A Formulation of the Porous Medium Equation with Time-Dependent Porosity: A Priori Estimates and Regularity Results

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.

Vulvectomy: Indications and Results in the General Surgery Department of the Ignace Deen Chu Hospital in Conakry

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.

How to use the Surveillance,Epidemiology,and End Results(SEER)data:research design and methodology

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.

Diagnostic challenges from conflicting results of tests and imaging

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.

Effect of Types and Orders of Electromagnetic Field Finite Element Meshes on Power Communication Harmonic Parameters Calculation Results of Tubular Hydrogenerators

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.

Problems and Development Suggestions of Nature Education in Jiangxi Province

The forest coverage rate of Jiangxi Province ranks second in China.It has rich natural resources,a long history of ancient color culture and rich red culture.In the development of nature education,Jiangxi Province has great potential and advantages.This paper introduces the development conditions of nature education in Jiangxi Province,summarizes the problems existing in the development of nature education in Jiangxi Province from the aspects of the types of nature education and the construction of nature education base,such as simple content and single form,imperfect infrastructure and lack of professionals,and puts forward some suggestions on the development of nature education in Jiangxi Province.

案例教学法联合Sandwich教学法在老年科教学中的应用

目的探讨案例教学法联合Sandwich教学法在老年科教学中的应用效果。方法选取2022年3月—2023年6月潍坊医学院附属医院的60名参加老年科教学的学生为研究对象,按照随机数表法分为两组,各30名。对照组行常规教学,观察组行案例教学法联合Sandwich教学法教学,比较两组教学效果。结果观察组各项模拟出科考试成绩高于对照组,差异有统计学意义(P均<0.05);观察组对实习教学效果的各项满意度评分高于对照组,差异有统计学意义(P<0.05)。结论案例教学法联合Sandwich教学法可提升老年科教学的效果,并提高学生对实习教学效果的满意度。

Influencing Factors and Improvement Suggestions for Agricultural Green Development Performance:Empirical Insights from China

Agricultural green development is an essential direction for global sustainable agriculture.The academic literature,however,needs to place greater emphasis on studying the factors influencing agricultural green development performance and how such performance can be improved.A theoretical framework for agricultural green development performance was constructed in this paper using the Super-SBM model,which considers undesirable outputs,to measure the agricultural green development performance of 330 cities at or above the prefecture level in China(excluding Tibet Autonomous Region,Hong Kong,Macao and Taiwan of China)from 2007 to2018.Furthermore,the influencing mechanism of agricultural green development performance was then analyzed using a spatial econometric model.The results show that:1)from 2007 to 2018,China’s agricultural green development performance experienced three stages of evolution:‘rise,decline and rise’.2)The regions with high performance agricultural green development are mainly distributed in eastern China,northeastern China,and southern Qinghai Province.3)The agricultural economic level,industrialization process,and labor quality play significant roles in promoting local agricultural green development performance,while such performance is obviously inhibited by the openness level and the government’s environmental regulations.Local agricultural green development performance is significant inhibited by the agricultural economic level and accelerated industrialization process in neighboring cities,while significantly promoted by the agricultural industrial structure in neighboring cities.Some suggestions for improving agricultural green development performance are proposed based on these research results,which can provide scientific references for promoting sustainable agriculture.

Parameter calculation and result storage for phase-field simulation in α-Mg dendrite growth of Mg-5-wt% Zn alloy

Parameter calculation and result storage, as two necessary steps in phase-field simulation play an important role in ensuring the accuracy of simulation results. A strategy of parameter calculation and result storage is presented for phase-field simulation in α-Mg dendrite growth of Mg-5-wt% Zn alloy under isothermal solidification. Based on the phase diagram and empirical formulas, key parameters of the phase-field model, such as equilibrium partition coefficient k, liquidus slope m, solutal diffusion coefficient in liquid Dl, and solutal diffusion coefficient in solid Ds, can be obtained.Both structured grid method and structured point method can be used to store simulation results, but using the latter method will reduce about 60% storage space and 37.5% storage time compared with the former. Finally, convergent simulation results of α-Mg dendrite growth are obtained and they are in good agreement with the experimental results about optical micrograph, which verify the accuracy of parameters and stability of storage method.

Analysis of Investigation on Ebian Spotted Cattle and Suggestions

Ebian spotted cattle has the ability to adapt to the local natural ecological environment,and is one of the excellent local cattle breeds in Sichuan.Ebian spotted cattle is a breed of cattle for both service and meat use and formed through long-term natural selection and artificial selection.Because of the weak development and utilization of this breed,the economic benefits of excellent breeds have not been fully brought into play,and farmers'enthusiasm in breeding is poor,so that the number of Ebian spotted cattle has reduced year by year.In order to strengthen the protection,development and utilization of Ebian spotted cattle as a local excellent breed,combined with the third national survey of livestock and poultry genetic resources in 2021,Ebian spotted cattle was investigated,and a comprehensive,scientific and objective analysis of its population numbers was conducted.Besides,reasonable suggestions were put forward.

