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The introduction of twin lamellae and dislocation interaction through Multi-directional forging (MDF) at room temperature (RT) has been reported to significantly improve the mechanical properties of Mg alloys. However, the Mg alloys typically exhibited poor plasticity at RT, making it highly susceptible to cracking. This study further enhanced the deformation capacity of AZ80 Mg alloy by adding a pre-cryogenic step before MDF. Compared to direct MDF at RT, MDF at cryogenic temperature (CT, −196 °C) further increased the alloy's deformation capacity from 0.72 (4P) to 1.08 (6P), with the tensile yield strength (TYS) and ultimate tensile strength (UTS) increasing to ∼420 MPa and ∼512 MPa. The alloy subjected to cryogenic MDF exhibited denser twin lamellae and a higher proportion of {10–12}-{10–12} twin interactions. The more frequent twin interactions under CT inhibited excessive twin growth and further increased the dislocation density of the matrix, facilitating the nucleation of new twins. Additionally, with increasing deformation passes, the texture of the RT specimens became more single, while the CT specimen showed a trend toward texture dispersion. The study elucidated that poor forgeability of the alloy under MDF at RT was hindered by unfavorable texture and limited twin activation. However, this issue was mitigated under CT, where the activation of more atypical twins with low Schmid factors (SFs) significantly enhanced the deformation coordination ability. Furthermore, the activation of atypical twins and extensive twin interactions promoted texture dispersion in CT specimens, which facilitated the activation of various slips/twins and suppressed excessive twinning-induced hardening, thereby improving forgeability.

Background Subtypes of sinusitis have different symptoms and prognoses due to different pathogens. Odontogenic maxillary sinusitis (OMS) mainly occurs unilaterally and is different from chronic rhinosinusitis (CRS) usually occurring bilaterally in terms of clinical characteristics. However, comprehensive microbiological comparisons between OMS and CRS have never been systematically conducted and most comparisons are methodologically biased. This study aims to provide a comprehensive analysis of the microbiology associated with OMS and CRS through a meta-analysis approach in order to provide evidence for differential diagnosis of OMS and CRS from a microbiological perspective.Methods The databases PubMed and CNKI were searched from their inception to July 2023. A random-effects model was employed to derive the pooled prevalence estimates of the identified bacterial species or genera.Results The 17 represented studies included 6 concerning OMS, 12 concerning CRS, and 4 concerning normal sinus, yielding 191, 610, and 92 samples, respectively. Though not statistically significant, the prevalence of Peptostreptococcusand Prevotellawas generally higher in OMS compared to CRS. Notably, Fusobacteriumwas identified as the only genus with a significantly higher prevalence in OMS compared to CRS.Conclusion Fusobacteriumwas significantly more prevalent in OMS compared with CRS, while Staphylococcus aureuswas more prevalent in CRS than in OMS. Such differences in bacterial profile may partly explain the distinct pathology observed and contribute to the development of novel strategies for diagnosis and therapeutic interventions in OMS.

The high electrical conductivity Al-Ce-Sc-Y and Al-Mg-Si-Ce-Sc-Y alloys were used to study the effects of laser shock peening on their mechanical property, pitting and intergranular corrosion resistance. The strength and elongation of the alloys were improved simultaneously at the expense of very low electrical conductivity after laser shock peening due to the gradient structure and residual compressive stress. After two side laser shock peening, the strength and elongation of Al-Ce-Sc-Y and Al-Mg-Si-Ce-Sc-Y alloys increased to 231 ± 3 MPa/16.2 ± 0.2 % and 359 ± 3 MPa/17.1 ± 0.3 %, respectively. The samples with two surface states were used to study the corrosion behaviors. The number and depth of corrosion pits can be significantly reduced by laser shock peening and the crystallographic corrosion morphology exists in the corrosion pits. After two side laser shock peening with polished surface, the intergranular corrosion depth of Al-Mg-Si-Ce-Sc-Y alloy can reach the minimum and the intergranular corrosion cracks are much finer at the same depth. The Al-Ce-Sc-Y alloy had no tendency of intergranular corrosion, but the unpolished surface was prone to form the deep corrosion pits rather than occurred uniform corrosion. According to the microstructure analysis, the corrosion mechanism of pitting and intergranular corrosion was revealed.

