Application of deep-learning to the automatic segmentation and classification of lateral lymph nodes on ultrasound images of papillary thyroid carcinoma.

PURPOSE: It is crucial to preoperatively diagnose lateral cervical lymph node (LN) metastases (LNMs) in papillary thyroid carcinoma (PTC) patients. This study aims to develop deep-learning models for the automatic segmentation and classification of LNM on original ultrasound images. METHODS: This study included 1000 lateral cervical LN ultrasound images (consisting of 512 benign and 558 metastatic LNs) collected from 728 patients at the Chongqing General Hospital between March 2022 and July 2023. Three instance segmentation models (MaskRCNN, SOLO and Mask2Former) were constructed to segment and classify ultrasound images of lateral cervical LNs by recognizing each object individually and in a pixel-by-pixel manner. The segmentation and classification results of the three models were compared with an experienced sonographer in the test set. RESULTS: Upon completion of a 200-epoch learning cycle, the loss among the three unique models became negligible. To evaluate the performance of the deep-learning models, the intersection over union threshold was set at 0.75. The mean average precision scores for MaskRCNN, SOLO and Mask2Former were 88.8%, 86.7% and 89.5%, respectively. The segmentation accuracies of the MaskRCNN, SOLO, Mask2Former models and sonographer were 85.6%, 88.0%, 89.5% and 82.3%, respectively. The classification AUCs of the MaskRCNN, SOLO, Mask2Former models and sonographer were 0.886, 0.869, 0.90.2 and 0.852 in the test set, respectively. CONCLUSIONS: The deep learning models could automatically segment and classify lateral cervical LNs with an AUC of 0.92. This approach may serve as a promising tool to assist sonographers in diagnosing lateral cervical LNMs among patients with PTC.

Non-contact, highly sensitive sugar concentration detection based on Co3Sn2S2 Weyl semimetal thin film sensor by terahertz wave.

Blood sugar is an important biomedical parameter of diabetic patients. The current blood sugar testing is based on an invasive method, which is not very friendly for patients who require long-term monitoring, while the non-invasive method is still in the developing stage. In this paper, we design a non-invasive and highly sensitive terahertz wave detector with Co3Sn2S2 semimetal thin film to test sugar concentration. As different concentrations have inconsistent responses to terahertz wave, we can deduce the concentration of the sugar solution to realize real-time highly sensitive detection of blood sugar concentration. This novel method can be further expanded to 6 G edge intelligence for non-invasive and real-time monitoring of blood sugar, and promote the development of 6 G technology.

The diagnostic value of GICA used for intraoperative lymph node FNA-Tg measurement to evaluate thyroid cancer metastases.

Objective: It is crucial to diagnose lymph node (LN) metastases (LNM) before or during thyroid carcinoma surgery. Measurement of thyroglobulin (Tg) in the fine needle aspirate washout (FNA-Tg) is useful to assist in the diagnosis of LNM for papillary thyroid carcinoma (PTC). This study aimed to assess the diagnostic performance of a new technique based on a colloidal gold-based immunochromatographic assay (GICA) for intraoperative FNA-Tg in diagnosing LNM. Clinical trial information: This study is registered with chictr.org.cn, ID: ChiCTR2200063561 (registered 11 September, 2022). Methods: This prospective study enrolled 51 PTC patients who underwent cervical LN dissection. A total of 150 LNs dissected from the central and lateral compartments were evaluated by FNA-Tg-GICA at three different time points and compared with frozen sections and the conventional Tg measurement method electrochemiluminescence immunoassay (ECLIA). Receiver operating characteristic curve (ROC) and area under the curve (AUC), cutoff value to discriminate benign and malignant LNs, sensitivity, specificity, and accuracy were provided. Results: The cutoff value of FNA-Tg to predict LNM was 110.83 ng/mL for ECLIA and 13.19 ng/mL, 38.69 ng/mL, and 77.17 ng/mL for GICA at 3, 10, and 15 min, respectively. There was no significant difference between the AUCs of GICA at different time points compared to using ECLIA and frozen sections. Besides, the diagnostic performance of GICA and ECLIA showed no significant difference in evaluating LNM from central and lateral compartments or between the TgAb-positive subgroup and TgAb-negative subgroup. Conclusion: GICA is a promising method for intraoperative FNA-Tg measurement and has high value in predicting LNM. It may be a novel alternative or supplementary method to frozen section or ECLIA.

