BACKGROUND Meniscal tears are one of the most common knee injuries.After the diagnosis of a meniscal tear has been made,there are several factors physicians use to guide clinical decision-making.The influence of time ...BACKGROUND Meniscal tears are one of the most common knee injuries.After the diagnosis of a meniscal tear has been made,there are several factors physicians use to guide clinical decision-making.The influence of time between injury and isolated meniscus repair on patient outcomes is not well described.Assessing this relationship is important as it may influence clinical decision-making and can add to the preoperative patient education process.We hypothesized that increasing the time from injury to meniscus surgery would worsen postoperative outcomes.AIM To investigate the current literature for data on the relationship between time between meniscus injury and repair on patient outcomes.METHODS PubMed,Academic Search Complete,MEDLINE,CINAHL,and SPORTDiscus were searched for studies published between January 1,1995 and July 13,2023 on isolated meniscus repair.Exclusion criteria included concomitant ligament surgery,incomplete outcomes or time to surgery data,and meniscectomies.Patient demographics,time to injury,and postoperative outcomes from each study were abstracted and analyzed.RESULTS Five studies met all inclusion and exclusion criteria.There were 204(121 male,83 female)patients included.Three of five(60%)studies determined that time between injury and surgery was not statistically significant for postoperative Lysholm scores(P=0.62),Tegner scores(P=0.46),failure rate(P=0.45,P=0.86),and International Knee Documentation Committee scores(P=0.65).Two of five(40%)studies found a statistically significant increase in Lysholm scores with shorter time to surgery(P=0.03)and a statistically significant association between progression of medial meniscus extrusion ratio(P=0.01)and increasing time to surgery.CONCLUSION Our results do not support the hypothesis that increased time from injury to isolated meniscus surgery worsens postoperative outcomes.Decision-making primarily based on injury interval is thus not recommended.展开更多
BACKGROUND Tourniquets are commonly used in elective extremity orthopaedic surgery to reduce blood loss,improve visualization in the surgical field,and to potentially reduce surgical time.There is a lack of consensus ...BACKGROUND Tourniquets are commonly used in elective extremity orthopaedic surgery to reduce blood loss,improve visualization in the surgical field,and to potentially reduce surgical time.There is a lack of consensus in existing guidelines regarding the optimal tourniquet pressure,placement site,and duration of use.There is a paucity of data on the relationship between the site of a tourniquet and postoperative pain in foot and ankle surgery.AIM To explore the relationship between tourniquet site and intensity of post-operative pain scores in patients undergoing elective foot and ankle surgery.METHODS Retrospective analysis of prospectively collected data on 201 patients who underwent foot and ankle surgery in a single institution was undertaken.Intraoperative tourniquet duration,tourniquet pressure and site,and postoperative pain scores using Visual Analogue Score were collected in immediate recovery,at six hours and at 24 h post-op.Scatter plots were used to analyse the data and to assess for the statistical correlation between tourniquet pressure,duration,site,and pain scores using Pearson correlation coefficient.RESULTS All patients who underwent foot and ankle surgery had tourniquet pressure of 250 mmHg for ankle tourniquet and 300 mmHg for thigh.There was no correlation between the site of the tourniquet and pain scores in recovery,at six hours and after 24 h.There was a weak correlation between tourniquet time and Visual Analogue Score immediately post-op(r=0.14,P=0.04)but not at six or 24 h post-operatively.CONCLUSION This study shows that there was no statistically significant correlation between tourniquet pressure,site and postop pain in patients undergoing foot and ankle surgery.The choice of using a tourniquet is based on the surgeon's preference,with the goal of minimizing the duration of its application at the operative site.展开更多
This study is focused on the simulation and optimization of packed-bed solar thermal energy storage by using sand as a storage material and hot-water is used as a heat transfer fluid and storage as well.The analysis h...This study is focused on the simulation and optimization of packed-bed solar thermal energy storage by using sand as a storage material and hot-water is used as a heat transfer fluid and storage as well.The analysis has been done by using the COMSOL multi-physics software and used to compute an optimization charging time of the storage.Parameters that control this optimization are storage height,storage diameter,heat transfer fluid flow rate,and sand bed particle size.The result of COMSOL multi-physics optimized thermal storage has been validated with Taguchi method.Accordingly,the optimized parameters of storage are:storage height of 1.4m,storage diameter of 0.4 m,flow rate of 0.02 kg/s,and sand particle size 12 mm.Among these parameters,the storage diameter result is the highest influenced optimized parameter of the thermal storage fromthe ANOVA analysis.For nominal packed bed thermal storage,the charging time needed to attain about 520 K temperature is more than 3500 s,while it needs only about 2000 s for the optimized storage which is very significant difference.Average charging energy efficiency of the optimized is greater than the nominal and previous concrete-based storage by 13.7%,and 13.1%,respectively in the charging time of 2700 s.展开更多
AIM To evaluate whether the neoadjuvant chemotherapy(NAc T)-surgery interval time significantly impacts the pathological complete response(pc R) rate and longterm survival.METHODS One hundred and seventy-six patients ...AIM To evaluate whether the neoadjuvant chemotherapy(NAc T)-surgery interval time significantly impacts the pathological complete response(pc R) rate and longterm survival.METHODS One hundred and seventy-six patients with gastric cancer undergoing NAc T and a planned gastrectomy at the chinese p LA General hospital were selected from January 2011 to January 2017. Univariate and multivariable analyses were used to investigate the impact of NAc T-surgery interval time(< 4 wk, 4-6 wk, and > 6 wk) on pc R rate and overall survival(OS).RESULTS The NAc T-surgery interval time and clinician T stage were independent predictors of pc R. The interval time > 6 wk was associated with a 74% higher odds of pc R as compared with an interval time of 4-6 wk(p = 0.044), while the odds ratio(OR) of clinical T3 vs clinical T4 stage for pc R was 2.90(95%c I: 1.04-8.01, p = 0.041). In cox regression analysis of long-term survival, postneoadjuvant therapy pathological N(yp N) stage significantly impacted OS(N0 vs N3: h R = 0.16, 95%c I: 0.37-0.70, p = 0.015; N1 vs N3: h R = 0.14, 95%c I: 0.02-0.81, p = 0.029) and disease-free survival(DFS)(N0 vs N3: h R = 0.11, 95%c I: 0.24-0.52, p = 0.005; N1 vs N3: h R = 0.17, 95%c I: 0.02-0.71, p = 0.020). The surgical procedure also had a positive impact on OS and DFS. The hazard ratio of distal gastrectomy vs total gastrectomy was 0.12(95%c I: 0.33-0.42, p = 0.001) for OS, and 0.13(95%c I: 0.36-0.44, p = 0.001) for DFS.CONCLUSION The NAc T-surgery interval time is associated with pc R but has no impact on survival, and an interval time > 6 wk has a relatively high odds of pc R.展开更多