Introduction and Protection Suggestions of Biodiversity

Through the introduction of the concept,content,conservation significance and species value of biodiversity,the cognition of the research content,analysis methods and research directions of biodiversity was deepened.In view of the problems faced by biodiversity conservation at present,such as the accelerated disappearance of species,the unsound protection regulation system,the irrational spatial pattern of species protection,and the lack of long-term follow-up research,specific improvement suggestions were put forward,and have a positive guiding significance for future biodiversity conservation.

Management Results and Financial Status of Rural Collective Economy under the Background of Rural Revitalization

Based on the analysis of financial statements,the performance and problems of rural collective economic organizations in their business activities were analyzed.It is believed that rural collective economy was developing continuously in a good way,with strong debt paying ability,but the operation ability and management efficiency need to be further improved.The operation was too conservative,and the asset utilization efficiency and profitability were weak.There were many unnecessary liabilities,and they developed mainly relying on their own accumulation.Therefore,it is proposed to crack the"talent dilemma"of rural collective economic operation and management,straighten out and clarify the relationship between rural collective economic organizations and villagers self-governing organizations,correctly handle the relationship between collective accumulation and member distribution,adhere to the financial input of blood replenishment and transfusion,and make liabilities reasonable according to the management development.

Vertebroplasty and Kyphoplasty: Indications and Results, a Preliminary Senegalese Experience from the Neurosurgery Department of the CHNU of Fann

Introduction: Vertebroplasty and kyphoplasty are percutaneous techniques that consist in injecting an acrylic cement into the body of a pathological vertebra. This work aims to report the experience the of Fann’s neurosurgery department in treating certain spinal pathologies by vertebroplasty and kyphoplasty. Methods: During a 3-year period from July 1, 2019 to July 31, 2022, we conducted a retrospective, descriptive and analytical study, including patients who underwent vertebroplasty or kyphoplasty for dorsolumbar spinal pathology. Results: The mean age of the 13 patients in our study was 51.61 years. Female gender was predominant in 62% (n = 8). The context of spontaneous onset was found in six patients. Nine patients had a VAS (visual analogue scale) ≥ 8 (69.23%). On clinical examination, all patients had a syndrome without neurological deficits. 84.61% of patients had a CT scan (n = 11). The dorsolumbar hinge was most affected with 53.85% of cases. Seven patients had a vertebral compression of between 25% and. The average degree of kyphosis was 8˚ and seven patients had a degree of kyphosis ≥ 10˚. Tumour aetiology accounted for 46.15% of cases. Kyphoplasty was performed in 61.53% (n = 9) of the cases and vertebroplasty was performed in 38.47% (n = 4) of the patients. Kyphoplasty was associated with biopsy in two cases and with osteosynthesis in one patient. Vertebroplasty was always associated with a biopsy. The evolution was favourable with a significant reduction in pain and vertebral kyphosis. The mean VAS decreased from 8.15 to 0.69 three months after treatment and the mean kyphosis decreased from 8˚ to 2˚. Conclusion: Kyphoplasty and vertebroplasty as percutaneous techniques allow consolidation of the vertebral body and pain relief. Kyphoplasty alone not only reduces pain but also restores the height of the compacted vertebral body.

Results and Application of Soil and Water Conservation Monitoring in the Yellow River Basin

Since water and soil conservation monitoring in the Yellow River Basin entered a new stage at the end of the 20th century,the monitoring scope has been expanding,the monitoring accuracy has been improving,the monitoring content and indicators have been increasing,and the monitoring technology and methods have been improving.This paper mainly analyzes the status of soil and water conservation monitoring in the Yellow River Basin,as well as the construction of the monitoring system and related research,in order to provide a reference for watershed management and development and the scientific research of water and soil conservation.

Risk Factors and Predictive Nomogram for Survival in Elderly Patients with Brain Glioma

Objective To determine the factors that contribute to the survival of elderly individuals diagnosed with brain glioma and develop a prognostic nomogram.Methods Data from elderly individuals(age≥65 years)histologically diagnosed with brain glioma were sourced from the Surveillance,Epidemiology,and End Results(SEER)database.The dataset was randomly divided into a training cohort and an internal validation cohort at a 6:4 ratio.Additionally,data obtained from Tangdu Hospital constituted an external validation cohort for the study.The identification of independent prognostic factors was achieved through the least absolute shrinkage and selection operator(LASSO)and multivariate Cox regression analysis,enabling the construction of a nomogram.Model performance was evaluated using C-index,ROC curves,calibration plot and decision curve analysis(DCA).Results A cohort of 20483 elderly glioma patients was selected from the SEER database.Five prognostic factors(age,marital status,histological type,stage,and treatment)were found to significantly impact overall survival(OS)and cancer-specific survival(CSS),with tumor location emerging as a sixth variable independently linked to CSS.Subsequently,nomogram models were developed to predict the probabilities of survival at 6,12,and 24 months.The assessment findings from the validation queue indicate a that the model exhibited strong performance.Conclusion Our nomograms serve as valuable prognostic tools for assessing the survival probability of elderly glioma patients.They can potentially assist in risk stratification and clinical decision-making.

