Frequency selection rule for the HDHF Lissajous scanning imaging with a low-voltage one axis actuated PZT scanner based on an asymmetric fiber cantilever.

Lissajous micro scanners are very attractive in compact laser scanning applications for biomedical endoscopic imaging, such as confocal microscopy, endomicroscopy or optical coherence tomography. The scanning frequencies have a very important effect on the quality of the resulting Lissajous scanning imaging. In this paper, we propose a frequency selection rule for high definition and high frame-rate (HDHF) Lissajous scanning imaging, by deriving the relationship among the scanning field of view (FOV), actuation frequencies and pixel size based on the characteristics of the scanning trajectory. The minimum sampling rate based on the proposed frequency selection rule is further discussed. We report a lead zirconate titanate piezoelectric ceramic (PZT) based Lissajous fiber scanner to achieve HDHF Lissajous scanning imaging. Based on the frequency selection rule, different frequency combinations are calculated, under which the Lissajous fiber scanner can work at the frame rate (FR) of 10 Hz, 20 Hz, 40 Hz and 52 Hz. The trajectory evolution of the Lissajous scanning at the frame rate of 10 Hz has been obtained to verify the applicability of the proposed rule. The measured resolution of the scanner is 50.8 lp/mm at the unit optical magnification, and the measured FOV at the FR of 10 Hz and 40 Hz are 1.620 mm ×1.095 mm and 0.405 mm ×0.27 mm, respectively. HDHF Lissajous scanning images of the customized spatial varying binary pattern are obtained and reconstructed at the FR of 10 Hz and 40 Hz, demonstrating the practicability of the frequency selection rule.

Full-range depth-encoded swept source polarization sensitive optical coherence tomography.

To realize the high sensitivity polarization sensitive optical coherence tomography (PS-OCT) imaging, a fiber-based full-range depth-encoded swept source PS-OCT (SS-PS-OCT) method is proposed. The two OCT images corresponding to the orthogonal polarized input light are located on the high sensitivity imaging region of the opposite sides relative to the zero optical path difference position. The full-range OCT images can be obtained by implementing the spatial phase modulation in the reference arm. The detection sensitivity of the system was measured experimentally to be 67 dB when the imaging depth approaching to 2 mm. The imaging of the biological tissue verifies that the proposed full-range depth-encoded SS-PS-OCT system has the higher detection sensitivity compared with the conventional depth encoded SS-PS-OCT system. Finally, we demonstrated the full-range high sensitivity phase retardation image of the bovine tendon and skin of human fingertip. The fiber-based full-range depth-encoded SS-PS-OCT method can realize the high sensitivity birefringence imaging in the medical diagnosis scenes with the requirements for long imaging range and high detection sensitivity.

Construction of a grpE-based plasmid addiction system in Escherichia coli and its application in phloroglucinol biosynthesis.

AIM: Biotechnical processes in Escherichia coli often operate with artificial plasmids. However, these bioprocesses frequently encounter plasmid loss. To ensure stable expression of heterologous genes in E. coli BL21(DE3), a novel plasmid addiction system (PAS) was developed. METHODS AND RESULTS: This PAS employed an essential gene grpE encoding a cochaperone in the DnaK-DnaJ-GrpE chaperone system as the selection marker, which represented a chromosomal ΔgrpE mutant harboring episomal expression plasmids that carry supplementary grpE alleles to restore the deficiency. To demonstrate the feasibility of this system, it was implemented in phloroglucinol (PG) biosynthesis, manifesting improved host tolerance to PG and increased PG production. Specifically, PG titer significantly improved from 0.78 ± 0.02 to 1.34 ± 0.04 g l-1, representing a 71.8% increase in shake-flask fermentation. In fed-batch fermentation, the titer increased from 3.71 ± 0.11 to 4.54 ± 0.10 g l-1, showing a 22.4% increase. RNA sequencing and transcriptome analysis revealed that the improvements were attributed to grpE overexpression and upregulation of various protective chaperones and the biotin acetyl-CoA carboxylase ligase coding gene birA. CONCLUSION: This novel PAS could be regarded as a typical example of nonanabolite- and nonmetabolite-related PAS. It effectively promoted plasmid maintenance in the host, improved tolerance to PG, and increased the titer of this compound.

