The effects of random long-range connections (shortcuts) on the transitions of neural firing patterns in coupled Hindmarsh-Rose neurons are investigated, where each neuron is subjected to an external current. It is ...The effects of random long-range connections (shortcuts) on the transitions of neural firing patterns in coupled Hindmarsh-Rose neurons are investigated, where each neuron is subjected to an external current. It is found that, on one hand, the system can achieve the transition of neural firing patterns from the fewer-period state to the multi-period one, when the number of the added shortcuts in the neural network is greater than a threshold value, indicating the occurrence of in-transition of neural firing patterns. On the other hand, for a stronger coupling strength, we can also find the similar but reverse results by adding some proper random connections. In addition, the influences of system size and coupling strength on such transition behavior, as well as the internality between the transition degree of firing patterns and its critical characteristics for different external stimulation current, are also discussed.展开更多
Process variations can reduce the accuracy in estimation of interconnect performance. This work presents a process variation based stochastic model and proposes an effective analytical method to estimate interconnect ...Process variations can reduce the accuracy in estimation of interconnect performance. This work presents a process variation based stochastic model and proposes an effective analytical method to estimate interconnect delay. The technique decouples the stochastic interconnect segments by an improved decoupling method. Combined with a polynomial chaos expression (PCE), this paper applies the stochastic Galerkin method (SGM) to analyze the system response. A finite representation of interconnect delay is then obtained with the complex approximation method and the bisection method. Results from the analysis match well with those from SPICE. Moreover, the method shows good computational efficiency, as the running time is much less than the SPICE simulation's.展开更多
Let Sn be the star with n vertices, and let G be any connected graph with p vertices. We denote by Eτp+(r-1)^G(i) the graph obtained from Sr and rG by coinciding the i-th vertex of G with the vertex of degree r ...Let Sn be the star with n vertices, and let G be any connected graph with p vertices. We denote by Eτp+(r-1)^G(i) the graph obtained from Sr and rG by coinciding the i-th vertex of G with the vertex of degree r - 1 of S,, while the i-th vertex of each component of (r - 1)G be adjacented to r - 1 vertices of degree 1 of St, respectively. By applying the properties of adjoint polynomials, We prove that factorization theorem of adjoint polynomials of kinds of graphs Eτp+(r-1)^G(i)∪(r - 1)K1 (1 ≤i≤p). Furthermore, we obtain structure characteristics of chromatically equivalent graphs of their complements.展开更多
We denote h(G,x) as the adjoint polynomial of graph G. In [5], Ma obtained the interpolation properties of the roots of adjoint polynomial of graphs containing triangles. By the properties, we prove the non-zero root ...We denote h(G,x) as the adjoint polynomial of graph G. In [5], Ma obtained the interpolation properties of the roots of adjoint polynomial of graphs containing triangles. By the properties, we prove the non-zero root of adjoint polynomial of Dn and Fn are single multiple.展开更多
AIM:To compare long-term results of gastric cancer patients undergoing laparoscopic and open gastrec-tomy in a single unit.METHODS:From February 2000 to September 2004,all patients with adenocarcinoma of the stomach w...AIM:To compare long-term results of gastric cancer patients undergoing laparoscopic and open gastrec-tomy in a single unit.METHODS:From February 2000 to September 2004,all patients with adenocarcinoma of the stomach were assessed to entry in this longitudinal prospective non-randomized trial.Primary endpoint was cancer-related survival and secondary endpoints were overall survival,evaluation of surgical complications and mortality.RESULTS:Fifty-eight patients were enrolled.Forty-seven patients were followed-up(range 11-103,me-dian 38 mo).Four patients were lost at follow up.Twenty-two patients underwent a laparoscopic gastric surgery(LGS)and 25 had a standard open procedure(OGS).No statistical difference was found between the two groups in terms of 5 years cancer-related mortality rate(50% vs 52%,P = 1),and 5 years overall mortal-ity rate(54.5% vs 56%,P = 1).Accordingly,cancer-related and overall survival probability by Kaplan-Meier method showed comparable results(P = 0.81 and P = 0.83,respectively).We found no differences in surgical complications in the 2 groups.There was no conversion to open surgery in this series.CONCLUSION:LGS is as effective as OGS in the man-agement of advanced gastric cancer.However LGS can-not be recommended routinely over OGS for the treat-ment of advanced gastric cancer.展开更多
