups, including free hydroxyl groups, and features practicality. Five-step routes based on the vinylene transfer reaction and Heck annulation have been devised to the total synthesis of 8-oxodehydrodiscretamine and 2-demethyl-oxypalmatine without the protection of the free hydroxyl functionality.

Study on the trade-off/synergy between ecosystem services and human well-being based on land use in Weinan City, China.

Change of land use have important impacts on ecosystem services (ESs) and human well-being (HWB), yet the trade-off/synergy among land use, ESs, and HWB has still not received sufficient attention at city regional scales level. Weinan City in the southern of the Loess Plateau of China was taken as the study area. Based on ArcGIS, InVEST model, and RUSLE model, the characteristics of spatial and temporal variations of land use and ESs from 2000 to 2020 were analyzed, and the trade-off/synergy relationship between land use, ESs, and HWB was quantified using correlation analysis. The results indicated that the area of cultivated land decreased significantly and the area of built-up land increased significantly from 2000 to 2020 in Weinan City. The grain production, soil conservation, and water yield functions showed an increasing trend, which was a synergistic relationship with HWB. Carbon storage and habitat quality functions showed a decreasing trend, which was a trade-off relationship with HWB. The index value of HWB has increased significantly, mainly in the added value of agricultural and rural per capita income. Land use intensity has a trade-off relationship with GP, WY functions, and HWB. There are many factors that affect this trade-off/synergy relationship, such as land use patterns, economic development, and population growth. The study can provide a theoretical basis for the sustainable development of regional economy and nature.

Clinical and non-contrast computed tomography characteristics and disease development in patients with benign pulmonary subsolid nodules with a solid component ≤ 5 mm.

OBJECTIVES: To evaluate the clinical and non-contrast computed tomography (CT) features of patients with benign pulmonary subsolid nodules (SSNs) with a solid component ≤ 5 mm and their development trends via follow-up CT. METHODS: We retrospectively collected 436 data from patients who had SSNs with a solid component ≤ 5 mm, including 69 with absorbable benign SSNs (AB-SSNs), 70 with nonabsorbable benign SSNs (NB-SSNs), and 297 with malignant SSNs (M-SSNs). Models 1, 2, and 3 for distinguishing the different types of SSNs were then developed and validated. RESULTS: Patients with AB-SSNs were younger and exhibited respiratory symptoms more frequently than those with M-SSNs. The frequency of nodules detected during follow-up CT was in the following order: AB-SSNs > NB-SSNs > M-SSNs. NB-SSNs were smaller than M-SSNs, and ill-defined margins were more frequent in AB-SSNs than in NB-SSNs and M-SSNs. Benign SSNs exhibited irregular shape, target sign, and lower CT values more frequently compared to M-SSNs, whereas the latter demonstrated bubble lucency more commonly compared to the former. Furthermore, AB-SSNs showed more thickened interlobular septa and satellite lesions than M-SSNs and M-SSNs had more pleural retraction than AB-SSNs (all p < 0.017). The three models had AUCs ranging 0.748-0.920 and 0.790-0.912 in the training and external validation cohorts, respectively. A follow-up CT showed nodule progression in four benign SSNs. CONCLUSIONS: The three SSN types have different clinical and imaging characteristics, with some benign SSNs progressing to resemble malignancy. CRITICAL RELEVANCE STATEMENT: A good understanding of the imaging features and development trends of benign SSNs may help reduce unnecessary follow-up or interventions. This retrospective study explores the CT characteristics of benign SSNs with a solid component ≤ 5 mm by comparing AB-SSNs, NB-SSNs, and M-SSNs and delineates their development trends via follow-up CT. KEY POINTS: 1. Different subsolid nodule types exhibit distinct clinical and imaging features. 2. A miniscule number of benign subsolid nodules can progress to resemble malignancy. 3. Knowing the clinical and imaging features and development trends of benign subsolid nodules can improve management.

Common mechanisms of Wumei pills in treating ulcerative colitis and type 2 diabetes: Exploring an integrative approach through network pharmacology.

