Current Classification Research Articles

Pathological Diagnostic Testing and Biomarkers for Perioperative System Therapy

Optimal personalized treatment planning for resectable lung cancer requires quality-assured, standardized and prompt processing of tissue samples in pathological laboratories, as well as the determination of relevant predictive and prognostic biomarkers. Pathological diagnostic testing includes histological tumor typing, staging and tumor grading, resection status and, if necessary, regression grading after neoadjuvant systemic therapy. Histopathological typing is performed according to the current WHO classification and includes adenocarcinomas, squamous cell carcinomas, other non-small cell lung carcinomas (NSCLCs), carcinoids, small cell and large cell neuroendocrine carcinomas. Standardized tumor grading currently plays an important role in invasive non-mucinous adenocarcinoma in particular and enables prognostic risk assessment. The R classification and regression grading are also prognostically relevant. In the early stages of NSCLC, molecular biomarkers such as EGFR, ALK and PD-L1, are relevant for decisions on individual treatment. Testing is performed on FFPE tissue samples and must be carried out in a quality-assured manner and in accordance with international standards.

Current development of molecular classifications of gastric cancer based on omics (Review).

Gastric cancer (GC) is a complex and heterogeneous disease with significant phenotypic and genetic variation. Traditional classification systems rely mainly on the evaluation of clinical pathological features and conventional biomarkers and might not capture the diverse clinical processes of individual GCs. The latest discoveries in omics technologies such as next‑generation sequencing, proteomics and metabolomics have provided crucial insights into potential genetic alterations and biological events in GC. Clustering strategies for identifying subtypes of GC might offer new tools for improving GC treatment and clinical trial outcomes by enabling the development of therapies tailored to specific subtypes. However, the feasibility and therapeutic significance of implementing molecular classifications of GC in clinical practice need to addressed. The present review examines the current molecular classifications, delineates the prevailing landscape of clinically relevant molecular features, analyzes their correlations with traditional GC classifications, and discusses potential clinical applications.

FedETC: Encrypted traffic classification based on federated learning

The current popular traffic classification methods based on feature engineering and machine learning are difficult to obtain suitable traffic feature sets for multiple traffic classification tasks. Besides, data privacy policies prohibit network operators from collecting and sharing traffic data that might compromise user privacy. To address these challenges, we propose FedETC, a federated learning framework that allows multiple participants to learn global traffic classifiers, while keeping locally encrypted traffic invisible to other participants. In addition, FedETC adopts one-dimensional convolutional neural network as the base model, which avoids manual traffic feature design. In the experiments, we evaluate the FedETC framework for the tasks of both application identification and traffic characterization in a publicly available real-world dataset. The results show that FedETC can achieve promising accuracy rates that are close to centralized learning schemes.

Update on Pathologic Conditions, Imaging Findings, Prevention, and Management of Human Papillomavirus-related Neoplasms.

Human papillomavirus (HPV) is the most common sexually transmitted infection that proliferates in the squamous epithelium and is the most common source of viral-related neoplasms. Low-risk subtypes (HPV-6 and -11) cause respiratory papillomas (laryngeal, tracheal, and bronchial) and condyloma acuminata of the penis, anus, and perineal region (anogenital warts). High-risk subtypes (HPV-16, -18, -31, and -33) are responsible for oropharyngeal squamous cell carcinoma (SCC) that involves the tongue base, tonsils, posterior pharyngeal wall, and larynx and malignancies of the anogenital region (cancers of the cervix, vagina, vulva, penis, and anal canal). Recent studies have increasingly shown a favorable treatment response and substantial differences in the overall prognosis associated with HPV-associated oropharyngeal cancers. Given this fact, oropharyngeal, cervical, and penile SCCs are classified as HPV-associated and HPV-independent cancers in the current World Health Organization classification. Imaging is essential in the early detection, diagnosis, and staging of HPV-associated cancers. Imaging also helps assess treatment response and postoperative complications and is used for long-term surveillance. HPV-associated oropharyngeal SCCs have well-defined borders and solid and cystic nodal metastases at imaging. Updated screening and vaccination guidelines are currently available that have great potential to decrease the overall disease burden and help control this worldwide public health concern. Novel therapeutic strategies, such as immunotherapies, are being explored, and imaging biomarkers that can predict treatment response and prognosis are being investigated; radiologists play a pivotal role in these efforts. ©RSNA, 2024 Supplemental material is available for this article.

