Objective:The management of urethral stricture disease depends on the location,length of stricture,and associated urethral pathology.These parameters are obtained from preoperative imaging,with conventional urethrogra...Objective:The management of urethral stricture disease depends on the location,length of stricture,and associated urethral pathology.These parameters are obtained from preoperative imaging,with conventional urethrogram(retrograde urethrogram and micturating cystourethrogram[RGU/MCU])being the diagnostic tool of choice despite its many shortcomings.Sono-urethrogram(SUG)is an alternative that addresses most issues of RGU/MCU.Studies comparing RGU/MCU with SUG are limited.With the objective of comparing these two imaging modalities in the evaluation of urethral stricture disease,a prospective study was conducted.Methods:Fifty-six patients suspected of urethral stricture disease on clinical evaluation and confirmed either on RGU/MCU or urethro-cystoscopy were included in the study.SUG was performed by the experienced consultant radiologist who was blinded to the report of RGU/MCU.Findings of RGU/MCU and SUG were compared to intraoperative findings,which served as the reference standard.Results:The median length of the stricture determined intraoperatively was 16.5 mm,by RGU/MCU was 5.8 mm,and by SUG was 13.5 mm.The diagnostic accuracy for determination of the stricture location was 93%for RGU/MCU and 98%for SUG.SUG identified spongiofibrosis in 90%of patients with higher accuracy for the severe degree of spongiofibrosis.Conclusion:SUG has been shown to be more accurate than RGU/MCU in estimating stricture length(both short and intermediate)and localizing the stricture location.Use of SUG in conjunction with RGU/MCU helps in better guidance of stricture management by improving preoperative assessment.Further studies with larger sample sizes are warranted.展开更多
Objective and Background Early and accurate diagnosis of spinal infections,including spinal tuberculosis,is pivotal for effective treatment but remains challenging.This study aims to assess the diagnostic yield of met...Objective and Background Early and accurate diagnosis of spinal infections,including spinal tuberculosis,is pivotal for effective treatment but remains challenging.This study aims to assess the diagnostic yield of metagenomic next-generation sequencing(mNGS)compared with that of conventional microbiological tests(CMTs)in identifying pathogens associated with spinal pathologies,with a special focus on infections leading to surgical interventions.Methods We enrolled 85 patients who underwent spinal surgery,comprising 63 patients with clinically diagnosed spinal infections,including patients with spinal tuberculosis,and 22 patients with noninfectious spinal conditions.The procedures involved irrigation and debridement for persistent wound drainage,with subsequent DNA extraction from plasma and joint fluid for mNGS and CMT analysis.Results Significantly increased C-reactive protein(CRP)levels were observed in patients with infections.The mNGS approach showed greater diagnostic sensitivity(92.06%)for detecting pathogens,including Mycobacterium tuberculosis,than did CMTs(36.51%).Despite its low specificity,mNGS had considerable negative predictive value(70.59%),underscoring its utility in ruling out infections.Conclusions The mNGS offers superior sensitivity over CMTs in the diagnosis of a variety of spinal infections,notably spinal tuberculosis.This study highlights the potential of mNGS in enhancing the diagnosis of complex spinal infections,thereby informing targeted treatment strategies.展开更多
Based on the petroleum exploration in the Cretaceous Qingshankou Formation,northern Songliao Basin,NE China,integrated with seismic,drilling and logging data,this study investigates the characteristics and genetic mec...Based on the petroleum exploration in the Cretaceous Qingshankou Formation,northern Songliao Basin,NE China,integrated with seismic,drilling and logging data,this study investigates the characteristics and genetic mechanisms of orderly distribution and the differential enrichment patterns of conventional and unconventional hydrocarbons in the formation.Key findings involve five aspects.First,the conventional and unconventional hydrocarbons coexist orderly.Laterally,conventional oil,tight oil,and shale oil form a pattern of orderly accumulation from basin margins to the center.Vertically,shale oil,tight oil,and conventional oil develop progressively upward.Second,the coupled tectonic-sedimentary processes govern sedimentary facies differentiation and diagenesis,influencing reservoir physical properties and lithology,thereby controlling the orderly distribution of conventional and unconventional hydrocarbons in space.Third,the coupling of source rock hydrocarbon generation evolution,fault sealing capacity,and reservoir densification determines the orderly coexistence pattern of conventional and unconventional hydrocarbons.Fourth,sequential variations in reservoir physical properties generate distinct dynamic fields that regulate hydrocarbon orderly accumulation.Fifth,enrichment controls are different depending on hydrocarbon types:buoyancy-driven,fault-transport,sandbody-connected,and trap-concentrated,for above-source conventional oil;overpressure-driven,fault-transport,multi-stacked sandbodies,and quasi-continuous distribution for near-source tight oil and gas;self-sourced reservoirs,retention through self-sealing,in-situ accumulation or micro-migration driven by hydrocarbon-generation overpressure for inner-source shale oil.From exploration practices,these findings will effectively guide the integrated deployment and three-dimensional exploration of conventional and unconventional hydrocarbon resources in the Qingshankou Formation,northern Songliao Basin.展开更多
Diaphragmatic function is central to respiration,and its evaluation is critical in intensive care unit(ICU)settings.Ultrasonography is a reliable bedside tool to assess diaphragmatic excursion(DE).[1,2]The conventiona...Diaphragmatic function is central to respiration,and its evaluation is critical in intensive care unit(ICU)settings.Ultrasonography is a reliable bedside tool to assess diaphragmatic excursion(DE).[1,2]The conventional M-mode(MM)offers high-resolution imaging but requires precise alignment,which can be diffi cult in ICU patients.[3-5]Anatomical M-mode(AMM)allows flexible line adjustment,enabling accurate DE measurements despite poor acoustic windows.[6]However,comparative data between MM and AMM are limited.This retrospective study evaluated the concordance between MM and AMM for assessing right DE.展开更多
Pore pressure is a decisive measure to assess the reservoir’s geomechanical properties,ensures safe and efficient drilling operations,and optimizes reservoir characterization and production.The conventional approache...Pore pressure is a decisive measure to assess the reservoir’s geomechanical properties,ensures safe and efficient drilling operations,and optimizes reservoir characterization and production.The conventional approaches sometimes fail to comprehend complex and persistent relationships between pore pressure and formation properties in the heterogeneous reservoirs.This study presents a novel machine learning optimized pore pressure prediction method with a limited dataset,particularly in complex formations.The method addresses the conventional approach's limitations by leveraging its capability to learn complex data relationships.It integrates the best Gradient Boosting Regressor(GBR)algorithm to model pore pressure at wells and later utilizes ContinuousWavelet Transformation(CWT)of the seismic dataset for spatial analysis,and finally employs Deep Neural Network for robust and precise pore pressure modeling for the whole volume.In the second stage,for the spatial variations of pore pressure in the thin Khadro Formation sand reservoir across the entire subsurface area,a three-dimensional pore pressure prediction is conducted using CWT.The relationship between the CWT and geomechanical properties is then established through supervised machine learning models on well locations to predict the uncertainties in pore pressure.Among all intelligent regression techniques developed using petrophysical and elastic properties for pore pressure prediction,the GBR has provided exceptional results that have been validated by evaluation metrics based on the R^(2) score i.e.,0.91 between the calibrated and predicted pore pressure.Via the deep neural network,the relationship between CWT resultant traces and predicted pore pressure is established to analyze the spatial variation.展开更多