ABSTRACTThe extremely competitive shipbuilding sector is going through a digital transformation in the context of Industry 4.0. The spatiotemporal problem has gained considerable attention during hull construction, particularly for blocks. There are fewer studies on intermediate products at lower levels, such as the dynamic spatiotemporal scheduling for hull parts under complex constraints in subassembly workshops. Therefore, this paper proposes a multi-queue two-level optimization method along with a dynamic spatiotemporal scheduling model based on the multi-directed acyclic graph (multi-DAG) and queueing theory. Firstly, a mathematical description of the complex constraints imposed by processing tasks and various resource types is provided. Then, a dynamic spatiotemporal scheduling model and an objective function are proposed to minimize the average time for parts in the system. At the sequencing level, different priority determination methods for queue events based on an improved genetic algorithm and the contribution ratio for release space strategy are proposed. At the service level, the allocation strategies for space and workers are constructed to improve utilization. Finally, several simulation experiments are conducted using the data gathered from the workshop. The proposed method is compared with the heuristic rules and combination rules using several queueing indicators and the space utilization vs. time graphs.

ABSTRACTIn clinical practice, anterior cruciate ligament (ACL) rupture is always repaired by the single-beam reconstruction method. Before the surgery, the surgeon made the diagnosis based on medical images, such as CT (computerized tomography) and MR (magnetic resonance) images. However, little is known about how biomechanics governs the biological nature for femoral tunnel position. In the present study, three volunteers’ motion trails were captured by six cameras when they were doing squat movement. The medical image can reconstruct the structure of the ligaments and bones and a left knee model was reconstructed by MIMICS by MRI data of DICOM format. Finally, the effects of different femoral tunnel positions on ACL biomechanics were characterized by the inverse dynamic analysis method. The results showed that there were significant differences in the direct mechanical effects of the anterior cruciate ligament at different locations of the femoral tunnel (p < 0.05), the peak stress of ACL in the low tension area was 1097.24 ± 25.55 N, and the peak stress of ACL in the distal femur was 356.81 ± 15.39 N, both of which were much higher than that in the direct fiber area (118.78 ± 20.68 N);

During the Carboniferous Period, the Qinghai-Tibetan Plateau and its surrounding areas were located in quite different paleogeographic positions with various sedimentary and biological types. It is important to systematically compile and summarize the Carboniferous strata and biotas of the Qinghai-Tibetan Plateau and its surrounding areas, to establish an integrated stratigraphic framework for correlation, and to reconstruct the paleogeography for correctly understanding the breakup of the Gondwana Continent and the evolution of the Paleo-Tethys Ocean in the Late Paleozoic. The Carboniferous of the Qinghai-Tibetan Plateau and its surrounding areas can be subdivided into the Gondwanan, Cimmerian, and Tethyan types. The Gondwanan-type Carboniferous are distributed in the North Himalayan, Kangmar-Lhunze, and Zanda-Zumba regions of the South Tibet Subprovince and northern India-Pakistan Area, where only the Mississippian is developed and the biota is of Gondwanan affinity. The Cimmerian-type Carboniferous, which are found in the Baoshan, Tengchong, Coqen-Xainza, Lhasa-Zayu, Nagqu-Biru, and South Qiangtang regions, as well as Shan-Thai and South Afghanistan-Pamir areas, also represent only the Mississippian strata, but their biota is characterized by mixed characters of European, South China, Australian, and North American types. The Tethyan-type Carboniferous are distributed in the Tanggula Mountains, Hoh Xil-Bayanhar, Chamdo-Hengduanshan, Tiekelike, West Kunlun, Karakorum, East Kunlun-Central Qinling, and Qilian regions, where the Carboniferous succession is well developed, and the biota is of warm-water Tethyan affinity. The biostratigraphical correlation of the Gond-wanan-type and Cimmerian-type Carboniferous is based mainly on conodonts and additionally on brachiopods and rugose corals. The Mississippian of the Tethyan-type Carboniferous is correlated mainly by using rugose corals and brachiopods, whereas in the Pennsylvanian foraminifera (fusuline) and conodonts are regarded as primary fossil groups, subordinated by rugose corals and brachiopods. Adhering to the International standard chronostratigraphy of the Carboniferous, we have reconstructed a framework of the litho- and biostratigraphic subdivision and correlation of the Qinghai-Tibetan Plateau and its surrounding areas. Further studies should focus on isotope geochronology, geochemistry, paleoclimates, and paleoenvironments of the Carboniferous in the Qinghai-Tibetan Plateau and its surrounding areas.