Comparison of endoscopic thyroidectomy by complete areola approach and conventional open surgery in the treatment of differentiated thyroid carcinoma: A retrospective study and meta-analysis.

Background: The feasibility of endoscopic thyroidectomy by complete areola approach (ETCA) remains controversial. This study was conducted by combining our clinical data with the data obtained from a systematic review literature search to examine the effectiveness and safety of ETCA compared with conventional open thyroidectomy (COT) in differentiated thyroid carcinoma (DTC). Methods: A total of 136 patients with a diagnosis of DTC who underwent unilateral thyroidectomy with central neck dissection from August 2020 to June 2021 were enrolled. The enrolled patients were divided into the ETCA group (n = 73) and the COT group (n = 63). The operative time, intraoperative bleeding volume, number of removed lymph nodes, number of metastatic lymph nodes, postoperative drainage volume, length of postoperative hospital stay, postoperative parathyroid hormone (PTH) levels, and complications were analyzed. Then, a systemic review and comprehensive literature search were conducted by using PubMed, Google Scholar, Embase, Web of Science, CNKI, Wanfang, and VIP database up to June 2022. Review Manager software version 5.3 was used for the meta-analysis. Results: The results of clinical data showed that there were significant differences between the two groups in the operative time, intraoperative bleeding volume, removed lymph nodes, and postoperative drainage volume. There were no statistical differences in the length of postoperative hospital stay, number of metastatic lymph nodes, postoperative PTH level, and complications. In the systematic review and meta-analysis, 2,153 patients from fourteen studies (including our data) were ultimately included. The results of the meta-analysis found that ETCA had a longer operative time, larger postoperative drainage volume, and lower intraoperative bleeding volume. In terms of the length of postoperative hospital stay, the number of removed lymph nodes, and surgical complications, there was no significant difference between the two groups. Conclusion: ETCA poses lower surgical bleeding and better cosmetic appearance compared with COT, while the length of operation and postoperative drainage in ETCA is less favorable compared with COT. In addition, ETCA is not inferior to COT in terms of the postoperative hospitalization stay, the number of removed lymph nodes, and surgical complications. Given its overall advantages and risks, ETCA is an effective and safe alternative for patients with cosmetic concerns.

Transformation of gemfibrozil by the interaction of chloride with sulfate radicals: Radical chemistry, transient intermediates and pathways.

The radical chemistry of SO4·- is strongly affected by its interaction with chloride in natural waters, during which SO4·- can be converted to HO· and reactive chlorine species (RCS). This study investigated the effects of chloride on gemfibrozil (GFRZ) transformation via the UV/peroxydisulfate (PDS) process, elucidating the kinetics, degradation pathways and solution toxicity. The pseudo-first-order rate constants (k') of GFRZ by UV/PDS changed slightly from 1.0 × 10-3 s-1 to 9.3 × 10-4 s-1 as the chloride content increased from 0 to 10 mM because the increase in HO· and RCS levels compensated for the decrease in SO4·- concentration. However, the transformation pathways in the presence of chloride changed significantly. From the transient absorption spectra, we inferred that RCS and SO4·- attacked GFRZ mainly through hydrogen abstraction and/or electron transfer, while HO· interacted with the GFRZ aromatic ring by addition. Hydroxylation, carboxylation and cleavage products were enhanced in UV/PDS/Cl- compared to UV/PDS through the addition of HO· and the cleavage of CO bonds by RCS, and total organic chlorine (TOCl) was undetectable. Interestingly, the acute toxicity was lowest in UV/PDS/Cl-, with an inhibition percentage of 1% at 30 min. The higher inhibition percentages in UV/PDS (13%) and UV alone (53%) at 30 min likely resulted from the stronger capacity of HO· and RCS to oxidize aldehydes to carboxylic groups and cleave CO bonds, respectively, than that of SO4·-. This study provides a better understanding of contaminant transformation mechanisms under UV/PDS treatment at chloride levels present in natural waters.