Effect of general and spinal anaesthesia on post-operative wound healing during laparoscopic totally extraperitoneal inguinal hernia repair: A meta-analysis.

Totally extraperitoneal prosthetic (TEP) is a surgical technique for the treatment of hernia. The purpose of this research is to compare the efficacy of both general anaesthesia and spine anaesthesia for TEP herniorrhaphy. The number of patients who received TEP operations related to the injury from 2008 to 2022 was counted in this study. Patients with TEP operation were classified into general anaesthesia and spine anaesthesia. In this research, 186 related articles were found in the data base, and in the end, 8 were analysed. This study involved 2452 cases of hernia. The data of the operation time, the infection of the wound and the bleeding of the wound were analysed. The analysis of the data was done with RevMan 5.3. Results indicated that there was no significant difference between general anaesthesia and spinal anaesthesia in post-surgical rates for post-operative wound infection (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.49-1.83; p = 0.86); In general anaesthesia, there was no difference in the risk of post-operative wound haematoma when compared with those treated with spinal anaesthesia (OR, 2.96; 95% CI, 0.37-23.69; p = 0.31). In the seven trials, there was no difference in the duration of the surgery between the general anaesthetic and the spinal anaesthesia group (mean difference, -1.44; 95% CI, -4.11 to 1.22; p = 0.29). Data from the available meta-analysis indicate that there is no difference in the risk of post-operative wound infection or wound haematoma when treated with TEP.

Polarization-multiplexed, single-cavity dual-comb fiber laser based on a birefringent crystal and a saturable absorber.

We introduce a calcium carbonate birefringent crystal into an Er-fiber laser mode-locked by a saturable absorber, where dual-comb ultrashort pulses with orthogonal polarization have been obtained. The two ultrashort pulse trains from the laser exhibit polarization contrast ratios of 30 dB and 20 dB, indicating that the dual-comb mode-locking is due to the polarization-multiplexing mechanism. The dual-comb ultrashort pulses have central wavelengths of 1564.41 nm and 1564.51 nm, and pulse durations of 825 fs and 805 fs respectively. The optical spectra and pulse durations of the asynchronous ultrashort pulses are nearly identical, so that the output of the laser could be directly used for dual-comb applications. Besides, the repetition-rate difference of the two mode-locked pulses is 673 Hz, while its drift is only 0.093 Hz within 2 hours' time. The low drift of the repetition-rate difference manifests the single-cavity dual-comb Er-fiber laser has a high stability and high common-mode noise suppression. At last, we have tested the dual-comb fiber laser in a ranging experiment, where clear interferogram signal can be observed. The experimental results prove that this single-cavity dual-comb Er-fiber laser based on the birefringent crystal and saturable absorber can be a potential source for spectroscopy, optical imaging, absolute distance measurement and other dual-comb applications.

Local polarization properties extraction using single incident state, single-mode-fiber-based spectral domain polarization-sensitive optical coherence tomography.

We showed the local polarization properties extraction method for the single incident state, all-single-mode-fiber-based spectral domain polarization-sensitive optical coherence tomography (SD-PS-OCT) system that uses the single linear-in-wavenumber spectral camera. Polarization controllers are used in the single-mode-fiber-based SD-PS-OCT system to provide a compact structure with polarization state stability. The local polarization properties of the birefringent sample are extracted from the cumulative polarization properties iteratively. The reconstructed polarization images demonstrate the local polarization properties extraction ability of the system.

First report of Tobacco Fusarium Root Rot Caused by Fusarium meridionale in China.