A novel two-terminal vertical bridge structure nanoscale vacuum electronic device (NVED) is proposed to optimize the device structure for improved frequency characteristics in this study. By introducing a bridge structure, the sacrificial layers used for supporting between the electrodes are completely released, resulting in suspended electrodes. This successful implementation has significantly reduced the interelectrode capacitance to a level comparable to that of planar lateral devices. As a result, the frequency characteristics of the vertical structure device have been greatly enhanced. The fabrication of this device is obtained by a combination of atomic layer deposition (ALD) and buffered oxide etching (BOE), which is compatible with the CMOS process. The emission characteristics of the fabricated device under atmospheric conditions are measured with excellent stability and repeatability. More importantly, for the first time, the scattering parameters of the NVED have been measured under 0-V bias conditions within a frequency range of 10 MHz–10 GHz. A high-frequency small-signal model has also been established and validated against the measured parameters, demonstrating good consistency over the entire frequency range. Ultimately, the study successfully validates the frequency conversion functionality of the proposed NVED. These results highlight the potential of the device for operation in the high-frequency range, which is particularly significant in communication and radar applications.

The increasing development of information technology has led to a higher demand for communication capacity. Moreover, the mode division multiplexing (MDM) is considered one of the important technologies to expand the optical fiber transmission capacity, and the few-mode erbium-doped fiber amplifier (FM-EDFA) is a main device applied for optical fiber loss compensation under long-haul communication transmission systems. This article reports the design and characterization of a six-mode erbium-doped fiber amplifier (6M-EDFA) for MDM systems. A center-depressed optical fiber with a trench-assisted structure, is designed and the adjustment of the relevant parameters is applied to reduce the splice loss between the six-mode erbium-doped fiber (6M-EDF) and the transmission fiber. The results show the lowest splice loss is theoretically 0.293 dB. By analyzing the mode field distribution, two erbium ion doping regions are initially identified, the ring region is further layered, and the doping concentration of the three layers is optimized to achieve high gain and low differential modal gain (DMG) using a genetic algorithm (GA). In the case of core forward pumping of the LP01 mode at 1480 nm, the simulation results show that the average gain of 25.7 dB and the DMG of 0.277 dB are obtained at 1550 nm considering the mode coupling. Moreover, a 6-mode MDM transmission system is built to fully verify the performance of the designed amplifier to meet the requirements of the MDM communication system.

Oil/water separation is an important pursuit because of the increasing worldwide oil pollution. The key to solving this problem is to develop high-performance materials and improve their separation efficiency. Polyurethane composite foam (PUCF) possesses large specific surface area, high open porosity, and good mechanical properties which have been developed for oil/water separation. This paper mainly summarizes the research progress of PUCF materials in oil/water separation, including the surface-wetting theory, the intrinsic wetting threshold theory, the main factors affecting the separation performance of foam materials, and the recent research status of the PUCF materials in oil/water separation. Finally, we look forward to the research focus on urgent problems that should be addressed for PUCF in oil/water separation, which will provide new strategies for further developing next-generation high-performance foam materials for oil/water separation.