AIM:To investigate the clinical features and prognostic factors of advanced hepatocellular carcinoma (HCC)patients presenting with lung metastasis at initial diagnosis. METHODS:Between 2001 and 2010,we recruited 76 co...AIM:To investigate the clinical features and prognostic factors of advanced hepatocellular carcinoma (HCC)patients presenting with lung metastasis at initial diagnosis. METHODS:Between 2001 and 2010,we recruited 76 consecutive HCC patients initially presenting with lung metastasis,without co-existing metastasis from other sites.These patients were divided into three groups:untreated group(n=22),single treatment group(n= 19),and combined treatment group(n=35). RESULTS:Metastasis of bilateral lung lobes was common and noted in 35 patients(46.1%),and most of patients(59/76,77.6%)presented with multiple lung metastatic nodules.Nineteen patients(25.0%) received single-method treatment,including hepatectomy in 4,transcatheter arterial chemoembolization in 6,radiotherapy in 5,and oral sorafenib in 4.Thirty-five patients(46.1%)received combined treatment modalities.The overall median survival of the all patients was 8.7±0.6 mo;4.1±0.3,6.3±2.5 and 18.6±3.9 mo, respectively in the untreated group,single treatment group and combined treatment group,respectively, with a significant difference(log-rank test,P<0.001). Multivariate analysis revealed that Child-Pugh score, the absence or presence of portal vein tumor thrombus,and treatment modality were three independent prognostic factors affecting survival of patients with advanced HCC and concomitant lung metastasis. CONCLUSION:Combined treatment modalities tend to result in a better survival as compared with the conservative treatment or single treatment modality for HCC patients initially presenting with lung metastasis.展开更多
Objective To prospectively evaluate the efficacy of Removing Stasis and Reducing Heat Formula in accelerating calculus clearance and improving lower urinary tract symptoms of patients with proximal ureteral calculi af...Objective To prospectively evaluate the efficacy of Removing Stasis and Reducing Heat Formula in accelerating calculus clearance and improving lower urinary tract symptoms of patients with proximal ureteral calculi after ureteroscopic Ho:YAG laser lithotripsy. Methods A total of 138 patients with proximal ureteral calculi underwent ureteroscopic Ho:YAG laser lithotripsy by a single endocrinologist. Stone size varied from 10 to 15 mm. After operation, the patients were randomly divided into three groups: the control group(group A), tamsulosin group(group B), and Removing Stasis and Reducing Heat Formula group(group C). The treatment lasted for 4 weeks or until stone clearance. The primary and secondary outcomes of the three groups at follow-up were assessed. Results Of the 131 patients available for follow-up, 44 cases were in the group A, 45 in the group B, and 42 in the group C, respectively. The stone free rate at 2 weeks in the groups B and C were significantly higher than that in the group A(95.56%, 97.62% vs. 79.55%; all P<0.05). The ureteral colic rate and mean time of fragment expulsion were significantly reduced in the groups B(4.44% and 7.86±4.99 days) and C(2.43% and 6.76±4.37 days) compared with the group A(22.73% and 11.54±9.89 days, all P<0.05). On the day of double-J ureteric stent removal, the group C differed significantly from the group A in the total International Prostate Symptom Score, irritative subscore, obstructive subscore, and quality of life score(all P<0.05). Conclusion Removing Stasis and Reducing Heat Formula in the medical expulsive therapy might be an effective modality for patients with calculus in the proximal uretera after ureteroscopic Ho:YAG laser lithotripsy.展开更多
Asian options are the popular second generation derivative products and embedded in many structured notes to enhance upside performance.The embedded options,as a result,usually have a long duration.The movement of int...Asian options are the popular second generation derivative products and embedded in many structured notes to enhance upside performance.The embedded options,as a result,usually have a long duration.The movement of interest rates becomes more important in pricing such long-dated options.In this paper,the pricing of Asian options under stochastic interest rates is studied.Assuming Hull and White model for the interest rates,a closed-form formula for geometric-average options is derived.As a by-product,pricing formula is also given for plan-vanilla options under stochastic interest rates.展开更多
Based on the Eigen and Crow-Kimura models with a single-peak fitness landscape, we propose the fitness values of all sequence types to be Gausslan distributed random variables to incorporate the effects of the fluctua...Based on the Eigen and Crow-Kimura models with a single-peak fitness landscape, we propose the fitness values of all sequence types to be Gausslan distributed random variables to incorporate the effects of the fluctuations of the fitness landscapes (noise of environments) and investigate the concentration distribution and error threshold of quasispecies by performing an ensemble average within this theoretical framework. We find that a small fluctuation of the fitness landscape causes only a slight change in the concentration distribution and error threshold, which implies that the error threshold is stable against small perturbations. However, for a sizable fluctuation, quite different from the previous deterministic models, our statistical results show that the transition from quasi-species to error catastrophe is not so sharp, indicating that the error threshold is located within a certain range and has a shift toward a larger value. Our results are qualitatively in agreement with the experimental data and provide a new implication for antiviral strategies.展开更多
