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In the contemporary big data era, data-driven prognostic and health management (PHM) methodologies have emerged as indispensable tools for ensuring the secure and reliable operation of complex equipment systems. Central to these methodologies is the accurate prediction of remaining useful life (RUL), which serves as a pivotal cornerstone for effective maintenance and operational decision-making. While significant advancements in computer hardware and artificial intelligence (AI) algorithms have catalyzed substantial progress in AI-based RUL prediction, extant research frequently exhibits a narrow focus on specific algorithms, neglecting a comprehensive and comparative analysis of AI techniques across diverse equipment types and operational scenarios. This study endeavors to bridge this gap through the following contributions: (1) A rigorous analysis and systematic categorization of application scenarios for equipment RUL prediction, elucidating their distinct characteristics and requirements. (2) A comprehensive summary and comparative evaluation of several AI algorithms deemed suitable for RUL prediction, delineating their respective strengths and limitations. (3) An in-depth comparative analysis of the applicability of AI algorithms across varying application contexts, informed by a nuanced understanding of different application scenarios and AI algorithm research. (4) An insightful discussion on the current challenges confronting AI-based RUL prediction technology, coupled with a forward-looking examination of its future prospects. By furnishing a meticulous and holistic understanding of the traits of various AI algorithms and their contextual applicability, this study aspires to facilitate the attainment of optimal application outcomes in the realm of equipment RUL prediction.

Background Gallbladder carcinogenesis, frequently occurredin chronic cholecystitis patients, requires radical resection. We herein describe a hemorrhagic cholecystitis case that failed to be differentiated from gallbladder cancer preoperatively owing to the neglected medication history of long term oral nonsteroidal anti-inflammatory drugs (NSIADs) intake. Case presentation A 57-year-old Chinese female was admitted for right upper quadrant pain with the initial diagnosis of cholecystitis. Radiological studies were unable to exclude the differential diagnosis of suspected gallbladder cancer. During the scheduled radical resection of the suspected lesions, the gross dissection showed an interesting presentation of hemorrhagic cholecystitis, without any pathological evidence of malignancies. Additional postoperative investigation revealed a neglected medication history of long-term NSAIDs use. Conclusions This case suggests the importance of preoperative review of medication history and patient education on prescription drug abuse.

Background Situs inversus totalis (SIT) is a rare congenital anomaly characterized by a complete transposition of all the viscera. SIT cases were usually reported because of the presence of tumors, leading to false association between them. Therefore, any research that advances our understanding on SIT is highly required. This study firstly describes a very rare case of SIT with “jumping” metastasis to pancreas of gallbladder carcinoma. Case presentation A 69-year-old female patient presented at our hospital with complaints of one month of epigastric pain was studied. She had not sought for treatment prior the visit. Imaging examinations of this patient revealed SIT and a variation of the common hepatic artery with concomitant tumors of gallbladder and pancreas. However, there was no evidence of distant metastases beyond the abdominal cavity. She underwent a combination of radical cholecystectomy, total pancreatectomy, splenectomy and hepatic artery-splenic artery reconstruction. Histological analyses revealed metastasis of the gallbladder carcinoma in to the pancreas. Although the patient opted against chemotherapy, she survived without tumor for 16 months following the surgery. A review of the current literature on association with SIT and tumor occurrence was presented. Conclusions It is a great surgical challenge for the resection of multicenter hepatobiliary and pancreatic tumors in such rare SIT anatomical abnormalities with vascular variants. A reliable surgical plan based on detailed preoperative imaging and intraoperative anatomical exploration is crucial to achieving radical resection.

To investigate the differences in the volatile compounds of plum fruit samples from different cultivars, the volatile compounds of the ‘Fengtang’ plum, ‘Kongxin’ plum, and ‘Cuihong’ plum fruits were analyzed using headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GC-MS). The results demonstrated that a total of 938 volatile compounds were identified in three plum fruits, including 200 terpenoids, 171 esters, 116 heterocyclic compounds, 89 hydrocarbons, 82 ketones and alcohols, 63 aldehydes, 54 aromatic hydrocarbons, 21 amines, 18 acids, 17 phenols, 10 nitrogenous compounds, 7 sulfur compounds, and other compounds, 470 of which were common to all the cultivars. Moreover, 704, 691, and 704 volatile substances were detected, respectively, in the ‘Fengtang’ plum, ‘Kongxin’ plum, and ‘Cuihong’ plum, with terpenoids, esters, and heterocycles as the main compounds, accounting for 62.12~72.03% of the volatile compounds. The results of principal component analysis (PCA) and cluster analysis (CA) illustrated that the ‘Fengtang’ plum and ‘Cuihong’ plum were similar in terms of volatile compounds; the ‘Kongxin’ plum compounds were different from those in the other cultivars. Orthogonal partial least squares discriminant analysis was performed, revealing the typical volatile compounds that differed among the plum fruits of the different varieties; thus, the three plum fruits could be better distinguished. These results can provide a theoretical basis for the studies of plum fruit flavor, quality, and geographical origin identification.