Wumei pills (WMP), a classical Chinese herbal formula, have shown efficacy in the treatment of ulcerative colitis (UC) and type 2 diabetes (T2DM). However, the underlying mechanisms by which WMP simultaneously targets these distinct diseases remain unclear. In this study, a network pharmacology approach was employed to unravel the potential molecular mechanisms of WMP in UC and T2DM treatment. This analysis provides a bioinformatics foundation for the traditional Chinese medicine concept of "treating different diseases with the same treatment." WMP was found to contain 65 active components, including flavonoids, sterols, and alkaloids, that act on 228 shared targets for UC and T2DM. Network analysis identified 5 core compounds (Quercetin, Kaempferol, beta-Sitosterol, Isocorypalmine, Stigmasterol) and 8 core proteins (AKT1, ESR1, TP53, IL6, JUN, MYC, TNF, EGFR) that play pivotal roles in the treatment of UC and T2DM by WMP. WMP exerts its therapeutic effects by modulating signaling pathways, including the NF-κB pathway, PI3K-Akt pathway, and p53 pathway. Molecular docking results indicate a strong binding affinity between core compounds and core genes. This study bridges the understanding of 2 diseases using network pharmacology and provides insights into shared therapeutic mechanisms, opening doors for further research in modern Chinese herbal formulations.

Copper regulates the host innate immune response against bacterial infection via activation of ALPK1 kinase.

Copper is an essential trace element for the human body, and its requirement for optimistic immune functions has been recognized for decades. How copper is involved in the innate immune pathway, however, remains to be clarified. Here, we report that copper serves as a signal molecule to regulate the kinase activity of alpha-kinase 1 (ALPK1), a cytosolic pattern-recognition receptor (PRR), and therefore promotes host cell defense against bacterial infection. We show that in response to infection, host cells actively accumulate copper in the cytosol, and the accumulated cytosolic copper enhances host cell defense against evading pathogens, including intracellular and, unexpectedly, extracellular bacteria. Subsequently, we demonstrate that copper activates the innate immune pathway of host cells in an ALPK1-dependent manner. Further mechanistic studies reveal that copper binds to ALPK1 directly and is essential for the kinase activity of this cytosolic PRR. Moreover, the binding of copper to ALPK1 enhances the sensitivity of ALPK1 to the bacterial metabolite ADP-heptose and eventually prompts host cells to elicit an enhanced immune response during bacterial infection. Finally, using a zebrafish in vivo model, we show that a copper-treated host shows an increased production of proinflammatory cytokines, enhanced recruitment of phagosome cells, and promoted bacterial clearance. Our findings uncover a previously unrecognized role of copper in the modulation of host innate immune response against bacterial pathogens and advance our knowledge on the cross talk between cytosolic copper homeostasis and immune system.

Biomarkers of heart failure: advances in omics studies.

Heart failure is a complex syndrome characterized by progressive circulatory dysfunction, manifesting clinically as pulmonary and systemic venous congestion, alongside inadequate tissue perfusion. The early identification of HF, particularly at the mild and moderate stages (stages B and C), presents a clinical challenge due to the overlap of signs, symptoms, and natriuretic peptide levels with other cardiorespiratory pathologies. Nonetheless, early detection coupled with timely pharmacological intervention is imperative for enhancing patient outcomes. Advances in high-throughput omics technologies have enabled researchers to analyze patient-derived biofluids and tissues, discovering biomarkers that are sensitive and specific for HF diagnosis. Due to the diversity of HF etiology, it is insufficient to study the diagnostic data of early HF using a single omics technology. This study reviewed the latest progress in genomics, transcriptomics, proteomics, and metabolomics for the identification of HF biomarkers, offering novel insights into the early clinical diagnosis of HF. However, the validity of biomarkers depends on the disease status, intervention time, genetic diversity and comorbidities of the subjects. Moreover, biomarkers lack generalizability in different clinical settings. Hence, it is imperative to conduct multi-center, large-scale and standardized clinical trials to enhance the diagnostic accuracy and utility of HF biomarkers.

Comprehensive bioinformatics analysis of FXR1 across pan-cancer: Unraveling its diagnostic, prognostic, and immunological significance.