Optimasi Support Vector Machine (SVM) Menggunakan Naive Bayes dan Decision Tree untuk Klasifikasi Tema Tugas Akhir Mahasiswa Sistem Informasi

-The School of Informatics and Computer Management (STMIK) Abulyatama faces challenges in classifying student thesis topics. The current manual classification process is inefficient and ineffective. Therefore, the implementation of data mining techniques is needed to manage this data, specifically to automate the classification process. This study aims to optimize the Support Vector Machine (SVM) model by integrating Naive Bayes and Decision Tree algorithms to improve the accuracy of thesis topic classification. Based on the analysis, it can be concluded that both SVM and K-Means can be utilized by decision-makers to categorize thesis topics as a decision support system. Naive Bayes and Decision Tree were shown to optimize SVM and enhance its accuracy. Naive Bayes achieved the highest accuracy at 82.50%, while Decision Tree recorded an accuracy of 62.50%, making Naive Bayes the most suitable model for thesis classification.

Salivary IL-1β, IL-6, and IL-10 Are Key Biomarkers of Periodontitis Severity.

To explore severity and progression biomarkers, we examined the clinical relevance of multiple cytokines and mediators involved in the inflammatory response in periodontitis. A cohort of 68 patients was enrolled in the study and periodontal status assessed by the current classification of periodontal diseases. Immune mediators present in saliva, of both patients and healthy controls, were quantified using a Legendplex-13 panel. Clinic parameters were significantly higher in PD patients compared with HC, with a strong significant association with the disease severity (stage) (p < 0.001), but not with progression (grade). The panel of immune mediators evidenced elevated levels of pro-inflammatory cytokines IL-6 and IL-1β as disease established (p < 0.01). IL-1β/IL-1RA ratio was increased in PD patients, being associated with disease stage. An anti-inflammatory response was spotted by higher IL-10. Lower levels of IL-23 and IP-10 were associated with disease severity. No significant statistical differences were found by grade classification. Moreover, salivary IL-1β and IL-6 exhibited significant positive correlations with several clinical measurements (PI, BOP, PPD, CAL), while IP-10 showed a statistical negative correlation with BOP, PPD, and CAL. These insights highlight the complexity of the periodontitis inflammatory network and the potential of cytokines as biomarkers for refined diagnostic and therapeutic strategies.

Molecular phylogeny of Chinese raspy crickets (Orthoptera: Gryllacrididae) reveals incongruences in current classification

Abstract The current classification system of the family Gryllacrididae primarily relies on morphological characteristics, with limited molecular studies conducted. In this study, we sequenced five genes (COI, COII, Cytb, 18S, and 28S) from a total of 46 gryllacridid individuals mainly from China. Subsequently, we utilized both the maximum likelihood method and the Bayesian inference method to construct a phylogenetic tree, aiming to elucidate the phylogenetic relationships within Gryllacrididae from China. Our results indicate that the genera Phryganogryllacris Karny, Capnogryllacris Karny, and Eugryllacris Karny are not monophyletic. Thus, we redescribe these genera, resurrect two genera (Marthogryllacris Karny stat. resurr. and Borneogryllacris Karny stat. resurr.), erect six new genera (Dracogryllacris gen. nov., Magnigryllacris gen. nov., Radigryllacris gen. nov., Sericgryllacris gen. nov., Bicornisgryllacris gen. nov., and Tenuigryllacris gen. nov.), and described two new species (Tenuigryllacris huanglianensis Li, Yin &amp; He sp. nov. and Tenuigryllacris yingjiangensis Li, Yin &amp; He sp. nov.). Besides, subgenus Bianigryllacris Cadena-Castañeda is a synonym of Apterolarnaca Gorochov.