In the present paper, we demonstrate the first outdoor free-space optical communication (FSOC) system with real-time video transmission in a 2-μm-band with a state-of-the-art data rate performance of 10 Gbit/s and a communication distance of ∼177 m. The measured wide-open eye diagram and zero bit-error-rate also validated the high communication quality. The FSOC system is constructed with all homemade components, including a single-frequency (SF) thulium-holmium co-doped fiber laser (THDFL), a modulation module, a demodulation module, three thulium-doped fiber amplifiers, an optical bandpass filter, two optical-antennas, and a display system. As the most important component, the SF THDFL, enabled by a uniform fiber Bragg grating and a passive fiber ring-compound cavity, is self-designed and fabricated by our group, presenting high lasing stability centered at 2048.98 nm, an optical signal-to-noise ratio of >81 dB, a relative intensity noise of &lt;−128.18 dB/Hz at >0.5 MHz and a linewidth of 5.290 kHz under a measurement integration time of 0.001 s. Our work is an important step forward for practical outdoor FSOC in a 2-μm-band, proving useful for engineers and scientists when our SF THDFL is implemented as a low-cost, high-performance laser source for the FSOC system.

ABSTRACTFatigue can significantly affect the biomechanics of the anterior cruciate ligament (ACL) during single-legged jumping, and these changes are closely related to ACL injuries. Unfortunately, there is no convenient way to accurately and quickly track these changes. This present study aimed to develop such a method based on video capture and inverse dynamics simulation.Are our method’s results accurate and reliable? Fifteen participants performed sing-legged jumping before and after the fatigue protocol, and their actions were videotaped. The videos were processed and converted to marked motion data, used to drive the mannequin model in AnyBody Modelling System (AMS) for the inverse dynamics simulations. The ACL segment was also constructed based on one participant’s MRI data and added the mannequin model.Our results were similar to the findings from previous studies. Neuromuscular fatigue decreased the peak flexion angles and increased the low-the-limb muscle strength and activation. These alterations might contribute to ACL tears and ruptures. In addition, the simulation showed that the ACL force significantly (p < 0.05) increased as a result of fatigue during single-legged jumping. Our study provides a facile and reliable method to study the effects of neuromuscular fatigue on lower-the-limb biomechanics. Such a method can be applied to investigate other risk factors on ACL injuries and assist in developing workable plans for athlete training in the future.

Policy decision of curling refers to providing strategy suggestions for curling competition with the help of computers. Existing curling agents have achieved good results in the digital scenarios, but cannot make correct decisions when applied to actual competition and training scenes. In this paper, a strategies decision agent in the real scene has been proposed. The competition situation was acquired by a Situation-Aware Network and mapped by a Digital Extraction module. We designed Curling MCTS to explore the best strategy in continuous space. The effectiveness of our framework has been verified by experiments and evaluated by China’s wheelchair curling team at China Disabled Sports Management Center. With the help of our system, China’s wheelchair curling team trained effectively and won the championship in the XIII Paralympic Winter Games (2022, Beijing). In addition, a new curling target detection dataset was provided.

Primary liver cancer is a common and lethal malignancy in China. Transcatheter arterial chemoembolization (TACE) is globally recognized as the preferred treatment modality for the non-surgical resection of hepatocellular carcinoma (HCC), while transcatheter arterial infusion (TAI) is another effective interventional treatment for HCC. In recent years, hepatic arterial infusion chemotherapy (HAIC) has gained increasing attention as an application-regulated modality for TAI. Owing to the current debate in the medical community regarding the use of HAIC and TACE for the treatment of HCC, the application of both approaches should be considered at a higher level, with a broader perspective and a more normative aspect. Accordingly, we aimed to define the rational combination of liver cancer TAI/HAIC with TACE as infusion transcatheter chemoembolization (iTACE), which suggests that the two interventions are not superior but lead to a mutually beneficial situation. In this review, we sought to discuss the development, specification, application, challenge and innovation, debate, and union of TAI/HAIC and TACE, and the clinical application and latest research on iTACE. We aimed to introduce new concepts of iTACE and expect new breakthroughs in the treatment of liver cancer owing to the combined use of the two major interventional tools.

