BACKGROUND Historically intraoperative drains were employed after pancreatic surgery but over the last decade,there has been debate over the routine usage of drains.AIM To assess the necessity of intra-abdominal drain...BACKGROUND Historically intraoperative drains were employed after pancreatic surgery but over the last decade,there has been debate over the routine usage of drains.AIM To assess the necessity of intra-abdominal drain placement,identify the most effective drain type,and determine the optimal timing for drain removal.METHODS A systematic review of electronic databases,including PubMed,MEDLINE,PubMed Central,and Google Scholar,was conducted using Medical Subject Headings and keywords until December 2023.From an initial pool of 1910 articles,48 were included after exclusion and screening.The primary outcomes analyzed were clinically relevant postoperative pancreatic fistula(CR-POPF),delayed gastric emptying(DGE),overall morbidity,and mortality.Subgroup analyses were performed for pancreaticoduodenectomy and distal pancreatectomy.RESULTS Routine use of drains is associated with a statistically significant increase in the risk of CR-POPF and DGE.Conversely,patients who did not have drains placed experienced a significant reduction in morbidity,readmission rates,and reoperations.No significant differences were observed between active and passive drain types.Early drain removal(<3 days)yielded favorable outcomes compared to delayed removal.CONCLUSION Analysis of randomized controlled trials and cohort studies did not demonstrate an advantage of routine drain placement following pancreatic resection,potentially contributing to increased morbidity and mortality.The decision to use drains should be left to the discretion of the operating surgeon.However,early drain removal can substantially reduce morbidity.展开更多
Dear Editor,We introduce a novel surgical instrument designed to overcome the challenges in draining fluid from the suprachoroidal space in patients with choroidal detachment.In the evolving landscape of ophthalmic su...Dear Editor,We introduce a novel surgical instrument designed to overcome the challenges in draining fluid from the suprachoroidal space in patients with choroidal detachment.In the evolving landscape of ophthalmic surgeries,procedures that were once considered complex,such as those for choroidal detachment,are becoming increasingly common.Drainage of subchoroidal fluid was derived from 1985[1]with indirect visualization during scleral buckle surgery[2-4].展开更多
Many dangerous effects arise from seepage through earth dams based on pervious layer. Therefore, the dam embankment must be provided with seepage control measures to avoid such effects. In the present work, different ...Many dangerous effects arise from seepage through earth dams based on pervious layer. Therefore, the dam embankment must be provided with seepage control measures to avoid such effects. In the present work, different control methods were used such as flat slopes, toe drainage systems, and a catch drain in the tail water. The hydraulic performance of each control measure was evaluated using the analytical solutions, previously developed, to estimate the seepage quantity (q), the height of seepage surface (h<sub>3</sub>), and the coordinates of the free surface (h<sub>x</sub>). Study was conducted on a physical model for a dam embankment having a top width (b) = 10.0 meter, height (H<sub>d</sub>) = 30.0 meter, and slope factor (m) = 1.5. The obtained results were analyzed and presented in dimensionless charts. Results showed that, the used control measures possess a great effect on the characteristics of seepage through earth dams based on pervious foundations. A comparative study was conducted between the studied toe drainage systems to enable the designers the better choice for design purposes.展开更多
OBJECTIVE:To evaluate the 10-year therapeutic efficacy of Traditional Chinese Medicine(TCM)using the Strengthening Spleen and Draining Dampness therapy in the management of idiopathic membranous nephropathy(IMN).METHO...OBJECTIVE:To evaluate the 10-year therapeutic efficacy of Traditional Chinese Medicine(TCM)using the Strengthening Spleen and Draining Dampness therapy in the management of idiopathic membranous nephropathy(IMN).METHODS:A single-center,retrospective analysis was conducted on patients diagnosed with IMN who met predefined inclusion and exclusion criteria.Data were collected from the Department of Nephrology at Longhua Hospital,affiliated with Shanghai University of Traditional Chinese Medicine,between January 2007 and December 2011.Clinical parameters including 24-h urinary protein,serum albumin,serum creatinine,and estimated glomerular filtration rate(e GFR,EPI)were assessed at baseline and at 1,3,5,and 10 years of follow-up.The efficacy of the Strengthening Spleen and Draining Dampness therapy was analyzed using repeated measures analysis of variance(ANOVA).Kaplan-Meier survival curves and multivariate proportional hazards model(Cox regression models)were employed to identify factors associated with treatment outcomes.RESULTS:A total of 265 patients were included,with a median follow-up duration of 96 months(36,122).TCM treatment significantly reduced 24-h urinary protein levels(P<0.001),and increased serum albumin levels(P<0.001),while serum creatinine remained stable(P=0.187).Remission rates at 1,3,5,and 10 years were 52.81%,69.71%,68.39%,and 72.36%,respectively,and the rates of avoiding composite outcome events at the same intervals were 98.27%,94.29%,94.19%,and 93.50%.In the subgroup receiving TCM only,remission rates were 56.67%,84.44%,76.32%,and 82.86%.For patients treated initially with Western Medicine followed by TCM,the rates were 52.83%,65.85%,67.47%and 67.75%.In the cohort of patients who received TCM as their first-line therapy,remission rates were 49.23%,62.50%,61.76%,and 69.23%.Multivariate Cox regression analysis revealed that the duration of TCM treatment[hazard ratio(HR)=0.826,95%confidence interval(CI)(0.779,0.876),P<0.001],presence of hypertension[HR=1.912,95%CI(1.181,3.094),P=0.008],baseline serum albumin level[HR=0.930,95%CI(0.894,0.969),P<0.001],and the rate of serum albumin increase within the first year of treatment[HR=0.930,95%CI(0.909,0.957),P<0.001]were significantly associated with clinical outcomes.CONCLUSION:The Strengthening Spleen and Draining Dampness therapy demonstrated robust short-and longterm efficacy in treating IMN,with high rates of remission and renal survival over 10 years.Key factors influencing clinical remission included the duration of TCM treatment,baseline serum albumin levels,the presence of hypertension,and the rate of increase in serum albumin within the first year.These findings suggest that this TCM approach provides a viable long-term treatment option for IMN.展开更多
