The pain following gynecological laparoscopic surgery is less intense than that following open surgery; however, patients often experience visceral pain after the former surgery. The aim of this study was to determine...The pain following gynecological laparoscopic surgery is less intense than that following open surgery; however, patients often experience visceral pain after the former surgery. The aim of this study was to determine the effects of preemptive ketamine on visceral pain in patients undergoing gynecological laparoscopic surgery. Ninety patients undergoing gynecological laparoscopic surgery were randomly assigned to one of three groups. Group 1 received placebo. Group 2 was intravenously injected with preincisional saline and local infiltration with 20 m L ropivacaine（4 mg/m L） at the end of surgery. Group 3 was intravenously injected with preincisional ketamine（0.3 mg/kg） and local infiltration with 20 m L ropivacaine（4 mg/m L） at the end of surgery. A standard anesthetic was used for all patients, and meperidine was used for postoperative analgesia. The visual analogue scale（VAS） scores for incisional and visceral pain at 2, 6, 12, and 24 h, cumulative analgesic consumption and time until first analgesic medication request, and adverse effects were recorded postoperatively. The VAS scores of visceral pain in group 3 were significantly lower than those in group 2 and group 1 at 2 h and 6 h postoperatively（P〈0.05 and P〈0.01, respectively）. At 2 h and 6 h, the VAS scores of incisional pain did not differ significantly between groups 2 and 3, but they were significantly lower than those in group 1（P〈0.01）. Groups 1 and 2 did not show any differences in visceral pain scores at 2 h and 6 h postoperatively. Moreover, the three groups showed no statistically significant differences in visceral and incisional pain scores at 12 h and 24 h postoperatively. The consumption of analgesics was significantly greater in group 1 than in groups 2 and 3, and the time to first request for analgesics was significantly longer in groups 2 and 3 than in group 1, with no statistically significant difference between groups 2 and 3. However, the three groups showed no significant difference in the incidence of shoulder pain or adverse effects. Preemptive ketamine may reduce visceral pain in patients undergoing gynecological laparoscopic surgery.展开更多
In order to study the epidemiological characteristics of cytomegalovirus(CMV)infection in allogeneichematopoietic stem cell transplantation(allo-HSCT)recipients by means of plasma real time quantitative polymerasechai...In order to study the epidemiological characteristics of cytomegalovirus(CMV)infection in allogeneichematopoietic stem cell transplantation(allo-HSCT)recipients by means of plasma real time quantitative polymerasechain reaction(RQ-PCR),141 adult patients undergoing allo-HSCT between January 2008 and June 2010 were seriallymonitored by RQ-PCR for detecting CMV and guiding the preemptive therapy followed up to 180 days post-HSCT.Theresults showed that the incidence of CMV infection and CMV pneumonia was 81.5%and 2.9%respectively,whichmainly occurred within 2 months post-HSCT.Single-therapy with ganciclovir(GCV)for 63 patients or foscarnet 6patients was performed for preemptive therapy.The total efficacy was 87.8%,and the response patterns were different.CMV infection was more frequent in female patients(P=0.044),and those with aGVHD(P=0.043),using ATG orbasiliximab in conditioning regimens(P=0.049),as well as earlier in patients using ATG or basiliximab or those withaGVHD(P=0.007;P=0.000).The aGVHD,maximum load,positive times of CMV-DNA detection and therapyduration all correlated with the efficacy(P<0.05).It is concluded that the incidence of CMV infection is still high afterHSCT.Plasma RQ-PCR assay for CMV-DNA shows a strong correlation with the clinical outcome of CMV infection,which is useful and suitable for management of CMV infection in HSCT.展开更多
BACKGROUND： Preemptive .analgesia involves introducing an analgesic prior to the onset of pain stimulation to prevent sensitizing the nervous system to subsequent stimuli that could amplify pain. OBJECTIVE： To treat...BACKGROUND： Preemptive .analgesia involves introducing an analgesic prior to the onset of pain stimulation to prevent sensitizing the nervous system to subsequent stimuli that could amplify pain. OBJECTIVE： To treat psychiatric patients with intravenous （i.v.） injection of butorphanol prior to modified electroconvulsive therapy, and to observe its effect on alleviating myalgia after treatment and adverse reactions. DESIGN： A randomized controlled observation. SETTING： Renmin Hospital of Wuhan University. PARTICIPANTS： A total of 120 psychiatric patients, who accepted modified electroconvulsive therapy, were selected from the Mental Health Center of Wuhan University from June to September in 2006. All patients corresponded to the Chinese Classification and Diagnostic Criteria of Mental Disorders, and those with diseases of heart, liver, lung and kidney, glaucoma, intracranial hypertension, hyperthyreosis, and hyperkalemia were excluded. The patients were randomly divided into a control group （n = 60） and treatment group （n = 60）. In the control group, there were 42 males and 18 females, aged 17-50 years, with a mean age of （34 ± 11） years. The patients weighed 50-70 kg, with a mean body mass of （63 ± 18） kg. In the treatment group, there were 40 males and 20 females, aged 20-54 years, with a mean age of （36 ± 13） years. The patients weighed 48-72 kg, with a mean body mass of （64 ± 16） kg. Approval was obtained from the Hospital＇s Ethics Committee. Informed consents were obtained from the patients＇ relatives. A SPECTRUM5000Q multifunctional mobile electroconvulsive therapy apparatus （CORPERATION, USA） was used. METHODS： （1） Treatments： In the control group, the patients were anesthetized by i.v. injection of propofol （AstraZeneca, Italy, No.CN309） containing 0.075% efedrina, and then modified electroconvulsive therapy was performed. Circulation, respiration, and firing of brain electrical activity were continuously monitored. In the treatment group, the patients were i.v. injected with 1 mg of butorphanol tartrate parenteral solution （Jiangsu Hengrui Medicine Co., Ltd., No.05100732） 5 minutes prior to anesthesia; the remaining treatments were the same as in the control group. （2） Evaluations： myalgia conditions were assessed 6 hours after the patients opened their eyes. The patients were evaluated by a visual analogue scale and Ramsay sedation scale immediately, and at 3 minutes and 6 hours after they opened their eyes. MAIN OUTCOME MEASURES： （1） Conditions of myalgia. （2） Scores of visual analogue scale and Ramsay sedation scale. RESULTS： All 120 psychiatric patients were involved in the final analysis. （1） Conditions of myalgia： 6 hours after modified electroconvulsive therapy, 22 patients in the control group and 1 patient in the treatment group complained of myalgia, which resulted in a significant difference between the two groups （P 〈 0.05）. （2） Scores of visual analogue scale and Ramsay sedation scale： the scores of visual analogue scale at 30 minutes and 6 hours after opening eyes were significantly lower in the treatment group than the control group （P 〈 0.05）, and the scores of Ramsay sedation scale were not significantly different between the two groups （P 〉 0.05）. CONCLUSION： Preemptive analgesia by butorphanol can effectively alleviate modified electroconvulsive therapy-induced myalgia, without adverse reactions.展开更多
