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The quality of the scanning tip is crucial for tip-enhanced Raman spectroscopy (TERS) experiments towards large signal enhancement and high spatial resolution. In this work, we report a controllable fabrication method to prepare TERS-active tips by modifying the tip apex at the atomic scale, and propose two important criteria to in-situ judge the tip's TERS activity for tip-enhanced Raman measurements. One criterion is based on the downshift of the first image potential state to monitor the coupling between the far-field incident laser and near-field plasmon; the other is based on the appearance of the low-wavenumber Raman peaks associated with an atomistic protrusion at the tip apex to judge the coupling efficiency of emissions from the near field to the far field. This work provides an effective method to quickly fabricate and judge TERS-active tips before real TERS experiments on target molecules and other materials, which is believed to be instrumental for the development of TERS and other tip-enhanced spectroscopic techniques.

Study of exciton recombination process is of great significance for the optoelectronic device applications of two-dimensional transition metal chalcogenides (TMDCs). This research investigated the decoupling MoS

Angle-resolved polarized (ARP) Raman spectroscopy can be utilized to characterize the Raman modes of two-dimensional layered materials based on crystal symmetry or crystal orientation. In this paper, the polarization properties of

Single-molecule tip-enhanced Raman spectroscopy (TERS) has emerged as an important technique for structural analysis at sub-molecular scale. Here in this work, we report a TERS study of an isolated free-base porphyrin molecule adsorbed on the Ag(100) surface at cryogenic temperature ( $\sim$ 7 K). Site-dependent TERS spectra reveal distinct local vibrational information for the chemical constituents within a single molecule. Moreover, distinct spatial features among different Raman peaks can be resolved from the TERS mapping images. These images are found to associate with related vibrational modes, enabling to resolve the mode associated with N-H bonds at the sub-nanometer level. This study will provide deep insights into the symmetry of adsorption configurations and local vibrational information within a single molecule.

To compare the clinical effect of wheat grain moxibustion and warming acupuncture on chronic superficial gastritis of spleen-stomach deficiency and cold.A total of 200 patients with chronic superficial gastritis of spleen-stomach deficiency and cold were randomly divided into a wheat grain moxibustion group (100 cases, 13 cases dropped off ) and a warming acupuncture group (100 cases, 16 cases dropped off ). The acupoints of Zhongwan (CV 12), Tianshu (ST 25), Qihai (CV 6), Liangqiu (ST 34) and Zusanli (ST 36) were selected in both groups. The patients in the wheat grain moxibustion group were treated with wheat grain moxibustion, and 5 cone were given on every acupoint each time. Moxibustion was performed after acupuncture in the warming acupuncture group, and 3 cone each acupoint. Both groups were treated every other day for 15 times. The scores of clinical symptoms and signs, scores of physical component summary (PCS) and mental component summary (MCS) of quality of life in the two groups were recorded before and after treatment and during follow-up 1 month after treatment, and the clinical effects of the two groups were evaluated after treatment and during follow-up.After treatment and during follow-up, the scores of clinical symptoms and signs of the two groups were lower than before treatment (The wheat grain moxibustion can effectively improve the clinical symptoms, signs and quality of life in patients with chronic superficial gastritis of spleen-stomach deficiency and cold, and its long-term effect is better than warming acupuncture.