BACKGROUND Esophagojejunal anastomotic leakage(EJAL)is a severe complication following gastrectomy for gastric cancer,typically treated with drainage and nutritional support.We report a case of intraluminal drain migr...BACKGROUND Esophagojejunal anastomotic leakage(EJAL)is a severe complication following gastrectomy for gastric cancer,typically treated with drainage and nutritional support.We report a case of intraluminal drain migration near the esophagojejunal anastomosis(EJA),resulting in persistent drainage and mimicking EJAL after total gastrectomy.CASE SUMMARY A 64-year-old male underwent open total gastrectomy with Roux-en-Y reconstruction for gastric adenocarcinoma,with two silicone drains placed near the EJA.On postoperative day(POD)4,the patient developed signs of peritonitis and sepsis,necessitating surgical re-exploration abscess drainage,peritoneal lavage,and drain repositioning.A contrast swallow study on POD 18 revealed rapid filling of the abdominal drain without extraluminal contrast collection.Persistent drainage prompted an upper gastrointestinal endoscopy on POD 59,which revealed approximately 5 cm of the drain within the esophagus,with the perforation site located 2 cm distal to the intact EJA.The drain was repositioned under endoscopic guidance.A repeat contrast radiograph on POD 67 demonstrated no evidence of extraluminal contrast extravasation or filling of the abdominal drain.The patient was subsequently discharged without further incident.CONCLUSION Intraluminal drain migration is a rare complication following gastric surgery but should be considered when persistent drainage occurs.展开更多
In vertical channel transistors(VCTs),source/drain ion implantation(I/I)represents a significant technical challenge due to inherent three-dimensional structural constraints,which induce complications such as difficul...In vertical channel transistors(VCTs),source/drain ion implantation(I/I)represents a significant technical challenge due to inherent three-dimensional structural constraints,which induce complications such as difficulties in dummy gate forma-tion and shadowing effects of I/I.This article systematically investigates the impact of different implantation conditions on the performance of VCTs with and without dummy gates through TCAD simulation.It reveals the significant role of the lightly doped regions(LDRs)naturally formed due to ion implantation in source/drain of VCTs.Furthermore,it was found that VCT with-out dummy gates can achieve an approximately 27%increase in on-state current(Ion)under the same implantation conditions,and can greatly simplify the process flow and reduce costs.Finally,N-type and P-type VCTs were successfully fabricated using this implantation method.展开更多
Background: Surgical drains are used in at least half of all surgical operations world-wide. The gold standard for the fixation of drains to the skin is currently the “Roman garter” (RG) technique, which involves kn...Background: Surgical drains are used in at least half of all surgical operations world-wide. The gold standard for the fixation of drains to the skin is currently the “Roman garter” (RG) technique, which involves knotting a suture around the drain. Its disadvantages include the time to perform the technique, possible loosening and accidental removal, and bacterial infection with biofilm formation if left in place for weeks. Methods: The Elist Drain Retainer (EDR) has been developed, and it consists of a short plastic tube bent to 90° with a side slit for the drain, fixed to a mounting patch with adhesive and an antiseptic. Results: In a clinical trial comparing 25 drain attachments with the RG versus 25 drain attachments with the new EDR, the former took an average of five minutes and the EDR took an average of one minute to place. Loosening occurred in five (20%) drains and accidental removal occurred in four (16%) for the RG group versus no incidences of loosening or accidental removal in the EDR group. Self-removal of the EDR was possible for seven (28%) patients. Conclusion: The EDR demonstrated a clear advantage over the RG in all tested parameters. The lack of instruments and the possibility of self-removal of the EDR when a drain is needed are particularly advantageous features.展开更多
The same floor drainage refers to sanitary wares in the washing room, to be specific, the drainage pipe （sewage and branch pipes respectively） which can be into other houses without going through floors! This techno...The same floor drainage refers to sanitary wares in the washing room, to be specific, the drainage pipe （sewage and branch pipes respectively） which can be into other houses without going through floors! This technology has many advantages, like easy to construct and install at the same floor on one hand; on the other hand, when sewage or waste reach the top compared with the same kind drainage systems and other drainage methods, it can smoothly enter the main pipe （the chief vertical one）. Moreover, once there is any situation needing dredge and cleaning, this problem can be solved at the same floor without interrupting the lives of other families. Last but not the least, it is so convenient to create a clean and tidy washing room. The branch pipe without being through floors is the very reason to solve the problem of surface condensation relative to sewage pipe in the rainy days, which correspondingly increases the hcight of head room indoor, is more favorable for fire prevention and much easier to keep smooth pipe flow.展开更多
Backflling represents an environmentally friendly mining waste disposal technique.It is increasingly used in underground mines all over the world.However,its primary purpose remains to improve ground stability and to ...Backflling represents an environmentally friendly mining waste disposal technique.It is increasingly used in underground mines all over the world.However,its primary purpose remains to improve ground stability and to reduce ore dilution.Previous investigations have shown that fll drainage plays a key role in backfll and barricade design.With a poor drainage system in the backflled stope,the required dimension of barricade,which is constructed at the base of the stope near the drift entrance,has to be increased.A poor backfll drainage system can also lead to a signifcant increase in drainage waiting time and further reduction in mining productivity.In this paper,the drainage of conventional backfll design in backflled stopes is briefly reviewed.For the frst time,the application of the wick drain is introduced in the backfll within mine stopes.The drainage improvement from the introduction of the wick drain is illustrated using numerical modeling.展开更多
