An Environment-Aware Adaptive Data-Gathering Method for Packet-Level Index Modulation in LPWA.

Low-power wide-area (LPWA) is a communication technology for the IoT that allows low power consumption and long-range communication. Additionally, packet-level index modulation (PLIM) can transmit additional information using multiple frequency channels and time slots. However, in a competitive radio access environment, where multiple sensors autonomously determine packet transmission, packet collisions occur when transmitting the same information. The packet collisions cause a reduction in the throughput. A method has been proposed to design a mapping table that shows the correspondence between indexes and information using a packet collision minimization criterion. However, the effectiveness of this method depends on how the probability of the occurrence of the information to be transmitted is modeled. We propose an environment-aware adaptive data-gathering method that identifies the location of factors affecting sensor information and constructs a model for the probability of the occurrence of sensor information. The packet collision rate of the environment-aware adaptive data-gathering method was clarified through computer simulations and actual experiments on a 429 MHz LPWA. We confirm that the proposed scheme improves the packet collision rate by 15% in the computer simulation and 30% in the experimental evaluation, respectively.

Three Level Recognition Based on the Average of the Phase Differences in Physical Wireless Parameter Conversion Sensor Networks and Its Effect to Localization with RSSI.

In recent years, there have been increased demands for aggregating sensor information from several sensors owing to the spread of the Internet of Things (IoT). However, packet communication, which is a conventional multiple-access technology, is hindered by packet collisions owing to simultaneous access by sensors and waiting time to avoid packet collisions; this increases the aggregation time. The physical wireless parameter conversion sensor network (PhyC-SN) method, which transmits sensor information corresponding to the carrier wave frequency, facilitates the bulk collection of sensor information, thereby reducing the communication time and achieving a high aggregation success rate. However, when more than one sensor transmits the same frequency simultaneously, the estimation accuracy of the number of accessed sensors deteriorates significantly because of multipath fading. Thus, this study focuses on the phase fluctuation of the received signal caused by the frequency offset inherent to the sensor terminals. Consequently, a new feature for detecting collisions is proposed, which is a case in which two or more sensors transmit simultaneously. Furthermore, a method to identify the existence of 0, 1, 2, or more sensors is established. In addition, we demonstrate the effectiveness of PhyC-SNs in estimating the location of radio transmission sources by utilizing three patterns of 0, 1, and 2 or more transmitting sensors.

[On-pump Beating Minimally Invasive Cardiac Surgery Valve Plasty for Infective Endocarditis Located in the Tricuspid Valve:Report of a Case].

The patient is a 50-year-old man. He was healthy by nature, had fever in the 38 ℃ range for about a week, blood culture identified methicillin-sensitive Staphylococcus aureus( MSSA), and ultrasoundcardiography(UCG) showed a 10 mm vegetation adherent to the tricuspid valve, which led to the diagnosis of infective endocarditis. The patient was transferred to our hospital for surgery because UCG showed severe tricuspid regurgitation and the vegetation enlarged to 20 mm in size. We resected the posterior apex with vegetation attachment and performed tricuspid valve plasty using the Kay stitches, and the regurgitation disappeared. The patient continued additional antimicrobial therapy and was discharged without any complications at 30 days after operation. Tricuspid valve surgery was considered to be a safe procedure that could be performed at minimally invasive cardiac surgery.

Estimation Based on Chirp Modulation for Desired and Interference Power and Channel Occupancy Ratio in LoRa.

In terms of low power consumption and long-range communication-low-power wide-area networks (LPWAN) are suitable for wireless sensor networks. Long-range (LoRa) wireless communication is one of the standards of LPWAN. LoRa shares common frequency spectrum bands with both multiple transmitters, which are the sensors in the LoRa system (and those in the other system). Therefore, co-channel interference (CCI) degrades the packet delivery rate. To avoid CCI, the CCI power and the occurrence probability of CCI in the target channel are estimated, then the sensor decides whether to use the channel and where the occurrence probability of CCI is defined as the channel occupancy ratio (COR). If a large signal power is obtained at the receiver, the received signal can be demodulated because of the capture effect. The desired signal power must also be estimated for the capture effect. In this study, we propose an estimation scheme based on chirp modulation of LoRa under spectrum sharing among other systems. The proposed scheme estimates the desired signal power, CCI power, and COR. From the computer simulation results, we clarify the advantages of the proposed scheme in terms of estimation accuracy and packet delivery rate.