Fragile X-related protein 1 (FXR1) is an RNA-binding protein that belongs to the fragile X-related (FXR) family. Studies have shown that FXR1 plays an important role in cancer cell proliferation, invasion and migration and is differentially expressed in cancers. This study aimed to gain a comprehensive and systematic understanding of the analysis of FXR1's role in cancers. This would lead to a better understanding of how it contributes to the development and progression of various malignancies. this study conducted through The Cancer Genome Atlas (TCGA), GTEx, cBioPortal, TISIDB, GEPIA2 and HPA databases to investigated FXR1's role in cancers. For data analysis, various software platforms and web platforms were used, such as R, Cytoscape, hiplot plateform. A significant difference in FXR1 expression was observed across molecular and immune subtypes and across types of cancer. FXR1 expression correlates with disease-specific survival (DSS), and overall survival (OS) in several cancer pathways, further in progression-free interval (PFI) in most cancers. Additionally, FXR1 showed a correlation with genetic markers of immunomodulators in different cancer types. Our study provides insights into the role of FXR1 in promoting, inhibiting, and treating diverse cancers. FXR1 has the potential to serve as a diagnostic and prognostic biomarker for cancer, with therapeutic value in immune-based, targeted, or cytotoxic treatments. Further clinical validation and exploration of FXR1 in cancer treatment is necessary.

Enhancing Vibrio vulnificus infection diagnosis for negative culture patients with metagenomic next-generation sequencing.

Objective: To evaluate the diagnostic value of metagenomic next-generation sequencing (mNGS) in Vibrio vulnificus (V. vulnificus) infection. Methods: A retrospective analysis of patients with V. vulnificus infection at the Fifth Affiliated Hospital of Sun Yat-Sen University from January 1, 2020 to April 23, 2023 was conducted. 14 enrolled patients were diagnosed by culture or mNGS. The corresponding medical records were reviewed, and the clinical data analyzed included demographics, epidemiology laboratory findings, physical examination, symptoms at presentation, antibiotic and surgical treatment, and outcome. Results: In this study, 78.6% (11/14) patients had a history of marine trauma (including fish stab, shrimp stab, crab splints and fish hook wounds), 7.1% (1/14) had eaten seafood, and the remaining 14.3% (2/14) had no definite cause. Isolation of V. vulnificus from clinical samples including blood, tissue, fester and secreta. 9 cases were positive for culture, 5 cases were detected synchronously by mNGS and got positive for V. vulnificus. 85.7% (12/14) cases accepted surgical treatment, with 1 patient suffering finger amputated. 14 enrolled patients received appropriate antibiotic therapy, and all of them had recovered and discharged. 9 strains V. vulnificus isolated in this study were sensitive to most beta-lactam antibiotics, aminoglycosides, quinolones, etc. Conclusion: Vibrio vulnificus infection is a common water-exposed disease in Zhuhai, which requires identification of a number of pathogens. Of severe infections with unknown pathogen, mNGS can be used simultaneously, and the potential to detect multiple pathogens is of great help in guiding treatment.

Network pharmacology and molecular docking study on the treatment of polycystic ovary syndrome with angelica sinensis- radix rehmanniae drug pair.

This study aimed to investigate the angelica sinensis - radix rehmanniae (AR) role in polycystic ovary syndrome (PCOS), employing network pharmacology and molecular docking techniques for active ingredient, targets, and pathway prediction. AR active components were obtained through TCMSP platform and literature search. The related targets of AR and PCOS were obtained through the disease and Swiss Target Prediction databases. An "active ingredient-target" network map was constructed using Cytoscape software, and gene ontology and Kyoto encyclopedia of genes and genomes enrichment analysis was conducted through Hiplot. Finally, Auto Dock Tools software was used to conduct molecular docking between active ingredients and core targets. The main bioactive ingredients of AR in the treatment of PCOS are acteoside, baicalin, caffeic acid, cistanoside F, geniposide, etc. These ingredients involve 10 core targets, such as SRC, HSP90AA1, STAT3, MAPK1, and JUN. The effect of AR on anti-PCOS mainly involves the AGE-RAGE signaling pathway, Relaxin signaling pathway, TNF signaling pathway, and ErbB signaling pathway. Molecular docking results showed that the main active components and key targets of AR could be stably combined. AR can improve hyperandrogen status, regulate glucose homeostasis, and correct lipid metabolism and other physiological processes through multi-component, multi-target, and multi-pathway. Thus, it could play a significant role in PCOS treatment. The results of our study provide a scientific foundation for basic research and clinical applications of AR for the treatment of PCOS.