Tobacco (Nicotiana tabacum L.) was an important economic crop in China. A survey in Yunnan Province in the last several years showed that the incidence of tobacco root rot was 3 to 30%. In July 2021, root rot symptoms were observed with an average incidence of 5% on tobacco (cultivar Yunyan 87) in Dali (25.61° N, 100.27° E). Typical disease symptoms included plants stunted at early stages, brown-colored withering lower leaves and roots that became brown. Under high humidity conditions, symptoms of rot expanded in the roots, also the whole plant became wilted and stunted, and some plants ultimately died. Infected pieces of stem tissues and root were dissected and then sterilized with 2% NaOCl for 30 s, rinsed three times with sterile distilled water, and dried with sterilized filter paper. Three pieces were plated onto potato dextrose agar (PDA) for 3 days at 25°C with a 12-h light period. Colonies on PDA were characterized by white to pale yellow flocculent aerial mycelium, and a pink to red pigment in the agar. To induce sporulation, mycelium on PDA was transferred to carnation leaf agar (CLA) medium. After incubation for 7 days, a single spore was isolated from representative isolate 21DL16 for morphological and molecular analyses. Macroconidia observed on CLA were falcate, slightly curved, three to five septate, measured 33.1 to 53.7 × 3.2 to 4.6 µm (n=50), with a typical foot shaped basal cell. Morphological characteristics of the fungus were in agreement with the description of Fusarium graminearum (Leslie and Summerell 2006). For further identification, the internal transcribed spacer (ITS) region rDNA, translation elongation factor 1ɑ (EF-1α) and RNA polymerase II second largest subunit (RPB2) gene were amplified and sequenced using primers ITS1/ITS4 (White et al. 1990), EF1/EF2 (O'Donnell et al. 2015) and RPB2-5F/RPB2-7cR (Reeb et al. 2004), respectively. Although the ITS sequence (GenBank accession no. OM392025) cannot distinguish F. meridionale from F. graminearum, combined phylogenetic analysis of the sequence of TEF1 (ON062055) and RPB2 (ON211932) clearly showed that the pathogen is F. meridionale that the sequences were 100% similarity, 0.0e-value and 100% query coverage to F. meridionale. Pathogenicity studies were conducted on six-leaf-stage tobacco seedlings cultivar Yunyan 87. A conidial suspension (1×105 spores/mL) was poured over the roots of tobacco seedlings. Three seedlings were treated with sterile water that served as controls. All 10 seedlings were maintained at 25°C at 70% relative humidity. After 5 days, the lower leaves showed symptoms of wilting and the roots of all inoculated seedlings become discolored, that were similar with the original symptoms, whereas the control seedlings did not develop symptoms. The fungus reisolated from the inoculated seedlings was identical to F. meridionale using the EF-1α gene sequence. To date, Fusarium root rot on tobacco in China was caused by F. oxysporium (Chen 2013). However, to the best of our knowledge, this is the first report of F. meridionale causing root rot on tobacco in China. Identification of F. meridionale as a root rot agent might provide important insight for disease management practices on tobacco caused by Fusarium species.

Design, synthesis and biological evaluation of 2-aminopyrimidine-based LSD1 inhibitors.

AZD9291, with excellent pharmaceutical properties, has been reported to have certain LSD1 inhibitory activity. Therefore, we carried out structural optimization based on the AZD9291 skeleton to increase the LSD1 inhibitory potential of the compound. Then, a series of 2-aminopyrimidine derivatives were designed and synthesized as LSD1 inhibitors, and their structure-activity relationships were studied. The most promising compound, X43, with an IC50 of 0.89 µM showed remarkable LSD1 selectivity not only to EGFRwt (>100-fold) but also to MAO-A/B (>50-fold). Further studies showed that X43 inhibited LSD1 activity and induced the apoptosis of A549 cells in a dose-dependent manner. Meanwhile, compound X43 showed a superior ability to inhibit the proliferation of A549 and THP-1 cells, with IC50 values of 1.62 µM and 1.21 µM, respectively. Then, analyses of the stability of human liver microsomes, CYP inhibition and in vivo pharmacokinetics in rats showed that X43 had favorable profiles in vitro and in vivo and the potential for further study. Our findings suggested that a 2-aminopyrimidine-based LSD1 inhibitor deserves further investigation as a treatment for LSD1-overexpressing cancer.

Polarization-sensitive imaging based on incoherent holography.