[Objective] The study aimed to confirm difference of nitrogen uptake and used efficiency with different nitrogen use efficiency for grain output (NUEg) types of indica rice.[Method] 88 and 122 conventional indica rice...[Objective] The study aimed to confirm difference of nitrogen uptake and used efficiency with different nitrogen use efficiency for grain output (NUEg) types of indica rice.[Method] 88 and 122 conventional indica rice cultivars were solution-cultured in 2001 and 2002, respectively. Dry matter weight (including root system, culm and sheath, leaves, panicle), nitrogen content of different organs, yield and its components were measured. The tested rice cultivars were classified into 6 types (i.e. A, B, C, D, E and F, A was the lowest, and F was the highest) based on their NUEg level by the MinSSw method.[Result](1)Difference of NUEg of the cultivars used in this study were very large; (2) No significant difference of N content at heading stage was observed among different NUEg types of indica rice. In the cultivars with higher NUEg, however, N content in leaf, stem-sheath and entire rice plant were lower at mature stage. (3)Cultivars with higher NUEg were characterized with lower N uptake before heading and at mature stage; (4) Cultivars with higher NUEg were characterized with higher N use efficiency in biomass production and harvest index. [Conclusion] The cultivars with higher NUEg showed lower N uptake and N content, while nitrogen use efficiency was higher.展开更多
Tumor models were simulated in purebred Beagles at the T9-10 levels of the spinal cord and treated with spinal image-guided radiation therapy or conventional radiation therapy with 50 or 70 Gy total radiation. Three m...Tumor models were simulated in purebred Beagles at the T9-10 levels of the spinal cord and treated with spinal image-guided radiation therapy or conventional radiation therapy with 50 or 70 Gy total radiation. Three months after radiation, neuronal injury at the T9-10 levels was observed, including reversible injury induced by spinal image-guided radiation therapy and apoptosis induced by conventional radiation therapy. The number of apoptotic cells and expression of the proapoptotic protein Fas were significantly reduced, but expression of the anti-apoptotic protein heat shock protein 70 was significantly increased after image-guided radiation therapy compared with the conventional method of the same radiation dose. Moreover, the spinal cord cell apoptotic index positively correlated with the ratio of Fas/heat shock protein 70. These findings indicate that 3 months of radiation therapy can induce a late response in the spinal cord to radiation therapy; image-guided radiation therapy is safer and results in less neuronal injury compared with conventional radiation therapy.展开更多
This systematic review assessed the safety and efficacy of the disposable circumcision suture device （DCSD） and conventional circumcision （CC） in the treatment of redundant prepuce and phimosis. Two independent re...This systematic review assessed the safety and efficacy of the disposable circumcision suture device （DCSD） and conventional circumcision （CC） in the treatment of redundant prepuce and phimosis. Two independent reviewers conducted a literature search for randomized controlled trials （RCTs） using the DCSD and CC for the treatment of redundant prepuce or phimosis in China and abroad. Nine RCTs （1898 cases） were included. Compared with the CC group, the DCSD group had a shorter operative time （standardized mean difference [SMD] = -21.44; 95% confidence intervals [95% CIs] [-25.08, -17.79]; P 〈 0.00001）, shorter wound healing time （SMD = -3.66; 95% CI [-5.46, -1.85]; P 〈 0.0001）, less intraoperative blood loss （SMD = -9.64; 95% CI [-11.37, -7.90]; P 〈 0.00001）, better cosmetic penile appearance （odds ratio [OR] =8.77; 95% CI [5.90, 13.02]; P 〈 0.00001）, lower intraoperative pain score, lower 24-h postoperative pain score, lower incidence of infection, less incision edema, and fewer adverse events. There were no differences between the CC and DCSD groups in the incidences of dehiscence, or hematoma. The results of this meta-analysis indicate that the DCSD appears to be safer and more effective than CC. However, additional high-quality RCTs with larger study populations are needed.展开更多
AIM： To evaluate the sensitivity and specificity of MR colonography （MRC） and CT performance in detecting colon lesions, and to compare their sensitivity and specificity with that of conventional colonoscopy. METH...AIM： To evaluate the sensitivity and specificity of MR colonography （MRC） and CT performance in detecting colon lesions, and to compare their sensitivity and specificity with that of conventional colonoscopy. METHODS： Forty-two patients suspected of having colonic lesions, because of rectal bleeding, positive fecal occult blood test results or altered bowel habits, underwent the examinations. After insertion of a rectal tube, the colon was filled with 1000-1500 mL of a mixture of 9 g/L NaCI solution, 15-20 mL of 0.5 mmol/L gadopentetate dimeglumine and 100 mL of iodinized contrast material. Once colonic distension was achieved, three-dimensional gradient-echo （3D-GRE） sequences for MR colonography and complementary MR images were taken in all cases. Immediately after MR colonography, abdominal CT images were taken by spiral CT in the axial and supine position. Then all patients were examined by conventional colonoscopy （CC）. RESULTS： The sensitivity and specificity of MRC for colon pathologies were 96.4% and 100%, respectively. The percentage of correct diagnosis by MRC was 97.6%. The sensitivity and specificity of CT for colon pathologies were 92.8%, 100%, respectively. The percentage of correct diagnosis by CT was 95.2%. CONCLUSION： In detecting colon lesions, MRC achieved a diagnostic accuracy similar to CC. However, MRC is minimally invasive, with no need for sedation or analgesics during investigation. There is a lower percentage of perforation risk, and all colon segments can be evaluated due to multi-sectional imaging availability; intramural, extra-intestinal components of colonic lesions, metastasis and any additional lesions can be evaluated easily. MRC and CT colonography are new radiological techniques that promise to be highly sensitive in the detection of colorectal mass and inflammatory bowel lesions.展开更多
Understanding the effects of warming on greenhouse gas（GHG, such as N2O, CH4 and CO2 ）feedbacks to climate change represents the major environmental issue. However, little information is available on how warming eff...Understanding the effects of warming on greenhouse gas（GHG, such as N2O, CH4 and CO2 ）feedbacks to climate change represents the major environmental issue. However, little information is available on how warming effects on GHG fluxes in farmland of North China Plain（NCP）. An infrared warming simulation experiment was used to assess the responses of N2O, CH4 and CO2 to warming in wheat season of 2012–2014 from conventional tillage（CT） and no-tillage（NT） systems. The results showed that warming increased cumulative N2O emission by 7.7% in CT but decreased it by 9.7% in NT fields（p 〈 0.05）. Cumulative CH4 uptake and CO2 emission were increased by 28.7%–51.7% and 6.3%–15.9% in both two tillage systems,respectively（p 〈 0.05）. The stepwise regressions relationship between GHG fluxes and soil temperature and soil moisture indicated that the supply soil moisture due to irrigation and precipitation would enhance the positive warming effects on GHG fluxes in two wheat seasons.However, in 2013, the long-term drought stress due to infrared warming and less precipitation decreased N2O and CO2 emission in warmed treatments. In contrast, warming during this time increased CH4 emission from deep soil depth. Across two years wheat seasons, warming significantly decreased by 30.3% and 63.9% sustained-flux global warming potential（SGWP） of N2O and CH4 expressed as CO2 equivalent in CT and NT fields, respectively. However, increase in soil CO2 emission indicated that future warming projection might provide positive feedback between soil C release and global warming in NCP.展开更多