Background and Objective: Post-operative nausea and vomiting (PONV) is a common adverse effect of the anesthesia in laparoscopic surgery. Ondansetron has been used for prevention and treatment of the PONV. The purpose...Background and Objective: Post-operative nausea and vomiting (PONV) is a common adverse effect of the anesthesia in laparoscopic surgery. Ondansetron has been used for prevention and treatment of the PONV. The purpose of the present study was to compare the effects of preemptive and preventive intravenous ondansetron on PONV in patients undergoing diagnostic gynecologic laparoscopy. Materials & Methods: In a randomized double-blind clinical trial, 80 women candidate of diagnostic laparoscopy, were enrolled to study in two preemptive or preventive groups (n = 40). Ondansetron 4 mg IV was administered 5 min before anesthesia induction or 5 min before extubation in preemptive or preventive groups, respectively. The frequency and severity of the PONV were compared at post-anesthetic care unit (PACU), 3th, 6th and 24th postoperatively in two groups. Also the first time of need for the antiemetic drug was studied. Results: Demographic data were similar but duration of anesthesia was shorter in preventive group. The PONV rate was similar in two groups [(37.5% and 32.5% in preemptive and preventive groups, respectively (P = 0.815)]. In preemptive group it was more intense at PACU and 24 hours after surgery (P-value <0.05) and rate of vomiting was high (11 vs. 3, P-value 0.037). The first request for antiemetic drug was earlier and the antiemetic consumption dose (P-value <0.05), recovery and hospital stay times were high in preemptive group (P-value = 0.001). Conclusion: Preventive ondansetron is more effective than preemptive form, in reducing the severity of PONV but not rate of the PONV in diagnostic gynecologic laparoscopy.展开更多
AIM To evaluate the outcomes of transplanting marginal kidneys preemptively compared to better-quality kidneys after varying dialysis vintage in older recipients.METHODS Using OPTN/United Network for Organ Sharing dat...AIM To evaluate the outcomes of transplanting marginal kidneys preemptively compared to better-quality kidneys after varying dialysis vintage in older recipients.METHODS Using OPTN/United Network for Organ Sharing database from 2001-2015, we identified deceased donor kidney(DDK) transplant recipients > 60 years of age who either underwent preemptive transplantation of kidneys with kidney donor profile index(KDPI) ≥ 85%(marginal kidneys) or received kidneys with KDPI of 35%-84%(better quality kidneys that older wait-listed patients would likely receive if waited longer) after being on dialysis for either 1-4 or 4-8 years. Using a multivariate Cox model adjusting for donor, recipient and transplant related factors-overall and death-censored graft failure risks along with patient death risk of preemptive transplant recipients were compared to transplant recipients in the 1-4 and 4-8 year dialysis vintage groups.RESUTLS The median follow up for the whole group was 37 mo(interquartile range of 57 mo). A total of 6110 DDK transplant recipients above the age of 60 years identified during the study period were found to be eligible to be included in the analysis. Among these patients350 received preemptive transplantation of kidneys with KDPI ≥ 85. The remaining patients underwent transplantation of better quality kidneys with KDPI 35-84% after being on maintenance dialysis for either 1-4 years(n = 3300) or 4-8 years(n = 2460). Adjusted overall graft failure risk and death-censored graft failure risk in preemptive high KDPI kidney recipients were similar when compared to group that received lower KDPI kidney after being on maintenance dialysis for either 1-4 years(HR 1.01, 95%CI: 0.90-1.14, P = 0.84 and HR 0.96, 95%CI: 0.79-1.16, P = 0.66 respectively) or 4-8 years(HR 0.82, 95%CI: 0.63-1.07, P = 0.15 and HR 0.81, 95%CI: 0.52-1.25, P = 0.33 respectively). Adjusted patient death risk in preemptive high KDPI kidney recipients were similar when compared to groups that received lower KDPI kidney after being on maintenance dialysis for 1-4 years(HR 0.99, 95%CI: 0.87-1.12, P = 0.89) but lower compared to patients who were on dialysis for 4-8 years(HR 0.74, 95%CI: 0.56-0.98, P = 0.037).CONCLUSION In summary, our study supports accepting a "marginal" quality high KDPI kidney preemptively in older waitlisted patients thus avoiding dialysis exposure.展开更多
BACKGROUND Preemptive living donor kidney transplantation(PLDKT)is recommended as the optimal treatment for end-stage renal disease.AIM To assess the rate of PLDKT among patients who accessed KT in our center and revi...BACKGROUND Preemptive living donor kidney transplantation(PLDKT)is recommended as the optimal treatment for end-stage renal disease.AIM To assess the rate of PLDKT among patients who accessed KT in our center and review the status of PLDKT in Egypt.METHODS We performed a retrospective review of the patients who accessed KT in our center from November 2015 to November 2022.In addition,the PLDKT status in Egypt was reviewed relative to the literature.RESULTS Of the 304 patients who accessed KT,32 patients(10.5%)had preemptive access to KT(PAKT).The means of age and estimated glomerular filtration rate were 31.7±13 years and 12.8±3.5 mL/min/1.73 m2,respectively.Fifty-nine patients had KT,including 3 PLDKTs only(5.1%of total KTs and 9.4%of PAKT).Twenty-nine patients(90.6%)failed to receive PLDKT due to donor unavailability(25%),exclusion(28.6%),regression from donation(3.6%),and patient regression on starting dialysis(39.3%).In multivariate analysis,known primary kidney disease(P=0.002),patient age(P=0.031)and sex(P=0.001)were independent predictors of achievement of KT in our center.However,PAKT was not significantly(P=0.065)associated with the achievement of KT.Review of the literature revealed lower rates of PLDKT in Egypt than those in the literature.CONCLUSION Patient age,sex,and primary kidney disease are independent predictors of achieving living donor KT.Despite its non-significant effect,PAKT may enhance the low rates of PLDKT.The main causes of non-achievement of PLDKT were patient regression on starting regular dialysis and donor unavailability or exclusion.展开更多
Objective:To explore the application of parecoxib preemptive analgesia effect on maternal inflammatory factor, substance P and the stress index in cesarean section.Methods:A total of 84 cases of cesarean section in ou...Objective:To explore the application of parecoxib preemptive analgesia effect on maternal inflammatory factor, substance P and the stress index in cesarean section.Methods:A total of 84 cases of cesarean section in our hospital from April 2015 to February 2017 were selected and randomly divided into the observation group and the control group with 42 cases each. The observation group received parecoxib sodium before anesthesia induction to 30 min, and control group was given normal saline, respectively. The venous blood samples were collected at the end of the operation, 30 min, 4 h, 8 h and 12 h after operation respectively. The inflammatory factors, P substances and stress indexes were compared between the two groups before and after operation.Results:Substance P in the two groups increased at the end of 30 min after operation, and reached a high peak at 4 h after operation, and then decreased gradually. E (epinephrine) and NE (norepinephrine) reached peak values at 30 min after surgery and then decreased gradually. After the operation, the 30 min, 4 h, postoperative 8 h and postoperative 12 h, P, E and NE indexes in the observation group were lower than those in the control group at the same time point, and the difference was statistically significant. Conclusion: The clinical effect of parecoxib sodium preemptive analgesia in cesarean section is better. It can effectively reduce inflammatory reaction, relieve pain, relieve stress reaction and promote postoperative recovery. It is recommended to be widely used in clinic.展开更多
We prove a heavy traffic limit theorem to justify diffusion approximations for multiclass queueing networks under preemptive priority service discipline and provide effective stochastic dynamical models for the system...We prove a heavy traffic limit theorem to justify diffusion approximations for multiclass queueing networks under preemptive priority service discipline and provide effective stochastic dynamical models for the systems. Such queueing networks appear typically in high-speed integrated services packet networks about telecommunication system. In the network, there is a number of packet traffic types. Each type needs a number of job classes （stages） of processing and each type of jobs is assigned the same priority rank at every station where it possibly receives service. Moreover, there is no inter-routing among different traffic types throughout the entire network.展开更多
