4.3†µm high-power amplified spontaneous emission fiber source based on CO2-filled nested hollow-core anti-resonant fiber.

We report a 4.3 µm mid-infrared (mid-IR) high-power amplified spontaneous emission (ASE) fiber source based on CO2-filled nested hollow-core anti-resonant fiber (Nested HC-ARF). The pump source is a homemade hundred-watt-level wavelength-tunable 2 µm single-frequency fiber laser. A 5.7 m long 8-tube Nested HC-ARF is used as the gas cell, with a core diameter of 110 µm and cladding diameter of 400 µm, which exhibits transmission loss of 0.1 dB/m at 2 µm and 0.24 dB/m at 4.3 µm respectively. To improve the coupling efficiency of the high-power pump laser and reduce the influence of the thermal effect at the input end of the hollow-core fiber, the fiber is designed for multimode transmission at the pump wavelength. A continuous wave output power of 6.6 W at 4.3 µm is achieved, and the slope efficiency is 17.05%. To the best of our knowledge, it is the highest output power for such gas-filled HC-ARF ASE sources in 4∼5 µm. This work demonstrates the great potential of gas-filled HC-ARF generating high-power mid-IR emission.

Low loss nested hollow-core anti-resonant fiber at 2 µm spectral range.

We report the fabrication and characterization of a five-tube nested hollow-core anti-resonant fiber (Nested HC-ARF), which exhibits outstanding optical performance in terms of a record attenuation value of 0.85 dB/km at 2 µm wavelength range with a 200 nm bandwidth below 2 dB/km and excellent modal purity. The power handling capability of the Nested HC-ARF is also demonstrated in this work. Pulses of 75 W, 160 ps from the thulium-doped fiber laser are delivered using a 6-m-long fabricated Nested HC-ARF. The tested fiber is coiled into a 20 cm bending radius and achieves a coupling efficiency of 86.7%. The maximum average power of 60.5 W is transmitted through our Nested HC-ARF in a robust single-mode fashion without introducing any damage to the input and output fiber end-faces, which demonstrates the superior ability of such a fiber for high-power laser delivery.

Predictive value of MRI-based deep learning model for lymphovascular invasion status in node-negative invasive breast cancer.

To retrospectively assess the effectiveness of deep learning (DL) model, based on breast magnetic resonance imaging (MRI), in predicting preoperative lymphovascular invasion (LVI) status in patients diagnosed with invasive breast cancer who have negative axillary lymph nodes (LNs). Data was gathered from 280 patients, including 148 with LVI-positive and 141 with LVI-negative lesions. These patients had undergone preoperative breast MRI and were histopathologically confirmed to have invasive breast cancer without axillary LN metastasis. The cohort was randomly split into training and validation groups in a 7:3 ratio. Radiomics features for each lesion were extracted from the first post-contrast dynamic contrast-enhanced (DCE)-MRI. The Least Absolute Shrinkage and Selection Operator (LASSO) regression method and logistic regression analyses were employed to identify significant radiomic features and clinicoradiological variables. These models were established using four machine learning (ML) algorithms and one DL algorithm. The predictive performance of the models (radiomics, clinicoradiological, and combination) was assessed through discrimination and compared using the DeLong test. Four clinicoradiological parameters and 10 radiomic features were selected by LASSO for model development. The Multilayer Perceptron (MLP) model, constructed using both radiomic and clinicoradiological features, demonstrated excellent performance in predicting LVI, achieving a high area under the curve (AUC) of 0.835 for validation. The DL model (MLP-radiomic) achieved the highest accuracy (AUC = 0.896), followed by DL model (MLP-combination) with an AUC of 0.835. Both DL models were significantly superior to the ML model (RF-clinical) with an AUC of 0.720. The DL model (MLP), which integrates radiomic features with clinicoradiological information, effectively aids in the preoperative determination of LVI status in patients with invasive breast cancer and negative axillary LNs. This is beneficial for making informed clinical decisions.

Template synthesis of test tube nanoparticles using non-destructive replication.

Nano test tubes are a promising delivery vehicle for a range of therapeutics, including small molecule drugs and biologics. However, current template synthesis methods of producing nano test tubes are prohibitively expensive and time consuming. Here, non-destructive template replication was used to increase nano test tube yield from porous alumina by more than a hundredfold. We demonstrate how to produce nano test tubes of several sizes and compositions, including hybrid tubes with different inner and outer surfaces for targeted surface chemistry. Nano test tubes were readily suspended and stored in aqueous solutions without the need for chemical treatment. These nano test tubes should find application as delivery vehicles for therapeutics, particularly for processive 'bionanoreactors' loaded with enzymes.

Antifungal effects of amaryllidaceous alkaloids from bulbs of Lycoris spp. against Magnaporthe oryzae.

