Exploring ideal operative time for best outcomes in gastric cancer surgery:A multi-institutional study based on KLASS-07 database

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.

Radiation therapy prior to a pancreaticoduodenectomy for adenocarcinoma is associated with longer operative times and higher blood loss

BACKGROUND Pancreatic adenocarcinoma is currently the fourth leading cause of cancer-related deaths in the United States.In patients with“borderline resectable”disease,current National Comprehensive Cancer Center guidelines recommend the use of neoadjuvant chemoradiation prior to a pancreaticoduodenectomy.Although neoadjuvant radiotherapy may improve negative margin resection rate,it is theorized that its administration increases operative times and complexity.AIM To investigate the association between neoadjuvant radiotherapy and 30-d morbidity and mortality outcomes among patients receiving a pancreaticoduodenectomy for pancreatic adenocarcinoma.METHODS Patients listed in the 2015-2019 National Surgery Quality Improvement Program data set,who received a pancreaticoduodenectomy for pancreatic adenocarcinoma,were divided into two groups based off neoadjuvant radiotherapy status.Multivariable regression was used to determine if there is a significant correlation between neoadjuvant radiotherapy,perioperative blood transfusion status,total operative time,and other perioperative outcomes.RESULTS Of the 11458 patients included in the study,1470(12.8%)underwent neoadjuvant radiotherapy.Patients who received neoadjuvant radiotherapy were significantly more likely to require a perioperative blood transfusion[adjusted odds ratio(aOR)=1.58,95%confidence interval(CI):1.37-1.82;P<0.001]and have longer surgeries(insulin receptor-related receptor=1.14,95%CI:1.11-1.16;P<0.001),while simultaneously having lower rates of organ space infections(aOR=0.80,95%CI:0.66-0.97;P=0.02)and pancreatic fistula formation(aOR=0.50,95%CI:0.40-0.63;P<0.001)compared to those who underwent surgery alone.CONCLUSION Neoadjuvant radiotherapy,while not associated with increased mortality,will impact the complexity of surgical resection in patients with pancreatic adenocarcinoma.

Associate factors for endoscopic submucosal dissection operation time and postoperative delayed hemorrhage of early gastric cancer

BACKGROUND Endoscopic submucosal dissection(ESD)is a treatment for early gastric cancer with the advantages of small invasion,fewer complications,and a low local recurrence rate.However,there is a high risk of complications such as bleeding and perforation,and the operation time is also longer.ESD operation time is closely related to bleeding and perforation.AIM To investigate the influencing factors associated with ESD operation time and postoperative delayed hemorrhage to provide a reference for early planning,early identification,and prevention of complications.METHODS We conducted a retrospective study based on the clinical data of 520 patients with early gastric cancer in the Second Affiliated Hospital of Hainan Medical University from January 2019 to December 2021.The baseline data,clinical features,and endoscopic and pathological characteristics of patients were collected.The multivariate linear regression model was used to investigate the influencing factors of ESD operation time.Logistic regression analysis was carried out to evaluate the influencing factors of postoperative delayed hemorrhage.RESULTS The multivariate analysis of ESD operation time showed that the maximum lesion diameter could affect 8.815%of ESD operation time when other influencing factors remained unchanged.The operation time increased by 3.766%or 10.247%if the lesion was mixed or concave.The operation time increased by 4.417%if combined with an ulcer or scar.The operation time increased by 3.692%if combined with perforation.If infiltrated into the submucosa,it increased by 2.536%.Multivariate analysis of delayed hemorrhage after ESD showed that the maximum diameter of the lesion,lesion morphology,and ESD operation time were independent influencing factors for delayed hemorrhage after ESD.Patients with lesion≥3.0 cm(OR=3.785,95%CI:1.165-4.277),lesion morphology-concave(OR=10.985,95%CI:2.133-35.381),and ESD operation time≥60 min(OR=2.958,95%CI:1.117-3.526)were prone to delayed hemorrhage after ESD.CONCLUSION If the maximum diameter of the lesion in patients with early gastric cancer is≥3.0 cm,and the shape of the lesion is concave,or accompanied by an ulcer or scar,combined with perforation,and infiltrates into the submucosa,the ESD operation will take a longer time.When the maximum diameter of the lesion is≥3.0 cm,the shape of the lesion is concave in patients and the operation time of ESD takes longer time,the risk of delayed hemorrhage after ESD is higher.

