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.

GoPubMed与Web of Knowledge分析工具Analyze Results的比较研究

GoPubMed是基于本体论的生物医学文献分析工具,它可以对检索到的PubMed文献进行全方位的统计分析,Web of Knowlegde平台的Analyze Results分析功能也可对检索结果进行统计分析。对这2种文献分析工具特点进行对比分析。

ISI Web of Knowledge新增分析工具Results Analysis探讨——BIOSIS Previews检索实践

针对检索结果的信息分析和信息挖掘的分析工具Results Analysis是ISI Web of Knowledge于2004年新增的服务功能。以BIOSIS Previews为检索实例,详细探讨Results Analysis分析工具的使用方法和功能,并提出改进的建议。

ISI Web of Science的Results Analysis功能与使用

详细介绍了美国Web of Science数据库的发展以及该数据库新推出的Results Analysis功能和使用方法。

THRESHOLD RESULT FOR SEMILINEAR PARABOLIC EQUATIONS WITH INDEFINITE NON-HOMOGENEOUS TERM

In this paper, we study the threshold result for the initial boundary value problem of non-homogeneous semilinear parabolic equations {μt-△μ=g（μ）＋λf（x）,（x,t）∈Ω×（0,T）,μ=0,（x,t）∈ Ω×[0,T）,μ（x,0）=μ0（x）≥0,x∈Ω.By combining a priori estimate of global solution with property of stationary solution set of problem （P）, we prove that the minimal stationary solution Uλ（x） of problem （P） is stable, whereas, any other stationary solution is an initial datum threshold for the existence and nonexistence of global solution to problem （P）.

ISI Proceedings分析工具Results Analysis的功能分析及检索实践

本文以ISI Proceedings的科技版ISTP具体检索为例,探讨了ISI Proceedings个性化服务的分析工具Results Analysis的功能和使用技巧,以及检索结果的信息分析和挖掘对用户的指导意义。

尿液分析仪打印出现“Invalid Result”的原因探索

Miditrom Junior尿分析仪是定灵曼公司生产的半自动反射光电比色计,用于半定量尿液试纸条读数。它可以提供尿比重、pH、白细胞、红细胞、亚硝酸盐、葡萄糖、蛋白质、尿胆原、尿胆红素和酮体测量结果,是目前临床常规尿液筛选检查的重要仪器。

(K_(0.5)Na_(0.5))Nb_(1-x)Ta_(x)O_(3)铁电性的第一性原理研究

随着铅基陶瓷的大量使用,造成了严重的环境和健康问题,为了能够找寻替代铅基陶瓷的材料,人们开始了对无铅陶瓷材料的探索.(K_(0.5)Na_(0.5))NbO_(3)材料由于其优异的铁电压电性能,成为了无铅陶瓷材料的代表,但是碱性组分在高温下的高挥发性使其应用范围受到了极大的限制.基于这样的考虑,本文基于密度泛函理论的第一性原理方法,探究了(K_(0.5)Na_(0.5))Nb_(1-x)TaxO_(3)(x=0.125,0.25,0.375,0.5,0.625,0.75,0.875,1)九种体系的铁电性能,结果表明:随着Ta浓度的增加,晶格常数发生了突变,由此猜测KNN材料随着Ta浓度的增加,发生了正交-单斜的相变;Ta的掺入能够降低KNN材料的烧结难度,且随着Ta浓度的增加,形成难度逐渐降低;掺杂体系中,Ta-4f轨道与Na-3p,K-4p以及O-2s轨道电子发生了杂化,使导带底Nb-4d与Na-3p电子的态密度峰向高能区移动,禁带宽度呈现增加的趋势;在分析KNN材料铁电性作用机理时发现KNN的铁电极化类型是离子位移型极化,且在[001]方向上不具有极化能力.分析掺杂后各个体系的极化强度,发现随着Ta浓度的增加,极化强度逐渐降低,但是在低浓度掺杂时极化有向上增加的趋势,这可能是体系在低浓存在着正交与单斜的准同型相界(Morphotropic phase boundary,MPB)导致的,由此可以判断,低浓度掺杂有利于提高KNN材料的铁电性能.