BACKGROUND: Rice blast caused by Magnaporthe oryzae is one of the most devastating diseases of rice, and novel fungicides for controlling rice blast are needed owing to the problem of resistance to commonly used control agents. We previously found that methanol extract of Lycoris radiata (L'Her.) Herb. showed an excellent inhibitory effect on mycelial growth of M. oryzae, indicating its potential for developing control agents against M. oryzae. In this study, we aim to investigate the antifungal effects of different Lycoris spp. against M. oryzae, and clarify the main active components. RESULTS: Extracts from bulbs of seven Lycoris spp. showed excellent inhibitory effects on mycelial growth and spore germination of M. oryzae at 400 mg L-1 . Liquid chromatography-tandem mass spectrometry was employed to analyze the components of the extracts, and heatmap clustering analysis with Mass Profiler Professional software revealed that lycorine and narciclasine may be the main active components. Lycorine and narciclasine, together with three other amaryllidaceous alkaloids (AAs), were then isolated from bulbs of Lycoris spp. Antifungal assays showed that lycorine and narciclasine had good inhibitory activities against M. oryzae in vitro, but the other three AAs showed no antifungal activities under test concentrations. In addition, lycorine and the ethyl acetate part of L. radiata showed good antifungal effects against M. oryzae in vivo, but narciclasine showed phototoxicity on rice when used alone. CONCLUSION: Extracts of test Lycoris spp. and the main active component lycorine have excellent antifungal activities against M. oryzae, and are good candidates for developing control agents against M. oryzae. © 2023 Society of Chemical Industry.

Giant Enhancement of Raman Scattering by a Hollow-Core Microstructured Optical Fiber Allows Single Exosome Probing.

Microstructured optical fibers (MOFs) provide solutions for breaking through the bottlenecks in areas of high-power transmission and high-efficiency optical waveguides. Other than transporting light waves, MOFs can synergistically combine microfluidics and optics in a single fiber with an unprecedented light path length not readily achievable by planar optofluidic configurations. Here, we demonstrate that hollow-core anti-resonant optical fibers (HcARFs) can significantly enhance Raman scattering by over three orders of magnitude (EF ≈ 5000) compared with a planar setup, due to the joint mechanisms of strong light-matter interaction in the fiber core and the cumulative effect of the fiber. The giant enhancement enables us to develop the first optical fiber sensor to achieve single cancer exosome detection via a sandwich-structured strategy. This enables a multiplexed analysis of surface proteins of exosome samples, potentially allowing an accurate identification of the cellular origin of exosomes for cancer diagnosis. Our findings could expand the applications of HcARF in many exciting areas beyond the waveguide.

A novel ß-cyclodextrin-rhein conjugate for improving the water solubility and bioavailability of rhein.

Rhein is a potential antitumor agent, but the poor water-solubility restricts its clinical applicability. ß-cyclodextrin-drug conjugates provide a possibility to improve the water-solubility of rhein and thereby enhance its bioavailability. A novel ß-cyclodextrin-rhein conjugate (ß-CD-RH) was synthesized by covalently link ß-cyclodextrin with rhein through a 1,8-diamino-3,6-dioxaoctane linker. The structure of ß-CD-RH was characterized by 1H NMR, FT-IR, Maldi-tof MS etc. The inclusion style of ß-CD-RH in water was detected by 2D NMR. The 2D ROESY spectrum provided details of the rhein moiety encapsulated in the ß-CD cavity. The water-solubility of ß-CD-RH is up to 3.24 µmol/mL ß-CD-RH exhibited higher cytotoxicity than rhein and rhein/ß-CD mixture against Hela cells. Our work provides a new way for the preparation of novel ß-CD-drug conjugate.

Geographical distribution and seasonal variation in paralytic shellfish toxins in the coastal water of the South China Sea.

Paralytic shellfish toxins (PSTs) are a group of the most harmful neurotoxins distributed worldwide. Marine organism samples, including mollusks, crustaceans and fish, collected from 11 sites around the coastal water of the South China Sea, were analyzed in terms of the PST and toxicity via high-performance liquid chromatography. The PST geographical distribution, detectable rate for PST and toxin content all increased slightly from 2006 to 2008 to 2015. High PST content with more than 2 nmol g-1 appeared in Shantou (ST), Shanwei (SW), Zhanjiang (ZJ), Beihai (BH), Xuwen (XW), Haikou (HK), Dongfang (DF), Wanning (WN) and Sanya (SY). Low PST content with less than 2 nmol g-1 appeared in Shenzhen (SZ) and Yangjiang (YJ). High PST toxicity over the safety limit 800 µg STXeq/kg appeared in ST, SW, ZJ, BH, DF, SY and XW. PST has significant seasonal characteristics and was mostly detected in spring, early summer (March-June) and autumn (September-November) in the coastal water of the South China Sea. PST was usually detected in some specific species of scallop, mussel, bloody clam, hard clam, razor clam, oyster, crab, shrimp and fish. Toxin profile variation of marine organism samples was influenced greatly by species, sampling time and site.