Combined hybrid energy storage system and transmission grid model for peak shaving based on time series operation simulation

This study proposes a combined hybrid energy storage system(HESS) and transmission grid(TG) model, and a corresponding time series operation simulation(TSOS) model is established to relieve the peak-shaving pressure of power systems under the integration of renewable energy. First, a linear model for the optimal operation of the HESS is established, which considers the different power-efficiency characteristics of the pumped storage system, electrochemical storage system, and a new type of liquid compressed air energy storage. Second, a TSOS simulation model for peak shaving is built to maximize the power entering the grid from the wind farms and HESS. Based on the proposed model, this study considers the transmission capacity of a TG. By adding the power-flow constraints of the TG, a TSOS-based HESS and TG combination model for peak shaving is established. Finally, the improved IEEE-39 and IEEE-118 bus systems were considered as examples to verify the effectiveness and feasibility of the proposed model.

Routine laboratory parameters in patients with necrotizing pancreatitis by the time of operative pancreatic debridement:Food for thought

BACKGROUND Timing of invasive intervention such as operative pancreatic debridement(OPD)in patients with acute necrotizing pancreatitis(ANP)is linked to the degree of encapsulation in necrotic collections and controlled inflammation.Additional markers of these processes might assist decision-making on the timing of surgical intervention.In our opinion,it is logical to search for such markers among routine laboratory parameters traditionally used in ANP patients,considering simplicity and cost-efficacy of routine laboratory methodologies.AIM To evaluate laboratory variables in ANP patients in the preoperative period for the purpose of their use in the timing of surgery.METHODS A retrospective analysis of routine laboratory parameters in 53 ANP patients undergoing OPD between 2017 and 2020 was performed.Dynamic changes of routine hematological and biochemical indices were examined in the preoperative period.Patients were divided into survivors and non-survivors.Survivors were divided into subgroups with short and long post-surgery length of stay(LOS)in hospital.Correlation analysis was used to evaluate association of laboratory variables with LOS.Logistic regression was used to assess risk factors for patient mortality.RESULTS Seven patients(15%)with severe acute pancreatitis(SAP)and 46 patients(85%)with moderately SAP(MSAP)were included in the study.Median age of participants was 43.2 years;33(62.3%)were male.Pancreatitis etiology included biliary(15%),alcohol(80%),and idiopathic/other(5%).Median time from diagnosis to OPD was≥4 wk.Median postoperative LOS was at the average of 53 d.Mortality was 19%.Progressive increase of platelet count in preoperative period was associated with shortened LOS.Increased aspartate aminotransferase and direct bilirubin(DB)levels the day before the OPD along with weak progressive decrease of DB in preoperative period were reliable predictors for ANP patient mortality.CONCLUSION Multifactorial analysis of dynamic changes of routine laboratory variables can be useful for a person-tailored timing of surgical intervention in ANP patients.

Effect of body mass index on the operation time and postoperative hospital stay of retroperitoneal laparoscopic renal cyst decortication