AIM:To investigate the short-term outcome of laparoscopic total mesorectal excision(TME) in patients with mid and low rectal cancers.METHODS:A consecutive series of 138 patients with middle and low rectal cancer were ...AIM:To investigate the short-term outcome of laparoscopic total mesorectal excision(TME) in patients with mid and low rectal cancers.METHODS:A consecutive series of 138 patients with middle and low rectal cancer were randomly assigned to either the laparoscopic TME(LTME) group or the open TME(OTME) group between September 2008 and July 2011 at the Department of Colorectal Cancer of Shanghai Cancer Center,Fudan University and pathological data,as well as surgical technique were reviewed retrospectively.Short-term clinical and oncological outcome were compared in these two groups.Patients were followed in the outpatient clinic 2 wk after the surgery and then every 3 mo in the first year if no adjuvant chemoradiation was indicated.Statistical analysis was performed using SPSS 13.0 software.RESULTS:Sixty-seven patients were treated with LTME and 71 patients were treated with OTME(sex ratio 1.3:1vs 1.29:1,age 58.4 ± 13.6 years vs 59.6 ± 9.4 years,respectively).The resection was considered curative in all cases.The sphincter-preserving rate was 65.7%(44/67) vs 60.6%(43/71),P = 0.046;mean blood loss was 86.9 ± 37.6 mL vs 119.1 ± 32.7 mL,P = 0.018;postoperative analgesia was 2.1 ± 0.6 d vs 3.9 ± 1.8 d,P = 0.008;duration of urinary drainage was 4.7 ± 1.8 d vs 6.9 ± 3.4 d,P = 0.016,respectively.The conversion rate was 2.99%.The complication rate,circumferential margin involvement,distal margins and lymph node yield were similar for both procedures.No port site recurrence,anastomotic recurrence or mortality was observed during a median follow-up period of 21 mo(range:9-56 mo).CONCLUSION:Laparoscopic TME is safe and feasible,with an oncological adequacy comparable to the open approach.Further studies with more patients and longer follow-up are needed to confirm the present results.展开更多
The evolutionary dynamics first conceived by Darwin and Wallace, referring to as Darwinian dynamics in the present paper, has been found to be universally valid in biology. The statistical mechanics and thermodynamics...The evolutionary dynamics first conceived by Darwin and Wallace, referring to as Darwinian dynamics in the present paper, has been found to be universally valid in biology. The statistical mechanics and thermodynamics, while enormous successful in physics, have been in an awkward situation of wanting a consistent dynamical understanding. Here we present from a formal point of view an exploration of the connection between thermodynamics and Darwinian dynamics and a few related topics. We first show that the stochasticity in Darwinian dynamics implies the existence temperature, hence the canonical distribution of Boltzmann-Gibbs type. In term of relative entropy the Second Law of thermodynamics is dynamically demonstrated without detailed balance condition, and is valid regardless of size of the system. In particular, the dynamical component responsible for breaking detailed balance condition does not contribute to the change of the relative entropy. Two types of stochastic dynamical equalities of current interest are explicitly discussed in the present approach: One is based on Feynman-Kac formula and another is a generalization of Einstein relation. Both are directly accessible to experimental tests. Our demonstration indicates that Darwinian dynamics represents logically a simple and straightforward starting point for statistical mechanics and thermodynamics and is complementary to and consistent with conservative dynamics that dominates the physical sciences. Present exploration suggests the existence of a unified stochastic dynamical framework both near and far from equilibrium.展开更多
A maximally flat FIR filter design method based on explicit formulas combined with simulated annealing and random search was presented. Utilizing the explicit formulas to calculate the ini- tial values, the firate-wor...A maximally flat FIR filter design method based on explicit formulas combined with simulated annealing and random search was presented. Utilizing the explicit formulas to calculate the ini- tial values, the firate-word-length FIR filter design problem was converted into optimization of the filter coefficients, An optimization method combined with local discrete random search and simulated annealing was proposed, with the result of optimum solution in the sense of Chebyshev approximation. The proposed method can simplify the design process of FIR filter and reduce the calculation burden. The simulation result indicates that the proposed method is superior to the traditional round off method and can reduce the value of the objective function to 41%~74%.展开更多
A single-mode laser noise model driven by quadratic colored pump noise and amplitude modulation signal is proposed. The real and imaginary parts of the pump noise are assumed to be cross-correlation. The effect of cro...A single-mode laser noise model driven by quadratic colored pump noise and amplitude modulation signal is proposed. The real and imaginary parts of the pump noise are assumed to be cross-correlation. The effect of cross- correlation of noise and amplitude modulation of signal on laser statistical properties is studied by using the linearized approximation. The analytic expression of signal-to-noise ratio (SNR) is calculated. It is found that the phenomena of stochastic resonance (SR) respectively exist in the curves of the SNR versus the noise cross-correlation coefficient λ and the SNR versus the pump parameter a, as well as the SNR versus the signal frequency ω in our model. It is shown that there are three different typies of SR in the model: the conventional form of SR, the SR in the broad sense, and the bona fide SR.展开更多