In this study, the influence of repair welding on microstructure evolution, mechanical properties, and corrosion resistance of SUS304-Q345B dissimilar metal active gas arc (MAG) welding plates was investigated via optical microscopy (OM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), hardness, tensile, fatigue, intergranular corrosion, and electrochemical tests, in which the zero (R0), primary (R1), and secondary repair welding (R2) were performed by MAG welding. The results showed that, after repair welding, the δ-ferrite morphology in the weld evolved from a continuous dendritic shape to a dispersed worm-like structure and the bar ferrite in the heat-affected zone of SUS304 (HAZSUS304) evolved into short bar ferrite. The grain size of the weld was reduced due to the remelting caused by repair welding. The hardness of the weld increased first and then decreased which was related to the decrease of δ-ferrite morphology and grain size of weld. In the tensile test, all specimens were fractured at Q345B base material (BMQ345B), which revealed that repair welding had little effect on the tensile properties. The fatigue limit strength of R1 didn't reduce significantly, while the fracture position of R2 transferred from the SUS304 base material (BMSUS304) to the fusion line of SUS304 (FLSUS304). The corrosion resistance of R1 weld possessed the best corrosion resistance owing to the finer grain size and better δ-ferrite morphology. The results indicated that repair welding was feasible for the repair and reuse of welded joints, and it was of great importance in engineering applications of welded plates.

Dissecting and understanding the cancer ecosystem, especially that around the tumor margins, which have strong implications for tumor cell infiltration and invasion, are essential for exploring the mechanisms of tumor metastasis and developing effective new treatments. Using a novel tumor border scanning and digitization model enabled by nanoscale resolution-SpaTial Enhanced REsolution Omics-sequencing (Stereo-seq), we identified a 500 µm-wide zone centered around the tumor border in patients with liver cancer, referred to as “the invasive zone”. We detected strong immunosuppression, metabolic reprogramming, and severely damaged hepatocytes in this zone. We also identified a subpopulation of damaged hepatocytes with increased expression of serum amyloid A1 and A2 (referred to collectively as SAAs) located close to the border on the paratumor side. Overexpression of CXCL6 in adjacent malignant cells could induce activation of the JAK-STAT3 pathway in nearby hepatocytes, which subsequently caused SAAs’ overexpression in these hepatocytes. Furthermore, overexpression and secretion of SAAs by hepatocytes in the invasive zone could lead to the recruitment of macrophages and M2 polarization, further promoting local immunosuppression, potentially resulting in tumor progression. Clinical association analysis in additional five independent cohorts of patients with primary and secondary liver cancer (n= 423) showed that patients with overexpression of SAAs in the invasive zone had a worse prognosis. Further in vivo experiments using mouse liver tumor models in situ confirmed that the knockdown of genes encoding SAAs in hepatocytes decreased macrophage accumulation around the tumor border and delayed tumor growth. The identification and characterization of a novel invasive zone in human cancer patients not only add an important layer of understanding regarding the mechanisms of tumor invasion and metastasis, but may also pave the way for developing novel therapeutic strategies for advanced liver cancer and other solid tumors.

A hallmark of symmetry-protected topological phases are topological boundary states, which are immune to perturbations that respect the protecting symmetry. It is commonly believed that any perturbation that destroys such a topological phase simultaneously destroys the boundary states. However, by introducing and exploring a weaker sub-symmetry requirement on perturbations, we find that the nature of boundary state protection is in fact more complex. Here we demonstrate that the boundary states are protected by only the sub-symmetry, using Su–Schrieffer–Heeger and breathing kagome lattice models, even though the overall topological invariant and the associated topological phase can be destroyed by sub-symmetry-preserving perturbations. By precisely controlling symmetry breaking in photonic lattices, we experimentally demonstrate such sub-symmetry protection of topological states. Furthermore, we introduce a long-range hopping symmetry in breathing kagome lattices, which resolves a debate on the higher-order topological nature of their corner states. Our results apply beyond photonics and could be used to explore the properties of symmetry-protected topological phases in the absence of full symmetry in different physical contexts.