Objective:To investigate the effect of body mass index(BMI)on the operation time and postoperative hospital stay for patients who underwent retroperitoneal laparoscopic decortication for a single simple renal cyst.Methods:A retrospective cohort study was conducted among 81 patients with single simple renal cyst who had undergone retroperitoneal laparoscopic cyst decortication from January 2017 to December 2019 in Wuxi Xishan People's Hospital.All patients were divided into three groups according to BMI:normal group(BMI<25 kg/m^(2),n=44),overweight group(BMI=25-30 kg/m^(2),n=21),and obese group(BMI>30 kg/m^(2),n=16).Multiple linear regression was conducted to investigate the correlation.Results:The three groups were comparable in terms of age,gender,maximum diameter of cyst,and cyst location.In the aspect of operation time,only the patients in obese group had longer duration when compared with those in the normal group(59.1±15.7 min vs.45.2±12.8 min,p=0.001).And the patients in the obese group had significantly longer hospital stay compared with those in the normal group(6.2±1.9 d vs.5.2±0.5 d,p=0.002)and overweight group(6.2±1.9 d vs.5.0±1.0d,p=0.001).In the analysis of multiple linear regression,it was found that operation time is significantly affected by BMI and location 2,with coefficients of 1.299 and -8.646 respectively.The influence of BMI was greater than location 2(0.335 vs.-0.289).For hospital stay,only BMI had an effect on it,with a coefficient of 0.110.Conclusion:BMI was a major factor that associated with longer operation time and hospital stay in patients with retroperitoneal laparoscopic renal cyst decortication.

Operative timing of liver transplantation for patients with severe hepatitis

BACKGROUND: Fulminant hepatic failure manifests a rapid onset, serious complications, and a high mortality, but still there is a possibility of recovery. Once the patient is able to pass a crisis, the liver is able to regenerate completely and regain its normal function. Therefore it is of vital importance to determine the eligible timing for transplantation. Premature surgery might result in a loss of the chance of internal medical treatment and misuse of liver resources, whereas delayed surgery might increase the difficulty of treatment in the preoperative period and the possibility of complications and medical expense, which eventually result in decreased rate of success and survival. This problem remains worldwide how to choose the optional timing of operation. METHODS: Thirty-six patients with severe hepatitis were treated by orthotopic liver transplantation. The distribution of MELD scores in these patients was: 10-19 in 8 patients, 20-29 in 10, 30-39 in 11, and 40 in 7. They were divided into two groups: MELD score <30 and MELD score >= 30. Parameters (1-year survival rate, complications, preoperative use of artificial liver, operative time, volume of bleeding and blood transfusion, and average hospital costs) were examined as prognostic factors after liver transplantation. RESULTS: The I-year survival rate of the MELD score <30 group was higher than that of the >= 30 group (77.8% and 33.3%, P=0.007), and the rate of complications in the <30 group was lower (P=0.012). There were no differences in the timing of artificial liver treatment, operative time, operative hemorrhage, and transfusion between the two groups (P=0.742). But the average daily hospital cost in the MELD score >= 30 group was higher (P=0.008). CONCLUSION: This study shows that when the MELD score is <30 it may be the optimal time to perform liver transplantation for patients with severe hepatitis.

Clinical efficacy and safety of kyphoplasty for the treatment of osteoporotic vertebral compression fractures at different surgical timings based on the theory of“dynamic-static integration”

Objective:To investigate the clinical efficacy and safety of percutaneous kyphoplasty at different surgical timings in the treatment of osteoporotic vertebral compression fracture(OVCF)based on the theory of“dynamic-static integration”.Methods:Patients with OVCF who underwent percutaneous kyphoplasty in our hospital were selected and divided into Groups A,B,and C for those undergoing surgery within 7,7—21,and>21 days of fracture occurrence.The variations in the amount of bone cement injected,pre-and post-operative pain levels,functional activity,deformity correction of the injured vertebrae,bone cement leakage,and vertebral body height loss were compared among the three groups.Results:Regarding pain relief and functional activity,the postoperative Visual Analog Scale and Oswestry Disability Index scores of the three groups significantly improved.Furthermore,the deformities of the injured vertebrae in the three groups were significantly corrected,with Groups A and B exhibiting superior correction compared to Group C.Moreover,the bone cement leakage rates in groups A and C were higher than that in Group B.At the 3-month follow-up,the loss of vertebral height in Group C was significantly higher than those in groups A and B.Conclusion:Kyphoplasty is effective for OVCF treatment.Early surgery can effectively restore the vertebral height of the injured vertebra,reduce kyphosis,and reduce height loss of the injured vertebra after surgery;nevertheless,treatment within 1—3 weeks of the fracture can reduce the occurrence of bone cement leakage,making the surgery safer.Therefore,surgical treatment within 1—3 weeks of fracture is safer and can achieve satisfactory therapeutic effects.From the perspective of traditional Chinese medicine,PKP surgery can transform the fracture end from a micromotion state to a fixed state,which fully embodies the theory of“dynamic-static integration”.