Photonic device combined optical microfiber coupler with saturable-absorption materials and its application in mode-locked fiber laser.

We demonstrated a mode-locked fiber laser based on a novel photonic device that combined optical microfiber coupler (OMC) and saturable absorption materials. The stable ultrafast laser was formed based on the interaction between the deposited Indium Antimonide (InSb) and the evanescent field on OMC. Different from optical microfiber (OM), OMC can directly output the mode-locked laser without additional beam splitting devices, which further improves the integrated characteristics of the fiber laser. The pulse duration of the output pulse is 405 fs at the central wavelength of 1560 nm. To the best of our knowledge, this is the first time that optical microfiber coupler based saturable absorber (OMC-SA) for mode-locked fiber laser is demonstrated.

Insights into the effects of bromide at fresh water levels on the radical chemistry in the UV/peroxydisulfate process.

Bromide (Br-) is a typical scavenger to sulfate radical (SO4•-) and hydroxyl radical (HO•), which simultaneously forms secondary reactive bromine species (RBS) such as Br• and Br2•-. This study investigated the effects of Br- at fresh water levels (~µM) on the radical chemistry in the UV/peroxydisulfate (UV/PDS) process by combining the degradation kinetics of probe compounds (nitrobenzene, metronidazole, and benzoate) with kinetic model. Br- at 1 - 50 µM promoted the conversion from SO4•- to HO• and RBS in the UV/PDS process. At pH 7, the concentration of SO4•- monotonically decreased by 31.5 - 94.8% at 1 - 50 µM Br-, while that of HO• showed an increasing and then decreasing pattern, with a maximum increase by 171.7% at 5 µM Br-. The concentrations of Br• and Br2•- (10-12 - 10-10 M) were 2 - 3 orders of magnitude higher than SO4•- and HO•. Alkaline condition promoted the conversion from SO4•- to HO•, and drove the transformation from RBS to HO•, resulting in much lower concentrations of RBS at pH 10. Br- at 1 µM and 5 µM decreased the pseudo-first-order reaction rates (k's) of 15 pharmaceuticals and personal care products (PPCPs) by 15.2 - 73.9%, but increased k's of naproxen and ibuprofen by 13.7 - 57.3% at pH 7. The co-existence of 10 - 1000 µM Cl- with 5 µM Br- further promoted the conversion from SO4•- to HO• compared to Br- alone. Bicarbonate consumed SO4•- and HO• but slightly affected RBS, while natural organic matter (NOM) exerted scavenging effects on HO• and RBS more significantly than SO4•-. This study demonstrated that Br- at fresh water levels significantly altered the radical chemistry of the UV/PDS process, especially for promoting the formation of HO•.

DBP alteration from NOM and model compounds after UV/persulfate treatment with post chlorination.

The UV/persulfate process is an effective advanced oxidation process (AOP) for the abatement of a variety of micropollutants via producing sulfate radicals (SO4•-). However, when this technology is used to reduce target pollutants, the precursors of disinfection byproducts (DBPs), such as natural organic matter (NOM) and organic nitrogen compounds, can be altered. This study systematically investigated the DBP formation from NOM and five model compounds after UV/H2O2 and UV/persulfate treatments followed with 24 h chlorination. Compared to chlorination alone, the yields of trichloromethane (TCM) and dichloroacetonitrile (DCAN) from NOM decreased by 50% and 54%, respectively, after UV/persulfate treatment followed with chlorination, whereas those of chloral hydrate (CH), 1,1,1-trichloropropanone (1,1,1-TCP) and trichloronitromethane (TCNM) increased by 217%, 136%, and 153%, respectively. The effect of UV/H2O2 treatment on DBP formation shared a similar trend to that of UV/persulfate treatment, but the DBP formation was higher from the former. As the UV/persulfate treatment time prolonged or the persulfate dosage increased, the formation of TCM and DCAN continuously decreased, while that of CH, 1,1,1-TCP and TCNM presented an increasing and then decreasing pattern. SO4•- activated benzoic acid (BA) to form phenolic compounds that enhanced the formation of TCM and CH, while it deactivated resorcinol to decrease the formation of TCM. SO4•- reacted with aliphatic amines such as methylamine (MA) and dimethylamine (DMA) to form nitro groups, which significantly increased the formation of TCNM in post chlorination, and the rate was determined to be higher than that of HO•. This study illuminated the diverse impacts of the structures of the precursors on DBP formation after UV/persulfate treatment, and DBP alteration depended on the reactivity between SO4•- and specific precursor.