Innovations in the classification of soft tissue tumors

Soft tissue tumors are avery heterogeneous group of tumors. Their classification is regularly updated by the World Health Organization (WHO), most recently in 2020. The current classification of soft tissue tumors emphasizes molecular biological tumor characteristics, which enable tumor-specific treatment. In addition to Ewing's sarcoma, which occurs as bone as well as extra-skeletal soft tissue tumors as asmall round cell sarcoma, three other subtypes of undifferentiated, small and round cell sarcomas have been introduced. Some names of the new sarcomas can be derived from the gene mutations. The groups of adipocytic and (myo)fibroblastic tumors have been extended by three further entities. There were further additions to vascular soft tissue tumors, smooth muscle cell tumors, peripheral nerve sheath tumors and tumors of uncertain differentiation. Adistinction is made between benign, intermediate locally aggressive, intermediate rarely metastatic and malignant soft tissue tumors.

Increase of HCN current in SOD1-associated amyotrophic lateral sclerosis.

The clinical manifestations of sporadic amyotrophic lateral sclerosis (ALS) vary widely. However, the current classification of ALS is mainly based on clinical presentations, while the roles of electrophysiological and biomedical biomarkers remain limited. Herein, we investigated a group of patients with sporadic ALS and an ALS mouse model with superoxide dismutase 1 (SOD1)/G93A transgenes using nerve excitability tests (NET) to investigate axonal membrane properties and chemical precipitation, followed by enzyme-linked immunosorbent assay analysis to measure plasma misfolded protein levels. Six of 19 patients (31.6%) with sporadic ALS had elevated plasma misfolded SOD1 protein levels. In sporadic ALS patients, only those with elevated misfolded SOD1 protein levels showed an increased inward rectification in the current-threshold (I/V) curve and an increased threshold reduction in the hyperpolarizing threshold electrotonus (TE) in the NET study. Two familial ALS patients with SOD1 mutations also exhibited similar electrophysiological patterns of NET. For patients with sporadic ALS showing significantly increased inward rectification in the I/V curve, we noted an elevation in plasma misfolded SOD1 level, but not in total SOD1, misfolded C9orf72, or misfolded phosphorylated TDP43 levels. Computer simulations demonstrated that the aforementioned axonal excitability changes are likely associated with an increase in hyperpolarization-activated cyclic nucleotide-gated (HCN) current. In SOD1/G93A mice, NET also showed an increased inward rectification in the I/V curve, which could be reversed by a single injection of the HCN channel blocker, ZD7288. Daily treatment of SOD1/G93A mice with ZD7288 partially prevented the early motor function decline and spinal motor neuron death. In summary, sporadic ALS patients with elevated plasma misfolded SOD1 exhibited similar patterns of motor axonal excitability changes as familial ALS patients and ALS mice with mutant SOD1 genes, suggesting the existence of SOD1-associated sporadic ALS. The observed NET pattern of increased inward rectification in the I/V curve was attributable to an elevation in the HCN current in SOD1-associated ALS.

Assessing receptivity to malaria using case surveillance and forest data in a near-elimination setting in northeast Thailand

BackgroundThailand aimed to eliminate malaria by 2024, and as such is planning for future prevention of re-establishment in malaria free provinces. Understanding the receptivity of local areas to malaria allows the appropriate targeting of interventions. Current approaches to assessing receptivity involve collecting entomological data. Forest coverage is known to be associated with malaria risk, as an environment conducive to both vector breeding and high-risk human behaviours.MethodsGeolocated, anonymized, individual-level surveillance data from 2011 to 2021 from the Thai Division of Vector-Borne Disease (DVBD) was used to calculate incidence and estimated Rc at village level. Forest cover was calculated using raster maps of tree crown cover density and year of forest loss from the publicly available Hansen dataset. Incidence and forest cover were compared graphically and using Spearman’s rho. The current foci classification system was applied to data from the last 5 years (2017–2021) and forest cover for 2021 compared between the classifications. A simple risk score was developed to identify villages with high receptivity.ResultsThere was a non-linear decrease in annual cases by 96.6% (1061 to 36) across the two provinces from 2011 to 2021. Indigenous Annual Parasite Index (API) and approximated Rc were higher in villages in highly forested subdistricts, and with higher forest cover within 5 km. Forest cover was also higher in malaria foci which consistently reported malaria cases each year than those which did not. An Rc > 1 was only reported in villages in subdistricts with > 25% forest cover. When applying a simple risk score using forest cover and recent case history, the classifications were comparable to those of the risk stratification system currently used by the DVBD.ConclusionsThere was a positive association between forest coverage around a village and indigenous malaria cases. Most local transmission was observed in the heavily forested subdistricts on the international borders with Laos and Cambodia, which are where the most receptive villages are located. These areas are at greater risk of importation of malaria due to population mobility and forest-going activities. Combining forest cover and recent case surveillance data with measures of vulnerability may be useful for prediction of malaria recurrence risk.