The polarization-sensitive imaging technology is proposed based on incoherent holography. The distribution of state of polarization (SoP) of the object light field can be reconstructed by measuring the phase difference and amplitude ratio of two components of the Jones vector on the basis of incoherent self-interference theory and the accurate point spread function (PSF) of the incoherent holographic system. In the analysis of Fresnel diffraction, we develop a new method to greatly simplify the calculation of the accurate PSF by means of imaging property of lens and symbolic mathematics tools. In the recording process, we utilize the automation of phase shift, photography, and synthesization of color hologram to greatly shorten the total recording time of a group of phase-shifted holograms. The experimental results show that the proposed technology can accurately realize polarization-sensitive imaging and it is much simpler for complete linearly polarized light.

Phase-difference imaging based on FINCH.

The diffraction theory was used to calculate the point spread function (PSF) of a typical Fresnel incoherent correlation holography (FINCH) system. It was found that the phase of the reconstructed image corresponds to the phase difference between the original points in two mutually perpendicular polarization directions. The experimental results show that the FINCH system with reasonable parameters can realize the phase-difference imaging of objects and measure the phase difference of cross-polarization directions in birefringent materials.

Miniaturized precalibration-based Lissajous scanning fiber probe for high speed endoscopic optical coherence tomography.

We present a miniaturized precalibration-based forward-viewing Lissajous scanning fiber probe for high speed endoscopic optical coherence tomography (OCT). The probe is based on an asymmetric fiber cantilever driven by the piezoelectric bender to realize two-dimensional (2D) Lissajous scanning. The stability and repeatability of the Lissajous scanning trajectory of the probe is tested by a position sensitive detector (PSD)-based position calibration setup. The two orthogonal resonant frequencies of the cantilever are measured to be 167.2 and 121 Hz. A 25 µm focal spot is formed at the working distance of 5 mm by the graded-index (GRIN) lens, and the field of view of the imaging probe is around ${1.5}\;{\rm mm} \times {1.5}\;{\rm mm}$1.5mm×1.5mm. The probe is fully packaged in a hypodermic tube for endoscopic imaging. The total rigid length and outer diameter are 35 mm and 3.5 mm, respectively. The probe is incorporated in a 50 KHz swept source OCT system with the axial resolution of 14 µm, and its imaging performance is validated by the 2D en face and 3D volumetric OCT imaging of the phantom and the biological tissue.

Molecule occupancy by a n-butylamine treatment to facilitate the conversion of PbI2 to perovskite in sequential deposition.

Herein, we propose a new approach of molecule occupancy via a vapor treatment to facilitate the conversion of PbI2 to perovskite in sequential deposition. We have shown that the morphology of PbI2 and the subsequent crystallization of perovskite can be effectively tuned, thus leading to the elimination of residual PbI2 and promotion of perovskite growth.

Multiple-image double-encryption via 2D rotations of a random phase mask with spatially incoherent illumination.

Optical image encryption technique has become extremely important in these years. However, most of the proposed multiple-image encryption systems are illuminated with coherent light source. Here we present a multiple-image double-encryption method with spatially incoherent illumination. The first-encryption of multiple images is based on the speckle rotation decorrelation property, and the second-encryption of images' order is based on the speckle shift decorrelation out of the angular memory-effect range. The double-encryption via two-dimensional rotations of the random phase mask enhances the security and keeps the simplicity of the cryptosystem. The capacity of the ciphertext is greatly increased by multiplexing, and further increased after crosstalk noise removal. The use of incoherent light source reduces the requirements for experimental conditions, and makes the cryptosystem easy to implement in various application scenarios.

Speckle rotation decorrelation based single-shot video through scattering media.

Optical imaging and tracking moving objects through scattering media is a challenge with important applications. However, previous works suffer from time-consuming recovery process, object complexity limit, or object information lost. Here we present a method based on the speckle rotation decorrelation property. The rotational speckles detected at short intervals are uncorrelated and multiplexed in a single-shot camera image. Object frames of the video are recovered by cross-correlation deconvolution of the camera image with a computationally rotated point spread function. The near real-time recovery provides sharp object image frames with accurate object relative positions, exact movement velocity, and continuous motion trails. This multiplexing technique has important implications for a wide range of real-world imaging scenarios.