In the present study, the cuticular wax morphology, composition and the relationship with storage quality in three plum cultivars of Prunus salicina ‘Kongxin’ (KXL), Prunus salicina ‘Fengtang’ (FTL) and Prunus salicina ‘Cuihong’ (CHL) were investigated during storage at room temperature of 25 ± 1 °C. The results illustrated that the highest cuticular wax concentration was discovered in KXL, followed by FTL and the lowest in CHL. The fruit wax composition of the three plum cultivars was similar and principally composed of alkanes, alcohols, fatty acids, ketones, aldehydes, esters, triterpenes and olefins. Alcohols, alkanes and triterpenes were the dominant fruit wax compounds of the three plum cultivars. After storage for 20 d at room temperature, the variation of cuticular wax crystal structure and composition showed significant cultivar-associated differences. The total wax content decreased for FTL and CHL and increased for KXL, and the wax crystal degraded and melted together over time. The higher contents of the main components in the three plum cultivars were nonacosane, 1-triacontanol, 1-heneicosanol, nonacosan-10-one, octacosanal, ursolic aldehyde and oleic acid. Alcohols, triterpenes, fatty acids and aldehydes were most dramatically correlated with the softening of fruit and storage quality, and alkanes, esters and olefins were most significantly correlated with the water loss. Nonacosane and ursolic aldehyde can enhance the water retention of fruit. Overall, this study will provide a theoretical reference for the further precise development of edible plum fruit wax.

The absorption and distribution of radiocarbon-labeled urea at the ultratrace level were investigated with a 14C-AMS biotracer method. The radiopharmaceutical concentrations in the plasma, heart, liver, spleen, lung, kidney, stomach, brain, bladder, muscle, testis, and fat of rats after oral administration of 14C urea at ultratrace doses were determined by AMS, and the concentration-time curves in plasma and tissues and pharmacokinetic distribution data were obtained. This study provides an analytical method for the pharmacokinetic parameters and tissue distribution of exogenous urea in rats at ultratrace doses and explores the feasibility of evaluation and long-term tracking of ultratrace doses of drugs with AMS.

The absorption and distribution of radiocarbon-labeled urea at the ultratrace level were investigated with a 14 C-AMS biotracer method. The radiopharmaceutical concentrations in the plasma, heart, liver, spleen, lung, kidney, stomach, brain, bladder, muscle, testis, and fat of rats after oral administration of 14 C urea at ultratrace doses were determined by AMS, and the concentration-time curves in plasma and tissues and pharmacokinetic distribution data were obtained. This study provides an analytical method for the pharmacokinetic parameters and tissue distribution of exogenous urea in rats at ultratrace doses and explores the feasibility of evaluation and long-term tracking of ultratrace doses of drugs with AMS.

As a required sample preparation method for 14 C graphite, the Zn-Fe reduction method has been widely used in various laboratories. However, there is still insufficient research to improve the efficiency of graphite synthesis, reduce modern carbon contamination, and test other condition methodologies at Guangxi Normal University (GXNU). In this work, the experimental parameters, such as the reduction temperature, reaction time, reagent dose, Fe powder pretreatment, and other factors, in the Zn-Fe flame sealing reduction method for 14 C graphite samples were explored and determined. The background induced by the sample preparation process was (2.06 ± 0.55) × 10 –15 , while the 12 C – beam current were better than 40μA. The results provide essential instructions for preparing 14 C graphite of ∼1 mg at the GXNU lab and technical support for the development of 14 C dating and tracing, contributing to biology and environmental science.

As a required sample preparation method for 14C graphite, the Zn-Fe reduction method has been widely used in various laboratories. However, there is still insufficient research to improve the efficiency of graphite synthesis, reduce modern carbon contamination, and test other condition methodologies at Guangxi Normal University (GXNU). In this work, the experimental parameters, such as the reduction temperature, reaction time, reagent dose, Fe powder pretreatment, and other factors, in the Zn-Fe flame sealing reduction method for 14C graphite samples were explored and determined. The background induced by the sample preparation process was (2.06 ± 0.55) × 10–15, while the 12C– beam current were better than 40μA. The results provide essential instructions for preparing 14C graphite of ∼1 mg at the GXNU lab and technical support for the development of 14C dating and tracing, contributing to biology and environmental science.

A new system for preparing 14C samples was established for a compact accelerator mass spectrometer (GXNU-AMS) at Guangxi Normal University. This sample preparation system consists of three units: a vacuum maintenance unit, a CO2 purification unit, and a CO2 reduction unit, all of which were made of quartz glass. A series of radiocarbon (14C) preparation experiments were conducted to verify the reliability of the system. The recovery rate of graphite obtained was more than 80%. The carbon content in the commercial toner and wood sample was linearly fitted to the CO2 pressure in the measurement unit of the system. The results showed a good linear relationship, indicating that the reliability of the sample preparation system. AMS measurements were conducted on a batch of standard, wood, and dead graphite samples prepared using this system. The results showed that the beam current of 12C- for each sample was more than 40 μA, the carbon contamination introduced during the sample preparation process was ∼ 2 × 10–15, and that the new sample preparation system is compact, low-contamination, and efficient and meets the GXNU-AMS requirements for 14C samples.