Imaging of Chromophobe Renal Cell Carcinoma with 99mTc-Sestamibi SPECT/CT: Considerations Regarding Risk Stratification and Histologic Reclassification.

Indeterminate renal masses are increasingly incidentally found on cross-sectional imaging. 99mTc-sestamibi single-photon emission computed tomography/computed tomography (SPECT/CT) scans can be used to identify oncocytomas and oncocytic renal neoplasms, including a subset of chromophobe renal cell carcinomas (chRCCs), which are viewed as false-positive. Patients imaged with renal sestamibi scans between 2014 and 2023 were reviewed. Those patients with solitary tumors that were originally classified as chRCC were included in the analysis. Imaging with SPECT/CT from the liver dome down had been carried out 75min after the administration of 925MBq of 99mTc-sestamibi. All available H&E and immunostained slides were re-reviewed and classified according to WHO 2022 criteria. Confirmatory immunohistochemical stains were performed in tumors considered morphologically suspicious for non-chRCC entities. A total of 18 patients with solitary tumors were included in the final analysis. 13/18 (72.2%) tumors in this cohort remained classified as chRCC, with 4/18 (22.2%) being eosinophilic-variant chRCC. The reclassified tumors (5/18 [27.8%]) included 2/18 (11.1%) low-grade oncocytic tumor (LOT), 1/18 (5.5%) eosinophilic vacuolated tumor (EVT), and 2/18 (11.1%) unclassified low-grade oncocytic neoplasms. As such, only 2/9 (22.2%) qualitatively "hot" tumors were chRCC other than eosinophilic-variant and only 1/9 (11.1%) "cold" tumors was a histology other than chRCC. Based on current histopathologic classification methods, it is likely that the "false-positive" rate of uptake on renal sestamibi scans with chRCC has been over-stated. Further study is warranted to better refine the optimal utility of renal sestamibi scans for non-invasive risk stratification of indeterminate renal masses.

Pediatric meniscal surgery in Italy: A 10-year epidemiological nationwide registry study

PurposeOver the last two decades the incidence of meniscal injuries has grown amongst the pediatric population predominantly due to greater involvement in sporting activities. The treatment and the natural history represent a socioeconomic burden for healthcare systems. This study demonstrates the epidemiology of meniscal tears treated surgically in Italy from 2010 to 2019 in a population up to 18 years. MethodsData was collected from the National Archive of Hospital Discharges. ICD9-CM classification was used to select surgically treated meniscal injuries. Concomitant treatment of associated lesions were excluded. Data on the national population was retrieved from the Italian National Institute for Statistics (ISTAT). Statistical analyses were performed. Results17,449 isolated meniscal tears were surgically treated with a mean incidence of 20.6 per 100.000 in the Italian population aged up to 18 from 2010 to 2019. The mean age of patients was 15.85 with 89 % aged 14 or older. 30 % of the population was female. The incidence of medial meniscal surgery was higher than for the lateral meniscus. A declining trend in surgical incidence was observed. The mean hospitalization time was 1.53 days. ConclusionsOur study reveals a reduction in the total number of surgeries performed over the time frame and a significant rise in the incidence of meniscal lesions in pediatric patient above at the age of 13, especially in males. Despite a worldwide shift towards meniscal preservation, this trend is not evident in Italy as the current ICD9-CM classification does not differentiate between meniscectomy and meniscal repair, although an overall reduction in surgery may imply better management. Study designCohort study; Level of evidence III.