AIM:To conduct a meta-analysis to determine the safety and efficacy of laparoscopic liver resection(LLR) and open liver resection(OLR) for hepatocellular carcinoma(HCC).METHODS:PubMed(Medline),EMBASE and Science Citat...AIM:To conduct a meta-analysis to determine the safety and efficacy of laparoscopic liver resection(LLR) and open liver resection(OLR) for hepatocellular carcinoma(HCC).METHODS:PubMed(Medline),EMBASE and Science Citation Index Expanded and Cochrane Central Register of Controlled Trials in the Cochrane Library were searched systematically to identify relevant comparative studies reporting outcomes for both LLR and OLR for HCC between January 1992 and February 2012.Two authors independently assessed the trials for inclusion and extracted the data.Meta-analysis was performed using Review Manager Version 5.0 software(The Cochrane Collaboration,Oxford,United Kingdom).Pooled odds ratios(OR) or weighted mean differences(WMD) with 95%CI were calculated using either fixed effects(Mantel-Haenszel method) or random effects models(DerSimonian and Laird method).Evaluated endpoints were operative outcomes(operation time,intraoperative blood loss,blood transfusion requirement),postoperative outcomes(liver failure,cirrhotic decompensation/ascites,bile leakage,postoperative bleeding,pulmonary complications,intraabdominal abscess,mortality,hospital stay and oncologic outcomes(positive resection margins and tumor recurrence).RESULTS:Fifteen eligible non-randomized studies were identified,out of which,9 high-quality studies involving 550 patients were included,with 234 patients in the LLR group and 316 patients in the OLR group.LLR was associated with significantly lower intraoperative blood loss,based on six studies with 333 patients [WMD:-129.48 mL;95%CI:-224.76-(-34.21) mL;P = 0.008].Seven studies involving 416 patients were included to assess blood transfusion requirement between the two groups.The LLR group had lower blood transfusion requirement(OR:0.49;95%CI:0.26-0.91;P = 0.02).While analyzing hospital stay,six studies with 333 patients were included.Patients in the LLR group were found to have shorter hospital stay [WMD:-3.19 d;95%CI:-4.09-(-2.28) d;P < 0.00001] than their OLR counterpart.Seven studies including 416 patients were pooled together to estimate the odds of developing postoperative ascites in the patient groups.The LLR group appeared to have a lower incidence of postoperative ascites(OR:0.32;95%CI:0.16-0.61;P = 0.0006) as compared with OLR patients.Similarly,fewer patients had liver failure in the LLR group than in the OLR group(OR:0.15;95%CI:0.02-0.95;P =0.04).However,no significant differences were found between the two approaches with regards to operation time [WMD:4.69 min;95%CI:-22.62-32 min;P = 0.74],bile leakage(OR:0.55;95%CI:0.10-3.12;P = 0.50),postoperative bleeding(OR:0.54;95%CI:0.20-1.45;P = 0.22),pulmonary complications(OR:0.43;95%CI:0.18-1.04;P = 0.06),intra-abdominal abscesses(OR:0.21;95%CI:0.01-4.53;P = 0.32),mortality(OR:0.46;95%CI:0.14-1.51;P = 0.20),presence of positive resection margins(OR:0.59;95%CI:0.21-1.62;P = 0.31) and tumor recurrence(OR:0.95;95%CI:0.62-1.46;P = 0.81).CONCLUSION:LLR appears to be a safe and feasible option for resection of HCC in selected patients based on current evidence.However,further appropriately designed randomized controlled trials should be undertaken to ascertain these findings.展开更多
A jack-up platform, with its particular structure, showed obvious dynamic characteristics under complex environmental loads in extreme conditions. In this paper, taking a simplified 3-D finite element dynamic model in...A jack-up platform, with its particular structure, showed obvious dynamic characteristics under complex environmental loads in extreme conditions. In this paper, taking a simplified 3-D finite element dynamic model in extreme storm conditions as research object, a transient dynamic analysis method was proposed, which was under both regular and irregular wave loads. The steps of dynamic analysis under extreme conditions were illustrated with an applied case, and the dynamic amplification factor (DAF) was calculated for each response parameter of base shear, overturning moment and hull sway. Finally, the structural response results of dynamic and static were compared and analyzed. The results indicated that the static strength analysis of the Jack-up Platforms was not enough under the dynamic loads including wave and current, further dynamic response analysis considering both computational efficiency and accuracy was necessary.展开更多
