Full C- and L-band covered second-order OAM mode generator based on a thinned helical long-period fiber grating.

A full C- and L-band covered second-order orbital-angular-momentum (OAM) mode generator has been proposed and experimentally demonstrated, which is realized by using a helical long-period fiber grating (HLPG) but inscribed in a thinned four-mode fiber. By optimizing the design of grating period and fiber diameter of the proposed HLPG, an ultra-broadband rejection filter with a depth of ∼23 dB, a bandwidth of ∼156 nm @-10 dB (ranging from 1522 nm to 1678 nm) and a bandwidth of ∼58 nm @-20 dB (ranging from 1574 nm to 1632 nm), has been successfully obtained as a typical sample. To the best of our knowledge, this is the first demonstration of such ultra-broadband second-order OAM mode generator by using only one fiber component, i.e., the thinned HLPG. In addition, the proposed generator is less polarization-dependent and less temperature-sensitive than those of the conventional HLPGs, which is believed to be considerably helpful to find potential applications of the device itself in wavelength division multiplexing (WDM) and OAM mode division multiplexing (MDM) optical fiber communication systems.

Temperature-insensitive high-sensitivity refractive index sensor based on a thinned helical fiber grating with an intermediate period.

A temperature-insensitive high-sensitivity refractive index sensor is proposed and experimentally demonstrated, which is based on utilization of a thinned helical fiber grating but with an intermediate period (THFGIP). Attributed to the reduced diameter and an intermediate period of the grating, the proposed sensor has a high surrounding refractive-index (SRI) sensitivity and a low temperature sensitivity. The average SRI sensitivity of the proposed sensor is up to 829.9 nm/RIU in the range of 1.3410-1.4480 RIU. Moreover, unlike the traditional sensitivity-enhancement method by increasing the waveguide dispersion factor, here the waveguide dispersion factor at the resonant wavelength was decreased by reducing the diameter of the fiber grating and as a result, the crosstalk effect due to the temperature change can be further suppressed. The proposed temperature-insensitive SRI sensor has the superiorities of simple structure, ease fabrication, and low cost, which could be found more potential applications in the SRI sensing fields.

Deficiency of P2RY11 causes narcolepsy and attenuates the recruitment of neutrophils and macrophages in the inflammatory response in zebrafish.

Purinergic receptor P2Y11, a G protein-coupled receptor that is stimulated by extracellular ATP, has been demonstrated to be related to the chemotaxis of granulocytes, apoptosis of neutrophils, and secretion of cytokines in vitro. P2Y11 mutations were associated with narcolepsy. However, little is known about the roles of P2RY11 in the occurrence of narcolepsy and inflammatory response in vivo. In this study, we generated a zebrafish P2Y11 mutant using CRISPR/Cas9 genome editing and demonstrated that the P2Y11 mutant replicated the narcolepsy-like features including reduced HCRT expression and excessive daytime sleepiness, suggesting that P2Y11 is essential for HCRT expression. Furthermore, we accessed the cytokine expression in the mutant and revealed that the P2RY11 mutation disrupted the systemic inflammatory balance by reducing il4, il10 and tgfb, and increasing il6, tnfa, and il1b. In addition, the P2RY11-deficient larvae with caudal fin injuries exhibited significantly slower migration and less recruitment of neutrophils and macrophages at damaged site, and lower expression of anti-inflammatory cytokines during tissue damage. All these findings highlight the vital roles of P2RY11 in maintaining HCRT production and secreting anti-inflammatory cytokines in the native environment, and suggested that P2RY11-deficient zebrafish can serve as a reliable and unique model to further explore narcolepsy and inflammatory-related diseases with impaired neutrophil and macrophage responses.

Intestinal epithelial Krüppel-like factor 4 alleviates endotoxemia and atherosclerosis through improving NF-κB/miR-34a-mediated intestinal permeability.