The diagnostic performance of gadoxetic acid disodium-enhanced magnetic resonance imaging and contrast-enhanced multi-detector computed tomography in detecting hepatocellular carcinoma: a meta-analysis of eight prospective studies.

AIM: The purpose of this study was to determine the relative diagnostic benefit of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) over contrast-enhanced multi-detector computed tomography (CEMDCT) for the detection of hepatocellular carcinoma (HCC). METHODS: Two investigators searched multiple databases from inception to January 8, 2019, for studies comparing Gd-EOB-DTPA-enhanced MRI with CEMDCT in adults suspected of HCC. Two reviewers independently selected studies and extracted data. RESULTS: Eight studies were included enrolling 498 patients. MRI showed significantly higher sensitivity than CT (0.85 vs. 0.68). There was no significant difference in the specificity of MRI and CT (0.94 vs. 0.93). The negative likelihood ratio and positive likelihood ratio of MRI and CT were not significantly different (0.16 vs. 0.15 and 14.7 vs. 11.2, respectively). The summary receiver operating characteristics (SROC) of MRI was higher than that of CT at 0.96 vs. 0.91. In the subgroup analysis with a lesion diameter below 2 cm, the sensitivity of MRI was significantly higher than that of CT (0.79 vs. 0.46). CONCLUSION: Gd-EOB-DTPA-enhanced MRI showed higher sensitivity and overall diagnostic accuracy than CEMDCT especially for hepatocellular carcinoma lesions smaller than 2 cm. KEY POINTS: • Gd-EOB-DTPA-enhanced MRI can detect small lesions of hepatocellular carcinoma. • Gd-EOB-DTPA-enhanced MRI showed higher sensitivity and overall diagnostic accuracy than CEMDCT in patients with hepatocellular carcinoma. • Eight prospective studies showed that Gd-EOB-DTPA-enhanced MRI provides greater diagnostic confidence.

Efficient simultaneous production of extracellular polyol esters of fatty acids and intracellular lipids from inulin by a deep-sea yeast Rhodotorula paludigena P4R5.

BACKGROUND: Polyol esters of fatty acids (PEFA) are a kind of promising biosurfactants and mainly secreted by Rhodotorula strains. In addition, some strains of Rhodotorula are reliable producers of microbial lipid. Therefore, it is feasible to establish a one step fermentation process for efficient simultaneous production of PEFA and microbial lipids by a suitable Rhodotorula strain. RESULTS: A newly isolated deep-sea yeast, Rhodotorula paludigena P4R5, was shown to simultaneously produce high level of intracellular lipid and extracellular PEFA. Under the optimized conditions, it could yield 48.5 g/L of PEFA and 16.9 g/L of intracellular lipid within 156 h from inulin during 10-L batch fermentation. The PEFA consisting of a mixture of mannitol esters of 3-hydroxy C14, C16 and C18 fatty acids with variable acetylation showed outstanding surface activity and emulsifying activity, while the fatty acids of the intracellular lipid were mainly C16 and C18 and could be high-quality feedstock for biodiesel production. CONCLUSION: The deep-sea yeast strain R. paludigena P4R5 was an excellent candidate for efficient simultaneous of biosurfactants and biodiesel from inulin. Our results also suggested that the establishment of fermentation systems with multiple metabolites production was an effective approach to improve the profitability.

Design, synthesis and biological evaluation of curcumin analogues as novel LSD1 inhibitors.

Histone lysine-specific demethylase 1 (LSD1) was the first discovered histone demethylase. Inactivating LSD1 or downregulating its expression inhibits cancer-cell development, and thus, it is an attractive molecular target for the development of novel cancer therapeutics. In this study, we worked on the structural optimization of natural products and identified 30 novel LSD1 inhibitors. Utilizing a structure-based drug design strategy, we designed and synthesized a series of curcumin analogues that were shown to be potent LSD1 inhibitors in the enzyme assay. Compound WB07 displayed the most potent LSD1 inhibitory activity, with an IC50 value of 0.8 µM. Moreover, WA20 showed an anticlonogenic effect on A549 cells with an IC50 value of 4.4 µM. Molecular docking simulations were also carried out, and the results indicated that the inhibitors bound to the protein active site located around the key residues of Asp555 and Asp556. These findings suggested that compounds WA20 and WB07 are the first curcumin analogue-based LSD1 inhibitors with remarkable A549 suppressive activity, providing a novel scaffold for the development of LSD1 inhibitors.