[n]Cycloparaphenylene ([n]CPP) molecules have attracted broad interests due to their unique properties resulting from the distorted and strained aromatic hoop structures. In this work, we apply sub-nanometer resolved tip-enhanced Raman spectroscopy (TERS) to investigate the adsorption configurations and structural deformations of [12]CPP molecules on metal substrates with different crystallographic orientations. The TERS spectra for a [12]CPP molecule adsorbed on the isotropic Cu(100) surface are found to be essentially the same over the whole nanohoop, indicating an alternately twisted structure that is similar to the [12]CPP molecule in free space. However, when the [12]CPP molecules are adsorbed on the anisotropic Ag(110) surface, the molecular shape is found to be severely deformed into two types of adsorption configurations: one showing an interesting "Mobius-like" feature and the other showing a symmetric bending structure. Their TERS spectral features are found to be site-dependent over the hoop and even show peak splitting for the out-of-plane C-H bending vibrations. The deformed structural models gain strong support from the spatial distribution of "symmetric" TERS spectra at different positions on the hoop. Further TERS imaging, with a spatial resolution down to ∼2 A, provides a panoramic view on the local structural deformations caused by different tilting of the benzene units in real space, which offers insights into the subtle changes in the aromatic properties over the deformed hoop owing to inhomogeneous molecule-substrate interactions. The ability of TERS to probe the molecular structure and local deformation at the sub-molecular level, as demonstrated here, is important for understanding surface science as well as molecular electronics and optoelectronics at the nanoscale.

Background Programmed cell death-ligand 1 (PD-L1) is overexpressed in tumor cells, which causes tumor cells to escape T cell killing, and promotes tumor cell survival, cell proliferation, migration, invasion, and angiogenesis. Britannin is a natural product with anticancer pharmacological effects. Purpose In this work, we studied the anticancer potential of britannin and explored whether britannin mediated its effect by inhibiting the expression of PD-L1 in tumor cells. Methods In vitro, the mechanisms underlying the inhibition of PD-L1 expression by britannin were investigated by MTT assay, homology modeling and molecular docking, RT-PCR, western blotting, co-immunoprecipitation, and immunofluorescence. The changes in tumor killing activity, cell proliferation, cell cycle, migration, invasion, and angiogenesis were analyzed by T cell killing assays, EdU labeling, colony formation, flow cytometry, wound healing, matrigel transwell invasion, and tube formation, respectively. In vivo, the antitumor activity of britannin was evaluated in the HCT116 cell xenograft model. Results Britannin reduced the expression of PD-L1 in tumor cells by inhibiting the synthesis of the PD-L1 protein but did not affect the degradation of the PD-L1 protein. Britannin also inhibited HIF-1α expression through the mTOR/P70S6K/4EBP1 pathway and Myc activation through the Ras/RAF/MEK/ERK pathway. Mechanistically, britannin inhibited the expression of PD-L1 by blocking the interaction between HIF-1α and Myc. In addition, britannin could enhance the activity of cytotoxic T lymphocytes and inhibit tumor cell proliferation and angiogenesis by inhibiting PD-L1. Finally, in vivo observations were confirmed by demonstrating the antitumor activity of britannin in a murine xenograft model. Conclusion Britannin inhibits the expression of PD-L1 by blocking the interaction between HIF-1α and Myc. Moreover, britannin stabilizes T cell activity and inhibits proliferation and angiogenesis by inhibiting PD-L1 in cancer. The current work highlights the anti-tumor effect of britannin, providing insights into the development of cancer therapeutics via PD-L1 inhibition.

Ambitions to reach atomic resolution with light have been a major force in shaping nano-optics, whereby a central challenge is achieving highly localized optical fields. A promising approach employs plasmonic nanoantennas, but fluorescence quenching in the vicinity of metallic structures often imposes a strict limit on the attainable spatial resolution, and previous studies have reached only 8 nm resolution in fluorescence mapping. Here, we demonstrate spatially and spectrally resolved photoluminescence imaging of a single phthalocyanine molecule coupled to nanocavity plasmons in a tunnelling junction with a spatial resolution down to ∼8 Å and locally map the molecular exciton energy and linewidth at sub-molecular resolution. This remarkable resolution is achieved through an exquisite nanocavity control, including tip-apex engineering with an atomistic protrusion, quenching management through emitter–metal decoupling and sub-nanometre positioning precision. Our findings provide new routes to optical imaging, spectroscopy and engineering of light–matter interactions at sub-nanometre scales., This work was supported by the National Key R&D Program of China (grant numbers 2016YFA0200600 and 2017YFA0303500), the National Natural Science Foundation of China, the Strategic Priority Research Program of the Chinese Academy of Sciences (grant number XDB36000000) and the Anhui Initiative in Quantum Information Technologies. J.A. acknowledges project IT1164-19 of the consolidated university groups from the Basque Government.