The purpose of this study was to compare the biomechanical stability obtained by using our technique featured an anatomical plate and compression bolts versus that of the conventional anatomic plate and cancellous scr...The purpose of this study was to compare the biomechanical stability obtained by using our technique featured an anatomical plate and compression bolts versus that of the conventional anatomic plate and cancellous screws in the fixation of intraarticular calcaneal fractures.Eighteen fresh frozen lower limbs of cadavers were used to create a reproductive Sanders type-Ⅲ calcaneal fracture model by using osteotomy.The calcaneus fractures were randomly selected to be fixed either using our anatomical plate and compression bolts or conventional anatomic plate and cancellous screws.Reduction of fracture was evaluated through X radiographs.Each calcaneus was successively loaded at a frequency of 1 Hz for 1000 cycles through the talus using an increasing axial force 20 N to 200 N and 20 N to 700 N,representing the partial weight bearing and full weight bearing,respectively,and then the specimens were loaded to failure.Data extracted from the mechanical testing machine were recorded and used to test for difference in the results with the Wilcoxon signed rank test.No significant difference was found between our fixation technique and conventional technique in displacement during 20-200 N cyclic loading(P=0.06),while the anatomical plate and compression bolts showed a great lower irreversible deformation during 20-700 N cyclic loading(P=0.008).The load achieved at loss of fixation of the constructs for the two groups had significant difference:anatomic plate and compression bolts at 3839.6±152.4 N and anatomic plate and cancellous screws at 3087.3±58.9 N(P=0.008).There was no significant difference between the ultimate displacements.Our technique featured anatomical plate and compression bolts for calcaneus fracture fixation was demonstrated to provide biomechanical stability as good as or better than the conventional anatomic plate and cancellous screws under the axial loading.The study supports the mechanical viability of using our plate and compression bolts for the fixation of calcaneal fracture.展开更多
Time-dependent diffusion coefficient and conventional diffusion constant are calculated and analyzed to study diffusion of nanoparticles in polymer melts. A generalized Langevin equa- tion is adopted to describe the d...Time-dependent diffusion coefficient and conventional diffusion constant are calculated and analyzed to study diffusion of nanoparticles in polymer melts. A generalized Langevin equa- tion is adopted to describe the diffusion dynamics. Mode-coupling theory is employed to calculate the memory kernel of friction. For simplicity, only microscopic terms arising from binary collision and coupling to the solvent density fluctuation are included in the formalism. The equilibrium structural information functions of the polymer nanocomposites required by mode-coupling theory are calculated on the basis of polymer reference interaction site model with Percus-Yevick closure. The effect of nanoparticle size and that of the polymer size are clarified explicitly. The structural functions, the friction kernel, as well as the diffusion coefficient show a rich variety with varying nanoparticle radius and polymer chain length. We find that for small nanoparticles or short chain polymers, the characteristic short time non-Markov diffusion dynamics becomes more prominent, and the diffusion coefficient takes longer time to approach asymptotically the conventional diffusion constant. This constant due to the microscopic contributions will decrease with the increase of nanoparticle size, while increase with polymer size. Furthermore, our result of diffusion constant from mode- coupling theory is compared with the value predicted from the Stokes-Einstein relation. It shows that the microscopic contributions to the diffusion constant are dominant for small nanoparticles or long chain polymers. Inversely, when nanonparticle is big, or polymer chain is short, the hydrodynamic contribution might play a significant role.展开更多
This paper presents a substructure online hybrid test system that is extensible for geographically distributed tests. This system consists of a set of devices conventionally used for cyclic tests to load the tested su...This paper presents a substructure online hybrid test system that is extensible for geographically distributed tests. This system consists of a set of devices conventionally used for cyclic tests to load the tested substructures onto the target displacement or the target force. Due to their robustness and portability, individual sets of conventional loading devices can be transported and reconfigured to realize physical loading in geographically remote laboratories. Another appealing feature is the flexible displacement-force mixed control that is particularly suitable for specimens having large disparities in stiffness during various performance stages. To conduct a substructure online hybrid test, an extensible framework is developed, which is equipped with a generalized interface to encapsulate each substructure. Multiple tested substructures and analyzed substructures using various structural program codes can be accommodated within the single framework, simply interfaced with the boundary displacements and forces. A coordinator program is developed to keep the boundaries among all substructures compatible and equilibrated. An Interuet-based data exchange scheme is also devised to transfer data among computers equipped with different software environments. A series of online hybrid tests are introduced, and the portability, flexibility, and extensibility of the online hybrid test system are demonstrated.展开更多
Objective: To compare the effects and safety of conventional transarterial chemoembolization(c TACE) and yttrium-90 transarterial radioembolization [TARE(90 Y)] for hepatocellular carcinoma(HCC)Methods: Nine high-qual...Objective: To compare the effects and safety of conventional transarterial chemoembolization(c TACE) and yttrium-90 transarterial radioembolization [TARE(90 Y)] for hepatocellular carcinoma(HCC)Methods: Nine high-quality observational studies, one low bias-risk randomized controlled trial(RCT), and one moderate biasrisk RCT included 1,652 patients [c TACE, 1,124; TARE(90 Y), 528], from whom data were extracted for this systematic review and meta-analysis.Results: The extracted study outcomes included 1-year and 2-year overall survival(OS) rates, objective responses(ORs), and serious adverse events(AEs). 1-year OS rates: OR = 0.939, 95 % CI: 0.705-1.251, P = 0.66. 2-year OS rates: overall pooled OR =0.641, 95% CI: 0.382-1.075, P = 0.092; observational study subgroup OR = 0.575, 95% CI: 0.336-0.984, P = 0.043; RCT subgroup OR* = 0.641, 95% CI: 0.382-1.075, P = 0.346. OR: overall pooled OR = 0.781, 95% CI: 0.454-1.343, P = 0.371; m RECIST subgroup OR = 0.584, 95 % CI: 0.349-0.976, P = 0.040; WHO subgroup OR = 1.065; 95% CI: 0.500-2.268, P = 0.870. Serious AEs: overall pooled RR = 1.477, 95% CI: 0.864-2.526, P = 0.154; RCT subgroup RR = 0.680, 95% CI: 0.325-1.423, P = 0.306; observational study subgroup RR = 1.925; 95 % CI: 0.978-3.788, P = 0.058.Conclusions: TARE(90 Y) increased 2-year OS rates in the observational subgroup and resulted in better OR rates, according to m RECIST criteria, in comparison with c TACE. Furthermore, a lower risk of AEs was observed for TARE(90 Y) than for c TACE.展开更多