The drainage areas(and volumes)near hydraulically fractured wells,computed and visualized in our study at high resolution,may be critically affected by the presence of natural fractures.Using a recently developed algo...The drainage areas(and volumes)near hydraulically fractured wells,computed and visualized in our study at high resolution,may be critically affected by the presence of natural fractures.Using a recently developed algorithm based on complex analysis methods(CAMs),the drained rock volume(DRV)is visualized for a range of synthetic constellations of natural fractures near hydraulic fractures.First,flow interference effects near a single hydraulic fracture are systematically investigated for a variety of natural fracture sets.The permeability contrast between the matrix and the natural fractures is increased stepwise in order to better understand the effect on the DRV.Next,a larger-scale model investigates flow interference for a full hydraulically fractured well with a variety of natural fracture sets.The time of flight contours(TOFCs)outlining the DRV are for all cases with natural fractures compared to a base case without any natural fractures.Discrete natural fractures,with different orientations,hydraulic conductivity,and fracture density,may shift the TOFC patterns in the reservoir region drained by the hydraulically fractured well,essentially shifting the location of the well’s drainage area.The CAM-based models provide a computationally efficient method to quantify and visualize the drainage in both naturally and hydraulically fractured reservoirs.展开更多
An analytical solution is derived from the generalized governing equations of equal-strain consolidation with vertical drains under multi-ramp surcharge preloading. The hydraulic boundary conditions at both top and bo...An analytical solution is derived from the generalized governing equations of equal-strain consolidation with vertical drains under multi-ramp surcharge preloading. The hydraulic boundary conditions at both top and bottom of the consolidating soil are modelled as impeded drainage. The impeded drainage is described by using the third type boundary condition with a characteristic factor of drainage efficiency. Fully drained and undrained boundary conditions can also be modelled by applying an infinite and a zero characteristic factor, respectively. Simultaneous radial and vertical flow conditions are considered, together with the effects of drain resistance and smear. An increase in total stress due to multi-ramp loading is reasonably modelled as a function of both time and depth. A solution to calculate excess pore-water pressure at any arbitrary point in soil is derived, and the overall average degree of consolidation is obtained. It shows that the proposed solution can be used to analyze not only vertical-drain consolidation but also one-dimensional consolidation under either one-way or two-way vertical drainage conditions. The characteristic factors of drainage efficiency of top and bottom boundaries have a potentially important influence on consolidation. The boundary may be considered fully drained when the characteristic factor is greater than 100 and fully undrained when the characteristic factor is less than 0.1. The stress distribution along depth induced by the surcharge loading has a limited effect on the overall average degree of consolidation.展开更多
A field experimental project was set up to assess the effects of controlled drainage on the distribution and concentration of nitrogen in the soil at the Irrigation and Drainage Experimental Station under Four-Lake En...A field experimental project was set up to assess the effects of controlled drainage on the distribution and concentration of nitrogen in the soil at the Irrigation and Drainage Experimental Station under Four-Lake Engineering Administration of Jingzhou City,Hubei Province.Two plots drain runoff by controlled drainage system,with an area of 0.1 hm^2(20 m×50 m)each.The third one with an area of 0.04 hm^2(8 m×50 m)has a conventional subsurface drainage system.Under this experimental condition,the study draws the following conclusions:①The controlled drainage system has a remarkable effect on the diminishing ratios of nitrate nitrogen between neighboring layers.It is presented that the diminishing ratio increases with the raising height of drain outlet.Controlled drainage system also reduces the transference of nitrate nitrogen in topsoil.②Different from nitrate nitrogen,the concentration of ammonium nitrogen is stable along the longitudinal section of soil,which is little affected by the controlled drainage system.It indicates that the concentration of ammonium nitrogen decreases according to the lowering of controlling height of the drain outlet.展开更多
Drainage management activities aim at maintaining the performance of drainage networks by assessing the major drainage management problems regarding sedimentation, bank erosion, vegetation, water quality, and biodiver...Drainage management activities aim at maintaining the performance of drainage networks by assessing the major drainage management problems regarding sedimentation, bank erosion, vegetation, water quality, and biodiversity, to find appropriate solutions for channel improvement in order to increase agricultural productivity and maintain agricultural land and the surrounding environment. In this research, we evaluate the drainage management problems to the surface drains Baloza and EL-Farama in the cultivated Tina Plain region (21,000 hectares) North Sinai, Egypt to provide an accurate data to help decision-makers to know the status of maintenance of the watercourses and the need for improvement. For this, Intensive field investigations were carried out regarding a hydrographic survey of the actual drains cross-section using total station and aqua sounder devices, visual stream bank erosion survey, and vegetation survey. In addition, monthly water samples from the drainage water were treated and analyzed for physical and chemical, bacteriological related indices. The results showed, the studied drains suffer from sedimentation, vegetation infection, and bank erosion in some reaches and need remedy. Estimated sedimentation in EL-Farama Drain was 34369 m3/year and in Baloza Drain 29153 m3/year;bank slope failures upstream and downstream pump stations were recorded;the average weed infection ratio for both drains was 30%. The results of water quality parameters showed acceptable concentrations for BOD, DO, NO3, and total coliform according to Egypt decree, 92/2013 for the protection of the Nile River and its waterways from pollution, except TDS (more than 10,000 mg/L). The drainage water was classified as high saline and it was unacceptable for irrigation. Therefore, the author recommends to remove sedimentation and vegetation every 2 years by mechanical methods, applying gabions lining to prevent bank erosion, and treating drainage water using wetland system and utilizing the treated wastewater in fish farming.展开更多