Research and application of key technologies for data delivery in railway engineering design based on metadata

In view of the problems of inconsistent data semantics,inconsistent data formats,and difficult data quality assurance between the railway engineering design phase and the construction and operation phase,as well as the difficulty in fully realizing the value of design results,this paper proposes a design and implementation scheme for a railway engineering collaborative design platform.The railway engineering collaborative design platform mainly includes functional modules such as metadata management,design collaboration,design delivery management,model component library,model rendering services,and Building Information Modeling(BIM)application services.Based on this,research is conducted on multi-disciplinary parameterized collaborative design technology for railway engineering,infrastructure data management and delivery technology,and design multi-source data fusion and application technology.The railway engineering collaborative design platform is compared with other railway design software to further validate its advantages and advanced features.The platform has been widely applied in multiple railway construction projects,greatly improving the design and project management efficiency.

Risk stratification in gastric cancer lung metastasis: Utilizing an overall survival nomogram and comparing it with previous staging

BACKGROUND Gastric cancer(GC)is prevalent and aggressive,especially when patients have distant lung metastases,which often places patients into advanced stages.By identifying prognostic variables for lung metastasis in GC patients,it may be po-ssible to construct a good prediction model for both overall survival(OS)and the cumulative incidence prediction(CIP)plot of the tumour.AIM To investigate the predictors of GC with lung metastasis(GCLM)to produce nomograms for OS and generate CIP by using cancer-specific survival(CSS)data.METHODS Data from January 2000 to December 2020 involving 1652 patients with GCLM were obtained from the Surveillance,epidemiology,and end results program database.The major observational endpoint was OS;hence,patients were se-parated into training and validation groups.Correlation analysis determined va-rious connections.Univariate and multivariate Cox analyses validated the independent predictive factors.Nomogram distinction and calibration were performed with the time-dependent area under the curve(AUC)and calibration curves.To evaluate the accuracy and clinical usefulness of the nomograms,decision curve analysis(DCA)was performed.The clinical utility of the novel prognostic model was compared to that of the 7th edition of the American Joint Committee on Cancer(AJCC)staging system by utilizing Net Reclassification Improvement(NRI)and Integrated Discrimination Improvement(IDI).Finally,the OS prognostic model and Cox-AJCC risk stratification model modified for the AJCC system were compared.RESULTS For the purpose of creating the OS nomogram,a CIP plot based on CSS was generated.Cox multivariate regression analysis identified eleven significant prognostic factors(P<0.05)related to liver metastasis,bone metastasis,primary site,surgery,regional surgery,treatment sequence,chemotherapy,radiotherapy,positive lymph node count,N staging,and time from diagnosis to treatment.It was clear from the DCA(net benefit>0),time-de-pendent ROC curve(training/validation set AUC>0.7),and calibration curve(reliability slope closer to 45 degrees)results that the OS nomogram demonstrated a high level of predictive efficiency.The OS prediction model(New Model AUC=0.83)also performed much better than the old Cox-AJCC model(AUC difference between the new model and the old model greater than 0)in terms of risk stratification(P<0.0001)and verification using the IDI and NRI.CONCLUSION The OS nomogram for GCLM successfully predicts 1-and 3-year OS.Moreover,this approach can help to ap-propriately classify patients into high-risk and low-risk groups,thereby guiding treatment.

Editor-in-Chief articles of choice and comments from January to June 2024

As the Editor-in-Chief of the World Journal of Gastroenterology,I carefully review all articles every week before a new issue’s online publication,including the title,clinical and research importance,originality,novelty,and ratings by the peer reviewers.Based on this review,I select the papers of choice and suggest pertinent changes(e.g.,in the title or text)to the company editors responsible for publication.This process,while time-consuming,is essential for assuring the quality of publications and highlighting important articles that readers may revisit.

Editor-in-Chief articles of choice and comments at the year-end of 2023

As the Editor-in-Chief of World Journal of Gastroenterology,every week prior to a new issue’s online publication,I perform a careful review of all encompassed articles,including the title,clinical and/or research importance,originality,novelty,and ratings by the peer reviewers.Based on this review,I select the papers of choice and suggest pertinent changes(e.g.,in the title)to the Company Editors responsible for publication.This process,while time-consuming,is very important for assuring the quality of publications and highlighting important articles that Readers may revisit.

Analysis of the Innovation of Zhuang Medical Culture from the Perspective of a Comprehensive Well-Off Society: Insights from Social Research and Public Engagement

Based on the inheritance and development of Zhuang medicine culture from the perspective of a comprehensive well-off society,traditional Chinese medicine is a treasure of Chinese civilization.The inheritance,innovation,and development of traditional Chinese medicine are crucial to the cause of socialism with Chinese characteristics in the new era.By engaging young people,reducing the aging of the medical team,and understanding the views and suggestions of various groups on Zhuang medicine culture,questionnaire surveys,field interviews,literature searches,and other methods were employed to gather and analyze public opinions and suggestions on Zhuang medicine.Additionally,online consultations were conducted to assess the popularity of Zhuang medicine and identify existing problems.Based on these findings,recommendations and strategies for improvement were formulated.Furthermore,the design of an online consultation app is proposed to enhance the role and effectiveness of Zhuang medicine’s inheritance and development.