Maintenance of intestinal barrier function contributes to gastrointestinal homeostasis and therefore cardiovascular diseases. A number of studies show that intestinal permeability is affected by excessive inflammatory responses. Krüppel-like factor (KLF) 4 is one of the critical transcriptional factors, which controls multiple immune responses. In this study we investigated the role of KLF4 in regulating intestinal inflammation and permeability during the atherosclerotic process. Atherosclerotic model was established in ApoE-/- mice by feeding a high fat high cholesterol (HFHC) diet. We showed that colon expression levels of KLF4 and tight junction proteins were significantly decreased whereas inflammatory responses increased in atherosclerotic mice. Overexpression of colon epithelial Klf4 decreased atherosclerotic plaque formation and vascular inflammation in atherosclerotic mice, accompanied by remarkable suppression of intestinal NF-κB activation. We found that overexpression of epithelial Klf4 in atherosclerotic mice significantly increased intestinal tight junction expression and ameliorated endotoxemia, whereas replenishment of LPS abolished these benefits. Overexpression of Klf4 reversed LPS-induced permeability and downregulation of ZO-1 and Occludin in Caco-2 cells in vitro. HFHC diet stimulated the expression of epithelial microRNA-34a, whereas silence of epithelial Klf4 abolished the benefits of microRNA-34a sponge, a specific miR-34a inhibitor, on intestinal permeability and atherosclerotic development. A clinical cohort of 24 atherosclerotic patients supported colon KLF4/NF-κB/tight junction protein axis mediated intestine/cardiovascular interaction in patients with atherosclerosis. Taken together, intestinal epithelial KLF4 protects against intestinal inflammation and barrier dysfunction, ameliorating atherosclerotic plaque formation.

[Meta-analysis and trial sequential analysis of Tanreqing Injection in treatment of severe pneumonia in elderly].

This study aimed to systematically evaluate the effectiveness and safety of Tanreqing Injection in the treatment of severe pneumonia in the elderly. Eighteen randomized controlled trials(RCTs) involving 1 457 elderly patients with severe pneumonia were included in the study after conducting searches in both Chinese and English databases as well as clinical trial registration platforms. The quality of the included studies was assessed using the Cochrane risk of bias assessment tool. Meta-analysis were conducted using RevMan 5.4 and Stata 17 software, and trial sequential analysis(TSA) was performed using TSA 0.9.5.10 beta software. Meta-analysis results showed that compared with conventional western medicine treatment, Tanreqing Injection + conventional western medical significantly improved the clinical effectiveness in elderly patients with severe pneumonia(RR=1.26, 95%CI[1.20, 1.32], P<0.000 01), arterial oxygen partial pressure(SMD=6.23, 95%CI[3.29, 9.18], P<0.000 1), oxygenation index(SMD=11.72, 95%CI[4.41, 19.04], P=0.002), reduce procalcitonin(SMD=-6.16, 95%CI[-8.10,-4.21], P<0.000 01), C-reactive protein(SMD=-8.50, 95%CI[-11.05,-5.96], P<0.000 01), white blood cell count(SMD=-4.56, 95%CI[-5.73,-3.39], P<0.000 01), and shortened the duration of fever(SMD=-3.12, 95%CI[-4.61,-1.63], P<0.000 1), cough(SMD=-4.84, 95%CI[-6.90,-2.79], P<0.000 01), lung rales(SMD=-0.99, 95%CI[-1.54,-0.44], P=0.000 4), and mechanical ventilation time(SMD=-3.26, 95%CI[-5.03,-1.50], P=0.000 3), increase CD4~+ T-cell levels(SMD=6.73, 95%CI[5.23, 8.23], P<0.000 01) and CD8~+ T-cell levels(SMD=7.47, 95% CI[5.32, 9.61], P<0.000 01) with no significant adverse reactions. TSA confirmed the stability and reliability of the results related to clinical effectiveness. This study suggests that Tanreqing Injection, as a Chinese medicinal preparation, has a significant therapeutic effect and good safety profile in the treatment of severe pneumonia in elderly patients. Due to the limited quality of the included studies, high-quality RCT is still needed to provide evidence support for the above conclusions.

Recognition of the orbital-angular-momentum spectrum for hybrid modes existing in a few-mode fiber via a deep learning method.