Objective: In this study, we evaluated the effect of preemptive analgesia of flurbiprofen axetil (FA) and tramadol on immune response in patients undergoing radical mastectomy. Methods: In this prospective randomized,...Objective: In this study, we evaluated the effect of preemptive analgesia of flurbiprofen axetil (FA) and tramadol on immune response in patients undergoing radical mastectomy. Methods: In this prospective randomized, double-blind, placebo-controlled study, 80 patients were randomly assigned to one of four groups (n = 20). The FA group (group A) patients received FA before tracheal intubation and at the end of surgery. The tramadol group (group B) patients received tramadol before tracheal intubation and at the end of surgery. The control group (group C) patients received saline before tracheal intubation and at the end of surgery. The combination group (group D) patients received FA and tramadol before tracheal intubation and at the end of surgery. Cluster of differentiation and lymphocytes were measured. Results: The CD3, CD4, CD8 and lymphocytes decreased postoperatively of all groups except of group A and D at 0.5 h postoperatively (P < 0.05). The CD3, CD4, CD8 and lymphocytes of group D were higher than those of group C at 0.5 h and 4 h postoperatively (P < 0.05). Conclusion: Preemptive analgesia using flurbiprofen axetil (FA) and tramadol may protect the immune system. The immune protective effect of FA may be better than that of tramadol. The combination of FA and tramadol may be the most effective among all the strategies.展开更多
BACKGROUND Pancreaticoduodenectomy is a technically demanding operation,with reported morbidity rates of approximately 40%-50%.A novel idea is to use endoscopic vacuum therapy(EVT)in a preemptive setting to prevent an...BACKGROUND Pancreaticoduodenectomy is a technically demanding operation,with reported morbidity rates of approximately 40%-50%.A novel idea is to use endoscopic vacuum therapy(EVT)in a preemptive setting to prevent anastomotic leakage and pancreatic fistulas.In a recent case series,EVT was proven to be effective in preventing leaks in patients with anastomotic ischemia.There have been no previous reports on preemptive EVT after pancreaticoduodenectomy.CASE SUMMARY We describe the case of a 71-year-old woman with hypertension and diabetes who was admitted to the emergency room with jaundice,choluria,fecal acholia,abdominal pain,and fever.Admission examinations revealed leukocytosis and hyperbilirubinemia(total:13 mg/dL;conjugated:12.1 mg/dL).Abdominal ultrasound showed cholelithiasis and dilation of the common bile duct.Magnetic resonance imaging demonstrated a stenotic area,and a biopsy confirmed cholangiocarcinoma. Considering the high risk of leaks after pancreaticoduodenectomy,preemptive endoluminal vacuum therapy was performed.The system comprised a nasogastric tube,gauze,and an antimicrobial incise drape.The negative pressure was 125 mmHg,and no adverse events occurred.The patient was discharged on postoperative day 5 without any symptoms.CONCLUSION Preemptive endoluminal vacuum therapy may be a safe and feasible technique to reduce leaks after pancreaticoduodenectomy.展开更多
We study a vacation queueing system with a single server simultaneously dealing with an M/G/1 and an M/D/1 queue. Two classes of units, priority and non-priority, arrive at the system in two independent Poisson stream...We study a vacation queueing system with a single server simultaneously dealing with an M/G/1 and an M/D/1 queue. Two classes of units, priority and non-priority, arrive at the system in two independent Poisson streams. Under a non-preemptive priority rule, the server provides a general service to the priority units and a deterministic service to the non-priority units. We further assume that the server may take a vacation of random length just after serving the last priority unit present in the system. We obtain steady state queue size distribution at a random epoch. Corresponding results for some special cases, including the known results of the M/G/1 and the M/D/1 queues, have been derived.展开更多
Objective:To investigate the effect of parecoxib sodium preemptive analgesia on postoperative pain and stress response in patients with laparoscopic surgery.Methods:118 patients with asymptomatic gallbladder polyps wh...Objective:To investigate the effect of parecoxib sodium preemptive analgesia on postoperative pain and stress response in patients with laparoscopic surgery.Methods:118 patients with asymptomatic gallbladder polyps who underwent elective laparoscopic surgery in our hospital between January 2018 and January 2019 were divided into the control group(n=59)and the preemptive analgesia group(n=59)by random number table.Control group received routine total intravenous anesthesia,and preemptive analgesia group received intravenous injection of parecoxib sodium 0.7mg/kg during anesthesia induction.The differences in serum levels of pain mediators[prostaglandin E2(PGE2),substance P(SP)and neuropeptide Y(NPY)],inflammatory factors[interleukin-1β(IL-1β),interleukin-6(IL-6)and interleukin-12(IL-12)]as well as stress mediators[cortisol(Cor),norepinephrine(NE)and epinephrine(E)]at before surgery(T0),30min after extubation(T1),6h after surgery(T2)and 24h after surgery(T3)were compared between the two groups of patients.Results:At T0,there was no significant difference in VAS score as well as inflammatory factor or stress mediator levels between the two groups(P>0.05).At T1,T2 and T3,VAS scores of the preemptive analgesia group were lower than those of the control group;serum IL-1β,IL-6,IL-12 and TNF-αlevels were lower than those of the control group;serum Cor,NE and E levels were lower than those of the control group(P<0.05).Conclusion:Parecoxib sodium preemptive analgesia has a positive effect on reducing postoperative pain and systemic stress in patients with laparoscopic cholecystectomy.展开更多
Objective: To study the effect of multimodal analgesia + preemptive analgesia on the postoperative recovery of elderly patients with hip replacement, and observe its effect on the postoperative pain-related neurotrans...Objective: To study the effect of multimodal analgesia + preemptive analgesia on the postoperative recovery of elderly patients with hip replacement, and observe its effect on the postoperative pain-related neurotransmitters, inflammatory factors and stress response. Methods: Elderly patients who received hip replacement in the hospital between February 2015 and December 2016 were selected and randomly divided into preemptive analgesia group, multimodal analgesia group and combined analgesia group. Serum levels of pain-related neurotransmitters, inflammatory factors and stress response molecules were detected before surgery as well as 6 h and 24 h after surgery. Results: Serum SP, PGE2, NO, 5-HT, ICAM-1, hs-CRP, IL-6, IL-10, Cor, NE and MDA levels of three groups of patients 6 h and 24 h after surgery were significantly higher than those before surgery, and serum SP, PGE2, NO, 5-HT, ICAM-1, hs-CRP, IL-6, IL-10, Cor, NE and MDA levels of combined analgesia group 6 h and 24 h after surgery were significantly lower than those of preemptive analgesia group and multimodal analgesia group. Conclusion: Multimodal analgesia + preemptive analgesia can be more effective than multimodal analgesia and preemptive analgesia in reducing postoperative pain, inflammatory response and stress response in elderly patients with hip replacement.展开更多
