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Direct detection of mid-infrared (MIR) at room temperature commonly suffers from the high background noise and the lack of ideal sensor material. An indirect upconversion method based on nonlinear optics bridges the desired MIR region to the well-developed near-infrared devices. In this paper, we report an experimental study of 3–8 µm MIR upconversion detection with a 1 µm laser-pumped BaGa_4Se_7 crystal. This detection scheme is integrated with an optical parametric oscillator and an optical receiver to form a coherent source and detection system that offers high temporal (nanosecond time scale) and spectral resolution (≤3cm^−1). The wide response band (>1.4 octave) and large dynamic range (11.5 orders) of this detection scheme benefits from the superior optical properties of this non-oxide crystal, and a minimum detectable energy of 1.02 fJ/pulse is observed with an InGaAs p-i-n photodiode. The upconversion technique outperforms commercial HgCdTe detectors in terms of both sensitivity (2–4.5 orders better) and wavelength response flatness. The aforementioned characteristics of this integrated MIR source and detection system make it of significant interest for applications in high-resolution gas analysis and spectral imaging.

We report an experimental study of long-wave infrared difference frequency generation based on BaGa_4Se_7 crystal. The sources of two input wavelengths were the fundamental output of a Nd:YAG laser and its second-harmonic pumped ∼1.2µmKTiOPO_4 optical parametric oscillator. A wide tuning range of 7.9–17.5 µm (>1.14 octave) was achieved, which reached the upper limit of the BaGa_4Se_7 transparency region. The spectra and pulse widths, input–output relationship, beam profile, wavelength tolerance, and angular acceptance of the phase-matching were characterized in detail. This presented coherent source can potentially be applied in multiple gas analyses and spectral imaging.

The polian vesicle and coelom of sea cucumber Apostichopus japonicuswere full of coelomic fluid in which many types of coelomocytes with different functions were suspended. Our previous work has indicated the differences of coelomocytes between two sites mainly in subtype proportion, non-specific immune enzymes activities and several immune-related genes expression levels in healthy A. japonicus. However, the functional similarities and differences of coelomic fluid in two sites including the coelom and polian vesicle after pathogenic infection still remain unclear. Here, we investigated the changes of the total coelomocyte density (TCD) and differential coelomocyte density (DCD) after pathogen infection by Vibrio splendidusin coelom and polian vesicle. After infected by V. splendidus, the TCD in the coelom and polian vesicle rapidly declined at 12 h, and then the TCD in the coelom showed a stably ascending trend, while the TCD in the polian vesicle reached a peak at 24 h post infection (hpi), and then showed a continuously decline trend from 24 hpi to 72 hpi followed by a slow elevation until recovering the normal level from 72 hpi to 96 hpi. Then the activities of acidic phosphatase (ACP), alkaline phosphatase (AKP), catalase (CAT) and superoxide dismutase (SOD) were determined to evaluate the response of cell-free coelomic fluid to V. splendidusinfection. The activities of ACP, AKP and CAT showed similar trends in the coelom and polian vesicle. The SOD activity significantly increased in the polian vesicle, whereas it exhibited a decreasing trend in the coelom. Finally, the expression profiles of nine immune-related genes including Aj-MyD88, Aj-IRAK4, Aj-i-Lys, Aj-Rel, Aj-p50, Aj-DMBT1, Aj-CDC, Aj-Rrp15and Aj-Fibrinogen Cwere detected after V. splendiduschallenge. The results suggested all the detected genes were significantly up-regulated both in the coelom and polian vesicle, and the expression levels of these genes in two sites shared similar trends except Aj-MyD88and Aj-DMBT1. This research provides a new insight into the differentially immune roles of coelomic fluid and coelomocytes in polian vesicle and coelom response to bacterial infections and supplements comprehensive resources for better understanding the innate immune response of A. japonicus.

In this study, combined analysis of expression profiling in the hippocampus of 76 patients with Alzheimer’s disease (AD) and 40 healthy controls was performed. The effects of covariates (including age, gender, postmortem interval, and batch effect) were controlled, and differentially expressed genes (DEGs) were identified using a linear mixed-effects model. To explore the biological processes, functional pathway enrichment and protein–protein interaction (PPI) network analyses were performed on the DEGs. The extended genes with PPI to the DEGs were obtained. Finally, the DEGs and the extended genes were ranked using the convergent functional genomics method. Eighty DEGs with q< 0.1, including 67 downregulated and 13 upregulated genes, were identified. In the pathway enrichment analysis, the 80 DEGs were significantly enriched in one Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, GABAergic synapses, and 22 Gene Ontology terms. These genes were mainly involved in neuron, synaptic signaling and transmission, and vesicle metabolism. These processes are all linked to the pathological features of AD, demonstrating that the GABAergic system, neurons, and synaptic function might be affected in AD. In the PPI network, 180 extended genes were obtained, and the hub gene occupied in the most central position was CDC42. After prioritizing the candidate genes, 12 genes, including five DEGs (ITGB5, RPH3A, GNAS, THY1, and SEPT6) and seven extended genes (JUN, GDI1, GNAI2, NEK6, UBE2D3, CDC42EP4, and ERCC3), were found highly relevant to the progression of AD and recognized as promising biomarkers for its early diagnosis.

To systematically collect differentially expressed genes (DEGs) from rodent models of chronic stress (CS) and apply them to research of stress-related disease. CS is an important environmental factor that may affect numerous complex diseases. Its relevant DEGs identified from rodent models provide valuable information for understanding the mechanisms underlying stress-related diseases. Currently, no suitable data tool have been developed to use such data.

Morphine can promote the pathogenesis of human acquired immunodeficiency syndrome through binding to the μ opioid receptor (MOR) in immune cells. Previous investigation has suggested that expression of the MOR gene in lymphocytes is triggered by cooperative interaction between transcription factors, specificity protein 1 (Sp1) and Ying Yang 1 (YY1), in the promoter region. However, the specific molecular mechanism by which immunodeficiency virus infection impacts regulation of the MOR gene expression in lymphocytes is still unclear. In this study, it was demonstrated that SIV (SIVmac239) infection may result in gradual reduction of the MOR gene expression and Sp1 during a period of 48 h postinfection by analysis of quantitative real‐time RT‐PCR and Western blotting. The results of methylation‐specific PCR showed that two of 14 CpG islands adjacent to the Sp1 and YY1 elements in the promoter region were methylated, which together with reduced Sp1, contributed to the failure of interaction of Sp1 with YY1 and their binding to the elements, as determined by coimmunoprecipitation, chromatin immunoprecipitation‐real‐time PCR, and EMSAs. The repression of the MOR gene secondary to SIVmac239 infection could be abolished by the demethylating agent 5‐aza‐2′‐deoxycytidine. Transfection with Sp1‐expressing vector (PN3‐Sp1) was also able to enhance the activity of the promoter in SIVmac239‐infected cells. We therefore concluded that aberrant methylation of the promoter and reduction of Sp1 resulting from SIVmac239 infection led to the silencing of the MOR gene. This finding will be helpful in understanding the synergistic mechanism of HIV infection and morphine addiction in the pathogenesis of AIDS.