In this study, we theoretically and experimentally demonstrate that the convolutional neural network (CNN) in combination with the residual blocks and the regression methods can be used to precisely and quickly reconstruct the OAM spectrum of a hybrid OAM mode no matter how the consistent OAM modes have the same or different order indices in both the azimuthal and the radial direction. For cases of the simulation testing, the mean errors of all recognized parameters for hybrid OAM modes in a four-mode fiber (4MF) and a six-mode fiber (6MF) are smaller than 0.003 and 0.008, respectively. To the best of our knowledge, this is the first time that all the OAM modes, probably existing in the core of 4MFs or 6MFs, can be precisely and quickly recognized from intensity distribution of the hybrid OAM mode itself via the deep learning method.

Probe-type all-fiber tiny-displacement sensor based on orbital-angular-momentum interferometry.

In this study, a probe-type all-fiber tiny-displacement sensor is proposed and experimentally demonstrated, which is realized by using an all-fiber orbital-angular-momentum (OAM) interferometer, where a probe is especially adopted and inserted into the testing arm of the OAM interferometer. The proposed device takes full advantages of the OAM interferometer and the probe-type fiber sensor, making it completely available to the tiny-displacement measurement. As a result, changes in displacement (ranging from 0 nm to 750 nm) with a real resolution of ∼8.81 nm have been successfully measured. To our knowledge, this is the first demonstration of an all-fiber probe-type OAM interferometer, which may find potential application to high-precision tiny displacement in a small confined space.

Antibacterial metabolites from the beetle-associated fungus Penicillium chrysogenum.

The antibacterial secondary metabolites of the fungus Penicillium chrysogenum associated with the beetle Aspongopus chinensis were investigated through chromatographic fractionation methods of ethyl acetate extracts of the fungal cultures. Five compounds were isolated, and their structures were determined as emodin, 4-(methoxymethyl)benzoic acid, isoochracinic acid, secalonic acid D, and dicerandrol A using mass spectroscopy and nuclear magnetic resonance spectroscopic analyses. Emodin exhibited strong antimicrobial activity, especially against Staphylococcus aureus even when growing on cooked pork, with a minimal inhibitory concentration (MIC) of 6.3 µg/mL. Dimeric tetrahydroxanthones, such as secalonic acid D and dicerandrol A, also exhibited potent activity, with MIC values ranging from 9.5 to 28.5 µg/mL. In summary, P. chrysogenum was isolated as a symbiotic fungus of the beetle A. chinensis for the first time and this strain could generate antibacterial secondary metabolites, which could potently inhibit gram-positive bacteria growth in vitro.

Circular RNA circ_0008305 aggravates hepatocellular carcinoma growth through binding to miR-186 and inducing TMED2.

Dysregulation of circRNAs is reported to exert crucial roles in cancers, including hepatocellular carcinoma (HCC). So far, the function of circRNAs in HCC development remains poorly known. Currently, our data showed that circ_0008305 was highly elevated in HCC cell lines and 30 paired tissue samples of HCC. As evidenced, suppression of circ_0008305 repressed HCC cell growth significantly. Meanwhile, up-regulation of circ_0008305 significantly reduced HCC cell growth. Mechanistically, we displayed that circ_0008305 could bind with miR-186 by using bioinformatics analysis. miR-186 has been reported to be a crucial tumour oncogene in many cancers. In addition, we proved miR-186 was greatly decreased in HCC. The direct correlation between miR-186 and circ_0008305 was confirmed in our work. In addition, up-regulation of miR-186 obviously restrained HCC progression. Increased expression of transmembrane p24 trafficking protein 2 (TMED2) is significantly related to the unfavourable outcomes in cancer patients. At our present work, we proved that TMED2 could act as a direct target of miR-186. Mechanistically, we demonstrated that circ_0008305 up-regulated TMED2 expression by sponging miR-186, which resulted in significantly induced HCC progression in vitro and in vivo. These revealed the significant role of circ_0008305 in HCC progression, which might indicate a new perspective on circRNAs in HCC development.