AIM To investigate the role of peritoneal macrophage (PM) polarization in the therapeutic effect of abdominal paracentesis drainage (APD) on severe acute pancreatitis (SAP). METHODS SAP was induced by 5% Na-taurocholate retrograde injection in Sprague-Dawley rats. APD was performed by inserting a drainage tube with a vacuum ball into the lower right abdomen of the rats immediately after the induction of SAP. To verify the effect of APD on macrophages, PMs were isolated and cultured in an environment, with the peritoneal inflammatory environment simulated by the addition of peritoneal lavage in complete RPMI 1640 medium. Hematoxylin and eosin staining was performed. The levels of pancreatitis biomarkers amylase and lipase as well as the levels of inflammatory mediators in the blood and peritoneal lavage were determined. The polarization phenotypes of the PMs were identified by detecting the marker expression of M1/M2 macrophages via flow cytometry, qPCR and immunohistochemical staining. The protein expression in macrophages that had infiltrated the pancreas was determined by Western blot. RESULTS APD treatment significantly reduced the histopathological scores and levels of amylase, lipase, tumor necrosis factor-α and interleukin (IL)-1β, indicating that APD ameliorates the severity of SAP. Importantly, we found that APD treatment polarized PMs towards the M2 phenotype, as evidenced by the reduced number of M1 macrophages and the reduced levels of pro-inflammatory mediators, such as IL-1β and L-selectin, as well as the increased number of M2 macrophages and increased levels of anti-inflammatory mediators, such as IL-4 and IL-10. Furthermore, in an in vitro study wherein peritoneal lavage from the APD group was added to the cultured PMs to simulate the peritoneal inflammatory environment, PMs also exhibited a dominant M2 phenotype, resulting in a significantly lower level of inflammation. Finally, APD treatment increased the proportion of M2 macrophages and upregulated the expression of the anti-inflammatory protein Arg-1 in the pancreas of SAP model rats. CONCLUSION These findings suggest that APD treatment exerts anti-inflammatory effects by regulating the M2 polarization of PMs, providing novel insights into the mechanism underlying its therapeutic effect.

Objective To investigate the effect of early stage abdominal paracentesis drainage (APD) on phenotype transition of peritoneal macrophage in rats with severe acute pancreatitis (SAP). Methods A total of 36 adult male Sprague Dawley (SD) rats were randomized into SAP, APD, and sham-operated (Sham) groups (n=12). Pancreatitis in SAP and APD groups were induced by 5% sodium taurocholate retrograde injection. In the APD group, a drainage tube was placed in the lower right abdomen of rats with pancreatitis before closure. In the Sham group, rats didn't receive the injection procedure, and a segment of the drainage tube was placed in the abdomen. The rats were sacrificed 12 hours after model established. The histopathological injury was evaluated by HE staining and scored using a previously described scoring system. The level of amylase and lipase, pro/ anti-inflammatory mediators in serum, were determined by ELISA. The polarization of peritoneal macrophage was analyzed by flow cytometry. The mRNA expression of M1-associated protein tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), CD163 and CD206 in peritoneal cells were detected by qPCR. Results The histopathological injury and its score of the pancreas in APD group decreased as well as the serum level of amylase, lipase, TNF-α, interleukin-1β (IL-1β) compared with SAP group, however, the level of anti-inflammatory cytokines interleukin-10 (IL-10) and transforming growth factor-β (TGF-β) in plasma increased significantly (P0.05). Conclusion APD ameliorates SAP by enhancing the M2 polarization of peritoneal macrophage and inhibiting systematic inflammation. DOI: 10.11855/j.issn.0577-7402.2018.10.05