Valvular heart disease is a pathologic process involving one or more of the four valves(aortic,pulmonary,mitral and tricuspid)of the heart typified by stenosis or regurgitation and leading to patient symptoms.The most...Valvular heart disease is a pathologic process involving one or more of the four valves(aortic,pulmonary,mitral and tricuspid)of the heart typified by stenosis or regurgitation and leading to patient symptoms.The most common causes are tissue degeneration,rheumatic fever and congenital heart diseases.Aortic valve replacement(AVR)using either mechanical or bioprosthetic(tissue)valves via open-heart surgical展开更多
Pebble bed reactors use cycling scheme of spherical fuel elements relying on fuel elements cycling system (FECS). The structure and control logic of FECS are very complex. Each control link has strict requirements on ...Pebble bed reactors use cycling scheme of spherical fuel elements relying on fuel elements cycling system (FECS). The structure and control logic of FECS are very complex. Each control link has strict requirements on time and sequence. This increases the difficulties of description and analysis. In this paper, timed places control Petri nets (TPCPN) is applied for the modeling of FECS. On this basis the simulation of two important processes, namely uploading fuel elements into the core for the first time and emptying the core is finished by simulation software Arena. The results show that as TPCPN is able to describe different kinds of logic relationship and has time properties and control properties, it’s very suitable for the modeling and analysis of FECS.展开更多
Quantity of bed load is an important physical parameter in sediment transport research. Aiming at the difficulties in the bed load measurement, this paper develops a bottom-mounted monitor to measure the bed load tran...Quantity of bed load is an important physical parameter in sediment transport research. Aiming at the difficulties in the bed load measurement, this paper develops a bottom-mounted monitor to measure the bed load transport rate by adopting the sedimentation pit method and resolving such key problems as weighing and desilting, which can achieve long-time, all-weather and real-time telemeasurement of the bed load transport rate of plain rivers, estuaries and coasts. Both laboratory and field tests show that this monitor is reasonable in design, stable in properties and convenient in measurement, and it can be used to monitor the bed load transport rate in practical projects.展开更多
The particle residence time distribution(RTD)and axial dispersion coefficient are key parameters for the design and operation of a pressurized circulating fluidized bed(PCFB).In this study,the effects of pressure(0.1-...The particle residence time distribution(RTD)and axial dispersion coefficient are key parameters for the design and operation of a pressurized circulating fluidized bed(PCFB).In this study,the effects of pressure(0.1-0.6 MPa),fluidizing gas velocity(2-7 m·s^(-1)),and solid circulation rate(10-90 kg·m^(-2)·s^(-1))on particle RTD and axial dispersion coefficient in a PCFB are numerically investigated based on the multiphase particle-in-cell(MP-PIC)method.The details of the gas-solid flow behaviors of PCFB are revealed.Based on the gas-solid flow pattern,the particles tend to move more orderly under elevated pressures.With an increase in either fluidizing gas velocity or solid circulation rate,the mean residence time of particles decreases while the axial dispersion coefficient increases.With an increase in pressure,the core-annulus flow is strengthened,which leads to a wider shape of the particle RTD curve and a larger mean particle residence time.The back-mixing of particles increases with increasing pressure,resulting in an increase in the axial dispersion coefficient.展开更多
Objective:While a rushed operation can omit essential procedures,prolonged operative time results in higher morbidity.Nevertheless,the optimal operative time range remains uncertain.This study aimed to estimate the id...Objective:While a rushed operation can omit essential procedures,prolonged operative time results in higher morbidity.Nevertheless,the optimal operative time range remains uncertain.This study aimed to estimate the ideal operative time range and evaluate its applicability in laparoscopic cancer surgery.Methods:A prospectively collected multicenter database of 397 patients who underwent laparoscopic distal gastrectomy were retrospectively reviewed.The ideal operative time range was statistically calculated by separately analyzing the operative time of uneventful surgeries.Finally,intraoperative and postoperative outcomes were compared among the shorter,ideal,and longer operative time groups.Results:The statistically calculated ideal operative time was 135.4-165.4 min.The longer operative time(LOT)group had a lower rate of uneventful,perfect surgery than the ideal or shorter operative time(IOT/SOT)group(2.8%vs.8.8%and 2.2%vs.13.4%,all P<0.05).Longer operative time increased bleeding,postoperative morbidities,and delayed diet and discharge(all P<0.05).Particularly,an uneventful,perfect surgery could not be achieved when the operative time exceeded 240 min.Regardless of ideal time range,SOT group achieved the highest percentage of uneventful surgery(13.4%),which was possible by surgeon's ability to retrieve a higher number of lymph nodes and perform≥150 gastrectomies annually.Conclusions:Operative time longer than the ideal time range(especially≥240 min)should be avoided.If the essential operative procedure were faithfully conducted without compromising oncological safety,an operative time shorter than the ideal range leaded to a better prognosis.Efforts to minimize operative time should be attempted with sufficient surgical experience.展开更多
