BACKGROUND Ampullary adenocarcinoma is a rare malignant tumor of the gastrointestinal tract.Currently,only a few cases have been reported,resulting in limited information on survival.AIM To develop a dynamic nomogram ...BACKGROUND Ampullary adenocarcinoma is a rare malignant tumor of the gastrointestinal tract.Currently,only a few cases have been reported,resulting in limited information on survival.AIM To develop a dynamic nomogram using internal and external validation to predict survival in patients with ampullary adenocarcinoma.METHODS Data were sourced from the surveillance,epidemiology,and end results stat database.The patients in the database were randomized in a 7:3 ratio into training and validation groups.Using Cox regression univariate and multivariate analyses in the training group,we identified independent risk factors for overall survival and cancer-specific survival to develop the nomogram.The nomogram was validated with a cohort of patients from the First Affiliated Hospital of the Army Medical University.RESULTS For overall and cancer-specific survival,12(sex,age,race,lymph node ratio,tumor size,chemotherapy,surgical modality,T stage,tumor differentiation,brain metastasis,lung metastasis,and extension)and 6(age;surveillance,epidemiology,and end results stage;lymph node ratio;chemotherapy;surgical modality;and tumor differentiation)independent risk factors,respectively,were incorporated into the nomogram.The area under the curve values at 1,3,and 5 years,respectively,were 0.807,0.842,and 0.826 for overall survival and 0.816,0.835,and 0.841 for cancer-specific survival.The internal and external validation cohorts indicated good consistency of the nomogram.CONCLUSION The dynamic nomogram offers robust predictive efficacy for the overall and cancer-specific survival of ampullary adenocarcinoma.展开更多
In the United States(US),the Surveillance,Epidemiology,and End Results(SEER)program is the only comprehensive source of population-based information that includes stage of cancer at the time of diagnosis and patient s...In the United States(US),the Surveillance,Epidemiology,and End Results(SEER)program is the only comprehensive source of population-based information that includes stage of cancer at the time of diagnosis and patient survival data.This program aims to provide a database about cancer incidence and survival for studies of surveillance and the development of analytical and methodological tools in the cancer field.Currently,the SEER program covers approximately half of the total cancer patients in the US.A growing number of clinical studies have applied the SEER database in various aspects.However,the intrinsic features of the SEER database,such as the huge data volume and complexity of data types,have hindered its application.In this review,we provided a systematic overview of the commonly used methodologies and study designs for retrospective epidemiological research in order to illustrate the application of the SEER database.Therefore,the goal of this review is to assist researchers in the selection of appropriate methods and study designs for enhancing the robustness and reliability of clinical studies by mining the SEER database.展开更多
In generator design field,waveform total harmonic distortion(THD)and telephone harmonic factor(THF)are parameters commonly used to measure the impact of generator no-load voltage harmonics on the power communication q...In generator design field,waveform total harmonic distortion(THD)and telephone harmonic factor(THF)are parameters commonly used to measure the impact of generator no-load voltage harmonics on the power communication quality.Tubular hydrogenerators are considered the optimal generator for exploiting low-head,high-flow hydro resources,and they have seen increasingly widespread application in China's power systems recent years.However,owing to the compact and constrained internal space of such generators,their internal magnetic-field harmonics are pronounced.Therefore,accurate calculation of their THD and THF is crucial during the analysis and design stages to ensure the quality of power communication.Especially in the electromagnetic field finite element modeling analysis of such generators,the type and order of the finite element meshes may have a significant impact on the THD and THF calculation results,which warrants in-depth research.To address this,this study takes a real 34 MW large tubular hydrogenerator as an example,and establishes its electromagnetic field finite element model under no-load conditions.Two types of meshes,five mesh densities,and two mesh orders are analyzed to reveal the effect of electromagnetic field finite element mesh types and orders on the calculation results of THD and THF for such generators.展开更多
