A polaron theory of quantum thermal transistor in nonequilibrium three-level systems

We investigate the quantum thermal transistor effect in nonequilibrium three-level systems by applying the polarontransformed Redfield equation combined with full counting statistics.The steady state heat currents are obtained via this unified approach over a wide region of system–bath coupling,and can be analytically reduced to the Redfield and nonequilibrium noninteracting blip approximation results in the weak and strong coupling limits,respectively.A giant heat amplification phenomenon emerges in the strong system–bath coupling limit,where transitions mediated by the middle thermal bath are found to be crucial to unravel the underlying mechanism.Moreover,the heat amplification is also exhibited with moderate coupling strength,which can be properly explained within the polaron framework.

Novel management indications for conservative treatment of chylous ascites after gastric cancer surgery

BACKGROUND Chylous ascites(CA) presents a challenge as a relatively common postoperative complication in gastric cancer(GC). Primary conservative therapy involved total parenteral nutrition, continuous low-pressure drainage, somatostatin, and a lowfat diet. Drainage tube(DT) clamping has been presented as a potential alternative conservative treatment for GC patients with CA.AIM To propose novel conservative treatment strategies for CA following GC surgery.METHODS The data of patients with CA after GC surgery performed at the Fudan University Shanghai Cancer Center between 2006 and 2021 were evaluated retrospectively.RESULTS 53 patients underwent surgery for GC and exhibited postoperative CA during the study period. Postoperative hospitalization and time of DT removal showed a significant positive association(R~2 = 0.979, P < 0.001). We further observed that delayed DT removal significantly extended the total and postoperative hospitalization, antibiotic usage duration, and hospitalization cost(postoperative hospitalization: 25.8 d vs 15.5 d, P < 0.001;total hospitalization: 33.2 d vs 24.7 d, P < 0.01;antibiotic usage duration: 10.8 d vs 6.2 d, P < 0.01;hospitalization cost: ￥9.2 × 104vs ￥6.5 × 104, P < 0.01). Multivariate analysis demonstrated that postoperative infection and antibiotic usage were independent factors for delayed DT removal.Furthermore, DT removal times were shorter in seven patients who underwent DT clamping(clamped DT vs normal group, 11.8 d vs 13.6 d, P = 0.047;clamped DT vs delayed group, 13.6 d vs 27.4 d, P < 0.001). In addition, our results indicated that removal of the DT may be possible after three consecutive days of drainage volumes less than 300 mL in GC patients with CA.CONCLUSION Infection and antibiotic usage were vital independent factors that influenced delayed DT removal in patients with CA. Appropriate standards for DT removal can significantly reduce the duration of hospitalization. Furthermore, DT clamping might be a recommended option for conservative treatment of postoperative CA.

Coherent excitation transfer via the dark-state channel in a bionic system

Light absorption and energy transfer were studied in a bionic system with donors and an acceptor.In the optimal case of uniform couplings,this seemingly complicated system was reduced to a three-level L-type system.With this observation,we showed that the efficiency of energy transfer through a dark-state channel,which is free of the spontaneous decay of the donors,was dramatically improved.After the overall average transfer time was evaluated,it was revealed that the time required for transfer through this channel was not optimal.To find the optimal parameters for the present system,we defined a new quantity,output power,which characterizes the average mean output of the whole transfer process.We estimated the optimal parameters of the system to achieve the maximum output power.The splitting behaviour of the maximum power may be used to explain the phenomenon of photosynthetic systems primarily absorbing two colours of light.