A one-dimensional cellular automaton model of traffic flow is proposed to introduce the different delay probabilities in the steps of rules and the stochastic deceleration prior to the deterministic one when the antic...A one-dimensional cellular automaton model of traffic flow is proposed to introduce the different delay probabilities in the steps of rules and the stochastic deceleration prior to the deterministic one when the anticipation velocity of vehicle is larger than the headway. The fundamental diagram shows the capacity of road more approaches to the observed data compared with that by the NaSch model. Moreover, the model is able to reproduce the complicated behavior of the real traffic, such as the metastability state, the separation of different phases and the effect of hysteresis.It is concluded that the order arrangement of the stochastic deceleration and deterministic acceleration has indeed remarkable effect on traffic flow and the modification presented in this paper is reasonable and realistic.展开更多
The parameter R(G) is the function about the front three coeffcients of the adjoint polynomial of graph G. In the paper, the range of R(G) is given when β(G) 〈 β(Dn), where β(G) is the minimum root of th...The parameter R(G) is the function about the front three coeffcients of the adjoint polynomial of graph G. In the paper, the range of R(G) is given when β(G) 〈 β(Dn), where β(G) is the minimum root of the adjoint polynomial of graph G and the chromatically equivalent classification of tDn is completely depicted.Furthermore, a sufficient and necessary condition for the class of graphs to be chromatically unique is obtained.展开更多
文摘The effects of random long-range connections (shortcuts) on the transitions of neural firing patterns in coupled Hindmarsh-Rose neurons are investigated, where each neuron is subjected to an external current. It is found that, on one hand, the system can achieve the transition of neural firing patterns from the fewer-period state to the multi-period one, when the number of the added shortcuts in the neural network is greater than a threshold value, indicating the occurrence of in-transition of neural firing patterns. On the other hand, for a stronger coupling strength, we can also find the similar but reverse results by adding some proper random connections. In addition, the influences of system size and coupling strength on such transition behavior, as well as the internality between the transition degree of firing patterns and its critical characteristics for different external stimulation current, are also discussed.
文摘Process variations can reduce the accuracy in estimation of interconnect performance. This work presents a process variation based stochastic model and proposes an effective analytical method to estimate interconnect delay. The technique decouples the stochastic interconnect segments by an improved decoupling method. Combined with a polynomial chaos expression (PCE), this paper applies the stochastic Galerkin method (SGM) to analyze the system response. A finite representation of interconnect delay is then obtained with the complex approximation method and the bisection method. Results from the analysis match well with those from SPICE. Moreover, the method shows good computational efficiency, as the running time is much less than the SPICE simulation's.
文摘Let Sn be the star with n vertices, and let G be any connected graph with p vertices. We denote by Eτp+(r-1)^G(i) the graph obtained from Sr and rG by coinciding the i-th vertex of G with the vertex of degree r - 1 of S,, while the i-th vertex of each component of (r - 1)G be adjacented to r - 1 vertices of degree 1 of St, respectively. By applying the properties of adjoint polynomials, We prove that factorization theorem of adjoint polynomials of kinds of graphs Eτp+(r-1)^G(i)∪(r - 1)K1 (1 ≤i≤p). Furthermore, we obtain structure characteristics of chromatically equivalent graphs of their complements.
基金Supported by the Foundation for University Key Teacher by the Ministry of Education(2000-2003)Supported by the National Natural Science Foundation of China(10061003)
文摘We denote h(G,x) as the adjoint polynomial of graph G. In [5], Ma obtained the interpolation properties of the roots of adjoint polynomial of graphs containing triangles. By the properties, we prove the non-zero root of adjoint polynomial of Dn and Fn are single multiple.
文摘AIM:To compare long-term results of gastric cancer patients undergoing laparoscopic and open gastrec-tomy in a single unit.METHODS:From February 2000 to September 2004,all patients with adenocarcinoma of the stomach were assessed to entry in this longitudinal prospective non-randomized trial.Primary endpoint was cancer-related survival and secondary endpoints were overall survival,evaluation of surgical complications and mortality.RESULTS:Fifty-eight patients were enrolled.Forty-seven patients were followed-up(range 11-103,me-dian 38 mo).Four patients were lost at follow up.Twenty-two patients underwent a laparoscopic gastric surgery(LGS)and 25 had a standard open procedure(OGS).No statistical difference was found between the two groups in terms of 5 years cancer-related mortality rate(50% vs 52%,P = 1),and 5 years overall mortal-ity rate(54.5% vs 56%,P = 1).Accordingly,cancer-related and overall survival probability by Kaplan-Meier method showed comparable results(P = 0.81 and P = 0.83,respectively).We found no differences in surgical complications in the 2 groups.There was no conversion to open surgery in this series.CONCLUSION:LGS is as effective as OGS in the man-agement of advanced gastric cancer.However LGS can-not be recommended routinely over OGS for the treat-ment of advanced gastric cancer.