Background: Surgical wound drainage is practiced routinely by many orthopaedic surgeons despite studies that challenge the practice. Among proponents, the advantages of drainage include prevention of haematoma and/or ...Background: Surgical wound drainage is practiced routinely by many orthopaedic surgeons despite studies that challenge the practice. Among proponents, the advantages of drainage include prevention of haematoma and/or seroma formation which potentially reduces the chances for infection, prevention of wound swelling, prevention of compartment syndrome and improvement of the local wound environment. Opponents argue that prophylactic wound drainage confers no significant advantages, increases the risk of infection and the need for blood transfusion with the attendant risks of this therapy. Aim: To ascertain if prophylactic drainage of clean orthopaedic wounds confer any significant advantages by evaluating wound and systemic factors in two treatment groups. Patients and Methods: A prospective analysis of 62 patients was undergoing clean orthopaedic procedures. The patients were randomly assigned to a “No drain” (study) group and a “drain” (control) group. Each group had 31 patients. Surgeons were blinded to the randomization process and the evaluation of clinical outcomes. The parameters assessed included pain, superficial wound infection, the need for post-operative transfusion, wound leakage, dressing changes and the surgery-discharge interval. Data was analysed using SPSS statistics version 20 (IBM Corp., New York). Results: There were no significant differences in the demographic data. Femoral fractures were the commonest indication for surgery (43.55%), and plate and screw osteosynthesis was the commonest procedure (48.4% in the drain group and 67.7% in the no-drain group). There was a significantly higher need for post-operative transfusion in the drain group (22.6% against 0%) as well as a significantly prolonged capillary refill time (2.39 + 0.56 secs versus 2.03 + 0.41 secs). Although not statistically significant, there were four cases (12.8%) of superficial wound infection in the drain group and 1 case (3.2%) in the no-drain group. Conclusion: Prophylactic wound drainage confers no significant advantages over no drainage and may contribute to increased treatment costs through an increased post-operative transfusion requirements.展开更多
There are some bad impacts from a critical land such as flood in rainy season and dryness in dry season. Long dryness could cause shortage of water for human consumption, industry and agriculture. Prevention has been ...There are some bad impacts from a critical land such as flood in rainy season and dryness in dry season. Long dryness could cause shortage of water for human consumption, industry and agriculture. Prevention has been made to avoid the both bad impacts by building hydraulic structures like reservoirs and ponds in order to reduce the peak flow during the rainy season and to store the water for use during the dry season. However, they gradually become full of sediment. This will make them work insufficiently and will cause high maintenance cost. Moreover, wells in agriculture field used as retention also suffer dryness to make crop failure. This study aims to develop a model of pond for conservation of land and water in non irrigated land. Community participation is crucial in order to solve the flood and dryness problems. The community, especially the farmers will participate actively in the implementation and maintenance of the model. There are benefits in using the pond model such as： （1） to control sediment transport to the rivers, reservoir or other hydraulic structures; （2） to reduce flood rate; （3） to increase ground water recharge; （4） to contain water for agriculture and （5） to control the fertility of land. The cost of making a unit of model （sedrainpond） of 1.5 m diameter and 1.5 meter depth is relatively cheap between $10 to $20 （US）, and the maintenance is done by the farmers. When the pond model becomes functional, besides containing water in the rainy season, the water can be used to sustain water for agriculture in the dry season to avoid any crop failure. When the pond becomes dry, the farmers can harvest the suspended load sediment such as clay or silt to spread onto their land to keep its fertility.展开更多
This article aims to study the efficiency of coupled vertical drains for the treatment of long-lasting compressible clay soils for the road project platform of the ring road of Porto Novo, capital of Benin. The experi...This article aims to study the efficiency of coupled vertical drains for the treatment of long-lasting compressible clay soils for the road project platform of the ring road of Porto Novo, capital of Benin. The experimental data allowed us to estimate a consolidation of 29% in 9 months, justifying the drainage of the soil. In order to study the efficiency of drainage, a FEM model was proposed simulating different scenarios. These include a drainless road, pavements equipped with vertical drains with meshes of 0.5 m 0.5 m, 1 m 1 m and 1.5 m 1.5 m respectively and horizontal drains. The results expressed in terms of variations in vertical stresses, effective stresses and shear deformations revealed significant variations in pavement performance depending on the mesh size of the vertical drains. The configuration with a mesh of 0.5 m 0.5 m showed the least deformations, thus indicating a reduction in deformations and better stress distribution. However, the other mesh configurations showed variable results, underlining the importance of choosing the right mesh for the specific project conditions.展开更多
AIM:To conduct a meta-analysis comparing outcomes after pancreaticoduodenectomy(PD)with or without prophylactic drainage.METHODS:Relevant comparative randomized and nonrandomized studies were systemically searched bas...AIM:To conduct a meta-analysis comparing outcomes after pancreaticoduodenectomy(PD)with or without prophylactic drainage.METHODS:Relevant comparative randomized and nonrandomized studies were systemically searched based on specific inclusion and exclusion criteria.Postoperative outcomes were compared between patients with and those without routine drainage.Pooled odds ratios(OR)with 95%CI were calculated using either fixed effects or random effects models.RESULTS:One randomized controlled trial and four non-randomized comparative studies recruiting 1728patients were analyzed.Patients without prophylactic drainage after PD had significantly higher mortality(OR=2.32,95%CI:1.11-4.85;P=0.02),despite the fact that they were associated with fewer overall complications(OR=0.62,95%CI:0.48-0.82;P=0.00),major complications(OR=0.75,95%CI:0.60-0.93;P=0.01)and readmissions(OR=0.77,95%CI:0.60-0.98;P=0.04).There were no significant differences in the rates of pancreatic fistula,intraabdominal abscesses,postpancreatectomy hemorrhage,biliary fistula,delayed gastric emptying,reoperation or radiologic-guided drains between the two groups.CONCLUSION:Indiscriminate abandonment of intraabdominal drainage following PD is associated with greater mortality,but lower complication rates.Future randomized trials should compare routine vs selective drainage.展开更多
Three dimensional （3D） DEM （discrete element method） simulations of drained triaxial compression and plane strain tests are presented for both dense and loose assemblies of polydisperse spheres using a periodic ce...Three dimensional （3D） DEM （discrete element method） simulations of drained triaxial compression and plane strain tests are presented for both dense and loose assemblies of polydisperse spheres using a periodic cell. In the work reported, drained tests were modelled by deforming the samples under constant mean stress conditions. The drained behaviour is shown to be qualitatively similar to published physical experimental results. The Bishop＇s formula for the estimation of the intermediate principal stress is evaluated. The existence of critical density is shown to be independent of initial packing densities and strain conditions. Different failure criteria have been compared based on the DEM simulation results, and the Lade criterion is found to be the most appropriate one. A new microscopic fabric parameter is introduced to give insight to structural anisotropy under general 3D fabric conditions. It is found that two parameters characterize the evolution of the stress and fabric respectively independent of strain conditions.展开更多