Dexmedetomidine (Dexm), a selective alpha-2 adrenoceptor agonist, and dexamethasone (Dexa), a very potent and highly selective glucocorticoid, have both been proven effectively to prolong the duration of local anesthetics (LA) in regional anesthesia. However, data comparing the efficacy of Dexm and Dexa as perineural adjuvants are inconsistent. Therefore, this systematic review and meta-analysis of randomized and quasi-randomized controlled trials (RCTs) was conducted to compare the effects of Dexm and Dexa when used as LA adjuvants on peripheral nerve block (PNB).We systematically searched PubMed, Cochrane Library, EMBASE, Web of Science, and ScienceDirect databases up to October, 2020. The primary outcome was the duration of analgesia. Secondary outcomes included incidence of rescue analgesia, cumulative opioid consumption, time required for onset of sensory and motor blockades, duration of sensory and motor blockades, incidence of postoperative nausea and vomiting (PONV), and side effect-associated outcomes (e.g., bradycardia, sedation, hypotension, rates of infection, and neurological complications). The study was registered on PROSPERO, number CRD42020188796.After screening of full-text relevant articles, 13 RCTs that met the inclusion criteria were retrieved for this systematic review. It was revealed that perineural Dexm provided equivalent analgesic duration to perineural Dexa. Besides, the intake of Dexm increased the incidence of rescue analgesia in limbs surgery, as well as the cumulative opioid consumption, and decreased the time required for onset of sensory and motor blockades for long-acting LA (all P .05). Other analysis revealed insignificant difference between the 2 groups in terms of the incidence of PONV (P .05). Additionally, 2 studies demonstrated that Dexm possesses more sedative properties than Dexa (P .05).This meta-analysis indicated that the analgesic duration of Dexm and Dexa as LA adjuvants in PNB is the same. Meanwhile, the effects of perineural Dexm and Dexa on some secondary outcomes, including the incidence of rescue analgesia, cumulative opioid consumption, and time required for onset of sensory and motor blockades, are associated with the surgical site and type of LA.

Algal cultures are generally co-cultures of algae and bacteria, especially when considering outdoor cultivation. However, the effects of associated bacteria on algal growth remain largely unexplored, particularly in the context of Isochrysis galbana. In the present study, we investigated the effects of antibiotic on the growth of I. galbana and its associated bacterial community. We found advantageous responses of I. galbana to antibiotic exposure, evidenced by the increased growth, and the maximal photochemical efficiency of PSII (Fv/Fm). Since antibiotics can cause major disturbances within bacterial community, we further conducted 16S rDNA amplicon sequencing to determine the changes of bacterial community diversity following antibiotic treatment. We found that antibiotic treatment considerably and negatively affected the abundance and diversity of bacterial community, and 17 significantly decreased bacterial species in the antibiotic-treated medium, including Pseudomonas stutzeri, were identified. Further co-culture experiments revealed that P. stutzeri inhibited the growth of I. galbana, and the inhibitory activity was retained in the cell-free bacterial filtrate. These results indicated that the negative effect of bacteria was not exclusively transmitted through contact with I. galbana but could be also mediated via secretory compounds. Taken together, our findings not only fully characterized the bacterial community associated with I. galbana and how the bacterial community changed in response to antibiotic perturbations, but also provided a valuable information about the interactions between I. galbana and its associated bacteria, which might help improve the yield, and quality of I. galbana during its cultivation processes.

