Identification and characterization of a Reeler domain containing protein in Procambarus clarkii provides new insights into antibacterial immunity in crustacean.

Crayfish, as an invertebrate, relies only on the innate immune system to resist external pathogens. In this study, a molecule containing a single Reeler domain was identified from red swamp crayfish Procambarus clarkii (named as PcReeler). Tissue distribution analysis showed that PcReeler was highly expressed in gills and its expression was induced by bacterial stimulation. Inhibiting the expression of PcReeler by RNA interference led to a significant increase in the bacterial abundance in the gills of crayfish, and a significant increase in the crayfish mortality. Silencing of PcReeler influenced the stability of the microbiota in the gills revealed by 16S rDNA high-throughput sequencing. Recombinant PcReeler showed the ability to bind microbial polysaccharide and bacteria and to inhibit the formation of bacterial biofilms. These results provided direct evidence for the involvement of PcReeler in the antibacterial immune mechanism of P. clarkii.

Switchable, Reagent-Controlled C(sp3)-H Selective Iodination and Acetoxylation of 8-Methylquinolines.

An efficient Pd-catalyzed C(sp3)-H selective iodination of 8-methylquinolines is reported herein for the first time. Because of the versatility of organic iodides, the method offers a facile access to various C8-substituted quinolines. By slightly switching the reaction conditions, an efficient C(sp3)-H acetoxylation of 8-methylquinolines has also been enabled. Both approaches feature mild reaction conditions, good tolerance of functional groups, and a broad substrate scope.

Improved YOLOv4-tiny network for real-time electronic component detection.

In the electronics industry environment, rapid recognition of objects to be grasped from digital images is essential for visual guidance of intelligent robots. However, electronic components have a small size, are difficult to distinguish, and are in motion on a conveyor belt, making target detection more difficult. For this reason, the YOLOv4-tiny method is used to detect electronic components and is improved. Then, different network structures are built for the adaptive integration of middle- and high-level features to address the phenomenon in which the original algorithm integrates all feature information indiscriminately. The method is deployed on an electronic component dataset for validation. Experimental results show that the accuracy of the original algorithm is improved from 93.74 to 98.6%. Compared with other current mainstream algorithms, such as Faster RCNN, SSD, RefineDet, EfficientDet, and YOLOv4, the method can maintain high detection accuracy at the fastest speed. The method can provide a technical reference for the development of manufacturing robots in the electronics industry.

C-Type Lectin Maintains the Homeostasis of Intestinal Microbiota and Mediates Biofilm Formation by Intestinal Bacteria in Shrimp.

Intestinal microbiota are closely related to host physiology. Over the long course of evolution and interaction, both commensal bacteria and their host have evolved multiple strategies to adapt to each other. However, in invertebrates, the regulatory mechanism of intestinal microbiota homeostasis is largely unknown. In the current study, a digestive tract-specific C-type lectin, designated as CTL33, was identified because of its abundance and response to bacteria in the intestine of kuruma shrimp (Marsupenaeus japonicus). Silencing of CTL33 expression led directly to intestinal dysbiosis, tissue damage, and shrimp death. CTL33 could facilitate biofilm formation by the intestinal bacteria. This function originated from its unique architecture, with a lectin domain responsible for bacteria recognition and a coiled coil region that mediated CTL33 dimerization and cross-linked the bacteria into a biofilm-like complex. By mediating the formation of a biofilm, CTL33 promoted the establishment of intestinal bacteria in intestine and maintained the homeostasis of the microbiota. Thus, to our knowledge, we demonstrated a new mechanism of C-type lectin-mediated biofilm formation by intestinal bacteria, providing new insights into intestinal homeostasis regulation in invertebrates.

A structure optimized fluorescent probe for highly sensitive monitoring drug induced lysosomal pH value changes.

Lysosomes generally maintain the weak acidic microenvironment, to ensure highly efficient activity and functions of hydrolytic enzymes and proteins. Aberrations of the lysosomal pH may result in cellular functional changes and influence human physiology, possibly causing serious diseases. Small-molecular fluorescent probes based imaging techniques capable of providing information on target locations are considerably appreciated. Herein, by reducing the size of the typical lysosome targetable group 4-(2-aminoethyl) morpholine, we rationally designed a rhodamine analogue probe Ly-HN2AM with N-Aminomorpholine as the ring-closed switch and the lysosome targetable moiety for visualizing lysosomal pH changes. With the benefit of constructing multi-pentacyclic intramolecular hydrogen bond when binding with the H+, Ly-HN2AM gives a highly sensitive response towards pH values ranging from 4.79 to 6.07, with a remarkable higher pKa 5.35 over the typical 4-(2-aminoethyl) morpholine modified probes. The new probe was successfully applied to visualize pH value changes in lysosome-associated physiological and pathological processes with excellent photostability and low cytotoxicity, indicating the potential applications of lysosome specific bioimaging.