The most effective treatment for postoperative pain is to reduce it by preventing or reducing the sensitivity and sensory disturbance on the central nervous system during the operation,prolonging the pain-relief time ...The most effective treatment for postoperative pain is to reduce it by preventing or reducing the sensitivity and sensory disturbance on the central nervous system during the operation,prolonging the pain-relief time and reducing the use of analgesics.Preemptive analgesia refers to the intervention of central neuraxis sensitization and peripheral sensitization to prevent the expansion and spread of pain,so as to achieve postoperative pain-relief.In postoperative patient-controlled analgesia,preemptive analgesia has become a common treatment method for anesthesiologists.However,the clinical specifications for advanced analgesia are still lacking.Based on this,this paper reviews the use of advanced analgesia drugs and their clinical applications.展开更多
We study preemptive scheduling on m uniform machines with non-simultaneous available times to minimize the makespan.Each machine has a different speed and a different available time.We first provide a lower bound on t...We study preemptive scheduling on m uniform machines with non-simultaneous available times to minimize the makespan.Each machine has a different speed and a different available time.We first provide a lower bound on the optimal makespan of the problem by converting the real machines to virtual machines that guarantee a machine with an earlier available time having a greater speed at any time.展开更多
Membership inference(MI)attacks threaten user privacy through determining if a given data example has been used to train a target model.Existing MI defenses protect the membership privacy through preemptive exclusion ...Membership inference(MI)attacks threaten user privacy through determining if a given data example has been used to train a target model.Existing MI defenses protect the membership privacy through preemptive exclusion of members techniques and knowledge distillation.Unfortunately,using either of these two defenses alone,the defense effect can still offers an unsatisfactory trade-off between membership privacy and utility.Given that the defense method that directly combines these two defenses is still very limited(e.g.,the test accuracy of the target model is decreased by about 40%(in our experiments)),in this work,we propose a dual defense(DD)method that includes the preemptive exclusion of high-risk member samples module and the knowledge distillation module,which thwarts the access of the resulting models to the private training data twice to mitigate MI attacks.Our defense method can be divided into two steps:the preemptive exclusion of high-risk member samples(Step 1)and the knowledge distillation to obtain the protected student model(Step 2).We propose three types of exclusions:existing MI attacks-based exclusions,sample distances of members and nonmembers-based exclusions,and mutual information value-based exclusions,to preemptively exclude the high-risk member samples.During the knowledge distillation phase,we add ground-truth labeled data to the reference dataset to decrease the protected student model's dependency on soft labels,aiming to maintain or improve its test accuracy.Extensive evaluation shows that DD significantly outperforms state-of-the-art defenses and offers a better privacy-utility trade-off.For example,DD achieves∼100%test accuracy improvement over the distillation for membership privacy(DMP)defense for ResNet50 trained on CIFAR100.DD simultaneously achieves the reductions in the attack effectiveness(e.g.,the TPR@0.01%FPR of enhanced MI attacks decreased by 2.10%on the ImageNet dataset,the membership advantage(MA)of risk score-based attacks decreased by 56.30%)and improvements of the target models'test accuracies(e.g.,by 42.80%on CIFAR100).展开更多
A single-server queueing system with preemptive access is considered.Each customer has one attempt to enter the system at its working interval[0,T].As soon as the customer request enters the system,the server immediat...A single-server queueing system with preemptive access is considered.Each customer has one attempt to enter the system at its working interval[0,T].As soon as the customer request enters the system,the server immediately starts the service.But when the next request arrives in the system,the previous one leaves the system even he has not finished his service yet.We study a non-cooperative game in which the customers wish to maximize their probability of obtaining service within a certain period of time.We characterize the Nash equilibrium and the price of anarchy,which is defined as the ratio between the optimal and equilibrium social utility.Two models are considered.In the first model the number of players is fixed,while in the second it is random and obeys the Poisson distribution.We demonstrate that there exists a unique symmetric equilibrium for both models.Finally,we calculate the price of anarchy for both models and show that the price of anarchy is not monotone with respect to the number of customers.展开更多
BACKGROUND Acute variceal bleeding(AVB)in patients with cirrhosis remains life-threatening;moreover,the current risk stratification methods have certain limitations.Rebleeding and mortality after AVB remain major chal...BACKGROUND Acute variceal bleeding(AVB)in patients with cirrhosis remains life-threatening;moreover,the current risk stratification methods have certain limitations.Rebleeding and mortality after AVB remain major challenges.Although preemptive transjugular intrahepatic portosystemic shunt(p-TIPS)can improve outcomes,not all patients benefit equally.Accurate risk stratification is needed to guide treatment decisions and identify those most likely to benefit from p-TIPS.AIM To develop an artificial intelligence(AI)-driven model to guide AVB treatment decisions,and identify candidates eligible for p-TIPS.METHODS Patients with cirrhosis and AVB,from two multicenter retrospective cohorts in China,who received endoscopic variceal ligation plus pharmacotherapy(n=1227)or p-TIPS(n=1863)were included.Baseline data within 24 hours of hospital admission were obtained.The AI-AVB model,based on the six-week failure and one-year mortality rates,was developed to predict treatment efficacy and compared with standard risk scores.Outcomes and adverse events of the treatments were compared across the high-and low-risk subgroups stratified using the AI-AVB model.RESULTS The AI-AVB model demonstrated superior predictive performance compared to traditional risk stratification methods.In the internal validation cohort,the model achieved an area under the curve(AUC)of 0.842 for predicting six-week treatment failure and 0.954 for one-year mortality.In the external validation cohort,the AUCs were 0.814 and 0.889,respectively.The model effectively identified patients at high risk of first-line treatment failure who may benefit from aggressive interventions such as p-TIPS.In contrast,advancing the treatment strategy for low-risk patients did not notably improve the short-term prognosis.CONCLUSION The AI-AVB model can predict treatment outcomes,stratify the failure risk in cirrhotic patients with AVB,aid in clinical decisions,identify p-TIPS beneficiaries,and optimize personalized treatment strategies.展开更多
Background Systemic non-steroidal anti-inflammatory drugs have been evaluated for their possible preemptive analgesic effects.The efficacy of flurbiprofen axetil for preemptive analgesia in patients undergoing radical...Background Systemic non-steroidal anti-inflammatory drugs have been evaluated for their possible preemptive analgesic effects.The efficacy of flurbiprofen axetil for preemptive analgesia in patients undergoing radical resection of esophageal carcinoma via the left thoracic approach needs further investigation.The aim of this study was to research the preemptive analgesic effects of flurbiprofen axetil in thoracic surgery,and the influence of preoperative administration on postoperative respiratory function.Methods This randomized,double-blind,controlled trial enrolled 60 patients undergoing radical resection of esophageal carcinoma via the left thoracic approach.Anesthesia management was standardized.Each patient was randomly assigned to receive either 100 mg flurbiprofen axetil intravenously 15 minutes before incision （PA group） or intravenous normal saline as a control （C group）.Postoperative analgesia was with sufentanil delivered by patient-controlled analgesia pump.Postoperative sufentanil consumption,visual analog scale pain scores,plasma levels of interleukin-8,and oxygenation index were measured.Results Compared with the preoperative baseline,postoperative patients in the PA group had no obvious increase in pain scores （P 〉0.05）,but patients in the C group had significantly increased pain scores （P〈0.05）.Pain scores in the C group were significantly higher at 24 hours postoperatively than preoperatively.Intergroup comparisons showed lower visual analog scale scores at 2-24 hours postoperatively in the PA group than the C group （P 〈0.05）.Sufentanil consumption and plasma interleukin-8 levels at 2 and 12 hours postoperatively were significantly lower in the PA group than the C group （P 〈0.05）.The oxygenation index at 2 and 12 hours postoperatively was significantly higher in the PA group than the C group （P〈0.05）.Conclusions Intravenous flurbiprofen axetil appears to have a preemptive analgesic effect in patients undergoing radical resection of esophageal carcinoma via the left thoracic approach,and appears to contribute to recovery of respiratorv function and to reduction of the postoperative inflammatory reaction.展开更多