BACKGROUND Varicosis is a common venous condition,which is typically treated surgically.However,selection of the optimal surgical approach can be challenging.Previous studies comparing endovenous laser treatment(EVLT)...BACKGROUND Varicosis is a common venous condition,which is typically treated surgically.However,selection of the optimal surgical approach can be challenging.Previous studies comparing endovenous laser treatment(EVLT)and conventional surgery were retrospective and observational in nature and the results may therefore have been influenced by selection bias and the presence of other confounding factors.In this study,we used propensity score matching to reduce selection bias when comparing EVLT and conventional surgery for the treatment of varicose great saphenous veins.METHODS We retrospectively reviewed the records of 1063 patients treated for primary varicosis of the great saphenous vein at the Second Affiliated Hospital of Xuzhou Medical University between January 2009 and December 2019.Among them,56 patients were excluded owing to additional small saphenous varicose vein involvement,81 owing to recurring varicose veins,83 owing to complicated varicose veins(CEAP clinical classification C5-C6),and 6 owing to perioperative phlebitis.Finally,772 patients were enrolled in this study.Standard demographic and clinicopathological data were collected from the medical records of the patients.For propensity score matching,522 patients(261 who underwent EVLT and 261 who underwent conventional surgery)were randomly matched 1:1 by age,sex,onset time,smoking status,presence of diabetes,family history,stress therapy,C class,and the affected leg.RESULTS Of the 772 patients included in the study,467 underwent EVLT and 305 underwent conventional surgery.There were significant differences in age,onset time,smoking and diabetes status,and family history between the two groups.Following propensity score matching,no significant differences in patients’characteristics remained between the two groups.ELVT was associated with a shorter operation time and hospital stay than conventional surgery,both before and after propensity score matching.There were no differences in complications between the two groups after propensity score matching.Patients who underwent EVLT had a higher recurrence rate during the two-year follow-up period than those who underwent conventional surgery(33.33%vs 21.46%,χ^(2)=11.506,P=0.001),and a greater percentage of patients who underwent EVLT experienced pain one week after the procedure(39.85%vs 19.54%,P=0.000).CONCLUSION EVLT may not always be the best option for the treatment of great saphenous vein varicosis.展开更多
In China, regions with abundant wind energy resources are generally located at the end of power grids. The power grid architecture in these regions is typically not sufficiently strong, and the energy structure is rel...In China, regions with abundant wind energy resources are generally located at the end of power grids. The power grid architecture in these regions is typically not sufficiently strong, and the energy structure is relatively simple. Thus, connecting large-capacity wind power units complicates the peak load regulation and stable operation of the power grids in these regions. Most wind turbines use power electronic converter technology, which affects the safety and stability of the power grid differently compared with conventional synchronous generators. Furthermore, fluctuations in wind power cause fluctuations in the output of wind farms, making it difficult to create and implement suitable power generation plans for wind farms. The generation technology and grid connection scheme for wind power and conventional thermal power generation differ considerably. Moreover, the active and reactive power control abilities of wind turbines are weaker than those of thermal power units, necessitating additional equipment to control wind turbines. Hence, to address the aforementioned issues with large-scale wind power generation, this study analyzes the differences between the grid connection and collection strategies for wind power bases and thermal power plants. Based on this analysis, the differences in the power control modes of wind power and thermal power are further investigated. Finally, the stability of different control modes is analyzed through simulation. The findings can be beneficial for the planning and development of large-scale wind power generation farms.展开更多
Soil samples at 0-10 cm in depth were collected periodically at paired fields in Corvallis, Oregon, USA to compare differences in soil microbial and faunal populations between organic and conventional agroecosystems. ...Soil samples at 0-10 cm in depth were collected periodically at paired fields in Corvallis, Oregon, USA to compare differences in soil microbial and faunal populations between organic and conventional agroecosystems. Results showed that the organic soil ecosystem had a significantly higher (P < 0.05) average number or biomass of soil bacteria; densities of flagellates, amoebae of protozoa; some nematodes, such as microbivorous and predaceous nematodes and plant-parasitic nematodes; as well as Collembola. Greater numbers of Rhabditida (such as Rhabditis spp.), were present in the organic soil ecosystem while Panagrolaimus spp. were predominant in the conventional soil ecosystem. The omnivores and predators of Acarina in the Mesostigmata (such as Digamasellidae and Laelapid), and Prostigmata (such as Alicorhaiidae and Rhagidiidae), were also more abundant in the organic soil ecosystem. However, fungivorous Prostigmata (such as Terpnacaridae and Nanorchestidae) and Astigmata (such as Acarida) were significantly higher (P < 0.05) in the conventional soil ecosystem, which supported the finding that total fungal biomass was greater in the conventional soil ecosystem. Seansonal variations of the population depended mostly on soil moisture condition and food web relationship. The population declined from May to October for both agroecosystems. However, higher diversities and densities of soil biota survived occurred in the organic soil ecosystem in the dry season.展开更多
Recently,peroral direct cholangioscopy(PDCS) using an ultra-slim endoscope has come into the spotlight.However,the working channel is too small to use various devices for lithotripsy.We report a case of endoscopic lit...Recently,peroral direct cholangioscopy(PDCS) using an ultra-slim endoscope has come into the spotlight.However,the working channel is too small to use various devices for lithotripsy.We report a case of endoscopic lithotripsy with PDCS using a conventional endoscope as a cholangioscope.Computed tomography scan on an 80-year-old female who was admitted with acute cholangitis showed two large stones in the bile duct.Endoscopic retrograde cholangiopancreatography was attempted first.However,mechanical lithotripsy failed because the stone was too large for the basket catheter.Finally,electric hydraulic lithotripsy with PDCS using a conventional endoscope was performed allowed the stones to be cleared completely.In conclusion,PDCS using a conventional endoscope can be an alternative solution for endoscopic lithotripsy for patients with large stones in the dilated bile duct.展开更多