基金Supported by Grants from National Natural Science Foundation of China,No.81000166Shanghai Science and Technology Development Commission,No.10411963300+1 种基金Shanghai Program for Excellent Talents in Health System,No.XYQ2011033Shanghai Health Bureau,No.ab8307000-2010-92
文摘AIM:To investigate the clinical features and prognostic factors of advanced hepatocellular carcinoma (HCC)patients presenting with lung metastasis at initial diagnosis. METHODS:Between 2001 and 2010,we recruited 76 consecutive HCC patients initially presenting with lung metastasis,without co-existing metastasis from other sites.These patients were divided into three groups:untreated group(n=22),single treatment group(n= 19),and combined treatment group(n=35). RESULTS:Metastasis of bilateral lung lobes was common and noted in 35 patients(46.1%),and most of patients(59/76,77.6%)presented with multiple lung metastatic nodules.Nineteen patients(25.0%) received single-method treatment,including hepatectomy in 4,transcatheter arterial chemoembolization in 6,radiotherapy in 5,and oral sorafenib in 4.Thirty-five patients(46.1%)received combined treatment modalities.The overall median survival of the all patients was 8.7±0.6 mo;4.1±0.3,6.3±2.5 and 18.6±3.9 mo, respectively in the untreated group,single treatment group and combined treatment group,respectively, with a significant difference(log-rank test,P<0.001). Multivariate analysis revealed that Child-Pugh score, the absence or presence of portal vein tumor thrombus,and treatment modality were three independent prognostic factors affecting survival of patients with advanced HCC and concomitant lung metastasis. CONCLUSION:Combined treatment modalities tend to result in a better survival as compared with the conservative treatment or single treatment modality for HCC patients initially presenting with lung metastasis.
文摘Objective To prospectively evaluate the efficacy of Removing Stasis and Reducing Heat Formula in accelerating calculus clearance and improving lower urinary tract symptoms of patients with proximal ureteral calculi after ureteroscopic Ho:YAG laser lithotripsy. Methods A total of 138 patients with proximal ureteral calculi underwent ureteroscopic Ho:YAG laser lithotripsy by a single endocrinologist. Stone size varied from 10 to 15 mm. After operation, the patients were randomly divided into three groups: the control group(group A), tamsulosin group(group B), and Removing Stasis and Reducing Heat Formula group(group C). The treatment lasted for 4 weeks or until stone clearance. The primary and secondary outcomes of the three groups at follow-up were assessed. Results Of the 131 patients available for follow-up, 44 cases were in the group A, 45 in the group B, and 42 in the group C, respectively. The stone free rate at 2 weeks in the groups B and C were significantly higher than that in the group A(95.56%, 97.62% vs. 79.55%; all P<0.05). The ureteral colic rate and mean time of fragment expulsion were significantly reduced in the groups B(4.44% and 7.86±4.99 days) and C(2.43% and 6.76±4.37 days) compared with the group A(22.73% and 11.54±9.89 days, all P<0.05). On the day of double-J ureteric stent removal, the group C differed significantly from the group A in the total International Prostate Symptom Score, irritative subscore, obstructive subscore, and quality of life score(all P<0.05). Conclusion Removing Stasis and Reducing Heat Formula in the medical expulsive therapy might be an effective modality for patients with calculus in the proximal uretera after ureteroscopic Ho:YAG laser lithotripsy.
文摘Asian options are the popular second generation derivative products and embedded in many structured notes to enhance upside performance.The embedded options,as a result,usually have a long duration.The movement of interest rates becomes more important in pricing such long-dated options.In this paper,the pricing of Asian options under stochastic interest rates is studied.Assuming Hull and White model for the interest rates,a closed-form formula for geometric-average options is derived.As a by-product,pricing formula is also given for plan-vanilla options under stochastic interest rates.
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10475008, 10675170, and 10435020, and the Department of Nuclear Physics of China Institute of Atomic Energy under Grant Nos. 11SZZ-200501 and 11SZZ-200601
文摘Based on the Eigen and Crow-Kimura models with a single-peak fitness landscape, we propose the fitness values of all sequence types to be Gausslan distributed random variables to incorporate the effects of the fluctuations of the fitness landscapes (noise of environments) and investigate the concentration distribution and error threshold of quasispecies by performing an ensemble average within this theoretical framework. We find that a small fluctuation of the fitness landscape causes only a slight change in the concentration distribution and error threshold, which implies that the error threshold is stable against small perturbations. However, for a sizable fluctuation, quite different from the previous deterministic models, our statistical results show that the transition from quasi-species to error catastrophe is not so sharp, indicating that the error threshold is located within a certain range and has a shift toward a larger value. Our results are qualitatively in agreement with the experimental data and provide a new implication for antiviral strategies.