A novel C-type lectin from Trichinella spiralis mediates larval invasion of host intestinal epithelial cells.

The aim of this study was to investigate the characteristics of a novel type C lectin from Trichinella spiralis (TsCTL) and its role in larval invasion of intestinal epithelial cells (IECs). TsCTL has a carbohydrate recognition domain (CRD) of C-type lectin. The full-length TsCTL cDNA sequence was cloned and expressed in Escherichia coli BL21. The results of qPCR, Western blotting and immunofluorescence assays (IFAs) showed that TsCTL was a surface and secretory protein that was highly expressed at the T. spiralis intestinal infective larva (IIL) stages and primarily located at the cuticle, stichosome and embryos of the parasite. rTsCTL could specifically bind with IECs, and the binding site was localized in the IEC nucleus and cytoplasm. The IFA results showed that natural TsCTL was secreted and bound to the enteral epithelium at the intestinal stage of T. spiralis infection. The rTsCTL had a haemagglutinating effect on murine erythrocytes, while mannose was able to inhibit the rTsCTL agglutinating effect for mouse erythrocytes. rTsCTL accelerated larval intrusion into the IECs, whereas anti-rTsCTL antibodies and mannose significantly impeded larval intrusion in a dose-dependent manner. The results indicated that TsCTL specifically binds to IECs and promotes larval invasion of intestinal epithelium, and it might be a potential target of vaccines against T. spiralis enteral stages.

Plant-Derived Molecule 4-Methylumbelliferone Suppresses FcεRI-Mediated Mast Cell Activation and Allergic Inflammation.

Mast cells (MCs) are an important treatment target for high-affinity IgE Fc receptor (FcεRI)-mediated allergic diseases. The plant-derived molecule 4-methylumbelliferone (4-MU) has beneficial effects in animal models of inflammation and autoimmunity diseases. The aim of this study was to examine 4-MU effects on MC activation and probe the underlying molecular mechanism(s). We sensitized rat basophilic leukemia cells (RBLs) and mouse bone marrow-derived mast cells (BMMCs) with anti-dinitrophenol (DNP) immunoglobulin (Ig)E antibodies, stimulated them with exposure to DNP-human serum albumin (HSA), and then treated stimulated cells with 4-MU. Signaling-protein expression was determined by immunoblotting. In vivo allergic responses were examined in IgE-mediated passive cutaneous anaphylaxis (PCA) and ovalbumin (OVA)-induced active systemic anaphylaxis (ASA) mouse models. 4-MU inhibited ß-hexosaminidase activity and histamine release dose-dependently in FcεRI-activated RBLs and BMMCs. Additionally, 4-MU reduced cytomorphological elongation and F-actin reorganization while down-regulating IgE/Ag-induced phosphorylation of SYK, NF-κB p65, ERK1/2, p38, and JNK. Moreover, 4-MU attenuated the PCA allergic reaction (i.e., less ear thickening and dye extravasation). Similarly, we found that 4-MU decreased body temperature, serum histamine, and IL4 secretion in OVA-challenged ASA model mice. In conclusion, 4-MU had a suppressing effect on MC activation both in vitro and in vivo and thus may represent a new strategy for treating IgE-mediated allergic conditions.

Anomalous circular photogalvanic effect in p-GaAs.

The anomalous circular photogalvanic effect (ACPGE) is observed in p-GaAs with a thickness of 2 µm at room temperature, in which circularly polarized light is used to inject spin-polarized carriers and the spin diffusion can generate a macroscopic detectable charge current due to the inverse spin Hall effect. The normalized ACPGE signals show first increasing and then decreasing with increasing the doping concentration. The role of the doping impurities is discussed by both extrinsic and intrinsic models, and both can well explain the variation of ACPGE with the doping concentration.

Application of low dose pancreas perfusion CT combined with enhancement scanning in diagnosis of pancreatic neuroendocrine tumors.