Both DNA cytosine methylation (5-methyl-2'-deoxycytidine, m5dC) and RNA cytosine methylation (5-methylcytidine, m5rC) are important epigenetic marks that play regulatory roles in diverse biological processes. m5dC and m5rC can be further oxidized by the ten-eleven translocation (TET) proteins to form 5-hydroxymethyl-2'-deoxycytidine (hm5dC) and 5-hydroxymethylcytidine (hm5rC), respectively. 2'-O-methyl-5-hydroxymethylcytidine (hm5rCm) was recently also identified as a second oxidative metabolite of m5rC in RNA. Previous studies showed that the dysregulation of cytidine modifications in both DNA and RNA are closely related to a variety of human diseases. These cytidine modifications are generally excreted from cell into urine. If these cytidine modifications exhibit specific features related to certain diseases, determination of the cytidine modifications in urine could be utilized as non-invasive diagnostic of diseases. Here, we established a solid-phase extraction in combination with liquid chromatography-mass spectrometry (LC-MS/MS) analysis for simultaneous detection of these cytidine modifications in human urine samples. The developed method enabled the distinct detection of these cytidine modifications. We reported, for the first time, the presence of hm5rCm in human urine. Furthermore, we found that compared to the healthy controls, the contents of hm5dC, hm5rC, and hm5rCm showed significant increases in urine samples of cancer patients, including lymphoma patients, gastric cancer patients, and esophageal cancer patients. This study indicates that the urinary hydroxylmethylation modifications of hm5dC, hm5rC, and hm5rCm may serve as potential indicator of cancers.

The strong spatial confinement of a nanocavity plasmonic field has made it possible to visualize the inner structure of a single molecule and even to distinguish its vibrational modes in real space. With such ever-improved spatial resolution, it is anticipated that full vibrational imaging of a molecule could be achieved to reveal molecular structural details. Here we demonstrate full Raman images of individual vibrational modes at the ångström level for a single Mg-porphine molecule, revealing distinct characteristics of each vibrational mode in real space. Furthermore, by exploiting the underlying interference effect and Raman fingerprint database, we propose a new methodology for structural determination, which we have called ‘scanning Raman picoscopy’, to show how such ultrahigh-resolution spectromicroscopic vibrational images can be used to visually assemble the chemical structure of a single molecule through a simple Lego-like building process.

Microalgae are primary producers in aquatic environments, and their growth is often accompanied and affected by bacteria. Although there are some studies about the relationship between microalgae and bacteria, few studies focused on bait-microalgae. Based on 16S rDNA amplicon sequencing, bacterial community structure and composition associated with seven common bait-microalgae, including Isochrysis galbana 3009, I. galbana 3010, I. galbana 3011, Thalassiosira pseudonana 9005, T. pseudonana 9006, Nannochloropsis oceanica 0001 and N. oceanica 0141, were comprehensively analyzed. Our results indicated that bacteria affiliated with phylum Alphaproteobacteria and Gammaproteobacteria and genera Marinobacter, Oceanicaulis and Dinoroseobacter dominated in all these seven bait-microalgae. Based on alpha and beta diversity analysis, we were interested to found that there were significant differences in the bacterial community between different microalgal species, while the differences were relatively small among the same species. When further searching for putative effect of dominant bacteria on the growth of microalgae, we found that the growth of all these seven microalgae was all improved significantly during co-cultivation with Marinobacter sp. When I. galbana 3011 was co-cultured with other three dominant bacteria, including Algoriphagus sp., Dinoroseobacter sp., and Oceanicaulis sp., the growth was improved significantly to different degrees. Taken together, the present work fully characterized the bacterial community associated with seven bait-microalgae and had a tentative exploration of algae-bacteria interaction, which will help improve the yield and quality of bait-microalgae during their cultivation processes.

With the improvement of requirements for vehicle comfort, people put forward higher requirements on the noise control of automotive air conditioning. As the power source of the automobile air conditioner, the compressor is also the main noise sources, so it is the major objective of vibration damping and noise reduction. In this paper, with analyzing the noise mechanism of compressor, introduces four identification methods of automotive air conditioning compressor noise source, providing theoretical basis for automobile air conditioning damping and noise reduction.