An Al–Zn–Mg–Cu alloy and an Al–Zn–Mg–Cu–Sc–Zr alloy are used to study effects of co-addition of minor Sc and Zr on aging precipitates and mechanical properties of Al–Zn–Mg–Cu alloys. After solid solution treatment, almost complete recrystallization occurs in the Al–Zn–Mg–Cu alloy, while recrystallization is significantly inhibited in the Al–Zn–Mg–Cu-Sc-Zr alloy, with a recrystallization fraction of 12.6%. The Al–Zn–Mg–Cu–Sc–Zr alloy has remarkably higher strength than the Al–Zn–Mg–Cu–Sc–Zr alloy in the solid solution-treated and water-quenched state, which is due to the Orwan strengthening of coherent Al3(Sc, Zr) particles and the grain boundary strengthening for finer grains. At the aging temperature of 120 °C，the co-addition of Sc and Zr accelerates the nucleation and growth of η′ phases in the grain interior, allowing the aged Al–Zn–Mg–Cu–Sc–Zr alloy to reach its peak strength earlier. At the aging temperature of 140 °C, the aging precipitate strengthening effect is weaker for the Al–Zn–Mg–Cu–Sc–Zr alloy than for the Al–Zn–Mg–Cu alloy because of the accelerated transformation from η′ phases to η phases and growth of η phases in the grain interior.

In recent years, artificial intelligence deep learning has gradually become a research hotspot in diagnosing and treating cervical and lumbar degenerative diseases, represented by cervical spondylosis and lumbar disc herniation.

Percutaneous transhepatic biliary drainage (PTBD) is an effective treatment for benign and malignant obstructive jaundice. Major bleeding complications occur in approximately 2–3% of patients after PTBD, which can result in death. A case involving a 63-year-old male with malignant obstructive jaundice, who experienced severe bleeding after PTBD, is reported. Emergency digital subtraction angiography, celiac trunk artery and superior mesenteric artery angiography were performed; however, no signs of arterial bleeding were found. To identify etiology, portal venography was performed under ultrasound guidance and portal vein bleeding was diagnosed. Ultimately, selective portal vein embolization successfully stopped the bleeding.

Odontogenic maxillary sinusitis (OMS) is a subtype of maxillary sinusitis (MS). It is actually inflammation of the maxillary sinus that secondary to adjacent infectious maxillary dental lesion. Due to the lack of unique clinical features, OMS is difficult to distinguish from other types of rhinosinusitis. Besides, the characteristic infectious pathogeny of OMS makes it is resistant to conventional therapies of rhinosinusitis. Its current diagnosis and treatment are thus facing great difficulties. The multi-disciplinary cooperation between otolaryngologists and dentists is absolutely urgent to settle these questions and to acquire standardized diagnostic and treatment regimen for OMS. However, this disease has actually received little attention and has been underrepresented by relatively low publication volume and quality. Based on systematically reviewed literature and practical experiences of expert members, our consensus focuses on characteristics, symptoms, classification and diagnosis of OMS, and further put forward multi-disciplinary treatment decisions for OMS, as well as the common treatment complications and relative managements. This consensus aims to increase attention to OMS, and optimize the clinical diagnosis and decision-making of OMS, which finally provides evidence-based options for OMS clinical management.

Effective collection, recognition, and analysis of sports information is the key to intelligent sports, which can help athletes to improve their skills and formulate scientific training plans and competition strategies. At present, wearable electronic devices used for movement monitoring still have some limitations, such as high cost and energy consumption, incompatibility of suitable flexibility and personalized spatial structure, dissatisfactory data analysis methods, etc. In this work, a novel three-dimensional-printed thermoplastic polyurethane is introduced as the elastic shell and friction layer, and it endows the proposed customizable and flexible triboelectric nanogenerator (CF-TENG) with personalized spatial structure and robust correlation to external pressure. In practical application, it exhibits highly sensitive responses to the joint-bending motion of the finger, wrist, or elbow. Furthermore, a pressure-sensing insole and smart ski pole based on CF-TENG are manufactured to build a comprehensive sports monitoring system to transmit the athletes’ motion information from feet and hands through the plantar pressure distribution and ski pole action. To recognize the movement status, the self-developed automatic peak recognition algorithm (P-Find) and machine learning algorithm (subspace K-Nearest Neighbors) were introduced to accurately distinguish the four typical motion behaviors and three primary sub-techniques of cross-country skiing, with accuracy rates of 98.2% and 100%. This work provides a novel strategy to promote the personalized applications of TENGs in intelligent sports.

