Introduction: Pulmonary arteriovenous malformation (PAVM) is a rare cardiovascular anomaly and represents direct communications between the branches of pulmonary artery and pulmonary veins, without an intervening pulmonary bed. The incidence of PAVM is 2–3 per 100,000 population. The male to female ratio varies from 1:1.5 to 1.8. A clinical manifestation may be from asymptomatic to severe hypoxia. Case presentation: A ten years old boy was admitted to a regional hospital because the mother noticed that the boy was slower in the game at the teacher noticed that the boy was slower and could not lift his eyes up of clinical and laboratory examinations have been shown polycythemia, and cyanosis, bat-like appearance of the fingers and polycythemia, RTG chest and CT have claimed AV malformation of the lower left lobes with the feeding artery Neurologic symptoms may be the presenting symptoms in up to 40% of patients. The patient was successfully treated with left lower lobectomy. Early post-operative recovery has been successful. Later checkups showed better blood saturation with oxygen, the same polycythemia, and a better clinical condition. Discussion and Conclusion: If the etiology of the hypoxemia often remains unclear pulmonary AVM should be considered. The diagnosis needs to be confirmed with a CT scan that should identify the food artery. If the AV malformation occupies large part of the lobe, a reasonable treatment options should be lobectomy. Longterm follow up, including chest CT examinations every 1 to 2 years, is recommended.

To alleviate the problem of scarce spectrum resources and meet the ever-increasing of mobile broadband data traffic demands, Licensed Assisted Access (LAA)-Long Term Evolution (LTE), operating in the unlicensed spectrum, is a promising solution. Considering that the unlicensed spectrum is shared by a few incumbent systems, such as IEEE 802.11 (i.e., WiFi), one main target is to guarantee the friendly and harmonious coexistence of LTE with other wireless systems in the unlicensed spectrum. Both listen-before-talk (LBT) and duty cycle methods are regarded as effective ways to solve the coexistence problem in academia and industry so far. Although there are a large number of theoretical researches on LTE in unlicensed spectrum (LTE-U), field trail results are still lacking. In this paper, an experimental testing platform is deployed to model the realistic environment. This paper focuses on three aspects. First, a typical indoor field trial scenario in 5.8 GHz unlicensed bands is deployed, and the performance of LTE-U and WiFi, including coverage and capacity, is evaluated. Specifically, a methodology to determine the proper clear channel assessment energy detection (CCA-ED) threshold for LTE-U is proposed to implement the friendly coexistence between LTE-U and WiFi systems. Second, supplementary downlink (SDL) and Cell ON/OFF mechanisms are investigated to verify the fair coexistence between LAA and WiFi in the unlicensed spectrum. Third, the Enhanced Cell ON/OFF scheme, which introduces Clear to Send (CTS)-to-Self (CTS2S) message, is discussed and evaluated. Based on the built testbed, we obtain threefold conclusions. First of all, introducing LTE into unlicensed spectrums can greatly improve the spectrum efficiency and optimize wireless resources. Furthermore, test results and analyses show that a proper CCA-ED threshold is necessary for coexisting friendly and fairly among different systems, and experiments are also provided to validate the feasibility of the suggested method in various scenarios. Second, experimental results show that SDL mechanism guarantees relatively friendly and harmonious coexistence between LAA and WiFi only in the sparse scenario, while basic Cell ON/OFF mechanism is more effective to ensure coexistence between LAA and WiFi than the SDL. Finally, with the introduction of CTS2S message, the Enhanced Cell ON/OFF scheme is able to achieve more peaceful coexistence between LTE and WiFi users employed in the same bands compared with the Basic Cell ON/OFF scheme.

Relaying over power line communication (PLC) channels can considerably enhance the performance and reliability of PLC systems. This paper is dedicated to study and analyze the energy efficiency of multi-hop cooperative relaying PLC systems. Incremental decode-and-forward (IDF) relying is exploited to reduce the transmit power consumption. The PLC channel is assumed to experience log-normal fading with impulsive noise. The performances of single-hop and conventional DF relaying systems are also analyzed in terms of outage probability and energy efficiency for which analytical expressions are derived. Results show that using more relays can improve the outage probability performance; however, this is achieved at the expense of increased power consumption due to the increased static power of the relays, especially when the total source-to-destination distance is relatively small. Results also demonstrate that the IDF PLC system has better energy efficiency performance compared to the other schemes.