Robust Q-switching based on stimulated Brillouin scattering assisted by Fabry-Perot interference.

Q-switching operation based on stimulated Brillouin scattering (SBS) has been developed for decades due to its inexpensive configuration, high pulse energy output, and the potential to be free from wavelength and material limitations. However, unstable and uncontrollable pulse output affected by SBS's stochastic nature hinders its development. In this work, we demonstrated a unique robust SBS-based Q-switched all-fiber laser. Firstly, a numerical model is developed and a general analysis about the robust Q-switching mechanism is presented. Simulation results show that the spectrum modulation effect such as FP interference is efficient for system to realize steady and controllable output. Secondly, we incorporated a Fabry-Perot (FP) interferometer made of two un-contact end faces of fiber connectors into a SBS-based Q-switched system and demonstrated passively robust Q-switching with simpler and cheaper configuration than most reported ones. Under 600 mW pump power, the SNR was measured to be as high as 62.96 dB, which is the highest SNR obtained from SBS-based Q-switched lasers. To our best knowledge, this is the first demonstration of robust SBS-based Q-switching without any external measures.

Kinetics and mechanisms of the degradation of PPCPs by zero-valent iron (Fe°) activated peroxydisulfate (PDS) system in groundwater.

The abatement of pharmaceuticals and personal care products (PPCPs), including carbamazepine (CBZ), acetaminophen (ACP) and sulfamethoxazole (SMX), by zero-valent iron (Fe°) activated peroxydisulfate (PDS) system (Fe°/PDS) in pure water and groundwater was investigated. The removal rates of CBZ, ACP and SMX were 85.4%, 100% and 73.1%, respectively, within 10 min by Fe°/PDS in pure water. SO4•-, •OH and O2•- were identified in the Fe°/PDS system, and O2•- was indicated to play an important role in the ACP degradation. The degradation of PPCPs increased with increasing dosages of Fe° and PDS or with decreasing pH and initial PPCP concentrations. Interestingly, the degradation of PPCPs by Fe°/PDS was significantly enhanced in groundwater compared with that in pure water, which was partially attributed to SO42- and Cl-. The first-order constants of CBZ, ACP and SMX increased from 0.021, 0.242 and 0.013 min-1 to 0.239, 2.536 and 0.259 min-1, and to 0.172, 1.516 and 0.197 min-1, respectively, with increasing the concentrations of SO42- and Cl- to 100 mg/L and 10 mg/L, respectively. This study firstly reports the unexpected enhancement of groundwater matrix on the degradation of micropollutants by Fe°/PDS, demonstrating that Fe°/PDS can be an efficient technology for groundwater remediation.

Chlorate Formation Mechanism in the Presence of Sulfate Radical, Chloride, Bromide and Natural Organic Matter.

Halides and natural organic matter (NOM) are inevitable in aquatic environment and influence the degradation of contaminants in sulfate radical (SO4•-)-based advanced oxidation processes. This study investigated the formation of chlorate in the coexposure of SO4•-, chloride (Cl-), bromide (Br-) and/or NOM in UV/persulfate (UV/PDS) and cobalt(II)/peroxymonosulfate (Co/PMS) systems. The formation of chlorate increased with increasing Cl- concentration in the UV/PDS system, however, in the Co/PMS system, it initially increased and then decreased. The chlorate formation involved the formation of hypochlorous acid/hypochlorite (HOCl/OCl-) as an intermediate in both systems. The formation was primarily attributable to SO4•- in the UV/PDS system, whereas Co(III) played a significant role in the oxidation of Cl- to HOCl/OCl- and SO4•- was important for the oxidation of HOCl/OCl- to chlorate in the Co/PMS system. The pseudo-first-order rate constants ( k') of the transformation from Cl- to HOCl/OCl- were 3.32 × 10-6 s-1 and 9.23 × 10-3 s-1 in UV/PDS and Co/PMS, respectively. Meanwhile, k' of HOCl/OCl- to chlorate in UV/PDS and Co/PMS were 2.43 × 10-3 s-1 and 2.70 × 10-4 s-1, respectively. Br- completely inhibited the chlorate formation in UV/PDS, but inhibited it by 45.2% in Co/PMS. The k' of SO4•- reacting with Br- to form hypobromous acid/hypobromite (HOBr/OBr-) was calculated to be 378 times higher than that of Cl- to HOCl/OCl-, but the k' of Co(III) reacting with Br- to form HOBr/OBr- was comparable to that of Cl- to HOCl/OCl-. NOM also significantly inhibited the chlorate formation, due to the consumption of SO4•- and reactive chlorine species (RCS, such as Cl·, ClO· and HOCl/OCl-). This study demonstrated the formation of chlorate in SO4•--based AOPs, which should to be considered in their application in water treatment.