PURPOSE: To explore the diagnostic value of pancreatic perfusion CT combined with contrast-enhanced CT in one-time scanning (PCECT) in pancreatic neuroendocrine tumors (PNETs) and to evaluate the difference of perfusion parameters between different grades of PNETs. MATERIALS AND METHODS: From October 2016 to December 2018, forty consecutive patients with histopathological-proven PNETs were identified retrospectively that received PCECT for the preoperative PNETs evaluation. Two board certified radiologists who were blinded to the clinical data evaluated the images independently. The image characters of PNETs vs. tumor-free pancreatic parenchymal and different grades of PNETs were analyzed. RESULTS: One-time PCECT scanning had a detection rate of 89.1% for PNETs, which was higher than the detection accuracy of the perfusion CT only (83.6%). The perfusion parameters of PNETs including blood volume (BV), blood flow (BF), mean slope of increase (MSI), and capillary surface permeability (PS) were significantly increased than those of tumor-free pancreatic parenchyma (p < 0.05, respectively). For differential comparison between grade I (G1) and grade II (G2) tumors, the parameters of BF and impulse residue function (IRF) of tumor tissue were significantly higher in the G2 tumors (p < 0.05, for both). In this study, the total radiation dose of the whole PCECT scan was 16.241 ± 2.289 mSv. CONCLUSION: The one-time PCECT scan may improve the detection of PNETs according to morphological features and perfusion parameters with a relative small radiation dose. The perfusion parameters of BF and IRF may be used to help distinguish G1 and G2 tumors in the preoperative evaluation.

Metabolic reprogramming by traditional Chinese medicine and its role in effective cancer therapy.

Metabolic reprogramming, characterized by alterations of cellular metabolic patterns, is fundamentally important in supporting the malignant behaviors of cancer cells. It is considered as a promising therapeutic target against cancer. Traditional Chinese medicine (TCM) and its bioactive components have been used in cancer therapy for an extended period, and they are well-known for their multi-target pharmacological functions and fewer side effects. However, the detailed and advanced mechanisms underlying the anticancer activities of TCM remain obscure. In this review, we summarized the critical processes of cancer cell metabolic reprogramming, including glycolysis, mitochondrial oxidative phosphorylation, glutaminolysis, and fatty acid biosynthesis. Moreover, we systemically reviewed the regulatory effects of TCM and its bioactive ingredients on metabolic enzymes and/or signal pathways that may impede cancer progress. A total of 46 kinds of TCMs was reported to exert antitumor effects and/or act as chemosensitizers via regulating metabolic processes of cancer cells, and multiple targets and signaling pathways were revealed to contribute to the metabolic-modulating functions of TCM. In conclusion, TCM has its advantages in ameliorating cancer cell metabolic reprogramming by its poly-pharmacological actions. This review may shed some new light on the explicit recognition of the mechanisms of anticancer actions of TCM, leading to the development of natural antitumor drugs based on reshaping cancer cell metabolism.

Biological properties and roles of a Trichinella spiralis inorganic pyrophosphatase in molting and developmental process of intestinal larval stages.

Inorganic pyrophosphatase (PPase) participates in energy cycle and plays a vital role in hydrolysis of inorganic pyrophosphate (PPi) into inorganic phosphate (Pi). The aim of this study was to investigate the biological properties of a Trichinella spiralis PPase (TsPPase) and its role in larval molting and developmental process. The predicted TsPPase consisted of 367 amino acids with a molecular mass of 41.48 kDa and a pI of 5.76. Amino acid sequence alignment and phylogenetic analysis showed that the TsPPase gene encodes a functional family I soluble PPase with the same characteristics as prokaryotic, plant and animal/fungal soluble PPase. The rTsPPase was expressed and purified, it has the activity to catalyze the hydrolysis of PPi to Pi, and the activity was dependent on Mg2+, pH and temperature. The enzymatic activity of rTsPPase was significantly inhibited after its metal binding sites mutation. TsPPase was transcribed and expressed in all T. spiralis phases, especially in muscle larvae (ML) and intestinal infective larvae (IIL). Immunofluorescence assay (IFA) revealed that TsPPase was mainly located in cuticle and stichosome. When the ML and IIL were treated with TsPPase-specific siRNA-279, TsPPase expression and enzymatic activity were obviously reduced, the larval molting and development were also impeded. Intestinal IIL as well as AW burden, IIL molting rates from mice infected with siRNA-treated ML were obviously suppressed. The results indicated that rTsPPase possesses the enzymatic activity of native inorganic pyrophosphatase, and TsPPase plays an important role in development and molting process of intestinal T. spiralis larval stages.