文摘AIM:To investigate the short-term outcome of laparoscopic total mesorectal excision(TME) in patients with mid and low rectal cancers.METHODS:A consecutive series of 138 patients with middle and low rectal cancer were randomly assigned to either the laparoscopic TME(LTME) group or the open TME(OTME) group between September 2008 and July 2011 at the Department of Colorectal Cancer of Shanghai Cancer Center,Fudan University and pathological data,as well as surgical technique were reviewed retrospectively.Short-term clinical and oncological outcome were compared in these two groups.Patients were followed in the outpatient clinic 2 wk after the surgery and then every 3 mo in the first year if no adjuvant chemoradiation was indicated.Statistical analysis was performed using SPSS 13.0 software.RESULTS:Sixty-seven patients were treated with LTME and 71 patients were treated with OTME(sex ratio 1.3:1vs 1.29:1,age 58.4 ± 13.6 years vs 59.6 ± 9.4 years,respectively).The resection was considered curative in all cases.The sphincter-preserving rate was 65.7%(44/67) vs 60.6%(43/71),P = 0.046;mean blood loss was 86.9 ± 37.6 mL vs 119.1 ± 32.7 mL,P = 0.018;postoperative analgesia was 2.1 ± 0.6 d vs 3.9 ± 1.8 d,P = 0.008;duration of urinary drainage was 4.7 ± 1.8 d vs 6.9 ± 3.4 d,P = 0.016,respectively.The conversion rate was 2.99%.The complication rate,circumferential margin involvement,distal margins and lymph node yield were similar for both procedures.No port site recurrence,anastomotic recurrence or mortality was observed during a median follow-up period of 21 mo(range:9-56 mo).CONCLUSION:Laparoscopic TME is safe and feasible,with an oncological adequacy comparable to the open approach.Further studies with more patients and longer follow-up are needed to confirm the present results.
基金The project supported in part by USA NIH Grant under HG002894
文摘The evolutionary dynamics first conceived by Darwin and Wallace, referring to as Darwinian dynamics in the present paper, has been found to be universally valid in biology. The statistical mechanics and thermodynamics, while enormous successful in physics, have been in an awkward situation of wanting a consistent dynamical understanding. Here we present from a formal point of view an exploration of the connection between thermodynamics and Darwinian dynamics and a few related topics. We first show that the stochasticity in Darwinian dynamics implies the existence temperature, hence the canonical distribution of Boltzmann-Gibbs type. In term of relative entropy the Second Law of thermodynamics is dynamically demonstrated without detailed balance condition, and is valid regardless of size of the system. In particular, the dynamical component responsible for breaking detailed balance condition does not contribute to the change of the relative entropy. Two types of stochastic dynamical equalities of current interest are explicitly discussed in the present approach: One is based on Feynman-Kac formula and another is a generalization of Einstein relation. Both are directly accessible to experimental tests. Our demonstration indicates that Darwinian dynamics represents logically a simple and straightforward starting point for statistical mechanics and thermodynamics and is complementary to and consistent with conservative dynamics that dominates the physical sciences. Present exploration suggests the existence of a unified stochastic dynamical framework both near and far from equilibrium.
文摘A maximally flat FIR filter design method based on explicit formulas combined with simulated annealing and random search was presented. Utilizing the explicit formulas to calculate the ini- tial values, the firate-word-length FIR filter design problem was converted into optimization of the filter coefficients, An optimization method combined with local discrete random search and simulated annealing was proposed, with the result of optimum solution in the sense of Chebyshev approximation. The proposed method can simplify the design process of FIR filter and reduce the calculation burden. The simulation result indicates that the proposed method is superior to the traditional round off method and can reduce the value of the objective function to 41%~74%.
基金The project supported by National Natural Science Foundation of China under Grant No.10275025
文摘A single-mode laser noise model driven by quadratic colored pump noise and amplitude modulation signal is proposed. The real and imaginary parts of the pump noise are assumed to be cross-correlation. The effect of cross- correlation of noise and amplitude modulation of signal on laser statistical properties is studied by using the linearized approximation. The analytic expression of signal-to-noise ratio (SNR) is calculated. It is found that the phenomena of stochastic resonance (SR) respectively exist in the curves of the SNR versus the noise cross-correlation coefficient λ and the SNR versus the pump parameter a, as well as the SNR versus the signal frequency ω in our model. It is shown that there are three different typies of SR in the model: the conventional form of SR, the SR in the broad sense, and the bona fide SR.