文摘BACKGROUND Historically intraoperative drains were employed after pancreatic surgery but over the last decade,there has been debate over the routine usage of drains.AIM To assess the necessity of intra-abdominal drain placement,identify the most effective drain type,and determine the optimal timing for drain removal.METHODS A systematic review of electronic databases,including PubMed,MEDLINE,PubMed Central,and Google Scholar,was conducted using Medical Subject Headings and keywords until December 2023.From an initial pool of 1910 articles,48 were included after exclusion and screening.The primary outcomes analyzed were clinically relevant postoperative pancreatic fistula(CR-POPF),delayed gastric emptying(DGE),overall morbidity,and mortality.Subgroup analyses were performed for pancreaticoduodenectomy and distal pancreatectomy.RESULTS Routine use of drains is associated with a statistically significant increase in the risk of CR-POPF and DGE.Conversely,patients who did not have drains placed experienced a significant reduction in morbidity,readmission rates,and reoperations.No significant differences were observed between active and passive drain types.Early drain removal(<3 days)yielded favorable outcomes compared to delayed removal.CONCLUSION Analysis of randomized controlled trials and cohort studies did not demonstrate an advantage of routine drain placement following pancreatic resection,potentially contributing to increased morbidity and mortality.The decision to use drains should be left to the discretion of the operating surgeon.However,early drain removal can substantially reduce morbidity.
基金Supported by Science and Technology Foundation of Tianjin Eye Hospital(No.YKPY2207)Tianjin Key Medical Discipline(Specialty)Construction Project(No.TJYXZDXK-016A).
文摘Dear Editor,We introduce a novel surgical instrument designed to overcome the challenges in draining fluid from the suprachoroidal space in patients with choroidal detachment.In the evolving landscape of ophthalmic surgeries,procedures that were once considered complex,such as those for choroidal detachment,are becoming increasingly common.Drainage of subchoroidal fluid was derived from 1985[1]with indirect visualization during scleral buckle surgery[2-4].
文摘Many dangerous effects arise from seepage through earth dams based on pervious layer. Therefore, the dam embankment must be provided with seepage control measures to avoid such effects. In the present work, different control methods were used such as flat slopes, toe drainage systems, and a catch drain in the tail water. The hydraulic performance of each control measure was evaluated using the analytical solutions, previously developed, to estimate the seepage quantity (q), the height of seepage surface (h<sub>3</sub>), and the coordinates of the free surface (h<sub>x</sub>). Study was conducted on a physical model for a dam embankment having a top width (b) = 10.0 meter, height (H<sub>d</sub>) = 30.0 meter, and slope factor (m) = 1.5. The obtained results were analyzed and presented in dimensionless charts. Results showed that, the used control measures possess a great effect on the characteristics of seepage through earth dams based on pervious foundations. A comparative study was conducted between the studied toe drainage systems to enable the designers the better choice for design purposes.
基金Supported by the National Key Research and Development Project,Clinical Study on the Treatment of Refractory Membranous Nephropathy with the Treatment of Strengthening Spleen and Draining Dampness in Method using Single Group Target Value Method(No.2019YFC1709403)Systematic Study on the Diagnosis and Treatment Rules of Membranous Nephropathy in Traditional Chinese Medicine(No.2023YFC35033501,No.2023YFC35033503)。
文摘OBJECTIVE:To evaluate the 10-year therapeutic efficacy of Traditional Chinese Medicine(TCM)using the Strengthening Spleen and Draining Dampness therapy in the management of idiopathic membranous nephropathy(IMN).METHODS:A single-center,retrospective analysis was conducted on patients diagnosed with IMN who met predefined inclusion and exclusion criteria.Data were collected from the Department of Nephrology at Longhua Hospital,affiliated with Shanghai University of Traditional Chinese Medicine,between January 2007 and December 2011.Clinical parameters including 24-h urinary protein,serum albumin,serum creatinine,and estimated glomerular filtration rate(e GFR,EPI)were assessed at baseline and at 1,3,5,and 10 years of follow-up.The efficacy of the Strengthening Spleen and Draining Dampness therapy was analyzed using repeated measures analysis of variance(ANOVA).Kaplan-Meier survival curves and multivariate proportional hazards model(Cox regression models)were employed to identify factors associated with treatment outcomes.RESULTS:A total of 265 patients were included,with a median follow-up duration of 96 months(36,122).TCM treatment significantly reduced 24-h urinary protein levels(P<0.001),and increased serum albumin levels(P<0.001),while serum creatinine remained stable(P=0.187).Remission rates at 1,3,5,and 10 years were 52.81%,69.71%,68.39%,and 72.36%,respectively,and the rates of avoiding composite outcome events at the same intervals were 98.27%,94.29%,94.19%,and 93.50%.In the subgroup receiving TCM only,remission rates were 56.67%,84.44%,76.32%,and 82.86%.For patients treated initially with Western Medicine followed by TCM,the rates were 52.83%,65.85%,67.47%and 67.75%.In the cohort of patients who received TCM as their first-line therapy,remission rates were 49.23%,62.50%,61.76%,and 69.23%.Multivariate Cox regression analysis revealed that the duration of TCM treatment[hazard ratio(HR)=0.826,95%confidence interval(CI)(0.779,0.876),P<0.001],presence of hypertension[HR=1.912,95%CI(1.181,3.094),P=0.008],baseline serum albumin level[HR=0.930,95%CI(0.894,0.969),P<0.001],and the rate of serum albumin increase within the first year of treatment[HR=0.930,95%CI(0.909,0.957),P<0.001]were significantly associated with clinical outcomes.CONCLUSION:The Strengthening Spleen and Draining Dampness therapy demonstrated robust short-and longterm efficacy in treating IMN,with high rates of remission and renal survival over 10 years.Key factors influencing clinical remission included the duration of TCM treatment,baseline serum albumin levels,the presence of hypertension,and the rate of increase in serum albumin within the first year.These findings suggest that this TCM approach provides a viable long-term treatment option for IMN.