基金supported by the Key Technologies R&D program of Henan Province,China(No.201503178)
文摘The pain following gynecological laparoscopic surgery is less intense than that following open surgery; however, patients often experience visceral pain after the former surgery. The aim of this study was to determine the effects of preemptive ketamine on visceral pain in patients undergoing gynecological laparoscopic surgery. Ninety patients undergoing gynecological laparoscopic surgery were randomly assigned to one of three groups. Group 1 received placebo. Group 2 was intravenously injected with preincisional saline and local infiltration with 20 m L ropivacaine（4 mg/m L） at the end of surgery. Group 3 was intravenously injected with preincisional ketamine（0.3 mg/kg） and local infiltration with 20 m L ropivacaine（4 mg/m L） at the end of surgery. A standard anesthetic was used for all patients, and meperidine was used for postoperative analgesia. The visual analogue scale（VAS） scores for incisional and visceral pain at 2, 6, 12, and 24 h, cumulative analgesic consumption and time until first analgesic medication request, and adverse effects were recorded postoperatively. The VAS scores of visceral pain in group 3 were significantly lower than those in group 2 and group 1 at 2 h and 6 h postoperatively（P〈0.05 and P〈0.01, respectively）. At 2 h and 6 h, the VAS scores of incisional pain did not differ significantly between groups 2 and 3, but they were significantly lower than those in group 1（P〈0.01）. Groups 1 and 2 did not show any differences in visceral pain scores at 2 h and 6 h postoperatively. Moreover, the three groups showed no statistically significant differences in visceral and incisional pain scores at 12 h and 24 h postoperatively. The consumption of analgesics was significantly greater in group 1 than in groups 2 and 3, and the time to first request for analgesics was significantly longer in groups 2 and 3 than in group 1, with no statistically significant difference between groups 2 and 3. However, the three groups showed no significant difference in the incidence of shoulder pain or adverse effects. Preemptive ketamine may reduce visceral pain in patients undergoing gynecological laparoscopic surgery.
基金Key Program of Capital Development Foundation(编号2007-2040)
文摘In order to study the epidemiological characteristics of cytomegalovirus(CMV)infection in allogeneichematopoietic stem cell transplantation(allo-HSCT)recipients by means of plasma real time quantitative polymerasechain reaction(RQ-PCR),141 adult patients undergoing allo-HSCT between January 2008 and June 2010 were seriallymonitored by RQ-PCR for detecting CMV and guiding the preemptive therapy followed up to 180 days post-HSCT.Theresults showed that the incidence of CMV infection and CMV pneumonia was 81.5%and 2.9%respectively,whichmainly occurred within 2 months post-HSCT.Single-therapy with ganciclovir(GCV)for 63 patients or foscarnet 6patients was performed for preemptive therapy.The total efficacy was 87.8%,and the response patterns were different.CMV infection was more frequent in female patients(P=0.044),and those with aGVHD(P=0.043),using ATG orbasiliximab in conditioning regimens(P=0.049),as well as earlier in patients using ATG or basiliximab or those withaGVHD(P=0.007;P=0.000).The aGVHD,maximum load,positive times of CMV-DNA detection and therapyduration all correlated with the efficacy(P<0.05).It is concluded that the incidence of CMV infection is still high afterHSCT.Plasma RQ-PCR assay for CMV-DNA shows a strong correlation with the clinical outcome of CMV infection,which is useful and suitable for management of CMV infection in HSCT.
文摘BACKGROUND： Preemptive .analgesia involves introducing an analgesic prior to the onset of pain stimulation to prevent sensitizing the nervous system to subsequent stimuli that could amplify pain. OBJECTIVE： To treat psychiatric patients with intravenous （i.v.） injection of butorphanol prior to modified electroconvulsive therapy, and to observe its effect on alleviating myalgia after treatment and adverse reactions. DESIGN： A randomized controlled observation. SETTING： Renmin Hospital of Wuhan University. PARTICIPANTS： A total of 120 psychiatric patients, who accepted modified electroconvulsive therapy, were selected from the Mental Health Center of Wuhan University from June to September in 2006. All patients corresponded to the Chinese Classification and Diagnostic Criteria of Mental Disorders, and those with diseases of heart, liver, lung and kidney, glaucoma, intracranial hypertension, hyperthyreosis, and hyperkalemia were excluded. The patients were randomly divided into a control group （n = 60） and treatment group （n = 60）. In the control group, there were 42 males and 18 females, aged 17-50 years, with a mean age of （34 ± 11） years. The patients weighed 50-70 kg, with a mean body mass of （63 ± 18） kg. In the treatment group, there were 40 males and 20 females, aged 20-54 years, with a mean age of （36 ± 13） years. The patients weighed 48-72 kg, with a mean body mass of （64 ± 16） kg. Approval was obtained from the Hospital＇s Ethics Committee. Informed consents were obtained from the patients＇ relatives. A SPECTRUM5000Q multifunctional mobile electroconvulsive therapy apparatus （CORPERATION, USA） was used. METHODS： （1） Treatments： In the control group, the patients were anesthetized by i.v. injection of propofol （AstraZeneca, Italy, No.CN309） containing 0.075% efedrina, and then modified electroconvulsive therapy was performed. Circulation, respiration, and firing of brain electrical activity were continuously monitored. In the treatment group, the patients were i.v. injected with 1 mg of butorphanol tartrate parenteral solution （Jiangsu Hengrui Medicine Co., Ltd., No.05100732） 5 minutes prior to anesthesia; the remaining treatments were the same as in the control group. （2） Evaluations： myalgia conditions were assessed 6 hours after the patients opened their eyes. The patients were evaluated by a visual analogue scale and Ramsay sedation scale immediately, and at 3 minutes and 6 hours after they opened their eyes. MAIN OUTCOME MEASURES： （1） Conditions of myalgia. （2） Scores of visual analogue scale and Ramsay sedation scale. RESULTS： All 120 psychiatric patients were involved in the final analysis. （1） Conditions of myalgia： 6 hours after modified electroconvulsive therapy, 22 patients in the control group and 1 patient in the treatment group complained of myalgia, which resulted in a significant difference between the two groups （P 〈 0.05）. （2） Scores of visual analogue scale and Ramsay sedation scale： the scores of visual analogue scale at 30 minutes and 6 hours after opening eyes were significantly lower in the treatment group than the control group （P 〈 0.05）, and the scores of Ramsay sedation scale were not significantly different between the two groups （P 〉 0.05）. CONCLUSION： Preemptive analgesia by butorphanol can effectively alleviate modified electroconvulsive therapy-induced myalgia, without adverse reactions.