Protein crystallization is a prevalent phenomenon existing in the formation of intricate protein-assembled structures in living cells. Whether the crystallization of a protein would exert a specific biological function, however, remains poorly understood. Here, we reconstructed a recombinant galectin-10 (gal-10) protein and artificially engineered a gal-10 protein assembly in two distinguishable states: i.e., an insoluble crystalline state and a soluble state. The potency of the gal-10 protein in either the crystalline state or the soluble state to induce chemokine or cytokine release in the primary human nasal epithelial cells and nasal polyps derived from chronic rhinosinusitis patients with nasal polyps was investigated. The crystalline gal-10 upregulated the gene expression of chemokines or cytokines, including IL-1β, IL-6, IL-8, TNF-α, and GM-CSF, in patient-derived primary cells and nasal polyps. In contrast, soluble gal-10 displayed a diminished potency to induce inflammation. Our results demonstrate that the gal-10 protein potency of activating inflammation is correlated with its crystalline state.

As one of the critical issues in operations management, spare parts planning classification systems based only on cost may not withstand the test of time because of continuing technological advancement or environmental degradation. This study, however, emphasizes using failure mode effect and criticality analysis (FMECA) as a basis for designing an ABC classification system that is capable of more accurately determining critical equipment and making maintenance more efficient. In the proposed methodology, risk priority numbers (RPN) and criticality as an index of safety and reliability can be obtained using a structured failure analysis technique. These indexes can be added to the economic indicator of maintenance cost, and then a classification model of spare parts can be established according to a comprehensive scoring method. The model is calibrated by using case data from a bus braking system, and the components of the braking system are compared and analyzed. The results show that the improved ABC classification method reduces the proportion of key and main components. This method can make maintenance work more efficient, targeting the most critical components, and can reduce administrative costs for enterprises.

Background and aims: No study has evaluated the diagnostic value of SpyGlass by comparing SpyGlass results and non-SpyGlass results. In this retrospective study, we aimed to compare the diagnostic value of EUS-guided fine-needle aspiration (EUS-FNA) and EUS-FNA combined with SpyGlass to evaluate whether SpyGlass is valuable for increasing the diagnostic yield of EUS-FNA. Methods: From April 2015 to April 2020, 251 patients suspected of having pancreatic cystic lesions (PCLs) by imaging techniques who then underwent EUS-FNA were retrospectively enrolled. Only 98 patients who underwent surgical resection with a pathological diagnosis of pancreatic cystic lesion (PCL) were studied. The diagnostic performance outcomes were compared between the EUS-FNA group (EUS-FNA alone, n= 40) and the SpyGlass group (EUS-FNA combined with SpyGlass, n= 58) to assess the value of SpyGlass in diagnosing PCLs. Results: There were 71 females and 27 males with an overall mean age of 47.6 years. The median diameter of the PCLs was 42.2 mm (range, 11.4–100.0 mm). Approximately 37 cysts were localized in the head/neck of the pancreas, while 61 in the body/tail. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of the EUS-FNA group were 96.4% (27/28), 83.3% (10/12), 93.1% (27/29), 90.9% (10/11) and 92.5% (37/40), while those in the SpyGlass group were 100% (54/54), 75% (3/4), 98.2% (54/55), 100% (3/3) and 98.3% (57/58), respectively. The diagnostic accuracy rate in the SpyGlass group was higher than that in the EUS-FNA group; however, no significant difference was found between the two groups (P= 0.368). The diagnostic accuracy of evaluating specific cyst types in the EUS-FNA group was 85% (34/40), similar to that in the SpyGlass group (85.0% vs 84.5%, P= 0.944). Conclusion: SpyGlass seems less valuable for the diagnosis of PCLs when EUS and EUS-FNA have been performed by experienced endoscopists.