Fractures are of great significance to tight oil and gas development.Fracture identification using conventional well logs is a feasible way to locate the underground fractures in tight sandstones.However,there are thr...Fractures are of great significance to tight oil and gas development.Fracture identification using conventional well logs is a feasible way to locate the underground fractures in tight sandstones.However,there are three problems affecting its interpretation accuracy and practical application,namely weak well log responses of fractures,a lack of specific logs for fracture prediction,and relative change omission in log responses.To overcome these problems and improve fracture identification accuracy,a fracture indicating parameter(FIP)method composed of a comprehensive index method(CIM)and a comprehensive fractal method(CFM)is introduced.The CIM tries to handle the first problem by amplifying log responses of fractures.The CFM addresses the third one using fractal dimensions.The flexible weight parameters corresponding to logs in the CIM and CFM make the interpretation possible for wells lacking specific logs.The reconstructed logs in the CIM and CFM try to solve the second problem.It is noted that the FIP method can calculate the probability of fracture development at a certain depth,but cannot show the fracture development degree of a new well compared with other wells.In this study,a formation fracture intensity(FFI)method is also introduced to further evaluate fracture development combined with production data.To test the validity of the FIP and FFI methods,fracture identification experiments are implemented in a tight reservoir in the Ordos Basin.The results are consistent with the data of rock core observation and production,indicating the proposed methods are effective for fracture identification and evaluation.展开更多
Heteroarm star-shaped polymers were synthesized by conventional free radical polymerization in two steps by the use of polyfunctional chain transfer agent.In the first step,free radical polymerization of methyl methac...Heteroarm star-shaped polymers were synthesized by conventional free radical polymerization in two steps by the use of polyfunctional chain transfer agent.In the first step,free radical polymerization of methyl methacrylate was carried out in the presence of a polyfunctional chain transfer agent,pentaerythritol tetrakis(3-mercaptopropinate).At appropriate monomer conversions,two-arm PMMA having two residual thiol groups at the chain center or three-arm PMMA having one residual thiol group at the core were o...展开更多
文摘Objective:The management of urethral stricture disease depends on the location,length of stricture,and associated urethral pathology.These parameters are obtained from preoperative imaging,with conventional urethrogram(retrograde urethrogram and micturating cystourethrogram[RGU/MCU])being the diagnostic tool of choice despite its many shortcomings.Sono-urethrogram(SUG)is an alternative that addresses most issues of RGU/MCU.Studies comparing RGU/MCU with SUG are limited.With the objective of comparing these two imaging modalities in the evaluation of urethral stricture disease,a prospective study was conducted.Methods:Fifty-six patients suspected of urethral stricture disease on clinical evaluation and confirmed either on RGU/MCU or urethro-cystoscopy were included in the study.SUG was performed by the experienced consultant radiologist who was blinded to the report of RGU/MCU.Findings of RGU/MCU and SUG were compared to intraoperative findings,which served as the reference standard.Results:The median length of the stricture determined intraoperatively was 16.5 mm,by RGU/MCU was 5.8 mm,and by SUG was 13.5 mm.The diagnostic accuracy for determination of the stricture location was 93%for RGU/MCU and 98%for SUG.SUG identified spongiofibrosis in 90%of patients with higher accuracy for the severe degree of spongiofibrosis.Conclusion:SUG has been shown to be more accurate than RGU/MCU in estimating stricture length(both short and intermediate)and localizing the stricture location.Use of SUG in conjunction with RGU/MCU helps in better guidance of stricture management by improving preoperative assessment.Further studies with larger sample sizes are warranted.
基金supported by the Hubei Provincial Natural Science Foundation of China(No.2023AFB646)Knowledge Innovation Program of Wuhan(No.2023020201010155)Educational Research Program of Huazhong University of Science and Technology(No.2022135).
文摘Objective and Background Early and accurate diagnosis of spinal infections,including spinal tuberculosis,is pivotal for effective treatment but remains challenging.This study aims to assess the diagnostic yield of metagenomic next-generation sequencing(mNGS)compared with that of conventional microbiological tests(CMTs)in identifying pathogens associated with spinal pathologies,with a special focus on infections leading to surgical interventions.Methods We enrolled 85 patients who underwent spinal surgery,comprising 63 patients with clinically diagnosed spinal infections,including patients with spinal tuberculosis,and 22 patients with noninfectious spinal conditions.The procedures involved irrigation and debridement for persistent wound drainage,with subsequent DNA extraction from plasma and joint fluid for mNGS and CMT analysis.Results Significantly increased C-reactive protein(CRP)levels were observed in patients with infections.The mNGS approach showed greater diagnostic sensitivity(92.06%)for detecting pathogens,including Mycobacterium tuberculosis,than did CMTs(36.51%).Despite its low specificity,mNGS had considerable negative predictive value(70.59%),underscoring its utility in ruling out infections.Conclusions The mNGS offers superior sensitivity over CMTs in the diagnosis of a variety of spinal infections,notably spinal tuberculosis.This study highlights the potential of mNGS in enhancing the diagnosis of complex spinal infections,thereby informing targeted treatment strategies.
基金Supported by the PetroChina Science and Technology Major Project(2023ZZ15).
文摘Based on the petroleum exploration in the Cretaceous Qingshankou Formation,northern Songliao Basin,NE China,integrated with seismic,drilling and logging data,this study investigates the characteristics and genetic mechanisms of orderly distribution and the differential enrichment patterns of conventional and unconventional hydrocarbons in the formation.Key findings involve five aspects.First,the conventional and unconventional hydrocarbons coexist orderly.Laterally,conventional oil,tight oil,and shale oil form a pattern of orderly accumulation from basin margins to the center.Vertically,shale oil,tight oil,and conventional oil develop progressively upward.Second,the coupled tectonic-sedimentary processes govern sedimentary facies differentiation and diagenesis,influencing reservoir physical properties and lithology,thereby controlling the orderly distribution of conventional and unconventional hydrocarbons in space.Third,the coupling of source rock hydrocarbon generation evolution,fault sealing capacity,and reservoir densification determines the orderly coexistence pattern of conventional and unconventional hydrocarbons.Fourth,sequential variations in reservoir physical properties generate distinct dynamic fields that regulate hydrocarbon orderly accumulation.Fifth,enrichment controls are different depending on hydrocarbon types:buoyancy-driven,fault-transport,sandbody-connected,and trap-concentrated,for above-source conventional oil;overpressure-driven,fault-transport,multi-stacked sandbodies,and quasi-continuous distribution for near-source tight oil and gas;self-sourced reservoirs,retention through self-sealing,in-situ accumulation or micro-migration driven by hydrocarbon-generation overpressure for inner-source shale oil.From exploration practices,these findings will effectively guide the integrated deployment and three-dimensional exploration of conventional and unconventional hydrocarbon resources in the Qingshankou Formation,northern Songliao Basin.
文摘Diaphragmatic function is central to respiration,and its evaluation is critical in intensive care unit(ICU)settings.Ultrasonography is a reliable bedside tool to assess diaphragmatic excursion(DE).[1,2]The conventional M-mode(MM)offers high-resolution imaging but requires precise alignment,which can be diffi cult in ICU patients.[3-5]Anatomical M-mode(AMM)allows flexible line adjustment,enabling accurate DE measurements despite poor acoustic windows.[6]However,comparative data between MM and AMM are limited.This retrospective study evaluated the concordance between MM and AMM for assessing right DE.
基金funded by the Basic Science Centre Project of the National Natural Science Foundation of China(Grant No.72088101)supported by the Higher Education Commission,Pakistan(Grant No.20-14925/NRPU/R&D/HEC/2021-2021)+1 种基金the Researchers Supporting Project Number(Grant No.RSP2025R351)King Saud University,Riyadh,Saudi Arabia,for funding this research article.