Berberine alleviates visceral hypersensitivity in rats by altering gut microbiome and suppressing spinal microglial activation.

Accumulating evidence shows that agents targeting gut dysbiosis are effective for improving symptoms of irritable bowel syndrome (IBS). However, the potential mechanisms remain unclear. In this study we investigated the effects of berberine on the microbiota-gut-brain axis in two rat models of visceral hypersensitivity, i.e., specific pathogen-free SD rats subjected to chronic water avoidance stress (WAS) and treated with berberine (200 mg· kg-1 ·d-1, ig, for 10 days) as well as germ-free (GF) rats subjected to fecal microbiota transplantation (FMT) from a patient with IBS (designated IBS-FMT) and treated with berberine (200 mg· kg-1 ·d-1, ig, for 2 weeks). Before the rats were sacrificed, visceral sensation and depressive behaviors were evaluated. Then colonic tryptase was measured and microglial activation in the dorsal lumbar spinal cord was assessed. The fecal microbiota was profiled using 16S rRNA sequencing, and short chain fatty acids (SCFAs) were measured. We showed that berberine treatment significantly alleviated chronic WAS-induced visceral hypersensitivity and activation of colonic mast cells and microglia in the dorsal lumbar spinal cord. Transfer of fecal samples from berberine-treated stressed donors to GF rats protected against acute WAS. FMT from a patient with IBS induced visceral hypersensitivity and pro-inflammatory phenotype in microglia, while berberine treatment reversed the microglial activation and altered microbial composition and function and SCFA profiles in stools of IBS-FMT rats. We demonstrated that berberine did not directly influence LPS-induced microglial activation in vitro. In both models, several SCFA-producing genera were enriched by berberine treatment, and positively correlated to the morphological parameters of microglia. In conclusion, activation of microglia in the dorsal lumbar spinal cord was involved in the pathogenesis of IBS caused by dysregulation of the microbiota-gut-brain axis, and the berberine-altered gut microbiome mediated the modulatory effects of the agent on microglial activation and visceral hypersensitivity, providing a potential option for the treatment of IBS.

Effects of Strain and Kinetics on the H2O2-Assisted Reconstruction of Ag-Au-Ag Nanorods.

Morphology of Ag nanocrystals (NCs) is essential to the NC application in catalysis, optics, and as antibacterial agents. Therefore, it is important to develop synthetic methods and understand the evaluation of NC morphology in different chemical environments. In this study, we report interesting findings of the morphological change of fivefold-twinned Ag-Au-Ag nanorods (NRs) under the effect of H2O2 both as an oxidant (etchant) and a reductant. At low H2O2 concentration, the reconstruction of Ag-Au-Ag NRs was dominated by the growth along the longitudinal direction of NRs. With the increase of H2O2 concentration, the reconstruction also occurs in the transverse direction, and a clear change in particle morphology was observed. We further systematically studied the mechanism of the reaction. The results showed that the transition of the morphology was a two-step process: (1) the etching of Ag on the seeds and (2) the reduction of Ag2O. In the second step, the reaction kinetics was highly affected by H2O2 concentration. At low H2O2 concentration, the growth mainly occurs along ⟨110⟩. However, at high H2O2 concentration, the reduction of Ag was not facet-selective. Using the developed method, we can prepare various bimetallic NCs (high aspect ratio NRs with abundant pinholes, nanoplates, and other NCs). The effect of the reconstruction process on the surface-enhanced Raman scattering (SERS) performance of NCs was investigated.

Effects of triphenyl phosphate on ciliate protozoa Tetrahymena thermophila following acute exposure and sub-chronic exposure.