The Carboniferous-Permian strata in the North China Block (NCB) contain abundant fossils, coals and natural gases. Establishing a high-resolution timescale for the Carboniferous and Permian in the NCB is essential to understand the geologic events and explore the spatial and temporal distributions of the natural resources. The upper Carboniferous and the basal part of Permian are relatively well correlated because they yield marine conodont and fusuline fossils. However, the Permian terrestrial strata mostly rely on poorly constrained palynostratigraphy and phytostratigraphy and are short of the precise geochronologic constraints on the correlation with the marine strata. This study provides a critical review on the state-of-the-art of the latest Carboniferous and Permian chronostratigraphic and biostratigraphic frameworks and stratigraphic correlation in the NCB. The Penchi Formation ranges from lower Bashkirian to lower Gzhelian; the Taiyuan Formation is assigned to the upper Gzhelian to lower Asselian; the Shansi and Lower Shihhotse formations are from middle Asselian to lower Sakmarian; the Upper Shihhotse Formation is assigned to upper Artinskian to lower Kungurian, and the Sunjiagou Formation was assigned to Lopingian, respectively. A long hiatus up to ∼20 Myr between the Upper Shihhotse and Sunjiagou formations, mainly marked by a large-scale erosional surface at the base of a coarse conglomeratic sandstone unit and/or multiple paleosol layers as well as significant differences of floras between these two lithostratigraphic units, is present probably due to tectonic uplift in association with the closure of the Paleo Asian Ocean (PAO) during the Cisuralian and Guadalupian. The possible amplitude of sea-level changes from Carboniferous to Permian on the NCB is estimated from 0 to 40 m. The floral succession, depositional records and organic carbon isotope profiles suggest that the latest Carboniferous and earliest Permian was a favorable period for coal accumulation under an ever-wet and warm climate, followed by a prominent shift to dry climate from early-middle Cisuralian. This climatic shift during the Permian was mainly resulted from northward migration of the Pangea and the closure of the PAO, which is comparable with the Carboniferous and Permian trends in central Europe.

The Carboniferous chronostratigraphic scale is a hierarchy of two subsystems, six series and seven stages developed during nearly two centuries of research. Carboniferous stage nomenclature developed with the proposal of numerous regional stages/substages based primarily on palaeobotanical, foraminiferal and ammonoid biostratigraphy, especially in Western Europe, the former Soviet Union, China and the USA. From the regional stages, seven ‘global stages’ have been identified (in ascending order): Tournaisian, Visean, Serpukhovian, Bashkirian, Moscovian, Kasimovian and Gzhelian. Three of the four ratified Carboniferous GSSPs use conodont evolutionary events as the primary signal for correlation – bases of Tournaisian, Bashkirian and base of Asselian. The GSSP of the Visean base has a foraminiferal event as its primary signal. Issues in the development of a Carboniferous chronostratigraphic scale include the rank of chronostratigraphic units, provinciality, conodont biostratigraphy, palaeobotanical biostratigraphy and the development of astrochronology and other methods of chronology and correlation.

The Carboniferous chronostratigraphic scale consists of two subsystems, six series and seven stages. Precise numerical age control within the Carboniferous is uneven, and a global magnetic polarity timescale for the Carboniferous is far from established. Isotope stratigraphy based on Sr, C and O isotopes is at an early stage but has already identified a few Sr and C isotope events of use to global correlation. Cyclostratigraphy has created a workable astrochronology for part of Pennsylvanian time that needs better calibration. Chronostratigraphic definitions of most of the seven Carboniferous stages remain unfinished. Future research on the Carboniferous timescale should focus on Global Stratotype Section and Point (GSSP) selection for the remaining, undefined stage bases, definition and characterization of substages, and further development and integration of the Carboniferous chronostratigraphic scale with radioisotopic, magnetostratigraphic, chemostratigraphic and cyclostratigraphic tools for calibration and correlation, and the cross-correlation of non-marine and marine chronologies.