全媒体融合背景下基于RESULTS模型的南京市口腔医院文化宣传与建设

目的:结合全媒体融合的时代背景,分析南京市口腔医院文化宣传与建设。方法:利用经典传播模型RESULTS模型,从Reach(到达)、Engage(互动)、Sociability(社交)、Usability(易用)、Longevity(长尾)、Transaction(交易)、Sentiment(情感)7个方面分别对南京市口腔医院文化宣传内容的传播效果进行梳理和总结。结果:在全媒体融合背景下,基于RESULTS模型的南京市口腔医院文化宣传与建设取得了一定的成就。结论:经过分析得出相关建议:丰富新媒体种类,增加医院文化传播路径;宣传医院文化理念,设置多途径患者沟通渠道;将大数据、人工智能融入新媒体,提升医院文化建设效率;建立医院文化长效机制,加深媒体融合程度和广度。

Long-term results of paclitaxel plus cisplatin with concurrent radiotherapy for loco-regional esophageal squamous cell carcinoma

AIM To evaluate the long-term effectiveness and late toxicities of paclitaxel(PTX) plus cisplatin(DDP) with concurrent radiotherapy for locally advanced esophageal squamous cancer.METHODS Between 2008 and 2011, 76 patients were enrolled in a phase Ⅱ study on the treatment of loco-regionally advanced esophageal cancer with radiotherapy(68.4 Gy/44 fractions or 61.2 Gy/34 fractions) combined with 4-cycle chemotherapy consisting of DDP(25 mg/m^2 per day for 3 d) and PTX(175 mg/m^2 for 3 h). The primary endpoints were overall survival and progression-free survival, and the secondary endpoints were toxicity and the treatment failure pattern.RESULTS A total of 76 patients were enrolled in this study, of whom 63.2% finished the whole regimen. The 5-year survival rates for the per-protocol population and intent-to-treat population were 25.4% and 26.4%, respectively, and the median survival rates were 23.7 mo and 28.5 mo, respectively. Grade 3 or 4 late toxicity was observed in only one patient(heart failure). In log-rank analysis, the pretreatment stage(stage Ⅱ + Ⅲ: 36.1 mo vs stage Ⅳ: 14.9 mo) and the completed cycle(1-3 cycles: 16.1 mo vs 4 cycles: 35.5 mo) were significant prognostic factors(P = 0.037 < 0.05 and P = 0.013 < 0.05).CONCLUSION Radiotherapy combined with chemotherapy consisting of PTX and DDP is a safe and effective definitive treatment for loco-regionally advanced esophageal squamous cancer.

NEW MAGNETOSTRATIGRAPHIC AND SEDIMENTOLOGIC RESULTS FROM TERTIARY SEDIMENTS OF THE HOH XIL BASIN, NORTHERN QINGHAI-TIBET PLATEAU: IMPLICATIONS FOR THE CENOZOIC TECTONIC HISTORY OF THE TIBET PLATEAU

To contribute to the understanding of the ages of large sedimentary basins in northern Tibet, and the Cenozoic tectonic history of Asia in general, we conducted an integrated paleomagnetic and stratigraphic study on the sedimentary sequences of the Hoh Xil basin, north of the Qinghai\|Tibet Plateau. Red sedimentary sections from the Fenghuoshan and Yaxicuo Groups have recorded a pattern of magnetic polarity reversals that correlates well with the known magnetic polarity time scale for the past 56Ma. Reliable magnetostratigraphy for the Fenghuoshan and Yaxicuo Groups suggests that the sediment ages for these two groups are about 56～29Ma and 29～25Ma, respectively.We collected more than 1000 paleomagnetic samples from 335 sites distributed in 3 sections of the Hoh Xil basin. Detailed litholostratigraphic, petrologic, and sedimentologic studies have also been carried out on these sections during the past three field sessions. Magnetic directions in these sites were obtained by progressive alternating\|field and thermal demagnetization experiments. Most samples exhibit two components of magnetization. The lower unblocking temperature component is an overprint resembling the geocentric axial dipole field direction at the sampling locality. The most stable, characteristic remanence (ChRM) appears to be an early chemical remanent magnetization residing mainly in hematite. Curie temperature determinations, acquisition of isothermal remanent magnetization (IRM) and backfield demagnetization of saturation IRM, hysteresis loop parameters, and low\|temperature demagnetization on representative samples all corroborate demagnetization behavior. The positive results of fold and reversal tests indicate that the ChRM is a record of the paleomagnetic field close to the time of formation of these sediments. Further evidence that the magnetization of these sediments was acquired close to their time of deposition is the fact that patterns of magnetic reversals have been identified, which can be matched with the established polarity time scale.