文摘Background and Objective: Post-operative nausea and vomiting (PONV) is a common adverse effect of the anesthesia in laparoscopic surgery. Ondansetron has been used for prevention and treatment of the PONV. The purpose of the present study was to compare the effects of preemptive and preventive intravenous ondansetron on PONV in patients undergoing diagnostic gynecologic laparoscopy. Materials & Methods: In a randomized double-blind clinical trial, 80 women candidate of diagnostic laparoscopy, were enrolled to study in two preemptive or preventive groups (n = 40). Ondansetron 4 mg IV was administered 5 min before anesthesia induction or 5 min before extubation in preemptive or preventive groups, respectively. The frequency and severity of the PONV were compared at post-anesthetic care unit (PACU), 3th, 6th and 24th postoperatively in two groups. Also the first time of need for the antiemetic drug was studied. Results: Demographic data were similar but duration of anesthesia was shorter in preventive group. The PONV rate was similar in two groups [(37.5% and 32.5% in preemptive and preventive groups, respectively (P = 0.815)]. In preemptive group it was more intense at PACU and 24 hours after surgery (P-value <0.05) and rate of vomiting was high (11 vs. 3, P-value 0.037). The first request for antiemetic drug was earlier and the antiemetic consumption dose (P-value <0.05), recovery and hospital stay times were high in preemptive group (P-value = 0.001). Conclusion: Preventive ondansetron is more effective than preemptive form, in reducing the severity of PONV but not rate of the PONV in diagnostic gynecologic laparoscopy.
文摘AIM To evaluate the outcomes of transplanting marginal kidneys preemptively compared to better-quality kidneys after varying dialysis vintage in older recipients.METHODS Using OPTN/United Network for Organ Sharing database from 2001-2015, we identified deceased donor kidney(DDK) transplant recipients > 60 years of age who either underwent preemptive transplantation of kidneys with kidney donor profile index(KDPI) ≥ 85%(marginal kidneys) or received kidneys with KDPI of 35%-84%(better quality kidneys that older wait-listed patients would likely receive if waited longer) after being on dialysis for either 1-4 or 4-8 years. Using a multivariate Cox model adjusting for donor, recipient and transplant related factors-overall and death-censored graft failure risks along with patient death risk of preemptive transplant recipients were compared to transplant recipients in the 1-4 and 4-8 year dialysis vintage groups.RESUTLS The median follow up for the whole group was 37 mo(interquartile range of 57 mo). A total of 6110 DDK transplant recipients above the age of 60 years identified during the study period were found to be eligible to be included in the analysis. Among these patients350 received preemptive transplantation of kidneys with KDPI ≥ 85. The remaining patients underwent transplantation of better quality kidneys with KDPI 35-84% after being on maintenance dialysis for either 1-4 years(n = 3300) or 4-8 years(n = 2460). Adjusted overall graft failure risk and death-censored graft failure risk in preemptive high KDPI kidney recipients were similar when compared to group that received lower KDPI kidney after being on maintenance dialysis for either 1-4 years(HR 1.01, 95%CI: 0.90-1.14, P = 0.84 and HR 0.96, 95%CI: 0.79-1.16, P = 0.66 respectively) or 4-8 years(HR 0.82, 95%CI: 0.63-1.07, P = 0.15 and HR 0.81, 95%CI: 0.52-1.25, P = 0.33 respectively). Adjusted patient death risk in preemptive high KDPI kidney recipients were similar when compared to groups that received lower KDPI kidney after being on maintenance dialysis for 1-4 years(HR 0.99, 95%CI: 0.87-1.12, P = 0.89) but lower compared to patients who were on dialysis for 4-8 years(HR 0.74, 95%CI: 0.56-0.98, P = 0.037).CONCLUSION In summary, our study supports accepting a "marginal" quality high KDPI kidney preemptively in older waitlisted patients thus avoiding dialysis exposure.
文摘BACKGROUND Preemptive living donor kidney transplantation(PLDKT)is recommended as the optimal treatment for end-stage renal disease.AIM To assess the rate of PLDKT among patients who accessed KT in our center and review the status of PLDKT in Egypt.METHODS We performed a retrospective review of the patients who accessed KT in our center from November 2015 to November 2022.In addition,the PLDKT status in Egypt was reviewed relative to the literature.RESULTS Of the 304 patients who accessed KT,32 patients(10.5%)had preemptive access to KT(PAKT).The means of age and estimated glomerular filtration rate were 31.7±13 years and 12.8±3.5 mL/min/1.73 m2,respectively.Fifty-nine patients had KT,including 3 PLDKTs only(5.1%of total KTs and 9.4%of PAKT).Twenty-nine patients(90.6%)failed to receive PLDKT due to donor unavailability(25%),exclusion(28.6%),regression from donation(3.6%),and patient regression on starting dialysis(39.3%).In multivariate analysis,known primary kidney disease(P=0.002),patient age(P=0.031)and sex(P=0.001)were independent predictors of achievement of KT in our center.However,PAKT was not significantly(P=0.065)associated with the achievement of KT.Review of the literature revealed lower rates of PLDKT in Egypt than those in the literature.CONCLUSION Patient age,sex,and primary kidney disease are independent predictors of achieving living donor KT.Despite its non-significant effect,PAKT may enhance the low rates of PLDKT.The main causes of non-achievement of PLDKT were patient regression on starting regular dialysis and donor unavailability or exclusion.
文摘Objective:To explore the application of parecoxib preemptive analgesia effect on maternal inflammatory factor, substance P and the stress index in cesarean section.Methods:A total of 84 cases of cesarean section in our hospital from April 2015 to February 2017 were selected and randomly divided into the observation group and the control group with 42 cases each. The observation group received parecoxib sodium before anesthesia induction to 30 min, and control group was given normal saline, respectively. The venous blood samples were collected at the end of the operation, 30 min, 4 h, 8 h and 12 h after operation respectively. The inflammatory factors, P substances and stress indexes were compared between the two groups before and after operation.Results:Substance P in the two groups increased at the end of 30 min after operation, and reached a high peak at 4 h after operation, and then decreased gradually. E (epinephrine) and NE (norepinephrine) reached peak values at 30 min after surgery and then decreased gradually. After the operation, the 30 min, 4 h, postoperative 8 h and postoperative 12 h, P, E and NE indexes in the observation group were lower than those in the control group at the same time point, and the difference was statistically significant. Conclusion: The clinical effect of parecoxib sodium preemptive analgesia in cesarean section is better. It can effectively reduce inflammatory reaction, relieve pain, relieve stress reaction and promote postoperative recovery. It is recommended to be widely used in clinic.
基金the National Natural Science Foundation of China(No.10371053)
文摘We prove a heavy traffic limit theorem to justify diffusion approximations for multiclass queueing networks under preemptive priority service discipline and provide effective stochastic dynamical models for the systems. Such queueing networks appear typically in high-speed integrated services packet networks about telecommunication system. In the network, there is a number of packet traffic types. Each type needs a number of job classes （stages） of processing and each type of jobs is assigned the same priority rank at every station where it possibly receives service. Moreover, there is no inter-routing among different traffic types throughout the entire network.