文摘AIM:To conduct a meta-analysis to determine the safety and efficacy of laparoscopic liver resection(LLR) and open liver resection(OLR) for hepatocellular carcinoma(HCC).METHODS:PubMed(Medline),EMBASE and Science Citation Index Expanded and Cochrane Central Register of Controlled Trials in the Cochrane Library were searched systematically to identify relevant comparative studies reporting outcomes for both LLR and OLR for HCC between January 1992 and February 2012.Two authors independently assessed the trials for inclusion and extracted the data.Meta-analysis was performed using Review Manager Version 5.0 software(The Cochrane Collaboration,Oxford,United Kingdom).Pooled odds ratios(OR) or weighted mean differences(WMD) with 95%CI were calculated using either fixed effects(Mantel-Haenszel method) or random effects models(DerSimonian and Laird method).Evaluated endpoints were operative outcomes(operation time,intraoperative blood loss,blood transfusion requirement),postoperative outcomes(liver failure,cirrhotic decompensation/ascites,bile leakage,postoperative bleeding,pulmonary complications,intraabdominal abscess,mortality,hospital stay and oncologic outcomes(positive resection margins and tumor recurrence).RESULTS:Fifteen eligible non-randomized studies were identified,out of which,9 high-quality studies involving 550 patients were included,with 234 patients in the LLR group and 316 patients in the OLR group.LLR was associated with significantly lower intraoperative blood loss,based on six studies with 333 patients [WMD:-129.48 mL;95%CI:-224.76-(-34.21) mL;P = 0.008].Seven studies involving 416 patients were included to assess blood transfusion requirement between the two groups.The LLR group had lower blood transfusion requirement(OR:0.49;95%CI:0.26-0.91;P = 0.02).While analyzing hospital stay,six studies with 333 patients were included.Patients in the LLR group were found to have shorter hospital stay [WMD:-3.19 d;95%CI:-4.09-(-2.28) d;P < 0.00001] than their OLR counterpart.Seven studies including 416 patients were pooled together to estimate the odds of developing postoperative ascites in the patient groups.The LLR group appeared to have a lower incidence of postoperative ascites(OR:0.32;95%CI:0.16-0.61;P = 0.0006) as compared with OLR patients.Similarly,fewer patients had liver failure in the LLR group than in the OLR group(OR:0.15;95%CI:0.02-0.95;P =0.04).However,no significant differences were found between the two approaches with regards to operation time [WMD:4.69 min;95%CI:-22.62-32 min;P = 0.74],bile leakage(OR:0.55;95%CI:0.10-3.12;P = 0.50),postoperative bleeding(OR:0.54;95%CI:0.20-1.45;P = 0.22),pulmonary complications(OR:0.43;95%CI:0.18-1.04;P = 0.06),intra-abdominal abscesses(OR:0.21;95%CI:0.01-4.53;P = 0.32),mortality(OR:0.46;95%CI:0.14-1.51;P = 0.20),presence of positive resection margins(OR:0.59;95%CI:0.21-1.62;P = 0.31) and tumor recurrence(OR:0.95;95%CI:0.62-1.46;P = 0.81).CONCLUSION:LLR appears to be a safe and feasible option for resection of HCC in selected patients based on current evidence.However,further appropriately designed randomized controlled trials should be undertaken to ascertain these findings.
基金Supported by the National Natural Science Foundation of China (Grant No.51079034) Fundamental Research Funds for the Central Universities (Grant No. HEUCFRI003).
文摘A jack-up platform, with its particular structure, showed obvious dynamic characteristics under complex environmental loads in extreme conditions. In this paper, taking a simplified 3-D finite element dynamic model in extreme storm conditions as research object, a transient dynamic analysis method was proposed, which was under both regular and irregular wave loads. The steps of dynamic analysis under extreme conditions were illustrated with an applied case, and the dynamic amplification factor (DAF) was calculated for each response parameter of base shear, overturning moment and hull sway. Finally, the structural response results of dynamic and static were compared and analyzed. The results indicated that the static strength analysis of the Jack-up Platforms was not enough under the dynamic loads including wave and current, further dynamic response analysis considering both computational efficiency and accuracy was necessary.
基金The project supported by National Natural Science Foundation of China under Grant Nos.19932020 and 10362001
文摘A one-dimensional cellular automaton model of traffic flow is proposed to introduce the different delay probabilities in the steps of rules and the stochastic deceleration prior to the deterministic one when the anticipation velocity of vehicle is larger than the headway. The fundamental diagram shows the capacity of road more approaches to the observed data compared with that by the NaSch model. Moreover, the model is able to reproduce the complicated behavior of the real traffic, such as the metastability state, the separation of different phases and the effect of hysteresis.It is concluded that the order arrangement of the stochastic deceleration and deterministic acceleration has indeed remarkable effect on traffic flow and the modification presented in this paper is reasonable and realistic.
基金Supported by the National Science Foundation of China(10761008)Supported by the Science Foundation of the State Education Ministry of China(205170)
文摘The parameter R(G) is the function about the front three coeffcients of the adjoint polynomial of graph G. In the paper, the range of R(G) is given when β(G) 〈 β(Dn), where β(G) is the minimum root of the adjoint polynomial of graph G and the chromatically equivalent classification of tDn is completely depicted.Furthermore, a sufficient and necessary condition for the class of graphs to be chromatically unique is obtained.