This paper presents a robust model reference adaptive control scheme to deal with un-certain time delay in the dynamical model of a ?uidized bed combustor for sewage sludge. Thetheoretical analysis and simulation resu...This paper presents a robust model reference adaptive control scheme to deal with un-certain time delay in the dynamical model of a ?uidized bed combustor for sewage sludge. Thetheoretical analysis and simulation results show that the proposed scheme can guarantee not onlystability and robustness, but also the adaptive decoupling performance of the system.展开更多
Anaerobic expanded bed reactor(AEBR) is mostly used for the treatment of fairly low strength wastewaters. Since the performance of AEBR largely depends on its hydraulic characteristics, residence time distribution(RTD...Anaerobic expanded bed reactor(AEBR) is mostly used for the treatment of fairly low strength wastewaters. Since the performance of AEBR largely depends on its hydraulic characteristics, residence time distribution(RTD) method is commonly used for investigation of the hydraulic characteristics of AEBR under different ascending velocity of mixed liquor. In this paper, a pilot-scale AEBR reactor is investigated for treatment of municipal sewage in which lithium chloride is used as a tracer. The results show that the AEBR could be considered as the superimposition of several constant stirred tank reactors(CSTR) and the increase of hydraulic up-flow velocity could increase the number of the CSTR and decrease the volume rate of the dead zone. The optimal up-flow velocity of the investigated AEBR was approximately 1.9 m/h in the municipal sewage treatment.展开更多
Introduction: Experimental Clinical studies have shown that loss of up to 77.0% of red cell mass can be tolerated as long as it kept the blood volume. However, the blood volume loss of about 34.0% is fatal. The initia...Introduction: Experimental Clinical studies have shown that loss of up to 77.0% of red cell mass can be tolerated as long as it kept the blood volume. However, the blood volume loss of about 34.0% is fatal. The initial attention in patients with bleeding should be given to maintaining blood volume and oxygen transport. Thus, transfusions of allogeneic blood products are associated with an increased risk of morbidity and mortality in cardiac surgery. Some transfusion risk scores have been proposed for cardiac surgery patients. Objective: To review and discuss literature blood transfusion (blood components gradient) in cardiovascular surgery versus polytrauma, gastrointestinal bleeding, and neoplastic diseases. Methods: The model followed for the review was PRISMA. We used the databases as Scielo, Lilacs, Google Scholar, PubMed articles and works of scientific and doctoral theses master. Results: According to the discussion in the literature, the acute bleeding of large volumes is challenging to emergency services. Accordingly, the need to support hemotherapeutics led to the development of protocols for more rational utilization of the monitored blood components. Conclusion: Hemotherapy services have adopted a very dynamic approach to the clinical condition presented by patients, the need for four or more red blood cell units.展开更多
In a spouted bed of 80mm in ID and 1700mm in height, the gas residence time distributions at different radial positions in both spout and annular area were measured with five different kinds of particles as spouting m...In a spouted bed of 80mm in ID and 1700mm in height, the gas residence time distributions at different radial positions in both spout and annular area were measured with five different kinds of particles as spouting material, air as spouting gas, and hydrogen as tracer. The effects of superficial gas velocity, operating pressure, particle size and its category on gas residence time distribution were discussed. It was found that the gas velocity profile in spout was more uniform than that in annulus. It could be concluded that the gas flow in the spout could be treated as a plug-flow, while that in the annulus inhibited a strong non-ideal flow behavior. Increasing the superficial gas velocity and decreasing the operating pressure, the particle density and its size gave rise to spouting disturbance, thus the measured tracer concentrations vs. time curves fluctuated. The variances of residence time distribution curves could be taken as a measure of the gas fluctuation degree.展开更多
<strong>Introduction:</strong> Gender differences are still quite prevalent in the present time. Although there is literature regarding gender differences in healthcare expenditure in India, there is no da...<strong>Introduction:</strong> Gender differences are still quite prevalent in the present time. Although there is literature regarding gender differences in healthcare expenditure in India, there is no data regarding gender differences in hospital stay, hospital seeking behaviors and mortality. <strong>Aim:</strong> To evaluate the Gender differences in a hospital seeking behavior, mortality and hospital stay. <strong>Methods:</strong> We prospectively analyzed, from a retrospective database, all patients who underwent surgical gastrointestinal, hepato-biliary, pancreatic and splenic surgeries from 1996 to 2018 in our unit. Patients were divided into groups based on gender, admission time period and priority of admission i.e., elective or emergency. Both the gender groups were compared with respect to total procedures done, hospital stay and mortality. Organ specific mortality was calculated as proportions, was analyzed and compared between the groups. Time trends of the same were observed and compared. <strong>Results:</strong> Of 12,411 patients, 7979 (64.3%) were males and 4432 (35.7%) were females. 9191 (74.1%) patients underwent elective procedures whereas 3220 (25.9%) had emergency procedures (<strong>p ≤ 0.001</strong>). Overall mortality was higher in males (n = 473, 5.92%) in comparison to females (n = 185, 4.17%) (p ≤ 0.001). Majority of surgeries in males were of small intestine (22.5%) in which small bowel resection was most commonly done (5.4%), whereas, gallbladder and biliary surgeries (27.4%) were the most common in females in which laparoscopic cholecystectomy was most commonly done (5.8%). Median hospital stay was higher in males (10 days vs 9 days), (<strong>p ≤ 0.001</strong>). Mortality was higher in females in all organ categories except in liver (6.34% vs 2.7%), pancreas (37.3% Vs 18.3%) and spleen (3.38% Vs 1.62%) where mortality was higher for male gender. Highest mortality for females was in small intestinal surgery (34%) and for males, it was pancreatic surgery (37.3%). Highest mortality in males was emergency open pancreatic necrosectomy (21.6%) and that in females was emergency small intestinal surgery (11.9%). Although the number of surgeries in females increased over time (380 in 1996-1999 Vs 951 in 2016-2018), the proportion remained constant (36.3% Vs 38.3% in 1996-1999 and 2016-2018 respectively). <strong>Conclusion:</strong> We conclude that mortality is found to be higher in males after gastrointestinal surgery, which may be explained by the fact that hospital seeking behavior is more in males though it is fairly increasing in females in the recent years.展开更多