文摘BACKGROUND Esophagojejunal anastomotic leakage(EJAL)is a severe complication following gastrectomy for gastric cancer,typically treated with drainage and nutritional support.We report a case of intraluminal drain migration near the esophagojejunal anastomosis(EJA),resulting in persistent drainage and mimicking EJAL after total gastrectomy.CASE SUMMARY A 64-year-old male underwent open total gastrectomy with Roux-en-Y reconstruction for gastric adenocarcinoma,with two silicone drains placed near the EJA.On postoperative day(POD)4,the patient developed signs of peritonitis and sepsis,necessitating surgical re-exploration abscess drainage,peritoneal lavage,and drain repositioning.A contrast swallow study on POD 18 revealed rapid filling of the abdominal drain without extraluminal contrast collection.Persistent drainage prompted an upper gastrointestinal endoscopy on POD 59,which revealed approximately 5 cm of the drain within the esophagus,with the perforation site located 2 cm distal to the intact EJA.The drain was repositioned under endoscopic guidance.A repeat contrast radiograph on POD 67 demonstrated no evidence of extraluminal contrast extravasation or filling of the abdominal drain.The patient was subsequently discharged without further incident.CONCLUSION Intraluminal drain migration is a rare complication following gastric surgery but should be considered when persistent drainage occurs.
文摘In vertical channel transistors(VCTs),source/drain ion implantation(I/I)represents a significant technical challenge due to inherent three-dimensional structural constraints,which induce complications such as difficulties in dummy gate forma-tion and shadowing effects of I/I.This article systematically investigates the impact of different implantation conditions on the performance of VCTs with and without dummy gates through TCAD simulation.It reveals the significant role of the lightly doped regions(LDRs)naturally formed due to ion implantation in source/drain of VCTs.Furthermore,it was found that VCT with-out dummy gates can achieve an approximately 27%increase in on-state current(Ion)under the same implantation conditions,and can greatly simplify the process flow and reduce costs.Finally,N-type and P-type VCTs were successfully fabricated using this implantation method.
文摘Background: Surgical drains are used in at least half of all surgical operations world-wide. The gold standard for the fixation of drains to the skin is currently the “Roman garter” (RG) technique, which involves knotting a suture around the drain. Its disadvantages include the time to perform the technique, possible loosening and accidental removal, and bacterial infection with biofilm formation if left in place for weeks. Methods: The Elist Drain Retainer (EDR) has been developed, and it consists of a short plastic tube bent to 90° with a side slit for the drain, fixed to a mounting patch with adhesive and an antiseptic. Results: In a clinical trial comparing 25 drain attachments with the RG versus 25 drain attachments with the new EDR, the former took an average of five minutes and the EDR took an average of one minute to place. Loosening occurred in five (20%) drains and accidental removal occurred in four (16%) for the RG group versus no incidences of loosening or accidental removal in the EDR group. Self-removal of the EDR was possible for seven (28%) patients. Conclusion: The EDR demonstrated a clear advantage over the RG in all tested parameters. The lack of instruments and the possibility of self-removal of the EDR when a drain is needed are particularly advantageous features.
文摘The same floor drainage refers to sanitary wares in the washing room, to be specific, the drainage pipe （sewage and branch pipes respectively） which can be into other houses without going through floors! This technology has many advantages, like easy to construct and install at the same floor on one hand; on the other hand, when sewage or waste reach the top compared with the same kind drainage systems and other drainage methods, it can smoothly enter the main pipe （the chief vertical one）. Moreover, once there is any situation needing dredge and cleaning, this problem can be solved at the same floor without interrupting the lives of other families. Last but not the least, it is so convenient to create a clean and tidy washing room. The branch pipe without being through floors is the very reason to solve the problem of surface condensation relative to sewage pipe in the rainy days, which correspondingly increases the hcight of head room indoor, is more favorable for fire prevention and much easier to keep smooth pipe flow.
基金the financial support of School of Advanced Technology(FIRPSIRE-research+1 种基金FDETS)the Natural Sciences and Engineering Research Council of Canada(RGPIN)
文摘Backflling represents an environmentally friendly mining waste disposal technique.It is increasingly used in underground mines all over the world.However,its primary purpose remains to improve ground stability and to reduce ore dilution.Previous investigations have shown that fll drainage plays a key role in backfll and barricade design.With a poor drainage system in the backflled stope,the required dimension of barricade,which is constructed at the base of the stope near the drift entrance,has to be increased.A poor backfll drainage system can also lead to a signifcant increase in drainage waiting time and further reduction in mining productivity.In this paper,the drainage of conventional backfll design in backflled stopes is briefly reviewed.For the frst time,the application of the wick drain is introduced in the backfll within mine stopes.The drainage improvement from the introduction of the wick drain is illustrated using numerical modeling.