Degradation of lipid regulators by the UV/chlorine process: Radical mechanisms, chlorine oxide radical (ClO•)-mediated transformation pathways and toxicity changes.

Degradation of three lipid regulators, i.e., gemfibrozil, bezafibrate and clofibric acid, by a UV/chlorine treatment was systematically investigated. The chlorine oxide radical (ClO•) played an important role in the degradation of gemfibrozil and bezafibrate with second-order rate constants of 4.2 (±0.3) × 108 M-1 s-1 and 3.6 (±0.1) × 107 M-1 s-1, respectively, whereas UV photolysis and the hydroxyl radical (HO•) mainly contributed to the degradation of clofibric acid. The first-order rate constants (k') for the degradation of gemfibrozil and bezafibrate increased linearly with increasing chlorine dosage, primarily due to the linear increase in the ClO• concentration. The k' values for gemfibrozil, bezafibrate, and clofibric acid degradation decreased with increasing pH from 5.0 to 8.4; however, the contribution of the reactive chlorine species (RCS) increased. Degradation of gemfibrozil and bezafibrate was enhanced in the presence of Br-, whereas it was inhibited in the presence of natural organic matter (NOM). The presence of ammonia at a chlorine: ammonia molar ratio of 1:1 resulted in decreases in the k' values for gemfibrozil and bezafibrate of 69.7% and 7%, respectively, but led to an increase in that for clofibric acid of 61.8%. Degradation of gemfibrozil by ClO• was initiated by hydroxylation and chlorine substitution on the benzene ring. Then, subsequent hydroxylation, bond cleavage and chlorination reactions led to the formation of more stable products. Three chlorinated intermediates were identified during ClO• oxidation process. Formation of the chlorinated disinfection by-products chloral hydrate and 1,1,1-trichloropropanone was enhanced relative to that of other by-products. The acute toxicity of gemfibrozil to Vibrio fischeri increased significantly when subjected to direct UV photolysis, whereas it decreased when oxidized by ClO•. This study is the first to report the transformation pathway of a micropollutant by ClO•.

ITO nanoparticles enhanced upconversion luminescence in Er3+/Yb3+-codoped silica glasses.

Upconversion (UC) materials have shown many applications in the solar cell industry, biomedical imaging, and LED lighting. For the first time, we report enhanced UC in Er3+/Yb3+-codoped silica glasses induced by the energy transfer between rare earth ions and indium tin oxide nanoparticles (ITO NPs), introduced by an in situ growth approach. The enhancements of the intensities of the emissions of red and green light were all more than 10 fold and in some cases up to 42 fold. This work in our opinion has contributed a novel method and materials for UC enhancement in Er3+/Yb3+-codoped silica glasses.

Factors affecting the roles of reactive species in the degradation of micropollutants by the UV/chlorine process.

