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
To determine the root cause of a bare-spot defect in a hot-dip galvanized boron-added steel sheet,we performed metallurgical characterizations using time-of-flight secondary ion mass spectrometry(ToF-SIMS)in addition ...To determine the root cause of a bare-spot defect in a hot-dip galvanized boron-added steel sheet,we performed metallurgical characterizations using time-of-flight secondary ion mass spectrometry(ToF-SIMS)in addition to glow discharge optical emission spectrometry,field-emission scanning electron microscopy(FE-SEM),and energy dispersive spectroscopy.Mn and B enrichments on the steel surface in the bare-spot area were detected through various methods.FE-SEM revealed external oxide nodules and zinc droplets,which indicated poor wettability.ToF-SIMS further revealed considerably more detailed lateral and depth distributions of Mn,B,and Al.The formation of external Mn-B compound oxides on the steel surface prior to hot dipping,which substantially deteriorated the wettability and prevented the formation of a Fe_(2)Al_(5)inhibition layer,resulted in the formation of a bare-spot defect.ToF-SIMS mapping of Al ion proved that a slight reaction still occurred between the dissolved Al in the molten zinc bath and steel substrate,although no evident Fe_(2)Al_(5)inhibition layer formed in the bare-spot area.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
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
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
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
To evaluate the safety of detergents,the toxicological test results of 580 collected detergents were analyzed.The results showed that,in the acute oral toxicity test,94.4%and 5.6%of the samples were classified as non-...To evaluate the safety of detergents,the toxicological test results of 580 collected detergents were analyzed.The results showed that,in the acute oral toxicity test,94.4%and 5.6%of the samples were classified as non-toxic and toxic respectively.In skin irritation test,95.1%of the samples were mild irritation or below,and 4.9%were moderate irritation or above.In the vaginal mucosa irritation test,79.0%of the samples were very mild irritation or below,while 21.0%were mild irritation or above.In the acute inhalation toxicity test,the proportion of the samples classified as actually non-toxic and toxic were 87.9%and 12.1%respectively.In the eye irritation test,95.7%of the samples belonged to mild irritation or below,and 4.3%of the samples belonged to moderate irritation or above.The products at risk in category A,B and C products account for 6.3%,7.7%and 14.2%respectively.Of the 580 tested samples,90.9%were relatively safe,while 9.1%were at risk.These data showed that most of the tested samples meet the safety requirements for use.展开更多
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 develop...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.展开更多
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 neu...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.展开更多
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 monitori...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.展开更多
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To determine the root cause of a bare-spot defect in a hot-dip galvanized boron-added steel sheet,we performed metallurgical characterizations using time-of-flight secondary ion mass spectrometry(ToF-SIMS)in addition to glow discharge optical emission spectrometry,field-emission scanning electron microscopy(FE-SEM),and energy dispersive spectroscopy.Mn and B enrichments on the steel surface in the bare-spot area were detected through various methods.FE-SEM revealed external oxide nodules and zinc droplets,which indicated poor wettability.ToF-SIMS further revealed considerably more detailed lateral and depth distributions of Mn,B,and Al.The formation of external Mn-B compound oxides on the steel surface prior to hot dipping,which substantially deteriorated the wettability and prevented the formation of a Fe_(2)Al_(5)inhibition layer,resulted in the formation of a bare-spot defect.ToF-SIMS mapping of Al ion proved that a slight reaction still occurred between the dissolved Al in the molten zinc bath and steel substrate,although no evident Fe_(2)Al_(5)inhibition layer formed in the bare-spot area.
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.
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.
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.
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To evaluate the safety of detergents,the toxicological test results of 580 collected detergents were analyzed.The results showed that,in the acute oral toxicity test,94.4%and 5.6%of the samples were classified as non-toxic and toxic respectively.In skin irritation test,95.1%of the samples were mild irritation or below,and 4.9%were moderate irritation or above.In the vaginal mucosa irritation test,79.0%of the samples were very mild irritation or below,while 21.0%were mild irritation or above.In the acute inhalation toxicity test,the proportion of the samples classified as actually non-toxic and toxic were 87.9%and 12.1%respectively.In the eye irritation test,95.7%of the samples belonged to mild irritation or below,and 4.3%of the samples belonged to moderate irritation or above.The products at risk in category A,B and C products account for 6.3%,7.7%and 14.2%respectively.Of the 580 tested samples,90.9%were relatively safe,while 9.1%were at risk.These data showed that most of the tested samples meet the safety requirements for use.
基金Supported by the Scientific Research Project for College Students of Hubei University of Economics in 2022.
文摘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.
文摘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.
文摘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.