Accurate diagnosis is the foundation of clinical care but accurate diagnosis is not easily reached in some cases.In rare instances,even a sophisticated multidisciplinary team at an academic medical center cannot relia...Accurate diagnosis is the foundation of clinical care but accurate diagnosis is not easily reached in some cases.In rare instances,even a sophisticated multidisciplinary team at an academic medical center cannot reliably reach an accurate diagnosis after extensive testing and imaging,and has to wait until histological diagnosis or even autopsy results are available.The underlying reason of challenging diagnoses is mostly conflicting data from history,tests,and imaging that point to different diagnoses.In this issue of World Journal of Clinical Cases,Huffaker et al reported such a challenging case of a tricuspid mass in a patient with Li-Fraumeni syndrome.The case by Huffaker et al powerfully illustrates the occasional diagnostic challenges inherent in our current diagnostic approach and the current technology.Clinicians should realize that in rare situations,agnosticism in diagnosis is unavoidable but a treatment has to be initiated so long as the principle of primum non nocere is upheld.展开更多
We consider a generalized form of the porous medium equation where the porosity ϕis a function of time t: ϕ=ϕ(x,t): ∂(ϕS)∂t−∇⋅(k(S)∇S)=Q(S).In many works, the porosity ϕis either assumed to be independent of (or to de...We consider a generalized form of the porous medium equation where the porosity ϕis a function of time t: ϕ=ϕ(x,t): ∂(ϕS)∂t−∇⋅(k(S)∇S)=Q(S).In many works, the porosity ϕis either assumed to be independent of (or to depend very little of) the time variable t. In this work, we want to study the case where it does depend on t(and xas well). For this purpose, we make a change of unknown function V=ϕSin order to obtain a saturation-like (advection-diffusion) equation. A priori estimates and regularity results are established for the new equation based in part on what is known from the saturation equation, when ϕis independent of the time t. These results are then extended to the full saturation equation with time-dependent porosity ϕ=ϕ(x,t). In this analysis, we make explicitly the dependence of the various constants in the estimates on the porosity ϕby the introduced transport vector w, through the change of unknown function. Also we do not assume zero-flux boundary, but we carry the analysis for the case Q≡0.展开更多
Introduction: The aim of this study was to report the indications and evaluate the results of vulvectomy in the general surgery department of Ignace Deen Hospital, CHU Conakry. Materials and Methods: This was a retros...Introduction: The aim of this study was to report the indications and evaluate the results of vulvectomy in the general surgery department of Ignace Deen Hospital, CHU Conakry. Materials and Methods: This was a retrospective descriptive study, conducted over a period of five (05) years from January 1, 2018 to December 31, 2022, in the general surgery department of Ignace Deen Hospital, CHU Conakry. We included in our study all patient records in whom vulvectomy was performed. Results: We recorded 15 cases of vulvectomy out of 453 perineal surgeries, i.e. 3.31%, with a mean age of 43.56 years and extremes of 35 and 69 years. Vulvar cancer was the most common diagnosis (46.67%), followed by Buschke-Lowenstein (33.33%) and anal canal cancer extending to the vulva (20%). Six patients had undergone biopsy (40%). Vulvectomy with lymph node dissection was performed in only 9 patients (60%), and all surgical specimens were sent to anatomical pathology (100%). Conclusion: Vulvectomy is a surgical technique most often indicated for the treatment of vulvar cancer.展开更多
基金Supported by the Appropriate Technology Promotion Program in Chongqing,No.2023jstg005.
文摘BACKGROUND Ampullary adenocarcinoma is a rare malignant tumor of the gastrointestinal tract.Currently,only a few cases have been reported,resulting in limited information on survival.AIM To develop a dynamic nomogram using internal and external validation to predict survival in patients with ampullary adenocarcinoma.METHODS Data were sourced from the surveillance,epidemiology,and end results stat database.The patients in the database were randomized in a 7:3 ratio into training and validation groups.Using Cox regression univariate and multivariate analyses in the training group,we identified independent risk factors for overall survival and cancer-specific survival to develop the nomogram.The nomogram was validated with a cohort of patients from the First Affiliated Hospital of the Army Medical University.RESULTS For overall and cancer-specific survival,12(sex,age,race,lymph node ratio,tumor size,chemotherapy,surgical modality,T stage,tumor differentiation,brain metastasis,lung metastasis,and extension)and 6(age;surveillance,epidemiology,and end results stage;lymph node ratio;chemotherapy;surgical modality;and tumor differentiation)independent risk factors,respectively,were incorporated into the nomogram.The area under the curve values at 1,3,and 5 years,respectively,were 0.807,0.842,and 0.826 for overall survival and 0.816,0.835,and 0.841 for cancer-specific survival.The internal and external validation cohorts indicated good consistency of the nomogram.CONCLUSION The dynamic nomogram offers robust predictive efficacy for the overall and cancer-specific survival of ampullary adenocarcinoma.
基金Guangdong Provincial Key Laboratory of Traditional Chinese Medicine Informatization(2021B1212040007)Clinical Frontier Technology Program of the First Affiliated Hospital of Jinan University,China(JNU1AF-CFTP-2022-a01235)Science and Technology Projects in Guangzhou,China(202201020054,2023A03J1032).