文摘Objective: In this study, we evaluated the effect of preemptive analgesia of flurbiprofen axetil (FA) and tramadol on immune response in patients undergoing radical mastectomy. Methods: In this prospective randomized, double-blind, placebo-controlled study, 80 patients were randomly assigned to one of four groups (n = 20). The FA group (group A) patients received FA before tracheal intubation and at the end of surgery. The tramadol group (group B) patients received tramadol before tracheal intubation and at the end of surgery. The control group (group C) patients received saline before tracheal intubation and at the end of surgery. The combination group (group D) patients received FA and tramadol before tracheal intubation and at the end of surgery. Cluster of differentiation and lymphocytes were measured. Results: The CD3, CD4, CD8 and lymphocytes decreased postoperatively of all groups except of group A and D at 0.5 h postoperatively (P < 0.05). The CD3, CD4, CD8 and lymphocytes of group D were higher than those of group C at 0.5 h and 4 h postoperatively (P < 0.05). Conclusion: Preemptive analgesia using flurbiprofen axetil (FA) and tramadol may protect the immune system. The immune protective effect of FA may be better than that of tramadol. The combination of FA and tramadol may be the most effective among all the strategies.
文摘BACKGROUND Pancreaticoduodenectomy is a technically demanding operation,with reported morbidity rates of approximately 40%-50%.A novel idea is to use endoscopic vacuum therapy(EVT)in a preemptive setting to prevent anastomotic leakage and pancreatic fistulas.In a recent case series,EVT was proven to be effective in preventing leaks in patients with anastomotic ischemia.There have been no previous reports on preemptive EVT after pancreaticoduodenectomy.CASE SUMMARY We describe the case of a 71-year-old woman with hypertension and diabetes who was admitted to the emergency room with jaundice,choluria,fecal acholia,abdominal pain,and fever.Admission examinations revealed leukocytosis and hyperbilirubinemia(total:13 mg/dL;conjugated:12.1 mg/dL).Abdominal ultrasound showed cholelithiasis and dilation of the common bile duct.Magnetic resonance imaging demonstrated a stenotic area,and a biopsy confirmed cholangiocarcinoma. Considering the high risk of leaks after pancreaticoduodenectomy,preemptive endoluminal vacuum therapy was performed.The system comprised a nasogastric tube,gauze,and an antimicrobial incise drape.The negative pressure was 125 mmHg,and no adverse events occurred.The patient was discharged on postoperative day 5 without any symptoms.CONCLUSION Preemptive endoluminal vacuum therapy may be a safe and feasible technique to reduce leaks after pancreaticoduodenectomy.
文摘We study a vacation queueing system with a single server simultaneously dealing with an M/G/1 and an M/D/1 queue. Two classes of units, priority and non-priority, arrive at the system in two independent Poisson streams. Under a non-preemptive priority rule, the server provides a general service to the priority units and a deterministic service to the non-priority units. We further assume that the server may take a vacation of random length just after serving the last priority unit present in the system. We obtain steady state queue size distribution at a random epoch. Corresponding results for some special cases, including the known results of the M/G/1 and the M/D/1 queues, have been derived.
基金2016 Key Technology Research Projects of Hebei Provincial Health and Planning Commission(No.182497-2)
文摘Objective:To investigate the effect of parecoxib sodium preemptive analgesia on postoperative pain and stress response in patients with laparoscopic surgery.Methods:118 patients with asymptomatic gallbladder polyps who underwent elective laparoscopic surgery in our hospital between January 2018 and January 2019 were divided into the control group(n=59)and the preemptive analgesia group(n=59)by random number table.Control group received routine total intravenous anesthesia,and preemptive analgesia group received intravenous injection of parecoxib sodium 0.7mg/kg during anesthesia induction.The differences in serum levels of pain mediators[prostaglandin E2(PGE2),substance P(SP)and neuropeptide Y(NPY)],inflammatory factors[interleukin-1β(IL-1β),interleukin-6(IL-6)and interleukin-12(IL-12)]as well as stress mediators[cortisol(Cor),norepinephrine(NE)and epinephrine(E)]at before surgery(T0),30min after extubation(T1),6h after surgery(T2)and 24h after surgery(T3)were compared between the two groups of patients.Results:At T0,there was no significant difference in VAS score as well as inflammatory factor or stress mediator levels between the two groups(P>0.05).At T1,T2 and T3,VAS scores of the preemptive analgesia group were lower than those of the control group;serum IL-1β,IL-6,IL-12 and TNF-αlevels were lower than those of the control group;serum Cor,NE and E levels were lower than those of the control group(P<0.05).Conclusion:Parecoxib sodium preemptive analgesia has a positive effect on reducing postoperative pain and systemic stress in patients with laparoscopic cholecystectomy.
文摘Objective: To study the effect of multimodal analgesia + preemptive analgesia on the postoperative recovery of elderly patients with hip replacement, and observe its effect on the postoperative pain-related neurotransmitters, inflammatory factors and stress response. Methods: Elderly patients who received hip replacement in the hospital between February 2015 and December 2016 were selected and randomly divided into preemptive analgesia group, multimodal analgesia group and combined analgesia group. Serum levels of pain-related neurotransmitters, inflammatory factors and stress response molecules were detected before surgery as well as 6 h and 24 h after surgery. Results: Serum SP, PGE2, NO, 5-HT, ICAM-1, hs-CRP, IL-6, IL-10, Cor, NE and MDA levels of three groups of patients 6 h and 24 h after surgery were significantly higher than those before surgery, and serum SP, PGE2, NO, 5-HT, ICAM-1, hs-CRP, IL-6, IL-10, Cor, NE and MDA levels of combined analgesia group 6 h and 24 h after surgery were significantly lower than those of preemptive analgesia group and multimodal analgesia group. Conclusion: Multimodal analgesia + preemptive analgesia can be more effective than multimodal analgesia and preemptive analgesia in reducing postoperative pain, inflammatory response and stress response in elderly patients with hip replacement.
文摘The most effective treatment for postoperative pain is to reduce it by preventing or reducing the sensitivity and sensory disturbance on the central nervous system during the operation,prolonging the pain-relief time and reducing the use of analgesics.Preemptive analgesia refers to the intervention of central neuraxis sensitization and peripheral sensitization to prevent the expansion and spread of pain,so as to achieve postoperative pain-relief.In postoperative patient-controlled analgesia,preemptive analgesia has become a common treatment method for anesthesiologists.However,the clinical specifications for advanced analgesia are still lacking.Based on this,this paper reviews the use of advanced analgesia drugs and their clinical applications.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(Nos.LZ23G010001 and LZ25F020012)the National Natural Science Foundation of China(Nos.62172356 and 61872321)the Ningbo Major Special Projects of the“Science and Technology Innovation 2025”(No.2024Z122)。
文摘We study preemptive scheduling on m uniform machines with non-simultaneous available times to minimize the makespan.Each machine has a different speed and a different available time.We first provide a lower bound on the optimal makespan of the problem by converting the real machines to virtual machines that guarantee a machine with an earlier available time having a greater speed at any time.