Stress-strain state zoning model and novel large deformation classification method for squeezing tunnels

Accurately assessing the level of large deformation in squeezing tunnels is of great importance for the design of support structures. The current large deformations classification methods fail to account for the effect of support pressure on the relative deformation of surrounding rock. In this study, a theoretical model for the stress–strain state zoning of the surrounding rock in squeezing tunnels is established. A sensitivity analysis of the model parameters is conducted. The distribution law of the strength-stress ratio, relative deformation, and relative support pressure indices in 43 field monitoring squeezing tunnels are statistically analyzed. A novel large-deformation classification method based on the relative support pressure index is proposed and applied in case studies. The parameter sensitivity analysis shows that mechanical parameters of the surrounding rock significantly affect the deformation and the stress–strain state zoning of the surrounding rock. The stress–strain state zoning and deformation of the surrounding rock are also primarily dependent on the matching relationship between strength-stress ratio and support pressure. Statistical analyses indicate that there is a nonlinear negative correlation between the relative deformation of the surrounding rock and the strength-stress ratio, as well as the relative support pressure, which includes the steel arch relative support pressure index (SSPI) and the anchor bolt relative support pressure Index (ASPI). The key to controlling surrounding rock deformation lies in the rational matching of support pressure to the strength-stress ratio. In the novel large deformation classification method, three key indexes of strong stress ratio, relative deformation and relative support pressure are quantitatively included, and squeezing large deformation is divided into three levels. Moreover, the case study demonstrated that the novel large deformation classification method has significant guiding importance in verifying feasibility and optimizing support design schemes during both the design and construction phases.

Looking back to look forward: Has the time arrived for active management of obstetricians in placenta accreta spectrum?

Placenta accreta spectrum (PAS) is a relatively new obstetric condition which, until recently, was poorly understood. The true incidence is unknown because of the poor quality and heterogeneous diagnostic criteria. Classification systems have attempted to provide clarity on how to grade and diagnose PAS, but these are no longer reflective of our current understanding of PAS. This is particularly true for placenta percreta, which referred to extrauterine disease, as recent studies have demonstrated that placental villi associated with PAS have minimal potential to invade beyond the uterine serosa. It is accepted that PAS is a direct consequence of previous iatrogenic uterine injury, most commonly a previous cesarean section. Here, we "look back to look forwards"-starting with the primary predisposing factor for PAS, an iatrogenic uterine injury and subsequent wound healing. We then consider the evolution of definitions and diagnostic criteria of PAS from its first description over a century ago to current classifications. Finally, we discuss why modifications to the current classifications are needed to allow accurate diagnosis of this rare but life-threatening complication, while avoiding overdiagnosis and potential patient harm.

A multi-step approach to overcome challenges in the management of head and neck lymphatic malformations, and response to treatment

BackgroundLymphatic malformations are vascular developmental anomalies varying from local superficial masses to diffuse infiltrating lesions, resulting in disfigurement. Patients’ outcomes range from spontaneous regression to severe sequelae notwithstanding appropriate treatment. The current classification guides, in part, clinicians through the decision-making process, prognosis prediction and choice of therapeutic strategies. Even though the understanding of molecular basis of the disease has been recently improved, a standardized management algorithm has not been reached yet.ResultsHere, we report our experience on five children with different lymphatic anomalies of the head and neck region treated by applying a multidisciplinary approach reaching a consensus among specialists on problem-solving and setting priorities.ConclusionsAlthough restitutio ad integrum was rarely achieved and the burden of care is challenging for patients, caregivers and healthcare providers, this study demonstrates how the referral to expert centres can significantly improve outcomes by alleviating parental stress and ameliorating patients’ quality of life. A flow-chart is proposed to guide the multidisciplinary care of children with LMs and to encourage multidisciplinary collaborative initiatives to implement dedicated patients’ pathways.