文摘Pore pressure is a decisive measure to assess the reservoir’s geomechanical properties,ensures safe and efficient drilling operations,and optimizes reservoir characterization and production.The conventional approaches sometimes fail to comprehend complex and persistent relationships between pore pressure and formation properties in the heterogeneous reservoirs.This study presents a novel machine learning optimized pore pressure prediction method with a limited dataset,particularly in complex formations.The method addresses the conventional approach's limitations by leveraging its capability to learn complex data relationships.It integrates the best Gradient Boosting Regressor(GBR)algorithm to model pore pressure at wells and later utilizes ContinuousWavelet Transformation(CWT)of the seismic dataset for spatial analysis,and finally employs Deep Neural Network for robust and precise pore pressure modeling for the whole volume.In the second stage,for the spatial variations of pore pressure in the thin Khadro Formation sand reservoir across the entire subsurface area,a three-dimensional pore pressure prediction is conducted using CWT.The relationship between the CWT and geomechanical properties is then established through supervised machine learning models on well locations to predict the uncertainties in pore pressure.Among all intelligent regression techniques developed using petrophysical and elastic properties for pore pressure prediction,the GBR has provided exceptional results that have been validated by evaluation metrics based on the R^(2) score i.e.,0.91 between the calibrated and predicted pore pressure.Via the deep neural network,the relationship between CWT resultant traces and predicted pore pressure is established to analyze the spatial variation.
基金Supported by the National Natural Science Foundation of China(30270777,30471013)~~
文摘[Objective] The study aimed to confirm difference of nitrogen uptake and used efficiency with different nitrogen use efficiency for grain output (NUEg) types of indica rice.[Method] 88 and 122 conventional indica rice cultivars were solution-cultured in 2001 and 2002, respectively. Dry matter weight (including root system, culm and sheath, leaves, panicle), nitrogen content of different organs, yield and its components were measured. The tested rice cultivars were classified into 6 types (i.e. A, B, C, D, E and F, A was the lowest, and F was the highest) based on their NUEg level by the MinSSw method.[Result](1)Difference of NUEg of the cultivars used in this study were very large; (2) No significant difference of N content at heading stage was observed among different NUEg types of indica rice. In the cultivars with higher NUEg, however, N content in leaf, stem-sheath and entire rice plant were lower at mature stage. (3)Cultivars with higher NUEg were characterized with lower N uptake before heading and at mature stage; (4) Cultivars with higher NUEg were characterized with higher N use efficiency in biomass production and harvest index. [Conclusion] The cultivars with higher NUEg showed lower N uptake and N content, while nitrogen use efficiency was higher.
基金supported by the National Natural Science Foundation of China,No.81060182the Natural Science Foundation of Xinjiang Uygur Autonomous Region,No.2012211B34the Key Technology Research and Development and Major Program of Xinjiang Uygur Autonomous Region,No.200833116
文摘Tumor models were simulated in purebred Beagles at the T9-10 levels of the spinal cord and treated with spinal image-guided radiation therapy or conventional radiation therapy with 50 or 70 Gy total radiation. Three months after radiation, neuronal injury at the T9-10 levels was observed, including reversible injury induced by spinal image-guided radiation therapy and apoptosis induced by conventional radiation therapy. The number of apoptotic cells and expression of the proapoptotic protein Fas were significantly reduced, but expression of the anti-apoptotic protein heat shock protein 70 was significantly increased after image-guided radiation therapy compared with the conventional method of the same radiation dose. Moreover, the spinal cord cell apoptotic index positively correlated with the ratio of Fas/heat shock protein 70. These findings indicate that 3 months of radiation therapy can induce a late response in the spinal cord to radiation therapy; image-guided radiation therapy is safer and results in less neuronal injury compared with conventional radiation therapy.
文摘This systematic review assessed the safety and efficacy of the disposable circumcision suture device （DCSD） and conventional circumcision （CC） in the treatment of redundant prepuce and phimosis. Two independent reviewers conducted a literature search for randomized controlled trials （RCTs） using the DCSD and CC for the treatment of redundant prepuce or phimosis in China and abroad. Nine RCTs （1898 cases） were included. Compared with the CC group, the DCSD group had a shorter operative time （standardized mean difference [SMD] = -21.44; 95% confidence intervals [95% CIs] [-25.08, -17.79]; P 〈 0.00001）, shorter wound healing time （SMD = -3.66; 95% CI [-5.46, -1.85]; P 〈 0.0001）, less intraoperative blood loss （SMD = -9.64; 95% CI [-11.37, -7.90]; P 〈 0.00001）, better cosmetic penile appearance （odds ratio [OR] =8.77; 95% CI [5.90, 13.02]; P 〈 0.00001）, lower intraoperative pain score, lower 24-h postoperative pain score, lower incidence of infection, less incision edema, and fewer adverse events. There were no differences between the CC and DCSD groups in the incidences of dehiscence, or hematoma. The results of this meta-analysis indicate that the DCSD appears to be safer and more effective than CC. However, additional high-quality RCTs with larger study populations are needed.
文摘AIM： To evaluate the sensitivity and specificity of MR colonography （MRC） and CT performance in detecting colon lesions, and to compare their sensitivity and specificity with that of conventional colonoscopy. METHODS： Forty-two patients suspected of having colonic lesions, because of rectal bleeding, positive fecal occult blood test results or altered bowel habits, underwent the examinations. After insertion of a rectal tube, the colon was filled with 1000-1500 mL of a mixture of 9 g/L NaCI solution, 15-20 mL of 0.5 mmol/L gadopentetate dimeglumine and 100 mL of iodinized contrast material. Once colonic distension was achieved, three-dimensional gradient-echo （3D-GRE） sequences for MR colonography and complementary MR images were taken in all cases. Immediately after MR colonography, abdominal CT images were taken by spiral CT in the axial and supine position. Then all patients were examined by conventional colonoscopy （CC）. RESULTS： The sensitivity and specificity of MRC for colon pathologies were 96.4% and 100%, respectively. The percentage of correct diagnosis by MRC was 97.6%. The sensitivity and specificity of CT for colon pathologies were 92.8%, 100%, respectively. The percentage of correct diagnosis by CT was 95.2%. CONCLUSION： In detecting colon lesions, MRC achieved a diagnostic accuracy similar to CC. However, MRC is minimally invasive, with no need for sedation or analgesics during investigation. There is a lower percentage of perforation risk, and all colon segments can be evaluated due to multi-sectional imaging availability; intramural, extra-intestinal components of colonic lesions, metastasis and any additional lesions can be evaluated easily. MRC and CT colonography are new radiological techniques that promise to be highly sensitive in the detection of colorectal mass and inflammatory bowel lesions.
基金supported by the National Natural Science Foundation of China(No.31170414)the 100 Talents Program of Chinese Academy of Science(No.2009)
文摘Understanding the effects of warming on greenhouse gas（GHG, such as N2O, CH4 and CO2 ）feedbacks to climate change represents the major environmental issue. However, little information is available on how warming effects on GHG fluxes in farmland of North China Plain（NCP）. An infrared warming simulation experiment was used to assess the responses of N2O, CH4 and CO2 to warming in wheat season of 2012–2014 from conventional tillage（CT） and no-tillage（NT） systems. The results showed that warming increased cumulative N2O emission by 7.7% in CT but decreased it by 9.7% in NT fields（p 〈 0.05）. Cumulative CH4 uptake and CO2 emission were increased by 28.7%–51.7% and 6.3%–15.9% in both two tillage systems,respectively（p 〈 0.05）. The stepwise regressions relationship between GHG fluxes and soil temperature and soil moisture indicated that the supply soil moisture due to irrigation and precipitation would enhance the positive warming effects on GHG fluxes in two wheat seasons.However, in 2013, the long-term drought stress due to infrared warming and less precipitation decreased N2O and CO2 emission in warmed treatments. In contrast, warming during this time increased CH4 emission from deep soil depth. Across two years wheat seasons, warming significantly decreased by 30.3% and 63.9% sustained-flux global warming potential（SGWP） of N2O and CH4 expressed as CO2 equivalent in CT and NT fields, respectively. However, increase in soil CO2 emission indicated that future warming projection might provide positive feedback between soil C release and global warming in NCP.
