Case Report: Dual resistance to dasatinib/olverembatinib in accelerated-phase cml: identification of a novel SPECC1L-inserted e8a2 BCR::ABL1 transcript and ABL1 V379I mutation

In chronic myeloid leukemia (CML), less than 2% of cases express atypical or rare BCR::ABL1 transcripts. The e8a2 BCR::ABL1 fusion transcript, a rare variant, has been reported in only 20 cases to date, primarily in case reports or case series. The direct junction between BCR exon 8 and ABL1 exon 2 generates a premature stop codon at position 7 after the fusion, while the insertion of certain sequences can result in the formation of an in-frame e8a2 transcript. To date, the insertion of SPECC1L gene sequences into e8a2 BCR::ABL1 fusion transcripts has been reported in two CML cases, and the V379I mutation (in ABL1) has been identified in two additional CML cases. We describe a case of accelerated-phase CML involving three key molecular abnormalities: the insertion of a 154 bp SPECC1L exon 4 sequence into the e8a2 BCR::ABL1 fusion transcript, a concomitant ABL1 V379I mutation, and deletions near the t(9;22) breakpoint on derivative chromosome 9 (der(9)). The patient’s clinical manifestations, cytogenetic features, and molecular genetic characteristics were summarized and discussed. Despite sequential therapy with full-dose dasatinib for 10 months and the third-generation tyrosine-kinase inhibitor (TKI) olverembatinib for 7 months, the patient experienced progressive disease. She ultimately achieved Major Molecular Response (MMR) after haploidentical hematopoietic stem-cell transplantation (haplo-HSCT). This case highlights the importance of comprehensive molecular profiling at diagnosis and the need to develop alternative therapeutic strategies for rare BCR::ABL1 variants

Charging strategies for wireless powered networks

With the growing popularity of the Internet of Things (IoT) and machine-to-machine (M2M) devices for automated remote control, massive smart devices are being envisioned. To cope with the heavy energy demand of such large-scale networks, new energy harvesting techniques have been considered. Among them, harvesting power from available radio frequency (RF) energy sources has attracted great attention. RF energy harvesting enjoys the advantages of mobility, sustainability and scalability. The mode of using RF signals makes it possible to combine RF energy harvesting with wireless communications, which allows data and energy transmission at the same time. Hence, deciding how to allocate resources and schedule charging for such systems is worth a lot of effort. In this thesis we firstly study a two-way relay system where the relay not only helps forward information but also provides energy to users. We propose a three-phase protocol and investigate the rate optimization problems by jointly optimizing time scheduling and power allocation at the relay and user side. Subsequently, we consider the energy consumption minimization problem with users’ quality-of-service (QoS) constraints. It is revealed that the energy consumption minimization problem actually contains the dual of rate maximization problems. Moreover, we obtain the capacity region for decode-and-forward (DF) relaying by solving the weighted sum rate maximization problem. We then consider a two-user multiple access channel (MAC) with a wireless-powered relay-to-destination (R-D) link where the relay harvests energy from an RF signal sent by a dedicated power beacon (PB). Each frame is divided into three phases. In the first phase, the relay harvests energy from an RF signal sent by a dedicated PB. The relay then receives information from user nodes in the second phase, and forwards it to the destination in the third phase using its harvested energy. We investigate the sum rate maximization problem and characterize the capacity region of such channel under both the amplify-and-forward (AF) and DF relay strategies. For comparison, we also analyze the problems under conventional relaying. It is interesting to find that the shape of the capacity region is still pentagonal with a wireless-powered relay. Finally, we look beyond the scenario of wireless communication and investigate a static network that consists of a PB and multiple wireless powered user nodes. Each user node is equipped with a rechargeable battery, and harvests energy only from the PB. We assume all user nodes are either in charge or work mode. Under this assumption, we first propose a charge scheduling scheme that achieves the system’s maximal energy efficiency. We then further investigate the system’s improvement with a multi-antenna PB using the energy beamforming technique. Next, we extend our scheduling scheme to a two-tier network architecture, where a first-tier PB first transfers energy to the second-tier sub-PBs, and then those sub-PBs deliver energy to the user nodes which belong to their clusters. It is shown that energy beamforming with multiple antennas brings a significant improvement to the system’s performance. Moreover, the two-tier architecture is shown to be superior to the one-tier architecture in terms of the energy transfer efficiency and the system’s realization complexity. As a supplement, the case that the PB has limited amount of energy is also investigated. The charge scheduling scheme that can achieve the maximal amount of total harvested energy is derived.</p

Optimal scheduling and power allocation for wireless powered two-way relaying systems

We consider a two-way wireless powered cooperative system where the relay not only helps to forward the information for the user nodes, but also acts as an energy beacon. Assuming that due to the hardware limitation, harvesting energy and information transmission cannot be performed simultaneously, we propose a novel three-phase energy harvesting and transmission protocol. In the first phase, the relay broadcasts radio frequency (RF) energy signals which is harvested by both user nodes. In the second and third phase, the user nodes communicate with each other via the relay node. Thus, in order to maximize the network throughput, it is critical to investigate the tradeoff between the durations of the wireless energy harvesting phase and the information transfer phases. In particular, we maximize the throughput for the proposed wireless powered two-way relaying systems by jointly optimizing the durations of wireless energy harvesting and information transmission phases, and the power allocation for transmissions. The optimal solution is obtained, and through simulations, we show the effectiveness of the proposed scheme as compared to the benchmark schemes. © 2016 IEEE

Capacity regions of a MAC with a wireless-powered relay-to-destination link under different relay strategies

We consider a two-user multiple access channel (MAC) with a wireless-powered relay-to-destination (R-D) link, where the relay harvests energy from a radio frequency (RF) signal sent by a dedicated Power Beacon (PB). Each frame is divided into three phases. In the first phase, the relay harvests energy from an RF signal sent by a dedicated PB. The relay then receives information from user nodes in the second phase and forwards it to the destination in the third phase using its harvested energy. We investigate the sum rate maximization problem and characterize the capacity region of such a channel with the relay’s maximum transmit power constraint, under both the amplify-and-forward (AF) and decode-and-forward (DF) relay strategies. Optimal solutions are obtained for both cases. It is interesting to find that the shape of the capacity region is still pentagonal with the wireless-powered relay. And the relay’s maximum transmission power constraint greatly affects the system’s performance. Finally, simulation results demonstrate the correctness of our analysis

Optimal Charge Scheduling for Energy-Constrained Wireless-Powered Network

As a candidate power supply solution for the Internet of Things, radio frequency (RF) energy harvesting has attracted great attention recently. In this paper, we consider an RF wireless-powered network, which consists of a dedicated power beacon (PB) and multiple user nodes. The PB is assumed to have limited energy and transfers its power to user nodes wirelessly. The user nodes work only based on energy harvested from the PB, and are assumed to be in either energy harvesting mode, energy consumption mode, or idle mode. To maximize the total harvested energy, we coordinate the behaviors of the PB and user nodes, and propose a general charge scheduling scheme that can achieve the system's maximum harvested energy. We then compare the results of our proposed scheme with the benchmark schemes, and simulation results demonstrate the effectiveness of our proposed scheduling