BACKGROUND Supracondylar humerus fractures account for more than 60%of all elbow fractures and about 1/5 of all pediatric fractures.Unfortunately,these fractures can be associated with risk of complications including ...BACKGROUND Supracondylar humerus fractures account for more than 60%of all elbow fractures and about 1/5 of all pediatric fractures.Unfortunately,these fractures can be associated with risk of complications including neurovascular injuries,malunions and limb deformities.Controversy exists regarding the effect of time of surgical intervention and/or level of surgeon performing the surgery on outcome of these fractures.AIM To determine whether time of surgical intervention and/or surgeon level influence the outcomes of surgically managed pediatric supracondylar humerus fractures.METHODS We retrospectively studied 155 pediatric patients presenting with a supracondylar humerus fracture in a level 1 trauma center from January 2006 to December 2019.The data extracted included demographic data,fracture characteristics,surgical data,and follow-up outcomes.The collected data was analyzed and P values of<0.05 were considered statistically significant.RESULTS Of the cohort,11%of patients had documented post-operative complications,of which the majority occurred in surgeries performed after day time working hours and in fractures requiring open reduction.While the lowest complication rate was found in surgeries performed by pediatric orthopaedic surgeons,this did not reach statistical significance.CONCLUSION In pediatric patients undergoing surgery for supracondylar fractures,we found a higher complication rate when surgeries were not performed during working hours.Surgeon level and training had no significant effect on the risk of post-operative complications.展开更多
Ordovician fracture-cavity carbonate reservoir beds are the major type of producing formations in the Tahe oilfield, Tarim Basin. The seismic responses of these beds clearly changes depending on the different distance...Ordovician fracture-cavity carbonate reservoir beds are the major type of producing formations in the Tahe oilfield, Tarim Basin. The seismic responses of these beds clearly changes depending on the different distance of the fracture-cavity reservoir bed from the top of the section. The seismic reflection becomes weak or is absent when the fracture-cavity reservoir beds are less than 20 ms below the top Ordovician. The effect on top Ordovician reflection became weaker with deeper burial of fracture-cavity reservoir beds but the developed deep fracture-cavity reservoir beds caused stronger reflection in the interior of the Ordovician. This interior reflection can be divided into strong long-axis, irregular and bead string reflections, and was present 80 ms below the top Ordovician. Aimed at understanding reflection characteristics, the spectral decomposition technique, which uses frequency to "tune-in" bed thickness, was used to predict Ordovician fracture-cavity carbonate formations in the Tahe oilfield. Through finely adjusting the processing parameters of spectral decomposition, it was found that the slice at 30 Hz of the tuned data cube can best represent reservoir bed development. Two large N-S-trending strong reflection belts in the mid-western part of the study area along wells TK440- TK427-TK417B and in the eastern part along wells TK404-TK409 were observed distinctly on the 30 Hz slice and 4-D time-frequency data cube carving. A small N-S trending reflection belt in the southern part along wells T403-TK446B was also clearly identified. The predicted reservoir bed development area coincides with the fracture-cavities connection area confirmed by drilling pressure testing results. Deep karst cavities occur basically in three reservoir bed-development belts identified by the Ordovician interior strong reflection. Spectral decomposition proved to be a useful technique in identifying fracture-cavity reservoir beds.展开更多
Background: Insufficient capacity for cardiac surgery results in extensive waiting time for patients requiring coronary artery bypass grafting (CABG). Previous studies have reported a consequence of an increased ...Background: Insufficient capacity for cardiac surgery results in extensive waiting time for patients requiring coronary artery bypass grafting (CABG). Previous studies have reported a consequence of an increased risk of mortality while waiting for CABG. Identification of risk factors for mortality is important in patients waiting for CABG. Objectives: To assess mortality rates and identify risk factors for mortality of patients waiting for CABG. Methods: This retrospective cohort study was done on patients waiting for elective CABG in dr. Kariadi General Hospital from January 2018 to December 2020. Identification of risk factors associated with mortality was done on patients who were waiting for CABG using logistic regression methods. Results: There were 162 patients fulfilling the criteria, with a mean waiting time for surgery of 9.8 months. While waiting for CABG surgery, 32 (19.7%) patients died of any cause. Independent risk factors for death while waiting for CABG included left ventricular ejection fraction ≤ 45% (OR 4.75;95% CI 1.76 - 12.78;p = 0.002), left main disease (OR 4.12;95% CI 1.50 - 11.27;p = 0.006), serum creatinine ≥ 1.5 mg/dl (OR 3.71;95% CI 1.41 - 9.74;p = 0.008), and a number of coronary artery disease risk factors ≥ 3 (OR 3.34;95% CI 1.24 - 8.99;p = 0.017). Conclusions: Long waiting time for CABG is associated with a high mortality rate which is influenced by left ventricular ejection fraction ≤ 45%, left main disease, serum creatinine ≥ 1.5 mg/dl, and a number of coronary arteries disease risk factors ≥ 3.展开更多