文摘The purpose of this study was to compare the biomechanical stability obtained by using our technique featured an anatomical plate and compression bolts versus that of the conventional anatomic plate and cancellous screws in the fixation of intraarticular calcaneal fractures.Eighteen fresh frozen lower limbs of cadavers were used to create a reproductive Sanders type-Ⅲ calcaneal fracture model by using osteotomy.The calcaneus fractures were randomly selected to be fixed either using our anatomical plate and compression bolts or conventional anatomic plate and cancellous screws.Reduction of fracture was evaluated through X radiographs.Each calcaneus was successively loaded at a frequency of 1 Hz for 1000 cycles through the talus using an increasing axial force 20 N to 200 N and 20 N to 700 N,representing the partial weight bearing and full weight bearing,respectively,and then the specimens were loaded to failure.Data extracted from the mechanical testing machine were recorded and used to test for difference in the results with the Wilcoxon signed rank test.No significant difference was found between our fixation technique and conventional technique in displacement during 20-200 N cyclic loading(P=0.06),while the anatomical plate and compression bolts showed a great lower irreversible deformation during 20-700 N cyclic loading(P=0.008).The load achieved at loss of fixation of the constructs for the two groups had significant difference:anatomic plate and compression bolts at 3839.6±152.4 N and anatomic plate and cancellous screws at 3087.3±58.9 N(P=0.008).There was no significant difference between the ultimate displacements.Our technique featured anatomical plate and compression bolts for calcaneus fracture fixation was demonstrated to provide biomechanical stability as good as or better than the conventional anatomic plate and cancellous screws under the axial loading.The study supports the mechanical viability of using our plate and compression bolts for the fixation of calcaneal fracture.
基金This work was supported by the National Natural Science Foundation of China （No.21173152）, the Ministry of Education of China （No.NCET-11-0359 and No.2011SCU04B31）, and the Science and Technology Department of Sichuan Province （No.2011HH0005）.
文摘Time-dependent diffusion coefficient and conventional diffusion constant are calculated and analyzed to study diffusion of nanoparticles in polymer melts. A generalized Langevin equa- tion is adopted to describe the diffusion dynamics. Mode-coupling theory is employed to calculate the memory kernel of friction. For simplicity, only microscopic terms arising from binary collision and coupling to the solvent density fluctuation are included in the formalism. The equilibrium structural information functions of the polymer nanocomposites required by mode-coupling theory are calculated on the basis of polymer reference interaction site model with Percus-Yevick closure. The effect of nanoparticle size and that of the polymer size are clarified explicitly. The structural functions, the friction kernel, as well as the diffusion coefficient show a rich variety with varying nanoparticle radius and polymer chain length. We find that for small nanoparticles or short chain polymers, the characteristic short time non-Markov diffusion dynamics becomes more prominent, and the diffusion coefficient takes longer time to approach asymptotically the conventional diffusion constant. This constant due to the microscopic contributions will decrease with the increase of nanoparticle size, while increase with polymer size. Furthermore, our result of diffusion constant from mode- coupling theory is compared with the value predicted from the Stokes-Einstein relation. It shows that the microscopic contributions to the diffusion constant are dominant for small nanoparticles or long chain polymers. Inversely, when nanonparticle is big, or polymer chain is short, the hydrodynamic contribution might play a significant role.
基金Public Benefit Research Foundation under Grant No.201108006Natural Science Foundation under Grant No.51161120360+2 种基金Heilongjiang Overseas Funding under Grant No.LC201002 of ChinaGrant-in-Aid for Scientific Research(Basic Research Category A,19206060)Japan Society for the Promotion of Science
文摘This paper presents a substructure online hybrid test system that is extensible for geographically distributed tests. This system consists of a set of devices conventionally used for cyclic tests to load the tested substructures onto the target displacement or the target force. Due to their robustness and portability, individual sets of conventional loading devices can be transported and reconfigured to realize physical loading in geographically remote laboratories. Another appealing feature is the flexible displacement-force mixed control that is particularly suitable for specimens having large disparities in stiffness during various performance stages. To conduct a substructure online hybrid test, an extensible framework is developed, which is equipped with a generalized interface to encapsulate each substructure. Multiple tested substructures and analyzed substructures using various structural program codes can be accommodated within the single framework, simply interfaced with the boundary displacements and forces. A coordinator program is developed to keep the boundaries among all substructures compatible and equilibrated. An Interuet-based data exchange scheme is also devised to transfer data among computers equipped with different software environments. A series of online hybrid tests are introduced, and the portability, flexibility, and extensibility of the online hybrid test system are demonstrated.
文摘Objective: To compare the effects and safety of conventional transarterial chemoembolization(c TACE) and yttrium-90 transarterial radioembolization [TARE(90 Y)] for hepatocellular carcinoma(HCC)Methods: Nine high-quality observational studies, one low bias-risk randomized controlled trial(RCT), and one moderate biasrisk RCT included 1,652 patients [c TACE, 1,124; TARE(90 Y), 528], from whom data were extracted for this systematic review and meta-analysis.Results: The extracted study outcomes included 1-year and 2-year overall survival(OS) rates, objective responses(ORs), and serious adverse events(AEs). 1-year OS rates: OR = 0.939, 95 % CI: 0.705-1.251, P = 0.66. 2-year OS rates: overall pooled OR =0.641, 95% CI: 0.382-1.075, P = 0.092; observational study subgroup OR = 0.575, 95% CI: 0.336-0.984, P = 0.043; RCT subgroup OR* = 0.641, 95% CI: 0.382-1.075, P = 0.346. OR: overall pooled OR = 0.781, 95% CI: 0.454-1.343, P = 0.371; m RECIST subgroup OR = 0.584, 95 % CI: 0.349-0.976, P = 0.040; WHO subgroup OR = 1.065; 95% CI: 0.500-2.268, P = 0.870. Serious AEs: overall pooled RR = 1.477, 95% CI: 0.864-2.526, P = 0.154; RCT subgroup RR = 0.680, 95% CI: 0.325-1.423, P = 0.306; observational study subgroup RR = 1.925; 95 % CI: 0.978-3.788, P = 0.058.Conclusions: TARE(90 Y) increased 2-year OS rates in the observational subgroup and resulted in better OR rates, according to m RECIST criteria, in comparison with c TACE. Furthermore, a lower risk of AEs was observed for TARE(90 Y) than for c TACE.
基金the Excellent Talents Fund Project of Xuzhou Medical University,No.XYFY2021019.