Cooperative algorithm for improving network connectivity in clustered wireless sensor networks

In order to improve network connectivity in clustered wireless sensor networks,a node cooperative algorithm based on virtual antenna arrays is proposed.All the nodes in the network are assumed to be clustered via Poisson Voronoi tessellation（PVT）.The activation of the node cooperative algorithm is determined by the cluster heads（CHs） according to communication links.When the cooperative algorithm is activated,the CH selects cooperative nodes（CNs） from its members to form a virtual antenna array.With the cooperation,nodes can extend the inter-cluster communication range to directly contact with further nodes after a coverage hole is detected,or compensate for channel gains while inter-cluster transmission fails due to deep channel fading.Simulation results show that the proposed algorithm achieves better network connectivity and energy efficiency.It can reduce outage probability,sustain network connectivity and maintain operations as long as possible,which prolongs network operation time.

Finite-difference time-domain studies of low-frequency stop band in superconductor-dielectric superlattice

The transmission coefficients of electromagnetic （EM） waves due to a superconductor-dielectric superlattice are numerically calculated. Shift operator finite difference time domain （SO-FDTD） method is used in the analysis. By using the SO-FDTD method, the transmission spectrum is obtained and its characteristics are investigated for different thicknesses of superconductor layers and dielectric layers, from which a stop band starting from zero frequency can be apparently observed. The relation between this low-frequency stop band and relative temperature, and also the London penetration depth at a superconductor temperature of zero degree are discussed, separately. The low-frequency stop band properties of superconductor-dielectric superlattice thus are well disclosed.

Analytical Solution for Single—Mode Time—Dependent Oscillator

Based on the general theory of time-dependent quantum transformation, we use the 'time evolutionoperator' method to solve the single-mode time-dependent oscillator.

The effect of weeding frequency and schedule on weeding operation time: a simulation study on a sugi (Cryptomeria japonica) plantation in Japan

This study quantified the effect of weeding frequency and weeding schedules on weeding operation time in a sugi(Cryptomeria japonica)plantation stand.A weeding operation time estimation model was developed;then the cumulative weeding operation time after six growing seasons was simulated using the developed model.The developed model included weed height,relative height of weeds to sugi,and initial planting density.The simulated cumulative weeding operation time decreased approximately 6%for each one-treatment decrease in weeding frequency.Under a three-treatment weeding frequency scenario,the simulated cumulative operation time when weeding was conducted during non-consecutive years was longer than that when weeding was conducted during three consecutive years.The results suggest that carrying out weeding treatment during consecutive years is the more effective for reduction of weeding costs.We conclude that weeding schedule as well as weeding frequency must be considered for reduction of weeding operation time.

Estimation of Standard Operation Time of Flight Legs Based on Clustering and Probability Analysis

A clustering algorithm and a probability statistics method were applied to different phases of a flight to analyze operation time during aircraft ground taxiing and airborne flight.And the clustering pattern,distribution characteristics and dynamically changing rules of the two phases were identified.Further,an estimate method was established to measure operation time of flight legs,with creative steps of calculating individual segment separately and then integrating them accordingly.The method can both objectively and dynamically measure operation time,and accurately reflect real situation.It helps to better utilize airport slot resources and provides a strong support for air traffic flow management when scheduling flight plan in strategic and pre-tactic phases.