Effects of music therapy on major depressive disorder: A study of prefrontal hemodynamic functions using fNIRS.

Major depressive disorder (MDD) is a recurrent, chronic mental illness. While music therapy has been established as an effective treatment for MDD patients, the effects of this therapy on brain function remain unclear. This research employed near-infrared spectroscopy (NIRS) to explore the effects of music therapy on brain activity in mild or moderate MDD patients and to illustrate the potential mechanism of music therapy. Methods: Fifteen MDD patients and fifteen healthy controls (HC) underwent neuropsychological evaluations and NIRS measurements. All participants were treated with continuous music therapy for 10 days. Subsequently, all individuals were evaluated with neuropsychological assessments and NIRS measurements again. Results: The verbal fluency task (VFT) performances of the participants yielded significantly higher scores after music therapy in terms of vegetables, four-footed animals and fruit blocks. After the music treatment, the NIRS data showed that the mean active oxy-Hb values of channels 21, 23, 19, and 41 were significantly increased in both the MDD and HC groups. The MDD group showed significant activation in the dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC) and ventromedial prefrontal cortex (VMPFC) after music therapy. The results indicate that music therapy could improve the brain function of MDD patients.

A novel two-photon fluorescent probe with long-wavelength emission for monitoring HClO in living cells and tissues.

Hypochlorous acid (HClO), one of the most important reactive oxygen species (ROS), is a potent antimicrobial agent for the immune system against invasive bacteria and a wide range of pathogens. Therefore, it is critical to develop sensitive and selective methods for visualization of HClO in biological samples. In this work, a two-photon fluorescent probe HN2-TP) with long-wavelength emission (far-red: 630 nm) based on rhodamine analogue for bioimaging HClO was developed. Owing to a specific HClO induced cyclization reaction, the new probe shows large fluorescence enhancement (about 106-fold), good linear range with high sensitivity (detection limit: 40 nM), high selectivity and fast response when monitoring HClO in vitro. More importantly, by successfully imaging HClO in living cells and tissues, this kind of two-photon fluorescent probe with long-wavelength emission is expected for accurate sensing in complex biosystems, which could eliminate undesired autofluorescence and self-absorption.

[Impact of Ammonia and H2O2 on Bromate and Disinfection By-products Control].

A pilot-scale study with conventional water treatment and ozone-biological activated carbon (O3-BAC) treatment was conducted to evaluate the impact of ammonia and hydrogen peroxide (H2O2) addition on the bromate and disinfection by-products formation potential (DBPFP) control, with bromide containing water as raw water. It was found that bromate concentration would exceed 10.00 µg·L-1 as ozone doses were higher than 1.0 mg·L-1 under different water qualities. Ammonia and H2O2could effectively control bromate formation and bromate concentration decreased as ammonia and H2O2 doses increased. Bromate concentration could be controlled below 10.00 µg·L-1 as ammonia dose was 0.10-0.30 mg·L-1 or the m(H2O2)/m(O3) was 0.2-1.0. However, as ammonia-H2O2 was combined for the same purpose, bromate increased firstly and then decreased. Ammonia addition would not significantly affect the THMFP control but H2O2 application would depress the efficiency of THMFP removal.

Dissipation Pattern, Processing Factors, and Safety Evaluation for Dimethoate and Its Metabolite (Omethoate) in Tea (Camellia Sinensis).

Residue levels of dimethoate and its oxon metabolite (omethoate) during tea planting, manufacturing, and brewing were investigated using a modified QuEChERS sample preparation and gas chromatography. Dissipation of dimethoate and its metabolite in tea plantation followed the first-order kinetic with a half-life of 1.08-1.27 d. Tea manufacturing has positive effects on dimethoate dissipation. Processing factors of dimethoate are in the range of 2.11-2.41 and 1.41-1.70 during green tea and black tea manufacturing, respectively. Omethoate underwent generation as well as dissipation during tea manufacturing. Sum of dimethoate and omethoate led to a large portion of 80.5-84.9% transferring into tea infusion. Results of safety evaluation indicated that omethoate could bring higher human health risk than dimethoate due to its higher hazard quotient by drinking tea. These results would provide information for the establishment of maximum residue limit and instruction for the application of dimethoate formulation on tea crop.

[Review on characteristics and detecting assay of bacterial endotoxin contamination in water environment].