Using structure prediction of negative sense RNA virus nucleoproteins to assess evolutionary relationships.

Negative sense RNA viruses (NSV) include some of the most detrimental human pathogens, including the influenza, Ebola, and measles viruses. NSV genomes consist of one or multiple single-stranded RNA molecules that are encapsidated into one or more ribonucleoprotein (RNP) complexes. These RNPs consist of viral RNA, a viral RNA polymerase, and many copies of the viral nucleoprotein (NP). Current evolutionary relationships within the NSV phylum are based on the alignment of conserved RNA-dependent RNA polymerase (RdRp) domain amino acid sequences. However, the RdRp domain-based phylogeny does not address whether NP, the other core protein in the NSV genome, evolved along the same trajectory or whether several RdRp-NP pairs evolved through convergent evolution in the segmented and non-segmented NSV genome architectures. Addressing how NP and the RdRp domain evolved may help us better understand NSV diversity. Since NP sequences are too short to infer robust phylogenetic relationships, we here used experimentally obtained and AlphaFold 2.0-predicted NP structures to probe whether evolutionary relationships can be estimated using NSV NP sequences. Following flexible structure alignments of modeled structures, we find that the structural homology of the NSV NPs reveals phylogenetic clusters that are consistent with RdRp-based clustering. In addition, we were able to assign viruses for which RdRp sequences are currently missing to phylogenetic clusters based on the available NP sequence. Both our RdRp-based and NP-based relationships deviate from the current NSV classification of the segmented Naedrevirales, which cluster with the other segmented NSVs in our analysis. Overall, our results suggest that the NSV RdRp and NP genes largely evolved along similar trajectories and even short pieces of genetic, protein-coding information can be used to infer evolutionary relationships, potentially making metagenomic analyses more valuable.

The ballistic articular structure injury classification (BASIC) system: clarifying ballistic articular injuries.

This study aims to (1) devise a classification system to categorize and manage ballistic fractures of the knee, hip, and shoulder; (2) assess the reliability of this classification compared to current classification schemas; and (3) determine the association of this classification with surgical management. We performed a retrospective review of a prospectively collected trauma database at an urban level 1 trauma centre. The study included 147 patients with 169 articular fractures caused by ballistic trauma to the knee, hip, and shoulder. Injuries were selected based on radiographic criteria from plain radiographs and CT scans. The AO/OTA classification system's reliability was compared to that of the novel ballistic articular injury classification system (BASIC), developed using a nominal group approach. The BASIC system's ability to guide surgical decision-making, aiming to achieve stable fixation and minimize post-traumatic arthritis, was also evaluated. The BASIC system was created after analysing 73 knee, 62 hip, and 34 shoulder fractures. CT scans were used in 88% of cases, with 44% of patients receiving surgery. The BASIC classification comprises five subgroups, with a plus sign indicating the need for soft tissue intervention. Interrater reliability showed fair agreement for AO/OTA (k = 0.373) and moderate agreement for BASIC (k = 0.444). The BASIC system correlated strongly with surgical decisions, with an 83% concurrence in treatment choices based on chart reviews. Conventional classification systems provide limited guidance for ballistic articular injuries. The BASIC system offers a pragmatic and reproducible alternative, with potential to inform treatment decisions for knee, hip, and shoulder ballistic injuries. Further research is needed to validate this system and its correlation with patient outcomes. Level III, Diagnostic Study.