Operative timing and indications for patients with severe acute pancreatitis: report of 172 cases

Objective: To investigate the operative timing and indi-cations for severe acute pancreatitis(SAP).Methods: Data collected from 172 patients with SAPtreated in our hospital since 1980 were analyzed retro-spectively.Results: In the 94 patients who had undergone early op-eration before June 1992, 57 (62.8%) healed, 35 (37.2%)died, and 16 (17.0%) had no postoperative compli-cations. In the 78 patients who had been treated after July1992 according to the principle of individualization, 66(84.6%) healed, 12 (15.4%) died, and 37 (47.4%)had no postoperative complications. In the 78 patients32 received non-operative treatment but 30 (93.8%)cured, 12 early operation but 7(58.3%)cured, 18 lateoperation but 13 (72.2%) cured, and 16 selected timeoperation but all cured.Conclusions: It is concluded that individualized thera-py is effective and reasonable for treating SAP. Theindications for early, late and selected time operationshould be emphasized.

Time and Energy Operators in Quantum Mechanics

Starting from a time operator, the form of the so called energy operator that is conjugate to the time operator is derived in time representation by analyzing the properties of time translation. This analysis also establishes the commutator between the time and the energy operators. It is seen from the analysis that the energy operator has nothing to do conceptually with the Hamiltonian operator of a system, so that the time operator is not conjugate to the Hamiltonian. Furthermore, it is shown that the Hermiticity of the energy operator requires introducing time integrate inner product. The time energy commutator and the time integral inner product put the time energy uncertainty relation on the same footing as the position momentum uncertainty relation.

Dynamical time versus system time in quantum mechanics

Properties of an operator representing the dynamical time in the extended parameterization invariant formulation of quantum mechanics are studied. It is shown that this time operator is given by a positive operator measure analogously to the quantities that are known to represent various measurable time operators. The relation between the dynamical time of the extended formulation and the best known example of the system time operator, i.e., for the free one- dimensional particle, is obtained.

High performance reconfigurable hardware system for real-time image processing

A novel reconfigurable hardware system which uses both muhi-DSP and FPGA to attain high performance and real-time image processing are presented. The system structure and working principle of mainly processing multi-BSP board, extended multi-DSP board are analysed. The outstanding advantage is that the communication among different board components of this system is supported by high speed link ports ＆ serial ports for increasing the system performance and computational power. Then the implementation of embedded real-time operating systems （RTOS） by us is discussed in detail. In this system, we adopt two kinds of parallel structures controlled by RTOS for parallel processing of algorithms. The experimental results show that exploitive period of the system is short, and maintenance convenient. Thus it is suitable for real-time image processing and can get satisfactory effect of image recognition.

Evolution and Generation of Dynamics of Two-Mode Squeezed States of Time-Dependent Coupled Boson System

The system of the Hamiltonian involving a driving part,a single mode part,and a two-mode squeezedone and a two-mode coupled one is discussed using the Lewis-Riesenfeld invariant theory.The time evolution operatoris obtained.When the initial state is a coherent state,the quantum fluctuation of the system is calculated,and it isdependent on the squeezed part and the two-mode coupled part,but not dependent on the driving one.

Improving entanglement of assistance by local parity–time symmetric operation

We investigate entanglement of assistance without and with decoherence using a local non-Hermitian operation, i.e.,parity–time(PT) symmetric operation. First we give the explicit expressions of entanglement of assistance for a general W-like state of a three-qubit system under a local parity–time symmetric operation. Then for a famous W state without decoherence, we find that entanglement of assistance shared by two parties can be obviously enhanced with the assistance of the third party by a local parity–time symmetric operation. For the decoherence case, we provide two schemes to show the effects of local parity–time symmetric operation on improvement of entanglement of assistance against amplitude damping noise. We find that for the larger amplitude damping case the scheme of PT symmetric operation performed on one of two parties with the influence of noise is superior to that of PT symmetric operation performed on the third party without the influence of noise in suppressing amplitude damping noise. However, for the smaller amplitude damping case the opposite result is given. The obtained results imply that the local PT symmetric operation method may have potential applications in quantum decoherence control.

A Note on the Expectation Value of Time

In this note, the expectation value of time based on quantum mechanics formalism is derived. It is found that the expectation value of time does not depend on space.