文摘The drainage areas(and volumes)near hydraulically fractured wells,computed and visualized in our study at high resolution,may be critically affected by the presence of natural fractures.Using a recently developed algorithm based on complex analysis methods(CAMs),the drained rock volume(DRV)is visualized for a range of synthetic constellations of natural fractures near hydraulic fractures.First,flow interference effects near a single hydraulic fracture are systematically investigated for a variety of natural fracture sets.The permeability contrast between the matrix and the natural fractures is increased stepwise in order to better understand the effect on the DRV.Next,a larger-scale model investigates flow interference for a full hydraulically fractured well with a variety of natural fracture sets.The time of flight contours(TOFCs)outlining the DRV are for all cases with natural fractures compared to a base case without any natural fractures.Discrete natural fractures,with different orientations,hydraulic conductivity,and fracture density,may shift the TOFC patterns in the reservoir region drained by the hydraulically fractured well,essentially shifting the location of the well’s drainage area.The CAM-based models provide a computationally efficient method to quantify and visualize the drainage in both naturally and hydraulically fractured reservoirs.
基金Project(51278171)supported by the National Natural Science Foundation of ChinaProject(B13024)supported by Program of Introducing Talents of Discipline to Universities("111" Project),ChinaProject(2014B04914)supported by the Fundamental Research Funds for the Central Universities of China
文摘An analytical solution is derived from the generalized governing equations of equal-strain consolidation with vertical drains under multi-ramp surcharge preloading. The hydraulic boundary conditions at both top and bottom of the consolidating soil are modelled as impeded drainage. The impeded drainage is described by using the third type boundary condition with a characteristic factor of drainage efficiency. Fully drained and undrained boundary conditions can also be modelled by applying an infinite and a zero characteristic factor, respectively. Simultaneous radial and vertical flow conditions are considered, together with the effects of drain resistance and smear. An increase in total stress due to multi-ramp loading is reasonably modelled as a function of both time and depth. A solution to calculate excess pore-water pressure at any arbitrary point in soil is derived, and the overall average degree of consolidation is obtained. It shows that the proposed solution can be used to analyze not only vertical-drain consolidation but also one-dimensional consolidation under either one-way or two-way vertical drainage conditions. The characteristic factors of drainage efficiency of top and bottom boundaries have a potentially important influence on consolidation. The boundary may be considered fully drained when the characteristic factor is greater than 100 and fully undrained when the characteristic factor is less than 0.1. The stress distribution along depth induced by the surcharge loading has a limited effect on the overall average degree of consolidation.
基金Supported by the National Science and Technology Pillar Program in the Eleventh Five-Year Plan Period(2006BAD11B06)
文摘A field experimental project was set up to assess the effects of controlled drainage on the distribution and concentration of nitrogen in the soil at the Irrigation and Drainage Experimental Station under Four-Lake Engineering Administration of Jingzhou City,Hubei Province.Two plots drain runoff by controlled drainage system,with an area of 0.1 hm^2(20 m×50 m)each.The third one with an area of 0.04 hm^2(8 m×50 m)has a conventional subsurface drainage system.Under this experimental condition,the study draws the following conclusions:①The controlled drainage system has a remarkable effect on the diminishing ratios of nitrate nitrogen between neighboring layers.It is presented that the diminishing ratio increases with the raising height of drain outlet.Controlled drainage system also reduces the transference of nitrate nitrogen in topsoil.②Different from nitrate nitrogen,the concentration of ammonium nitrogen is stable along the longitudinal section of soil,which is little affected by the controlled drainage system.It indicates that the concentration of ammonium nitrogen decreases according to the lowering of controlling height of the drain outlet.
文摘Drainage management activities aim at maintaining the performance of drainage networks by assessing the major drainage management problems regarding sedimentation, bank erosion, vegetation, water quality, and biodiversity, to find appropriate solutions for channel improvement in order to increase agricultural productivity and maintain agricultural land and the surrounding environment. In this research, we evaluate the drainage management problems to the surface drains Baloza and EL-Farama in the cultivated Tina Plain region (21,000 hectares) North Sinai, Egypt to provide an accurate data to help decision-makers to know the status of maintenance of the watercourses and the need for improvement. For this, Intensive field investigations were carried out regarding a hydrographic survey of the actual drains cross-section using total station and aqua sounder devices, visual stream bank erosion survey, and vegetation survey. In addition, monthly water samples from the drainage water were treated and analyzed for physical and chemical, bacteriological related indices. The results showed, the studied drains suffer from sedimentation, vegetation infection, and bank erosion in some reaches and need remedy. Estimated sedimentation in EL-Farama Drain was 34369 m3/year and in Baloza Drain 29153 m3/year;bank slope failures upstream and downstream pump stations were recorded;the average weed infection ratio for both drains was 30%. The results of water quality parameters showed acceptable concentrations for BOD, DO, NO3, and total coliform according to Egypt decree, 92/2013 for the protection of the Nile River and its waterways from pollution, except TDS (more than 10,000 mg/L). The drainage water was classified as high saline and it was unacceptable for irrigation. Therefore, the author recommends to remove sedimentation and vegetation every 2 years by mechanical methods, applying gabions lining to prevent bank erosion, and treating drainage water using wetland system and utilizing the treated wastewater in fish farming.