Giant cell carcinoma of the urinary bladder

We present the clinicopathological features of 23 cases of the giant cell subtype of urothelial carcinoma, a rare subtype of bladder cancer recognized in the current World Health Organization classification of urological tumors. Histologically, the architectural pattern of the tumor varied from infiltrating to the solid expansile pleomorphic tumor with giant, bizarre, anaplastic cells. Typical or atypical mitotic figures were frequently present in all cases. Between 10 and 30% of the tumor had a giant cell component. All cases were associated with conventional high-grade urothelial carcinoma, with areas of squamous cell divergent differentiation and micropapillary carcinoma present in six and two cases, respectively. In one case each had sarcomatoid, nested, small cell, or glandular divergent differentiation. At diagnosis, 35% of patients had advanced disease and 12% had distant metastases. When comparing giant cell urothelial carcinoma with conventional urothelial carcinoma in a matched analysis, differences in overall and cancer-specific survival were observed, particularly in the T1 stage category. Immunohistochemical staining showed a similar profile of urothelial lineage with frequent positive expression of uroplakin II, GATA3, CK20, CK7, and S100P in both giant cell and conventional urothelial carcinomas. High Ki67 proliferation (range, 60–90%; mean, 71%) and nuclear p53 accumulation (mutant profile; range, 50–90%; mean, 64%) were observed. Using the 22C3 assay, the expression of PD-L1 was found to be variable in two cases, and beta-HCG was negative. In conclusion, giant cell carcinoma is a subtype of urothelial carcinoma associated with advanced clinical stage and a trend to lower survival rates.

Prosthodontic criteria for maxillary immediate occlusal loading, surgical classifications of atrophic maxillae, and presentation of a new implant/anatomic classification system for immediate maxillary rehabilitation.

Immediate full-arch occlusal loading for patients with atrophic edentulous maxillae satisfies critical needs for this specific type of edentulous patient after placement of implants with high levels of primary implant stability. The needs include improved aesthetics, limited immediate improved function, and elimination of removable prostheses. Classification systems exist for edentulous maxillae but they do not include specifics regarding posterior implant placement. In conjunction with anterior implants, posterior implants improve Anterior/Posterior (A/P) spreads, decrease cantilevered segments (CLs), and likely will improve implant and prosthetic success rates. The purposes of this article include presenting a new classification system that outlines the different types of implants now available which will likely achieve the requisite primary stability for immediate fixed rehabilitation. This proposed classification system identifies a relationship between different implant options currently available and the remaining quantity of bone in the first and second maxillary molar zones. The available literature regarding current classification systems was reviewed. The benefits and limitations of each system were described. The parameters associated with Immediate Occlusal Loading (IOL) for full arch maxillary prostheses include: posterior cantilever lengths of full arch fixed prostheses; existing A/P spread considerations for full arch prostheses; and introduction of a new classification system for atrophic posterior maxillary edentulous ridges were identified. Currently, there are no available classification systems that outline specific implant options for posterior maxillae which will likely achieve the minimum primary stability needed for immediate rehabilitation. A new classification system was proposed where the rationale was to show clinicians that when a certain amount of bone remains in the posterior maxilla, there are specific implants designed to maximize primary stability. High implant primary stability is required for rehabilitation with immediate fixed implant-supported provisional prostheses. The proposed classification system assists clinicians in understanding what implant geometry is available and can be expected to achieve the requisite primary stability for immediate occlusal loading based on the available bone in the posterior maxillary molar zone. This article reviewed current classification systems for edentulous maxillary patients, as well as clinical parameters required for full arch, immediate occlusal loading. It also presented a new classification system to assist clinicians in selecting appropriate implants and surgical techniques for immediate fixed rehabilitation of patients with atrophic maxillae.

An Analysis of Traditional Methods and Deep Learning Methods in SSVEP-Based BCI: A Survey

The brain–computer interface (BCI) is a direct communication channel between humans and machines that relies on the central nervous system. Neuroelectric signals are collected by placing electrodes, and after feature sampling and classification, they are converted into control signals to control external mechanical devices. BCIs based on steady-state visual evoked potential (SSVEP) have the advantages of high classification accuracy, fast information conduction rate, and relatively strong anti-interference ability, so they have been widely noticed and discussed. From k-nearest neighbor (KNN), multilayer perceptron (MLP), and support vector machine (SVM) classification algorithms to the current deep learning classification algorithms based on neural networks, a wide variety of discussions and analyses have been conducted by numerous researchers. This article summarizes more than 60 SSVEP- and BCI-related articles published between 2015 and 2023, and provides an in-depth research and analysis of SSVEP-BCI. The survey in this article can save a lot of time for scholars in understanding the progress of SSVEP-BCI research and deep learning, and it is an important guide for designing and selecting SSVEP-BCI classification algorithms.