The mitochondrial energy metabolism pathway-related signature predicts prognosis and indicates immune microenvironment infiltration in osteosarcoma.

BACKGROUND: Abnormalities in the mitochondrial energy metabolism pathways are closely related to the occurrence and development of many cancers. Furthermore, abnormal genes in mitochondrial energy metabolism pathways may be novel targets and biomarkers for the diagnosis and treatment of osteosarcoma. In this study, we aimed to establish a mitochondrial energy metabolism-related gene signature for osteosarcoma prognosis. METHODS: We first obtained differentially expressed genes based on the metastatic status of 84 patients with osteosarcoma from the TARGET database. After Venn analysis of differentially expressed genes and mitochondrial energy metabolism pathway-related genes (MMRGs), 2 key genes were obtained using univariate Cox regression and least absolute shrinkage and selection operator (LASSO) regression analysis. Next, we used these 2 genes to establish a prognostic signature. Subsequent analyses elucidated the correlation between these 2 key genes with clinical features and 28 types of immune cells. Pathway changes in osteosarcoma pathogenesis under different metastatic states were clarified using gene set enrichment analysis (GSEA) of differentially expressed genes. RESULTS: A gene signature composed of 2 key prognosis-related genes (KCNJ5 and PFKFB2) was identified. A risk score was calculated based on the gene signature, which divided osteosarcoma patients into low- or high-risk groups that showed good and poor prognosis, respectively. High expression of these 2 key genes is associated with low-risk group in patients with osteosarcoma. We constructed an accurate nomogram to help clinicians assess the survival time of patients with osteosarcoma. The results of immune cell infiltration level showed that the high-risk group had lower levels of immune cell infiltration. GSEA revealed changes in immune regulation and hypoxia stress pathways in osteosarcoma under different metastatic states. CONCLUSION: Our study identified an excellent gene signature that could be helpful in improving the prognosis of patients with osteosarcoma.

Genome-wide association study exploring the genetic architecture of eggshell speckles in laying hens.

BACKGROUND: Eggshell speckle phenotype is an important trait in poultry production because they affect eggshell quality. However, the genetic architecture of speckled eggshells remains unclear. In this study, we determined the heritability of eggshell speckles and conducted a genome-wide association study (GWAS) on purebred Rhode Island Red (RIR) hens at 28 weeks to detect potential genomic loci and candidate genes associated with eggshell speckles. RESULTS: The heritability of eggshell speckles was 0.35 at 28 weeks, and the speckle level is not related to other eggshell quality traits in terms of phenotypic correlation. We detected 311 SNPs (6 significantly, and 305 suggestively associated) and 39 candidate genes associated with eggshell speckles. Based on the pathway analysis, the 39 candidate genes were mainly involved in alpha-linolenic acid metabolism, linoleic acid metabolism, ether lipid metabolism, GnRH signaling pathway, vascular smooth muscle contraction, and MAPK signaling pathway. Ultimately, ten genes, LOC423226, SPTBN5, EHD4, LOC77155, TYRO3, ITPKA, DLL4, PLA2G4B, PLA2G4EL5, and PLA2G4EL6 were considered the most promising genes associated with eggshell speckles that were implicated in immunoregulation, calcium transport, and phospholipid metabolism, while its function in laying hens requires further studies. CONCLUSIONS: This study provides new insights into understanding the genetic basis of eggshell speckles and has practical application value for the genetic improvement of eggshell quality.

Emerging roles of RNA binding proteins in intervertebral disc degeneration and osteoarthritis.