A comparison of exposure of Glottis using the Airtraq or the Macintosh Laryngoscope in Potentially difficult airway management: A self-controlled clinical trial.

OBJECTIVE: To compare glottis exposure of the same patients with potentially difficult tracheal intubation (PDTI) subjected to Airtraq laryngoscopy and Macintosh laryngoscopy under consciousness and topical anesthesia. METHODS: A total of 147 PDTI patients with American Society of Anesthesiologists (ASA) I-III were subjected to Airtraq and Macintosh laryngoscopy performed by experienced anesthesiologists under consciousness and topical anesthesia. RESULTS: All patients were successfully intubated. Among them, three patients were intubated with fiberoptic bronchoscopy, 13 with Macintosh laryngoscopy and 131 with Airtraq laryngoscopy. Of the patients with Cormack and Lehance (C&L) Grade-I glottic view, 88 were subjected to Airtraq laryngoscopy and five to Macintosh laryngoscopy; Of the patients with C&L Grade-II glottic view, 56 were subjected to Airtraq laryngoscopy and 21 to Macintosh bronchoscopy; Of the patients with C&L Grade-III glottic view, three were subjected to Airtraq laryngoscopy and 112 to Macintosh bronchoscopy; Of the patients with C&L Grade-IV glottic view, none was subjected to Airtraq laryngoscopy and 9 to Macintosh laryngoscopy. CONCLUSIONS: Airtraq laryngoscopy could significantly improve the glottis exposure and reduce the difficulty of intubation for patients with potentially tracheal intubation compared to the traditional Macintosh laryngoscopy.

Spin-Dependent Weakly-Interacting-Massive-Particle-Nucleon Cross Section Limits from First Data of PandaX-II Experiment.

New constraints are presented on the spin-dependent weakly-interacting-massive-particle–- (WIMP-)nucleon interaction from the PandaX-II experiment, using a data set corresponding to a total exposure of 3.3×10^{4} kg day. Assuming a standard axial-vector spin-dependent WIMP interaction with ^{129}Xe and ^{131}Xe nuclei, the most stringent upper limits on WIMP-neutron cross sections for WIMPs with masses above 10 GeV/c^{2} are set in all dark matter direct detection experiments. The minimum upper limit of 4.1×10^{-41} cm^{2} at 90% confidence level is obtained for a WIMP mass of 40 GeV/c^{2}. This represents more than a factor of 2 improvement on the best available limits at this and higher masses. These improved cross-section limits provide more stringent constraints on the effective WIMP-proton and WIMP-neutron couplings.

Expression and characterization of soybean seed coat peroxidase in Escherichia coli BL21(DE3).

Soybean seed coat peroxidase (SBP) is a valuable enzyme having a broad variety of applications in analytical chemistry, biochemistry, and food processing. In the present study, the sscp gene (Gene ID: 548068) was optimized based on the preferred codon usage of Escherichia coli, synthesized, and expressed in E. coli BL21(DE3). SDS-PAGE and western blot analysis of this expressed protein revealed that its molecular weight is approximately 39 kDa. The effects of induction temperature, concentration of isopropyl-ß-D-thiogalactoside and hemin, induction time, expression time were optimized to enhance SBP production with a maximum activity of 11.23 U/mL (8.64 U/mg total protein). Furthermore, the kinetics of enzyme-catalyzed reactions of recombinant protein was determined. When 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) was used as substrate, optimum reaction temperature and pH of the enzyme were 85°C and 5.0, respectively. The effects of metal ions on the enzymatic reaction were also further investigated. The SBP was successfully expressed in E. coli BL21(DE3) which would provide a more efficient production strategy for industrial applications of SBP.