Background: The hepatic hemodynamics is an essential parameter in surgical planning as well as in various disease processes. The transit time ultrasound(TTUS) perivascular flow probe technology is widely used in clini...Background: The hepatic hemodynamics is an essential parameter in surgical planning as well as in various disease processes. The transit time ultrasound(TTUS) perivascular flow probe technology is widely used in clinical practice to evaluate the hepatic inflow, yet invasive. The phase-contrast-MRI(PC-MRI) is not invasive and potentially applicable in assessing the hepatic blood flow. In the present study, we compared the hepatic inflow rates using the PC-MRI and the TTUS probe, and evaluated their predictive value of post-hepatectomy adverse events. Methods: Eighteen large white pigs were anaesthetized for PC-MRI and approximately 75% hepatic resection was performed under a unified protocol. The blood flow was measured in the hepatic artery(Qha), the portal vein(Qpv), and the aorta above the celiac trunk(Qca) using PC-MRI, and was compared to the TTUS probe. The Bland-Altman method was conducted and a partial least squares regression(PLS) model was implemented. Results: The mean Qpv measured in PC-MRI was 0.55 ± 0.12 L/min, and in the TTUS probe was 0.74 ± 0.17 L/min. Qca was 1.40 ± 0.47 L/min in the PC-MRI and 2.00 ± 0.60 L/min in the TTUS probe. Qha was 0.17 ± 0.10 L/min in the PC-MRI, and 0.13 ± 0.06 L/min in the TTUS probe. The Bland-Altman method revealed that the estimated bias of Qca in the PC-MRI was 32%(95% CI:-49% to 15%); Qha 17%(95% CI:-15% to 51%); and Qpv 40%(95% CI:-62% to 18%). The TTUS probe had a higher weight in predicting adverse outcomes after 75% resection compared to the PC-MRI( β= 0.35 and 0.43 vs β = 0.22 and 0.07, for tissue changes and premature death, respectively). Conclusions: There is a tendency of the PC-MRI to underestimate the flow measured by the TTUS probes. The TTUS probe measures are more predictive of relevant post-hepatectomy outcomes.展开更多
文摘BACKGROUND Meniscal tears are one of the most common knee injuries.After the diagnosis of a meniscal tear has been made,there are several factors physicians use to guide clinical decision-making.The influence of time between injury and isolated meniscus repair on patient outcomes is not well described.Assessing this relationship is important as it may influence clinical decision-making and can add to the preoperative patient education process.We hypothesized that increasing the time from injury to meniscus surgery would worsen postoperative outcomes.AIM To investigate the current literature for data on the relationship between time between meniscus injury and repair on patient outcomes.METHODS PubMed,Academic Search Complete,MEDLINE,CINAHL,and SPORTDiscus were searched for studies published between January 1,1995 and July 13,2023 on isolated meniscus repair.Exclusion criteria included concomitant ligament surgery,incomplete outcomes or time to surgery data,and meniscectomies.Patient demographics,time to injury,and postoperative outcomes from each study were abstracted and analyzed.RESULTS Five studies met all inclusion and exclusion criteria.There were 204(121 male,83 female)patients included.Three of five(60%)studies determined that time between injury and surgery was not statistically significant for postoperative Lysholm scores(P=0.62),Tegner scores(P=0.46),failure rate(P=0.45,P=0.86),and International Knee Documentation Committee scores(P=0.65).Two of five(40%)studies found a statistically significant increase in Lysholm scores with shorter time to surgery(P=0.03)and a statistically significant association between progression of medial meniscus extrusion ratio(P=0.01)and increasing time to surgery.CONCLUSION Our results do not support the hypothesis that increased time from injury to isolated meniscus surgery worsens postoperative outcomes.Decision-making primarily based on injury interval is thus not recommended.
文摘BACKGROUND Tourniquets are commonly used in elective extremity orthopaedic surgery to reduce blood loss,improve visualization in the surgical field,and to potentially reduce surgical time.There is a lack of consensus in existing guidelines regarding the optimal tourniquet pressure,placement site,and duration of use.There is a paucity of data on the relationship between the site of a tourniquet and postoperative pain in foot and ankle surgery.AIM To explore the relationship between tourniquet site and intensity of post-operative pain scores in patients undergoing elective foot and ankle surgery.METHODS Retrospective analysis of prospectively collected data on 201 patients who underwent foot and ankle surgery in a single institution was undertaken.Intraoperative tourniquet duration,tourniquet pressure and site,and postoperative pain scores using Visual Analogue Score were collected in immediate recovery,at six hours and at 24 h post-op.Scatter plots were used to analyse the data and to assess for the statistical correlation between tourniquet pressure,duration,site,and pain scores using Pearson correlation coefficient.RESULTS All patients who underwent foot and ankle surgery had tourniquet pressure of 250 mmHg for ankle tourniquet and 300 mmHg for thigh.There was no correlation between the site of the tourniquet and pain scores in recovery,at six hours and after 24 h.There was a weak correlation between tourniquet time and Visual Analogue Score immediately post-op(r=0.14,P=0.04)but not at six or 24 h post-operatively.CONCLUSION This study shows that there was no statistically significant correlation between tourniquet pressure,site and postop pain in patients undergoing foot and ankle surgery.The choice of using a tourniquet is based on the surgeon's preference,with the goal of minimizing the duration of its application at the operative site.
文摘This study is focused on the simulation and optimization of packed-bed solar thermal energy storage by using sand as a storage material and hot-water is used as a heat transfer fluid and storage as well.The analysis has been done by using the COMSOL multi-physics software and used to compute an optimization charging time of the storage.Parameters that control this optimization are storage height,storage diameter,heat transfer fluid flow rate,and sand bed particle size.The result of COMSOL multi-physics optimized thermal storage has been validated with Taguchi method.Accordingly,the optimized parameters of storage are:storage height of 1.4m,storage diameter of 0.4 m,flow rate of 0.02 kg/s,and sand particle size 12 mm.Among these parameters,the storage diameter result is the highest influenced optimized parameter of the thermal storage fromthe ANOVA analysis.For nominal packed bed thermal storage,the charging time needed to attain about 520 K temperature is more than 3500 s,while it needs only about 2000 s for the optimized storage which is very significant difference.Average charging energy efficiency of the optimized is greater than the nominal and previous concrete-based storage by 13.7%,and 13.1%,respectively in the charging time of 2700 s.