文摘Background: Surgical wound drainage is practiced routinely by many orthopaedic surgeons despite studies that challenge the practice. Among proponents, the advantages of drainage include prevention of haematoma and/or seroma formation which potentially reduces the chances for infection, prevention of wound swelling, prevention of compartment syndrome and improvement of the local wound environment. Opponents argue that prophylactic wound drainage confers no significant advantages, increases the risk of infection and the need for blood transfusion with the attendant risks of this therapy. Aim: To ascertain if prophylactic drainage of clean orthopaedic wounds confer any significant advantages by evaluating wound and systemic factors in two treatment groups. Patients and Methods: A prospective analysis of 62 patients was undergoing clean orthopaedic procedures. The patients were randomly assigned to a “No drain” (study) group and a “drain” (control) group. Each group had 31 patients. Surgeons were blinded to the randomization process and the evaluation of clinical outcomes. The parameters assessed included pain, superficial wound infection, the need for post-operative transfusion, wound leakage, dressing changes and the surgery-discharge interval. Data was analysed using SPSS statistics version 20 (IBM Corp., New York). Results: There were no significant differences in the demographic data. Femoral fractures were the commonest indication for surgery (43.55%), and plate and screw osteosynthesis was the commonest procedure (48.4% in the drain group and 67.7% in the no-drain group). There was a significantly higher need for post-operative transfusion in the drain group (22.6% against 0%) as well as a significantly prolonged capillary refill time (2.39 + 0.56 secs versus 2.03 + 0.41 secs). Although not statistically significant, there were four cases (12.8%) of superficial wound infection in the drain group and 1 case (3.2%) in the no-drain group. Conclusion: Prophylactic wound drainage confers no significant advantages over no drainage and may contribute to increased treatment costs through an increased post-operative transfusion requirements.
文摘There are some bad impacts from a critical land such as flood in rainy season and dryness in dry season. Long dryness could cause shortage of water for human consumption, industry and agriculture. Prevention has been made to avoid the both bad impacts by building hydraulic structures like reservoirs and ponds in order to reduce the peak flow during the rainy season and to store the water for use during the dry season. However, they gradually become full of sediment. This will make them work insufficiently and will cause high maintenance cost. Moreover, wells in agriculture field used as retention also suffer dryness to make crop failure. This study aims to develop a model of pond for conservation of land and water in non irrigated land. Community participation is crucial in order to solve the flood and dryness problems. The community, especially the farmers will participate actively in the implementation and maintenance of the model. There are benefits in using the pond model such as： （1） to control sediment transport to the rivers, reservoir or other hydraulic structures; （2） to reduce flood rate; （3） to increase ground water recharge; （4） to contain water for agriculture and （5） to control the fertility of land. The cost of making a unit of model （sedrainpond） of 1.5 m diameter and 1.5 meter depth is relatively cheap between $10 to $20 （US）, and the maintenance is done by the farmers. When the pond model becomes functional, besides containing water in the rainy season, the water can be used to sustain water for agriculture in the dry season to avoid any crop failure. When the pond becomes dry, the farmers can harvest the suspended load sediment such as clay or silt to spread onto their land to keep its fertility.
文摘This article aims to study the efficiency of coupled vertical drains for the treatment of long-lasting compressible clay soils for the road project platform of the ring road of Porto Novo, capital of Benin. The experimental data allowed us to estimate a consolidation of 29% in 9 months, justifying the drainage of the soil. In order to study the efficiency of drainage, a FEM model was proposed simulating different scenarios. These include a drainless road, pavements equipped with vertical drains with meshes of 0.5 m 0.5 m, 1 m 1 m and 1.5 m 1.5 m respectively and horizontal drains. The results expressed in terms of variations in vertical stresses, effective stresses and shear deformations revealed significant variations in pavement performance depending on the mesh size of the vertical drains. The configuration with a mesh of 0.5 m 0.5 m showed the least deformations, thus indicating a reduction in deformations and better stress distribution. However, the other mesh configurations showed variable results, underlining the importance of choosing the right mesh for the specific project conditions.
文摘AIM:To conduct a meta-analysis comparing outcomes after pancreaticoduodenectomy(PD)with or without prophylactic drainage.METHODS:Relevant comparative randomized and nonrandomized studies were systemically searched based on specific inclusion and exclusion criteria.Postoperative outcomes were compared between patients with and those without routine drainage.Pooled odds ratios(OR)with 95%CI were calculated using either fixed effects or random effects models.RESULTS:One randomized controlled trial and four non-randomized comparative studies recruiting 1728patients were analyzed.Patients without prophylactic drainage after PD had significantly higher mortality(OR=2.32,95%CI:1.11-4.85;P=0.02),despite the fact that they were associated with fewer overall complications(OR=0.62,95%CI:0.48-0.82;P=0.00),major complications(OR=0.75,95%CI:0.60-0.93;P=0.01)and readmissions(OR=0.77,95%CI:0.60-0.98;P=0.04).There were no significant differences in the rates of pancreatic fistula,intraabdominal abscesses,postpancreatectomy hemorrhage,biliary fistula,delayed gastric emptying,reoperation or radiologic-guided drains between the two groups.CONCLUSION:Indiscriminate abandonment of intraabdominal drainage following PD is associated with greater mortality,but lower complication rates.Future randomized trials should compare routine vs selective drainage.
基金funded by the Engineering and Physical Sciences Research Council, UK (Grant No.GR/R91588)
文摘Three dimensional （3D） DEM （discrete element method） simulations of drained triaxial compression and plane strain tests are presented for both dense and loose assemblies of polydisperse spheres using a periodic cell. In the work reported, drained tests were modelled by deforming the samples under constant mean stress conditions. The drained behaviour is shown to be qualitatively similar to published physical experimental results. The Bishop＇s formula for the estimation of the intermediate principal stress is evaluated. The existence of critical density is shown to be independent of initial packing densities and strain conditions. Different failure criteria have been compared based on the DEM simulation results, and the Lade criterion is found to be the most appropriate one. A new microscopic fabric parameter is introduced to give insight to structural anisotropy under general 3D fabric conditions. It is found that two parameters characterize the evolution of the stress and fabric respectively independent of strain conditions.