基金supported by the National Natural Science Foundation of China(61941105,61772406,U2336203,U1836210)National Key Research and Development Program of China(2023YFB3106400,2023QY1202)+1 种基金Beijing Natural Science Foundation(4242031)the Key Research and Development Science and Technology of Hainan Province(GHYF2022010).
文摘Membership inference(MI)attacks threaten user privacy through determining if a given data example has been used to train a target model.Existing MI defenses protect the membership privacy through preemptive exclusion of members techniques and knowledge distillation.Unfortunately,using either of these two defenses alone,the defense effect can still offers an unsatisfactory trade-off between membership privacy and utility.Given that the defense method that directly combines these two defenses is still very limited(e.g.,the test accuracy of the target model is decreased by about 40%(in our experiments)),in this work,we propose a dual defense(DD)method that includes the preemptive exclusion of high-risk member samples module and the knowledge distillation module,which thwarts the access of the resulting models to the private training data twice to mitigate MI attacks.Our defense method can be divided into two steps:the preemptive exclusion of high-risk member samples(Step 1)and the knowledge distillation to obtain the protected student model(Step 2).We propose three types of exclusions:existing MI attacks-based exclusions,sample distances of members and nonmembers-based exclusions,and mutual information value-based exclusions,to preemptively exclude the high-risk member samples.During the knowledge distillation phase,we add ground-truth labeled data to the reference dataset to decrease the protected student model's dependency on soft labels,aiming to maintain or improve its test accuracy.Extensive evaluation shows that DD significantly outperforms state-of-the-art defenses and offers a better privacy-utility trade-off.For example,DD achieves∼100%test accuracy improvement over the distillation for membership privacy(DMP)defense for ResNet50 trained on CIFAR100.DD simultaneously achieves the reductions in the attack effectiveness(e.g.,the TPR@0.01%FPR of enhanced MI attacks decreased by 2.10%on the ImageNet dataset,the membership advantage(MA)of risk score-based attacks decreased by 56.30%)and improvements of the target models'test accuracies(e.g.,by 42.80%on CIFAR100).
基金supported by the Russian Science Foundation(No.22-11-20015,https://rscf.ru/project/22-11-20015/)jointly with support of the authorities of the Republic of Karelia with funding from the Venture Investment Foundation of the Republic of Karelia.Also the research was supported by the National Natural Science Foundation of China(No.72171126).
文摘A single-server queueing system with preemptive access is considered.Each customer has one attempt to enter the system at its working interval[0,T].As soon as the customer request enters the system,the server immediately starts the service.But when the next request arrives in the system,the previous one leaves the system even he has not finished his service yet.We study a non-cooperative game in which the customers wish to maximize their probability of obtaining service within a certain period of time.We characterize the Nash equilibrium and the price of anarchy,which is defined as the ratio between the optimal and equilibrium social utility.Two models are considered.In the first model the number of players is fixed,while in the second it is random and obeys the Poisson distribution.We demonstrate that there exists a unique symmetric equilibrium for both models.Finally,we calculate the price of anarchy for both models and show that the price of anarchy is not monotone with respect to the number of customers.
基金Supported by Key Research and Development Program of Jiangsu Province,No.BE2023767Xuzhou Key Research and Development Program under Grant,No.KC23273+1 种基金Affiliated Hospital of Xuzhou Medical University,No.2022ZL26Construction Project of High-Level Hospital of Jiangsu Province,No.GSPSJ20240802.
文摘BACKGROUND Acute variceal bleeding(AVB)in patients with cirrhosis remains life-threatening;moreover,the current risk stratification methods have certain limitations.Rebleeding and mortality after AVB remain major challenges.Although preemptive transjugular intrahepatic portosystemic shunt(p-TIPS)can improve outcomes,not all patients benefit equally.Accurate risk stratification is needed to guide treatment decisions and identify those most likely to benefit from p-TIPS.AIM To develop an artificial intelligence(AI)-driven model to guide AVB treatment decisions,and identify candidates eligible for p-TIPS.METHODS Patients with cirrhosis and AVB,from two multicenter retrospective cohorts in China,who received endoscopic variceal ligation plus pharmacotherapy(n=1227)or p-TIPS(n=1863)were included.Baseline data within 24 hours of hospital admission were obtained.The AI-AVB model,based on the six-week failure and one-year mortality rates,was developed to predict treatment efficacy and compared with standard risk scores.Outcomes and adverse events of the treatments were compared across the high-and low-risk subgroups stratified using the AI-AVB model.RESULTS The AI-AVB model demonstrated superior predictive performance compared to traditional risk stratification methods.In the internal validation cohort,the model achieved an area under the curve(AUC)of 0.842 for predicting six-week treatment failure and 0.954 for one-year mortality.In the external validation cohort,the AUCs were 0.814 and 0.889,respectively.The model effectively identified patients at high risk of first-line treatment failure who may benefit from aggressive interventions such as p-TIPS.In contrast,advancing the treatment strategy for low-risk patients did not notably improve the short-term prognosis.CONCLUSION The AI-AVB model can predict treatment outcomes,stratify the failure risk in cirrhotic patients with AVB,aid in clinical decisions,identify p-TIPS beneficiaries,and optimize personalized treatment strategies.
基金This study was supported by the National Natural Science Foundation of China （No.30872433）.
文摘Background Systemic non-steroidal anti-inflammatory drugs have been evaluated for their possible preemptive analgesic effects.The efficacy of flurbiprofen axetil for preemptive analgesia in patients undergoing radical resection of esophageal carcinoma via the left thoracic approach needs further investigation.The aim of this study was to research the preemptive analgesic effects of flurbiprofen axetil in thoracic surgery,and the influence of preoperative administration on postoperative respiratory function.Methods This randomized,double-blind,controlled trial enrolled 60 patients undergoing radical resection of esophageal carcinoma via the left thoracic approach.Anesthesia management was standardized.Each patient was randomly assigned to receive either 100 mg flurbiprofen axetil intravenously 15 minutes before incision （PA group） or intravenous normal saline as a control （C group）.Postoperative analgesia was with sufentanil delivered by patient-controlled analgesia pump.Postoperative sufentanil consumption,visual analog scale pain scores,plasma levels of interleukin-8,and oxygenation index were measured.Results Compared with the preoperative baseline,postoperative patients in the PA group had no obvious increase in pain scores （P 〉0.05）,but patients in the C group had significantly increased pain scores （P〈0.05）.Pain scores in the C group were significantly higher at 24 hours postoperatively than preoperatively.Intergroup comparisons showed lower visual analog scale scores at 2-24 hours postoperatively in the PA group than the C group （P 〈0.05）.Sufentanil consumption and plasma interleukin-8 levels at 2 and 12 hours postoperatively were significantly lower in the PA group than the C group （P 〈0.05）.The oxygenation index at 2 and 12 hours postoperatively was significantly higher in the PA group than the C group （P〈0.05）.Conclusions Intravenous flurbiprofen axetil appears to have a preemptive analgesic effect in patients undergoing radical resection of esophageal carcinoma via the left thoracic approach,and appears to contribute to recovery of respiratorv function and to reduction of the postoperative inflammatory reaction.