The UV/chlorine process is an emerging advanced oxidation process (AOP) that produces various reactive species, such as hydroxyl radicals (HO) and reactive chlorine species (RCS). The effects of the treatment conditions, such as chlorine dosage and pH, and the water matrix components of natural organic matter (NOM), alkalinity, ammonia and halides, on the kinetics and reactive species in the degradation of four micropollutants, metronidazole (MDZ), nalidixic acid (NDA), diethyltoluamide (DEET) and caffeine (CAF), by the UV/chlorine process were investigated. The degradation of MDZ and CAF was primarily attributable to HO and ClO, respectively, while that of NDA was primarily attributable to both ClO and CO3-. HO, Cl and CO3- are important for the degradation of DEET. The second-order rate constants for ClO with CAF and CO3- with NDA were determined to be 5.1 (±0.2) × 107 M-1s-1 and 1.4 (±0.1) × 107 M-1s-1, respectively. Increasing chlorine dosage slightly changed the contribution of HO but linearly increased that of ClO to micropollutant degradation. Increasing pH decreased the contribution of either HO or Cl but not that of ClO. Both NOM and bicarbonate decreased the contributions of HO and Cl, whereas NOM but not bicarbonate significantly decreased that of ClO. The contribution of either HO or Cl first rose and then fell as the molar ratio of ammonia to chlorine increased from 0 to 1:1, while that of ClO decreased. The co-presence of high concentrations of Cl- and Br- enhanced the contribution of ClBr- and BrCl.

Radical Chemistry and Structural Relationships of PPCP Degradation by UV/Chlorine Treatment in Simulated Drinking Water.

The UV/chlorine process is an emerging advanced oxidation process (AOP) used for the degradation of micropollutants. However, the radical chemistry of this AOP is largely unknown for the degradation of numerous structurally diverse micropollutants in water matrices of varying quality. These issues were addressed by grouping 34 pharmaceuticals and personal care products (PPCPs) according to the radical chemistry of their degradation in the UV/chlorine process at practical PPCP concentrations (1 µg L-1) and in different water matrices. The contributions of HO• and reactive chlorine species (RCS), including Cl•, Cl2•-, and ClO•, to the degradation of different PPCPs were compound specific. RCS showed considerable reactivity with olefins and benzene derivatives, such as phenols, anilines, and alkyl-/alkoxybenzenes. A good linear relationship was found between the RCS reactivity and negative values of the Hammett ∑σp+ constant for aromatic PPCPs, indicating that electron-donating groups promote the attack of benzene derivatives by RCS. The contribution of HO•, but not necessarily RCS, to PPCP removal decreased with increasing pH. ClO• showed high reactivity with some PPCPs, such as carbamazepine, caffeine, and gemfibrozil, with second-order rate constants of 9.2 × 107, 1.03 × 108, and 4.16 × 108 M-1 s-1, respectively, which contributed to their degradation. Natural organic matter (NOM) induced significant scavenging of ClO• and greatly decreased the degradation of PPCPs that was attributable to ClO•, with a second-order rate constant of 4.5 × 104 (mg L-1)-1 s-1. Alkalinity inhibited the degradation of PPCPs that was primarily attacked by HO• and Cl• but had negligible effects on the degradation of PPCPs by ClO•. This is the first study on the reactivity of RCS, particularly ClO•, with structurally diverse PPCPs under simulated drinking water condition.

Kinetic Study of Hydroxyl and Sulfate Radical-Mediated Oxidation of Pharmaceuticals in Wastewater Effluents.

Advanced oxidation processes (AOPs), such as hydroxyl radical (HO•)- and sulfate radical (SO4•-)-mediated oxidation, are alternatives for the attenuation of pharmaceuticals and personal care products (PPCPs) in wastewater effluents. However, the kinetics of these reactions needs to be investigated. In this study, kinetic models for 15 PPCPs were built to predict the degradation of PPCPs in both HO•- and SO4•--mediated oxidation. In the UV/H2O2 process, a simplified kinetic model involving only steady state concentrations of HO• and its biomolecular reaction rate constants is suitable for predicting the removal of PPCPs, indicating the dominant role of HO• in the removal of PPCPs. In the UV/K2S2O8 process, the calculated steady state concentrations of CO3•- and bromine radicals (Br•, Br2•- and BrCl•-) were 600-fold and 1-2 orders of magnitude higher than the concentrations of SO4•-, respectively. The kinetic model, involving both SO4•- and CO3•- as reactive species, was more accurate for predicting the removal of the 9 PPCPs, except for salbutamol and nitroimidazoles. The steric and ionic effects of organic matter toward SO4•- could lead to overestimations of the removal efficiencies of the SO4•--mediated oxidation of nitroimidazoles in wastewater effluents.