Endotoxins, also known as lipopolysaccharide complexes, are anchored in the outer membrane cell wall of most Gram-negative bacteria and some cyanobacteria. They are continuously released to environment during cell decay. Being common pyrogens and highly immunogenic molecules, endotoxins are related to many human diseases. Due to the tolerances and thermo-stability of endotoxin molecules, they were hard to be removed by common methods. The health risk caused by the endotoxin contamination in drinking water and water environment by various exposure pathways have attracted more and more attention in recent years. In this paper, the physical and chemical properties, biological activities and detection assay of the endotoxin contamination were reviewed, and interfere factors of the main assay, the LAL/TAL (Limulus amebocyte lysate/Tachypleus amebocyte lysate) assay, for detecting endotoxin in water sample were investigated, and the development tendency of the endotoxin detection assay was analyzed.

[Detection of endotoxin activity in water environment and analysis of influence factors for TAL assay].

Endotoxins, derived from cell walls of most Gram-negative bacteria and some cyanobacteria, are common pyrogen and highly immunogenic molecules, and related to many diseases. In this paper, a detection method for endotoxin activity in water environment using kinetic-turbid assay of Tachypleus Amebocyte Lysate (TAL) was established, the influence of pH and salts on TAL assay was investigated. Results showed that it was favorable for TAL assay in the pH range of 6.0-8.4, at low pHs, inhibition results were observed and opposite results were obtained at high pHs. The pH should be adjusted by Tris-HCl (pH = 7.4) buffer before the endotoxin detection. No significant interference was shown in the detection of water containing NaCl, Na2SO4, CaCl2, MgCl2 and KCl with a concentration of less than 50 mg x L(-1), however, the inhibition occurred at the concentration up to 1000-10,000 mg x L(-1). Only 2. 5 mg x L(-1) of FeCl, Fe2(SO4)3, AlCl3 and Al2 (SO4)3 caused significant inhibition. Endotoxin activities of ultrapure water, tap water and recreational water were detected by TAL assay, and their endotoxin activities were < 0.06 EU x mL(-1), 0.46 EU x mL(-1) and 432. 68 EU x mL(-1), respectively.

[Detection and quantification of hepatitis A virus in Tianjin coastal seawater of Bohai Bay].

Hepatitis A virus (HAV) is single-strainded RNA virus that causes infectious hepatitis A. Detection and quantification of hepatitis A virus in Tianjin coastal seawater of Bohai Bay were carried out by conventional RT-PCR and SYBR Green real-time quantitative RT-PCR using the primers based on the conserved sequence at the VP1-VP2 genes of HAV. The nine samples were taken at Tianjin coastal seawater of Bohai Bay locating in the south of Tanggu, in summer, autumn and winter of 2007 and spring of 2008. For viral detection, seawater samples were concentrated either using a small ultrafiltration system (Millipore Pellicon Mini TFF) or a Centriprep-100 centrifugal ultrafiltration device (Millipore Centricon Plus-70). RT-PCR analysis showed that a 192 bp HAV cDNA was amplified from all nine seawater samples and the sequence identities of these cDNAs to the homologous sequence in the GenBank were between 95% and 100%. SYBR Green real-time quantitative RT-PCR analysis indicated that HAV concentration in these samples ranged from 5.35 x 10(6) to 4.51 x 10(7) virus particles/L.

Genetic rearrangement strategy for optimizing the dibenzothiophene biodesulfurization pathway in Rhodococcus erythropolis.

Dibenzothiophene (DBT) and its derivatives can be microbially desulfurized by enzymes DszC, DszA, and DszB, which are encoded by the operon dszABC and contribute to the conversion in tandem. We investigated the expression characteristics of the dsz operon. Our results revealed that the levels of transcription and translation of dszA, dszB, and dszC decreased according to the positions of the genes in the dsz operon. Furthermore, the translation of dszB was repressed by an overlapping structure in the dsz operon. In order to get better and steady expression of the Dsz enzymes and optimize the metabolic flux of DBT, we rearranged the dsz operon according to the catalytic capabilities of the Dsz enzymes and expressed the rearranged dsz operon, dszBCA, in Rhodococcus erythropolis. After rearrangement, the ratio of dszA, dszB, and dszC mRNAs in the cells was changed, from 11:3.3:1 to 1:16:5. Western blot analysis revealed that the levels of expression of dszB and dszC had been enhanced but that the expression of dszA had decreased. The desulfurization activity of resting cells prepared from R. erythropolis DRB, which carried the rearranged dsz operon, was about 12-fold higher than that of resting cells of R. erythropolis DRA, which carried the original operon in a similarly constructed vector.