Triphenyl phosphate (TPHP) is one of the most widely used organophosphate flame retardants (OPFRs) and is frequently detected in a variety of environmental media. Previous studies reported that TPHP had toxic effects on vertebrates, but little toxic information was available in lower trophic aquatic organisms which were more sensitive to the exposure of many toxic substances. In this study, protozoa Tetrahymena thermophila (T. thermophila) were exposed to 0, 0.01, 0.17 or 2.35 mg/L TPHP for 5 days to study the effects of sub-chronic exposure on theoretical population, cell viability, cell size and number of cilia. Additionally, the effects of TPHP on gene transcription were assessed by transcriptome sequencing technique (RNA-Seq). Cell viability and number of cilia were significantly reduced in all TPHP exposure groups compared with the control. In addition, exposure to 0.17 or 2.35 mg/L TPHP significantly reduced the theoretical population, circumference and body width, and there was a significant decrease in body length in the 2.35 mg/L exposure group. Comparative transcriptome sequencing identified a total of 4105 up- and 4487 down-regulated genes after exposure to 2.35 mg/L TPHP for 5 days compared with the control. KEGG analysis showed that dysfunction of pathways associated with ribosome, spliceosome, phagosome, proteasome and protein processing in endoplasmic reticulum in this study might be responsible for the toxicity of T. thermophila caused by TPHP. In general, the results indicated that TPHP had an adverse effect on the protozoa T. thermophila.

[Application of sustained lung inflation in preterm infants with a gestational age of <34 weeks: a Meta analysis].

OBJECTIVE: To systematically review the effect of sustained lung inflation (SLI) in preterm infants with a gestational age of <34 weeks. METHODS: PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Wanfang Database, China Biology Medicine disc, Chinese Journal Full-text Database, and Weipu Database were searched for randomized controlled trials (RCTs) on the application of SLI versus noninvasive positive pressure ventilation alone in preterm infants. Revman 5.3 was used to perform a Meta analysis for the RCTs which met the inclusion criteria. RESULTS: A total of 9 RCTs were included, with 1 432 preterm infants in total (with a gestational age of 23-33.7 weeks). The Meta analysis showed that compared with the control group, the SLI group had a significantly lower proportion of the infants who needed mechanical ventilation within 72 hours (51.9% vs 56.9%, RR=0.91, P=0.04, 95%CI: 0.83-0.99). There were no significant differences between the two groups in the mortality rate, rate of use of pulmonary surfactant, and incidence rates of related complications (bronchopulmonary dysplasia, pneumothorax, and grade III-IV intracranial hemorrhage) (P>0.05). CONCLUSIONS: SLI can reduce the use of mechanical ventilation in preterm infants with a gestational age of <34 weeks and does not increase the risk of other complications.

Enhanced second harmonic emission with simultaneous polarization state tuning by aluminum metal-insulator-metal cross nanostructures.

Aluminum (Al) plasmonic nanostructures have recently demonstrated remarkable optical nonlinear phenomena, such as enhanced second harmonic (SH) generation. However, the relatively weak field enhancement resulted from large optical losses associated with aluminum nanostructures in combination with the difficulties in controlling the emission polarization pose as a challenge for SH enhancement and tuning. In this paper, we show that the SH emission of aluminum nanostructures can be efficiently enhanced with the polarization properties simultaneously tunable by using metal-insulator-metal (MIM) nanostructures, constituting of Al cross nanoantenna arrays on top of Al mirrors with a SiO2 spacing layer. Specifically, femtosecond laser beam with a linear polarization parallel to one arm illuminates on the structure while the orthogonal arms were physically modified by the laser-induced photothermal reshaping technique to control the SH radiation by the plasmonic resonances. Under the resonance at the SH wavelength, we observed one order of magnitude larger emission enhancement compared to that at the off-resonant condition. Interestingly, the polarization states can be well manipulated simultaneously by controlling the resonances of the orthogonal arms. The enhanced SH conversion and tunable polarization states pave the way for the development of nonlinear optical sources and advanced functional metasurfaces.