基金Supported by the Beijing Municipal Science and Technology Plan,No.D141100000414002the National Natural Science Foundation of China,No.81272698,No.81672319,and No.81602507
文摘AIM To evaluate whether the neoadjuvant chemotherapy(NAc T)-surgery interval time significantly impacts the pathological complete response(pc R) rate and longterm survival.METHODS One hundred and seventy-six patients with gastric cancer undergoing NAc T and a planned gastrectomy at the chinese p LA General hospital were selected from January 2011 to January 2017. Univariate and multivariable analyses were used to investigate the impact of NAc T-surgery interval time(< 4 wk, 4-6 wk, and > 6 wk) on pc R rate and overall survival(OS).RESULTS The NAc T-surgery interval time and clinician T stage were independent predictors of pc R. The interval time > 6 wk was associated with a 74% higher odds of pc R as compared with an interval time of 4-6 wk(p = 0.044), while the odds ratio(OR) of clinical T3 vs clinical T4 stage for pc R was 2.90(95%c I: 1.04-8.01, p = 0.041). In cox regression analysis of long-term survival, postneoadjuvant therapy pathological N(yp N) stage significantly impacted OS(N0 vs N3: h R = 0.16, 95%c I: 0.37-0.70, p = 0.015; N1 vs N3: h R = 0.14, 95%c I: 0.02-0.81, p = 0.029) and disease-free survival(DFS)(N0 vs N3: h R = 0.11, 95%c I: 0.24-0.52, p = 0.005; N1 vs N3: h R = 0.17, 95%c I: 0.02-0.71, p = 0.020). The surgical procedure also had a positive impact on OS and DFS. The hazard ratio of distal gastrectomy vs total gastrectomy was 0.12(95%c I: 0.33-0.42, p = 0.001) for OS, and 0.13(95%c I: 0.36-0.44, p = 0.001) for DFS.CONCLUSION The NAc T-surgery interval time is associated with pc R but has no impact on survival, and an interval time > 6 wk has a relatively high odds of pc R.
基金supported by the Department of Anesthesiology and Pain Medicine,University of California Davis Health
文摘Valvular heart disease is a pathologic process involving one or more of the four valves(aortic,pulmonary,mitral and tricuspid)of the heart typified by stenosis or regurgitation and leading to patient symptoms.The most common causes are tissue degeneration,rheumatic fever and congenital heart diseases.Aortic valve replacement(AVR)using either mechanical or bioprosthetic(tissue)valves via open-heart surgical
文摘Pebble bed reactors use cycling scheme of spherical fuel elements relying on fuel elements cycling system (FECS). The structure and control logic of FECS are very complex. Each control link has strict requirements on time and sequence. This increases the difficulties of description and analysis. In this paper, timed places control Petri nets (TPCPN) is applied for the modeling of FECS. On this basis the simulation of two important processes, namely uploading fuel elements into the core for the first time and emptying the core is finished by simulation software Arena. The results show that as TPCPN is able to describe different kinds of logic relationship and has time properties and control properties, it’s very suitable for the modeling and analysis of FECS.
基金supported by the special program to enhance the navigation capacity of the Golden Waterway funded by the Ministry of Transport of the People’s Republic of China"Research on Key Techniques to Monitor and Simulate the River Flow and Sediment Transport"(Grant No.2011-328-746-40)
文摘Quantity of bed load is an important physical parameter in sediment transport research. Aiming at the difficulties in the bed load measurement, this paper develops a bottom-mounted monitor to measure the bed load transport rate by adopting the sedimentation pit method and resolving such key problems as weighing and desilting, which can achieve long-time, all-weather and real-time telemeasurement of the bed load transport rate of plain rivers, estuaries and coasts. Both laboratory and field tests show that this monitor is reasonable in design, stable in properties and convenient in measurement, and it can be used to monitor the bed load transport rate in practical projects.
基金Financial support of this work by National Natural Science Foundation of China(51976037)。
文摘The particle residence time distribution(RTD)and axial dispersion coefficient are key parameters for the design and operation of a pressurized circulating fluidized bed(PCFB).In this study,the effects of pressure(0.1-0.6 MPa),fluidizing gas velocity(2-7 m·s^(-1)),and solid circulation rate(10-90 kg·m^(-2)·s^(-1))on particle RTD and axial dispersion coefficient in a PCFB are numerically investigated based on the multiphase particle-in-cell(MP-PIC)method.The details of the gas-solid flow behaviors of PCFB are revealed.Based on the gas-solid flow pattern,the particles tend to move more orderly under elevated pressures.With an increase in either fluidizing gas velocity or solid circulation rate,the mean residence time of particles decreases while the axial dispersion coefficient increases.With an increase in pressure,the core-annulus flow is strengthened,which leads to a wider shape of the particle RTD curve and a larger mean particle residence time.The back-mixing of particles increases with increasing pressure,resulting in an increase in the axial dispersion coefficient.
文摘Objective:While a rushed operation can omit essential procedures,prolonged operative time results in higher morbidity.Nevertheless,the optimal operative time range remains uncertain.This study aimed to estimate the ideal operative time range and evaluate its applicability in laparoscopic cancer surgery.Methods:A prospectively collected multicenter database of 397 patients who underwent laparoscopic distal gastrectomy were retrospectively reviewed.The ideal operative time range was statistically calculated by separately analyzing the operative time of uneventful surgeries.Finally,intraoperative and postoperative outcomes were compared among the shorter,ideal,and longer operative time groups.Results:The statistically calculated ideal operative time was 135.4-165.4 min.The longer operative time(LOT)group had a lower rate of uneventful,perfect surgery than the ideal or shorter operative time(IOT/SOT)group(2.8%vs.8.8%and 2.2%vs.13.4%,all P<0.05).Longer operative time increased bleeding,postoperative morbidities,and delayed diet and discharge(all P<0.05).Particularly,an uneventful,perfect surgery could not be achieved when the operative time exceeded 240 min.Regardless of ideal time range,SOT group achieved the highest percentage of uneventful surgery(13.4%),which was possible by surgeon's ability to retrieve a higher number of lymph nodes and perform≥150 gastrectomies annually.Conclusions:Operative time longer than the ideal time range(especially≥240 min)should be avoided.If the essential operative procedure were faithfully conducted without compromising oncological safety,an operative time shorter than the ideal range leaded to a better prognosis.Efforts to minimize operative time should be attempted with sufficient surgical experience.
基金Supported by National Natural Science Foundation of P.R.China(60374001,60334030)the Chinese Ministry of Education(20030006003)
文摘This paper presents a robust model reference adaptive control scheme to deal with un-certain time delay in the dynamical model of a ?uidized bed combustor for sewage sludge. Thetheoretical analysis and simulation results show that the proposed scheme can guarantee not onlystability and robustness, but also the adaptive decoupling performance of the system.