文摘BACKGROUND Varicosis is a common venous condition,which is typically treated surgically.However,selection of the optimal surgical approach can be challenging.Previous studies comparing endovenous laser treatment(EVLT)and conventional surgery were retrospective and observational in nature and the results may therefore have been influenced by selection bias and the presence of other confounding factors.In this study,we used propensity score matching to reduce selection bias when comparing EVLT and conventional surgery for the treatment of varicose great saphenous veins.METHODS We retrospectively reviewed the records of 1063 patients treated for primary varicosis of the great saphenous vein at the Second Affiliated Hospital of Xuzhou Medical University between January 2009 and December 2019.Among them,56 patients were excluded owing to additional small saphenous varicose vein involvement,81 owing to recurring varicose veins,83 owing to complicated varicose veins(CEAP clinical classification C5-C6),and 6 owing to perioperative phlebitis.Finally,772 patients were enrolled in this study.Standard demographic and clinicopathological data were collected from the medical records of the patients.For propensity score matching,522 patients(261 who underwent EVLT and 261 who underwent conventional surgery)were randomly matched 1:1 by age,sex,onset time,smoking status,presence of diabetes,family history,stress therapy,C class,and the affected leg.RESULTS Of the 772 patients included in the study,467 underwent EVLT and 305 underwent conventional surgery.There were significant differences in age,onset time,smoking and diabetes status,and family history between the two groups.Following propensity score matching,no significant differences in patients’characteristics remained between the two groups.ELVT was associated with a shorter operation time and hospital stay than conventional surgery,both before and after propensity score matching.There were no differences in complications between the two groups after propensity score matching.Patients who underwent EVLT had a higher recurrence rate during the two-year follow-up period than those who underwent conventional surgery(33.33%vs 21.46%,χ^(2)=11.506,P=0.001),and a greater percentage of patients who underwent EVLT experienced pain one week after the procedure(39.85%vs 19.54%,P=0.000).CONCLUSION EVLT may not always be the best option for the treatment of great saphenous vein varicosis.
基金This work was supported by National Key Research and Development Program of China(2018YFB0904000).
文摘In China, regions with abundant wind energy resources are generally located at the end of power grids. The power grid architecture in these regions is typically not sufficiently strong, and the energy structure is relatively simple. Thus, connecting large-capacity wind power units complicates the peak load regulation and stable operation of the power grids in these regions. Most wind turbines use power electronic converter technology, which affects the safety and stability of the power grid differently compared with conventional synchronous generators. Furthermore, fluctuations in wind power cause fluctuations in the output of wind farms, making it difficult to create and implement suitable power generation plans for wind farms. The generation technology and grid connection scheme for wind power and conventional thermal power generation differ considerably. Moreover, the active and reactive power control abilities of wind turbines are weaker than those of thermal power units, necessitating additional equipment to control wind turbines. Hence, to address the aforementioned issues with large-scale wind power generation, this study analyzes the differences between the grid connection and collection strategies for wind power bases and thermal power plants. Based on this analysis, the differences in the power control modes of wind power and thermal power are further investigated. Finally, the stability of different control modes is analyzed through simulation. The findings can be beneficial for the planning and development of large-scale wind power generation farms.
文摘Soil samples at 0-10 cm in depth were collected periodically at paired fields in Corvallis, Oregon, USA to compare differences in soil microbial and faunal populations between organic and conventional agroecosystems. Results showed that the organic soil ecosystem had a significantly higher (P < 0.05) average number or biomass of soil bacteria; densities of flagellates, amoebae of protozoa; some nematodes, such as microbivorous and predaceous nematodes and plant-parasitic nematodes; as well as Collembola. Greater numbers of Rhabditida (such as Rhabditis spp.), were present in the organic soil ecosystem while Panagrolaimus spp. were predominant in the conventional soil ecosystem. The omnivores and predators of Acarina in the Mesostigmata (such as Digamasellidae and Laelapid), and Prostigmata (such as Alicorhaiidae and Rhagidiidae), were also more abundant in the organic soil ecosystem. However, fungivorous Prostigmata (such as Terpnacaridae and Nanorchestidae) and Astigmata (such as Acarida) were significantly higher (P < 0.05) in the conventional soil ecosystem, which supported the finding that total fungal biomass was greater in the conventional soil ecosystem. Seansonal variations of the population depended mostly on soil moisture condition and food web relationship. The population declined from May to October for both agroecosystems. However, higher diversities and densities of soil biota survived occurred in the organic soil ecosystem in the dry season.
文摘Recently,peroral direct cholangioscopy(PDCS) using an ultra-slim endoscope has come into the spotlight.However,the working channel is too small to use various devices for lithotripsy.We report a case of endoscopic lithotripsy with PDCS using a conventional endoscope as a cholangioscope.Computed tomography scan on an 80-year-old female who was admitted with acute cholangitis showed two large stones in the bile duct.Endoscopic retrograde cholangiopancreatography was attempted first.However,mechanical lithotripsy failed because the stone was too large for the basket catheter.Finally,electric hydraulic lithotripsy with PDCS using a conventional endoscope was performed allowed the stones to be cleared completely.In conclusion,PDCS using a conventional endoscope can be an alternative solution for endoscopic lithotripsy for patients with large stones in the dilated bile duct.
基金supported by the National Science and Technology Major Project(Grant No.2017ZX05009001-002 and 2017ZX05013002-004)the Fundamental Research Funds for the Central Universities(Grant No.2462020YJRC005)Science Foundation of China University of Petroleum,Beijing(Grant No.2462020XKJS02).
文摘Fractures are of great significance to tight oil and gas development.Fracture identification using conventional well logs is a feasible way to locate the underground fractures in tight sandstones.However,there are three problems affecting its interpretation accuracy and practical application,namely weak well log responses of fractures,a lack of specific logs for fracture prediction,and relative change omission in log responses.To overcome these problems and improve fracture identification accuracy,a fracture indicating parameter(FIP)method composed of a comprehensive index method(CIM)and a comprehensive fractal method(CFM)is introduced.The CIM tries to handle the first problem by amplifying log responses of fractures.The CFM addresses the third one using fractal dimensions.The flexible weight parameters corresponding to logs in the CIM and CFM make the interpretation possible for wells lacking specific logs.The reconstructed logs in the CIM and CFM try to solve the second problem.It is noted that the FIP method can calculate the probability of fracture development at a certain depth,but cannot show the fracture development degree of a new well compared with other wells.In this study,a formation fracture intensity(FFI)method is also introduced to further evaluate fracture development combined with production data.To test the validity of the FIP and FFI methods,fracture identification experiments are implemented in a tight reservoir in the Ordos Basin.The results are consistent with the data of rock core observation and production,indicating the proposed methods are effective for fracture identification and evaluation.
文摘Heteroarm star-shaped polymers were synthesized by conventional free radical polymerization in two steps by the use of polyfunctional chain transfer agent.In the first step,free radical polymerization of methyl methacrylate was carried out in the presence of a polyfunctional chain transfer agent,pentaerythritol tetrakis(3-mercaptopropinate).At appropriate monomer conversions,two-arm PMMA having two residual thiol groups at the chain center or three-arm PMMA having one residual thiol group at the core were o...