Anterior rectopexy for full-thickness rectal prolapse: Technical and functional results

AIM:To assess effectiveness, complications, recurrence rate, and recent improvements of the anterior rectopexy procedure for treatment of total rectal prolapse.METHODS:MEDLINE, Pub Med, EMBASE, and other relevant database were searched to identify studies.Randomized controlled trials, non-randomized studies and original articles in English language, with more than 10 patients who underwent laparoscopic ventral rectopexy for full-thickness rectal prolapse, with a follow-up over 3 mo were considered for the review.RESULTS:Twelve non-randomized case series studies with 574 patients were included in the review.No surgical mortality was described.Conversion was needed in 17 cases(2.9%), most often due to difficult adhesiolysis.Twenty eight patients(4.8%) presented with major complications.Seven(1.2%) mesh-related complications were reported.Most frequent complications were urinary tract infection and urinary retention.Mean recurrence rate was 4.7% with a median follow-up of 23 mo.Improvement of constipation ranged from 3%-72% of the patients and worsening or new onset occurred in 0%-20%.Incontinence improved in 31%-84% patients who presented fecal incontinence at various stages.Evaluation of functional score was disparate between studies.CONCLUSION:Based on the low long-term recurrence rate and favorable outcome data in terms of low de novo constipation rate, improvement of anal incontinence, and low complications rate, laparoscopic anterior rectopexy seems to emerge as an efficient procedure for the treatment of patients with total rectal prolapse.

Long-term results of laparoscopic fenestration for patients with congenital liver cysts

BACKGROUND: The feasibility and immediate outcome of laparoscopic fenestration for patients with congenital liver cysts have been generally recognized. The aim of the present study was to assess the long-term results after laparoscopic fenestration. METHODS: A retrospective study was performed on 44 patients with congenital liver cysts who had undergone laparoscopic fenestration between June 1998 and December 2004. Among them, 30 were women and 14 men, aged 57 years on average (range 18-76 years). While 14 patients had solitary cysts, 20 had multiple cysts, and 10 had polycystic liver disease. The results of laparoscopic fenestration, including mortality, morbidity, mean postoperative hospital stay, and recurrences of cysts were evaluated. RESULTS: There was no perioperative death and the morbidity rate was 11% (5/44). All complications were treated conservatively. The mean postoperative hospital stay was 4 days. A mean follow-up of 57 months showed that the rates of cyst recurrence and symptom recurrence were 9% and 4.5%, respectively. CONCLUSION: Laparoscopic fenestration as a feasible and safe treatment procedure for patients with congenital liver cysts can yield very good long-term results.

Deformation field around a thrust fault:A comparison between laboratory results and GPS observations of the 2008 Wenchuan earthquake

On May 12,2008,an Mw7.9 earthquake occurred in Wenchuan County,Sichuan Province,China.Movement of Yingxiu–Beichuan Fault in the Longmenshan Fault Zone was considered to be the main cause of the earthquake.Earthquakes are closely related to fault activities.Therefore,studying the strain distribution and evolution process around active fault zones is important to the understanding of seismic activities.In this study,we conduct laboratory experiments with uniaxial compression applied to marble sheets with intentionally fabricated cracks.The speckle patterns of the rock samples under different loading conditions are recorded in real time by a digital camera.To calculate the deformation fields of the deliberately cracked marble sheets during different stages of the loading processes,the recorded images are processed by the digital image correlation method.The distribution and variation of the displacement and strain are further analyzed in order to understand the strain localization of and observed damage in the experimental fracture zones.Finally,we compare these laboratory results with the GPS-observed coseismic displacements during the 2008 Wenchuan earthquake,to assess the consistency between our laboratory observations and the field observations of the earthquake,but also to suggest how laboratory results can improve thinking about how earthquake patterns do and do not reflect fault patterns.

THREE-DIMENSIONAL INTERACTIONS OF A HALF-PLANE CRACK IN A TRANSVERSELY ISOTROPIC PIEZOELECTRIC SPACE WITH RESULTANT SOURCES

Exact solutions in elementary functions are derived for the stress and electric displacement intensity factors of a half-plane crack in a transversely isotropic piezoelectric space interacting with various resultant sources, including force dipole, electric dipole, moment, force dilatation and rotation. Such force and charge sources may model defects like vacancies, foreign particles and dislocations. The locations and orientations of the stress and charge sources with respect to the crack are arbitrary.

Preliminary results of the High Energetic Particle Package on-board the China Seismo-Electromagnetic Satellite

The high energetic particle package(HEPP) on-board the China Seismo-Electromagnetic Satellite(CSES) was launched on February 2, 2018. This package includes three independent detectors: HEPP-H, HEPP-L, and HEPP-X. HEPP-H and HEPP-L can detect energetic electrons from 100 keV to approximately 50 MeV and protons from 2 MeV to approximately 200 MeV. HEPP-X can measure solar X-rays in the energy range from 1 keV to approximately 20 keV. The objective of the HEPP payload was to provide a survey of energetic particles with high energy, pitch angle, and time resolutions in order to gain new insight into the space radiation environments of the near-Earth system. Particularly, the HEPP can provide new measurements of the magnetic storm related precipitation of electrons in the slot region, and the dynamics of radiation belts. In this paper, the HEPP scientific data sets are described and initial results are provided.The scientific data can show variations in the flux of energetic particles during magnetic storms.