文摘Anaerobic expanded bed reactor(AEBR) is mostly used for the treatment of fairly low strength wastewaters. Since the performance of AEBR largely depends on its hydraulic characteristics, residence time distribution(RTD) method is commonly used for investigation of the hydraulic characteristics of AEBR under different ascending velocity of mixed liquor. In this paper, a pilot-scale AEBR reactor is investigated for treatment of municipal sewage in which lithium chloride is used as a tracer. The results show that the AEBR could be considered as the superimposition of several constant stirred tank reactors(CSTR) and the increase of hydraulic up-flow velocity could increase the number of the CSTR and decrease the volume rate of the dead zone. The optimal up-flow velocity of the investigated AEBR was approximately 1.9 m/h in the municipal sewage treatment.
文摘Introduction: Experimental Clinical studies have shown that loss of up to 77.0% of red cell mass can be tolerated as long as it kept the blood volume. However, the blood volume loss of about 34.0% is fatal. The initial attention in patients with bleeding should be given to maintaining blood volume and oxygen transport. Thus, transfusions of allogeneic blood products are associated with an increased risk of morbidity and mortality in cardiac surgery. Some transfusion risk scores have been proposed for cardiac surgery patients. Objective: To review and discuss literature blood transfusion (blood components gradient) in cardiovascular surgery versus polytrauma, gastrointestinal bleeding, and neoplastic diseases. Methods: The model followed for the review was PRISMA. We used the databases as Scielo, Lilacs, Google Scholar, PubMed articles and works of scientific and doctoral theses master. Results: According to the discussion in the literature, the acute bleeding of large volumes is challenging to emergency services. Accordingly, the need to support hemotherapeutics led to the development of protocols for more rational utilization of the monitored blood components. Conclusion: Hemotherapy services have adopted a very dynamic approach to the clinical condition presented by patients, the need for four or more red blood cell units.
基金Supported by the National Natural Science Foundation of China (No. 20490201) the Ministry of Education of China through the Doctorate Discipline Foundation (No. 2000042503).
文摘In a spouted bed of 80mm in ID and 1700mm in height, the gas residence time distributions at different radial positions in both spout and annular area were measured with five different kinds of particles as spouting material, air as spouting gas, and hydrogen as tracer. The effects of superficial gas velocity, operating pressure, particle size and its category on gas residence time distribution were discussed. It was found that the gas velocity profile in spout was more uniform than that in annulus. It could be concluded that the gas flow in the spout could be treated as a plug-flow, while that in the annulus inhibited a strong non-ideal flow behavior. Increasing the superficial gas velocity and decreasing the operating pressure, the particle density and its size gave rise to spouting disturbance, thus the measured tracer concentrations vs. time curves fluctuated. The variances of residence time distribution curves could be taken as a measure of the gas fluctuation degree.
文摘<strong>Introduction:</strong> Gender differences are still quite prevalent in the present time. Although there is literature regarding gender differences in healthcare expenditure in India, there is no data regarding gender differences in hospital stay, hospital seeking behaviors and mortality. <strong>Aim:</strong> To evaluate the Gender differences in a hospital seeking behavior, mortality and hospital stay. <strong>Methods:</strong> We prospectively analyzed, from a retrospective database, all patients who underwent surgical gastrointestinal, hepato-biliary, pancreatic and splenic surgeries from 1996 to 2018 in our unit. Patients were divided into groups based on gender, admission time period and priority of admission i.e., elective or emergency. Both the gender groups were compared with respect to total procedures done, hospital stay and mortality. Organ specific mortality was calculated as proportions, was analyzed and compared between the groups. Time trends of the same were observed and compared. <strong>Results:</strong> Of 12,411 patients, 7979 (64.3%) were males and 4432 (35.7%) were females. 9191 (74.1%) patients underwent elective procedures whereas 3220 (25.9%) had emergency procedures (<strong>p ≤ 0.001</strong>). Overall mortality was higher in males (n = 473, 5.92%) in comparison to females (n = 185, 4.17%) (p ≤ 0.001). Majority of surgeries in males were of small intestine (22.5%) in which small bowel resection was most commonly done (5.4%), whereas, gallbladder and biliary surgeries (27.4%) were the most common in females in which laparoscopic cholecystectomy was most commonly done (5.8%). Median hospital stay was higher in males (10 days vs 9 days), (<strong>p ≤ 0.001</strong>). Mortality was higher in females in all organ categories except in liver (6.34% vs 2.7%), pancreas (37.3% Vs 18.3%) and spleen (3.38% Vs 1.62%) where mortality was higher for male gender. Highest mortality for females was in small intestinal surgery (34%) and for males, it was pancreatic surgery (37.3%). Highest mortality in males was emergency open pancreatic necrosectomy (21.6%) and that in females was emergency small intestinal surgery (11.9%). Although the number of surgeries in females increased over time (380 in 1996-1999 Vs 951 in 2016-2018), the proportion remained constant (36.3% Vs 38.3% in 1996-1999 and 2016-2018 respectively). <strong>Conclusion:</strong> We conclude that mortality is found to be higher in males after gastrointestinal surgery, which may be explained by the fact that hospital seeking behavior is more in males though it is fairly increasing in females in the recent years.