In order to study the working features of automotive air conditioning scroll compressor, this paper uses mathematical model of working process to analyze it. After studying working process, a equation of suction volume is given. The thermodynamic model of compression chamber and back pressure chamber includes mass conservation and energy conservation. Based on Hydromechanics, leakage models of radial leakage and tangential leakage are discussed. The model lays a foundation of automotive air conditioning scroll compressor performance simulation.

The microalga Isochrysis galbana exhibits a seasonal fluctuation of biomass referred to as ‘decline’ during summer, leading to a great economic loss in the mariculture industry. In the present study, we aimed to explore the role of ultraviolet radiation (UVR) in I. galbana decline at high temperature by integrated analysis of metabolomic and transcriptomic data. The positive effects of UVR deprivation on the growth and photosynthetic activity of I. galbana were preliminarily evidenced by the increase in biomass concentration, the effective photochemical efficiency of photosystem II (PSII) (Fv′/Fm′), and oxygen evolution rate. Furthermore, we compared the contents of eight organic acids, total lipids and gene expression of I. galbana grown under natural sunlight versus UVR-deprived conditions, as well as. The contents of some tricarboxylic acid (TCA) cycle-related organic acids were higher in the UVR-deprived group. Lipidomic analysis indicated that UVR deprivation resulted in the accumulation of monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), sulfoquinovosyldiacylglycerol (SQDG), diacylglycerylcarboxyhydroxymethylcholine (DGCC), diacylglyceryl-N,N,N-trimethylhomoserine (DGTS), and lyso-lipids, while triacylglycerol (TAG) was decreased. Consistent with these results, the transcriptomic data showed that the expressions of some key genes involved in the TCA cycle and the photosynthesis pathways were clearly induced by UVR deprivation. Besides, the down-regulation of diacylglycerol O-acyltransferases (DGAT) and the up-regulation of TAG lipase collectively resulted in the lower accumulation of TAG, which was consistent with the metabolomic data. Taken together, the decline of I. galbana in summer could be explained by the disorder of a series of biological processes caused by UVR, especially the damage to photosynthesis, the slowdown of TCA cycle, and the disturbance of lipid metabolism. This study allowed us to better understand the responses of I. galbana to UVR stress and provided useful information for the cultivation of I. galbana in summer, greatly expanding our current knowledge on the genetic information of I. galbana.

With the continuous development of superfine powder industry and the application scope, the environmental safety of superfine powder preparation has been getting more and more attention. This article discusses the possible pollution source causing hazards to environmental safety and put forwards some corresponding control measures by analyzing the production factors in the process of super fine power preparation.

With the increasing growing of metal mine exploitation degree and the developing of modern metal industry, the environmental pollution of production process in metal mine more and more gets the attention of people. Accord to the production technology of metal mines, this paper analyses the reason of environmental pollution, concludes the existent pollution factors and their harmfulness and finally discussed technology measures of treating and controlling for environmental pollution in production process of metal mine.

A growth trial was conducted to estimate the optimum levels of dietary phosphorus (P) for juvenile hybrid tilapia (Oreochromis niloticus × O. aureus) fed fishmeal-free practical diets. Hybrid tilapia (1.68 ± 0.08 g) were fed diets containing various levels (0.0%, 0.2%, 0.4%, 0.6%, 0.8% and 1.0%) of additional inorganic phosphorus for 10 weeks using two different sources of phosphorus：calcium dihydrogen phosphate (MCP), and sodium dihydrogen phosphate (MSP). Hybrid tilapia fed the P-supplemented diets showed significantly higher weight gain (WG) and mineral deposition than those fed the unsupplemented diet. Based on weight gain and vertebral phosphorus content, the available phosphorus requirements of hybrid tilapia were estimated as 1% and 1.31% (0.6% and 0.9% based on additional phosphorus content) respectively, when MSP was used as a phosphorus source. When MCP was the phosphorus source, the requirement estimated for weight gain was 0.95% (0.61% based on additional phosphorus content). In addition, MCP contributed to increased growth and a higher mineral deposition rate than did MSP, in freshwater-reared hybrid tilapia.