文摘In the United States(US),the Surveillance,Epidemiology,and End Results(SEER)program is the only comprehensive source of population-based information that includes stage of cancer at the time of diagnosis and patient survival data.This program aims to provide a database about cancer incidence and survival for studies of surveillance and the development of analytical and methodological tools in the cancer field.Currently,the SEER program covers approximately half of the total cancer patients in the US.A growing number of clinical studies have applied the SEER database in various aspects.However,the intrinsic features of the SEER database,such as the huge data volume and complexity of data types,have hindered its application.In this review,we provided a systematic overview of the commonly used methodologies and study designs for retrospective epidemiological research in order to illustrate the application of the SEER database.Therefore,the goal of this review is to assist researchers in the selection of appropriate methods and study designs for enhancing the robustness and reliability of clinical studies by mining the SEER database.
基金sponsored by the National Natural Science Foundation,Youth Foundation of China,Grant/Award Number:51607146Sichuan Natural Sciences Fund,Grant/Award Number:2023NSFSC0295。
文摘In generator design field,waveform total harmonic distortion(THD)and telephone harmonic factor(THF)are parameters commonly used to measure the impact of generator no-load voltage harmonics on the power communication quality.Tubular hydrogenerators are considered the optimal generator for exploiting low-head,high-flow hydro resources,and they have seen increasingly widespread application in China's power systems recent years.However,owing to the compact and constrained internal space of such generators,their internal magnetic-field harmonics are pronounced.Therefore,accurate calculation of their THD and THF is crucial during the analysis and design stages to ensure the quality of power communication.Especially in the electromagnetic field finite element modeling analysis of such generators,the type and order of the finite element meshes may have a significant impact on the THD and THF calculation results,which warrants in-depth research.To address this,this study takes a real 34 MW large tubular hydrogenerator as an example,and establishes its electromagnetic field finite element model under no-load conditions.Two types of meshes,five mesh densities,and two mesh orders are analyzed to reveal the effect of electromagnetic field finite element mesh types and orders on the calculation results of THD and THF for such generators.
文摘Accurate diagnosis is the foundation of clinical care but accurate diagnosis is not easily reached in some cases.In rare instances,even a sophisticated multidisciplinary team at an academic medical center cannot reliably reach an accurate diagnosis after extensive testing and imaging,and has to wait until histological diagnosis or even autopsy results are available.The underlying reason of challenging diagnoses is mostly conflicting data from history,tests,and imaging that point to different diagnoses.In this issue of World Journal of Clinical Cases,Huffaker et al reported such a challenging case of a tricuspid mass in a patient with Li-Fraumeni syndrome.The case by Huffaker et al powerfully illustrates the occasional diagnostic challenges inherent in our current diagnostic approach and the current technology.Clinicians should realize that in rare situations,agnosticism in diagnosis is unavoidable but a treatment has to be initiated so long as the principle of primum non nocere is upheld.
文摘We consider a generalized form of the porous medium equation where the porosity ϕis a function of time t: ϕ=ϕ(x,t): ∂(ϕS)∂t−∇⋅(k(S)∇S)=Q(S).In many works, the porosity ϕis either assumed to be independent of (or to depend very little of) the time variable t. In this work, we want to study the case where it does depend on t(and xas well). For this purpose, we make a change of unknown function V=ϕSin order to obtain a saturation-like (advection-diffusion) equation. A priori estimates and regularity results are established for the new equation based in part on what is known from the saturation equation, when ϕis independent of the time t. These results are then extended to the full saturation equation with time-dependent porosity ϕ=ϕ(x,t). In this analysis, we make explicitly the dependence of the various constants in the estimates on the porosity ϕby the introduced transport vector w, through the change of unknown function. Also we do not assume zero-flux boundary, but we carry the analysis for the case Q≡0.
文摘Introduction: The aim of this study was to report the indications and evaluate the results of vulvectomy in the general surgery department of Ignace Deen Hospital, CHU Conakry. Materials and Methods: This was a retrospective descriptive study, conducted over a period of five (05) years from January 1, 2018 to December 31, 2022, in the general surgery department of Ignace Deen Hospital, CHU Conakry. We included in our study all patient records in whom vulvectomy was performed. Results: We recorded 15 cases of vulvectomy out of 453 perineal surgeries, i.e. 3.31%, with a mean age of 43.56 years and extremes of 35 and 69 years. Vulvar cancer was the most common diagnosis (46.67%), followed by Buschke-Lowenstein (33.33%) and anal canal cancer extending to the vulva (20%). Six patients had undergone biopsy (40%). Vulvectomy with lymph node dissection was performed in only 9 patients (60%), and all surgical specimens were sent to anatomical pathology (100%). Conclusion: Vulvectomy is a surgical technique most often indicated for the treatment of vulvar cancer.