基金Ethical approval was obtained from the Imam Abdulrahman Bin Faisal University review board(IRB-UGS-2019-01-333)。
文摘BACKGROUND Supracondylar humerus fractures account for more than 60%of all elbow fractures and about 1/5 of all pediatric fractures.Unfortunately,these fractures can be associated with risk of complications including neurovascular injuries,malunions and limb deformities.Controversy exists regarding the effect of time of surgical intervention and/or level of surgeon performing the surgery on outcome of these fractures.AIM To determine whether time of surgical intervention and/or surgeon level influence the outcomes of surgically managed pediatric supracondylar humerus fractures.METHODS We retrospectively studied 155 pediatric patients presenting with a supracondylar humerus fracture in a level 1 trauma center from January 2006 to December 2019.The data extracted included demographic data,fracture characteristics,surgical data,and follow-up outcomes.The collected data was analyzed and P values of<0.05 were considered statistically significant.RESULTS Of the cohort,11%of patients had documented post-operative complications,of which the majority occurred in surgeries performed after day time working hours and in fractures requiring open reduction.While the lowest complication rate was found in surgeries performed by pediatric orthopaedic surgeons,this did not reach statistical significance.CONCLUSION In pediatric patients undergoing surgery for supracondylar fractures,we found a higher complication rate when surgeries were not performed during working hours.Surgeon level and training had no significant effect on the risk of post-operative complications.
文摘Ordovician fracture-cavity carbonate reservoir beds are the major type of producing formations in the Tahe oilfield, Tarim Basin. The seismic responses of these beds clearly changes depending on the different distance of the fracture-cavity reservoir bed from the top of the section. The seismic reflection becomes weak or is absent when the fracture-cavity reservoir beds are less than 20 ms below the top Ordovician. The effect on top Ordovician reflection became weaker with deeper burial of fracture-cavity reservoir beds but the developed deep fracture-cavity reservoir beds caused stronger reflection in the interior of the Ordovician. This interior reflection can be divided into strong long-axis, irregular and bead string reflections, and was present 80 ms below the top Ordovician. Aimed at understanding reflection characteristics, the spectral decomposition technique, which uses frequency to "tune-in" bed thickness, was used to predict Ordovician fracture-cavity carbonate formations in the Tahe oilfield. Through finely adjusting the processing parameters of spectral decomposition, it was found that the slice at 30 Hz of the tuned data cube can best represent reservoir bed development. Two large N-S-trending strong reflection belts in the mid-western part of the study area along wells TK440- TK427-TK417B and in the eastern part along wells TK404-TK409 were observed distinctly on the 30 Hz slice and 4-D time-frequency data cube carving. A small N-S trending reflection belt in the southern part along wells T403-TK446B was also clearly identified. The predicted reservoir bed development area coincides with the fracture-cavities connection area confirmed by drilling pressure testing results. Deep karst cavities occur basically in three reservoir bed-development belts identified by the Ordovician interior strong reflection. Spectral decomposition proved to be a useful technique in identifying fracture-cavity reservoir beds.
文摘Background: Insufficient capacity for cardiac surgery results in extensive waiting time for patients requiring coronary artery bypass grafting (CABG). Previous studies have reported a consequence of an increased risk of mortality while waiting for CABG. Identification of risk factors for mortality is important in patients waiting for CABG. Objectives: To assess mortality rates and identify risk factors for mortality of patients waiting for CABG. Methods: This retrospective cohort study was done on patients waiting for elective CABG in dr. Kariadi General Hospital from January 2018 to December 2020. Identification of risk factors associated with mortality was done on patients who were waiting for CABG using logistic regression methods. Results: There were 162 patients fulfilling the criteria, with a mean waiting time for surgery of 9.8 months. While waiting for CABG surgery, 32 (19.7%) patients died of any cause. Independent risk factors for death while waiting for CABG included left ventricular ejection fraction ≤ 45% (OR 4.75;95% CI 1.76 - 12.78;p = 0.002), left main disease (OR 4.12;95% CI 1.50 - 11.27;p = 0.006), serum creatinine ≥ 1.5 mg/dl (OR 3.71;95% CI 1.41 - 9.74;p = 0.008), and a number of coronary artery disease risk factors ≥ 3 (OR 3.34;95% CI 1.24 - 8.99;p = 0.017). Conclusions: Long waiting time for CABG is associated with a high mortality rate which is influenced by left ventricular ejection fraction ≤ 45%, left main disease, serum creatinine ≥ 1.5 mg/dl, and a number of coronary arteries disease risk factors ≥ 3.
基金supported mainly by the “Agence de la Biomedecine” through its program of Research(AOR 2009)BM,AC,BP,WM,VCI and VE acknowledged funding of project ANR-13-TECS-0006 by the Agence Nationale de la Recherche
文摘Background: The hepatic hemodynamics is an essential parameter in surgical planning as well as in various disease processes. The transit time ultrasound(TTUS) perivascular flow probe technology is widely used in clinical practice to evaluate the hepatic inflow, yet invasive. The phase-contrast-MRI(PC-MRI) is not invasive and potentially applicable in assessing the hepatic blood flow. In the present study, we compared the hepatic inflow rates using the PC-MRI and the TTUS probe, and evaluated their predictive value of post-hepatectomy adverse events. Methods: Eighteen large white pigs were anaesthetized for PC-MRI and approximately 75% hepatic resection was performed under a unified protocol. The blood flow was measured in the hepatic artery(Qha), the portal vein(Qpv), and the aorta above the celiac trunk(Qca) using PC-MRI, and was compared to the TTUS probe. The Bland-Altman method was conducted and a partial least squares regression(PLS) model was implemented. Results: The mean Qpv measured in PC-MRI was 0.55 ± 0.12 L/min, and in the TTUS probe was 0.74 ± 0.17 L/min. Qca was 1.40 ± 0.47 L/min in the PC-MRI and 2.00 ± 0.60 L/min in the TTUS probe. Qha was 0.17 ± 0.10 L/min in the PC-MRI, and 0.13 ± 0.06 L/min in the TTUS probe. The Bland-Altman method revealed that the estimated bias of Qca in the PC-MRI was 32%(95% CI:-49% to 15%); Qha 17%(95% CI:-15% to 51%); and Qpv 40%(95% CI:-62% to 18%). The TTUS probe had a higher weight in predicting adverse outcomes after 75% resection compared to the PC-MRI( β= 0.35 and 0.43 vs β = 0.22 and 0.07, for tissue changes and premature death, respectively). Conclusions: There is a tendency of the PC-MRI to underestimate the flow measured by the TTUS probes. The TTUS probe measures are more predictive of relevant post-hepatectomy outcomes.