The etiology of intervertebral disc degeneration (IDD) and osteoarthritis (OA) is complex and multifactorial. Both predisposing genes and environmental factors are involved in the pathogenesis of IDD and OA. Moreover, epigenetic modifications affect the development of IDD and OA. Dysregulated phenotypes of nucleus pulposus (NP) cells and OA chondrocytes, including apoptosis, extracellular matrix disruption, inflammation, and angiogenesis, are involved at all developmental stages of IDD and OA. RNA binding proteins (RBPs) have recently been recognized as essential post-transcriptional regulators of gene expression. RBPs are implicated in many cellular processes, such as proliferation, differentiation, and apoptosis. Recently, several RBPs have been reported to be associated with the pathogenesis of IDD and OA. This review briefly summarizes the current knowledge on the RNA-regulatory networks controlled by RBPs and their potential roles in the pathogenesis of IDD and OA. These initial findings support the idea that specific modulation of RBPs represents a promising approach for managing IDD and OA.

A dense SERS substrate of the AgNPs@GO compound film for detecting homocysteine molecules.

This study focuses on the development of a highly sensitive surface-enhanced Raman scattering (SERS) sensor for detecting homocysteine (Hcy) molecules. The Hcy sensor was created by depositing silver nanoparticles (AgNPs) onto the surface of graphene oxide (GO) film to form a dense AgNPs@GO composite film. The AgNPs on the composite film interacted with sulfur atoms (S) of Hcy molecules to form Ag-S bonds, which boosted the chemisorption of Hcy molecules and enabled them to be specifically recognized. The SERS sensor exhibited a maximum enhancement factor of up to 1.1 × 104, with a reliable linear response range from 1 to 60 ng mL-1. The limit of detection (LOD) for Hcy molecules was as low as 1.1 × 10-9 M. Moreover, Hcy molecules were successfully distinguished in a mixed solution of γ-aminobutyric acid and Hcy molecules. In this study, a simple preparation process of SERS substrate and a novel detection method for Hcy molecules provided a new pathway for the rapid and effective detection of Hcy molecules in the food and biomedicine fields.

Dynamic Changes of Composition of Particulate Matter Emissions during Residential Biomass Combustion.

Residential biomass combustion in developing countries produces significant primary particulate matter (PM) emissions. Highly time-resolved aerosol mass spectrometry and aethalometer measurements were used to investigate the dynamic changes of emitted PM chemical composition from a typical improved stove burning with wood and crop straw in China. Combustion temperature and organic aerosol (OA) concentration increased quickly during the ignition stage. The flaming stage was characterized by high combustion temperature and high pollutant [including OA, black carbon (BC), inorganic salts, and polycyclic aromatic hydrocarbons (PAHs)] emissions, while the burnout stage is characterized by low combustion temperature and lower pollutant emissions. OA was the primary emitted species; emission factors of OA in the flaming stage were generally higher (24.5-792%) than those in the burnout stage. Mass spectral signatures of OA were obtained. The ratio of Cl-/OA for wood combustion (0.05 ± 0.01) is much lower than that from burning crop straw (0.32 ± 0.19). Hydrocarbon OA emissions dominated during the ignition and flaming stages. A high percentage of oxidized OA was emitted during the burnout stage. The relationship between PAHs and BC/OA emissions under different burning conditions was investigated, and PAHs may act as intermediate products in the conversion of OA to BC.

Pulse-shaped high-energy and high-average-power fiber laser in the nanosecond regime.

A high-energy and high-average-power pulsed fiber laser has been investigated in a master oscillator power amplifier (MOPA) configuration seeding with a diode laser at a programmed pulse duration of ∼250ns. The fiber amplifier successfully demonstrates the pulse with 21.4 mJ at the repetition rate of 50 kHz and a maximum average output power of 1535 W with a slope efficiency of 81.6% at 250 kHz. To overcome fiber nonlinearities such as stimulated Raman scattering (SRS) and self-phase modulation (SPM), extra-large mode area ytterbium (Yb)-doped step-index dual cladding fiber has been utilized as gain fiber in the MOPA laser system. The gain saturation effect in the power amplifier was greatly mitigated by the programmed seed signal. This pulse-shaped MOPA system can provide practical applications in many fields such as laser cleaning, paint stripping, and other applications requiring special pulse shapes.