Effect of nadir hematocrit during cardiopulmonary bypass on the early outcomes after surgical repair of acute type A aortic dissection.

OBJECTIVE: Although hemodilution during hypothermic cardiopulmonary bypass (CPB) had been thought to improve microcirculation and reduce blood viscosity, there has been no report investigating the effect of low nadir hematocrit (Hct) values caused by severe hemodilution on the surgical outcomes of patients with acute type A aortic dissection (ATAAD). METHODS: We retrospectively reviewed 112 consecutive patients who emergently underwent emergency surgical repair of ATAAD at our institution. The patients were classified into the high Hct (nadir Hct ≥ 21% during CPB; n = 51) and low Hct (nadir Hct < 21% during CPB; n = 61) groups. After propensity score matching of preoperative characteristics, surgical outcomes were compared between the groups. RESULTS: Although there was no difference in the surgical procedure, longer CPB time and more blood transfusion during surgery were needed in the low Hct group than in the high Hct group. After surgery, estimated glomerular filtration rate was significantly lower (p = .015), lactaic acid was higher (p = .045), and intubation time was longer (p = .018) in the low Hct group than in the high Hct group, although there was no difference in hospital mortality between the groups. The AUC of the nadir Hct during CPB as a prognostic indicator of prolonged postoperative ventilator support was 0.8, with the highest accuracy at 16.7% (sensitivity 88%, specificity 76.9%). In all cohorts, female sex was an independent risk factor for a lower nadir Hct value of <21% during CPB. CONCLUSION: A lower nadir Hct value of <21% during CPB may be associated with postoperative renal dysfunction and prolonged ventilator support in patients with ATAAD.

Randomized controlled trial of daily teriparatide, weekly high-dose teriparatide, or bisphosphonate in patients with postmenopausal osteoporosis: The TERABIT study.

PURPOSE: The effects of daily teriparatide (20 µg) (D-PTH), weekly high-dose teriparatide (56.5 µg) (W-PTH), or bisphosphonates (BPs) on areal bone mineral density (aBMD), bone turnover markers (BTMs), volumetric BMD (vBMD), microarchitecture, and estimated strength were investigated in postmenopausal osteoporosis patients. METHODS: The study participants were 131 women with a history of fragility fractures. They were randomized to receive D-PTH, W-PTH, or BPs (alendronate or risedronate) for 18 months. Dual-energy X-ray absorptiometry (DXA), BTMs, and high-resolution peripheral quantitative CT (HR-pQCT) parameters were evaluated at baseline and after 6 and 18 months of treatment. The primary endpoint was the change (%) in cortical thickness (Ct.Th) after 18 months' treatment compared with baseline. RESULTS: DXA showed that D-PTH, W-PTH, and BPs increased lumbar spine aBMD (+12.0%, +8.5%, and +6.8%) and total hip aBMD (+3.0%, +2.1%, and +3.0%), but D-PTH and W-PTH decreased 1/3 radius aBMD (-4.1%, -3.0%, -1.4%) after 18 months. On HR-pQCT, D-PTH increased trabecular vBMD (Tb.vBMD) at the distal radius and tibia after 18 months (+6.4%, +3.7%) compared with the BPs group, decreased cortical volumetric tissue mineral density (Ct.vTMD) (-1.8%, -0.9%) compared with the other groups, increased Ct.Th (+1.3%, +3.9%), and increased failure load (FL) (+4.7%, +4.4%). W-PTH increased Tb.vBMD (+5.3%, +1.9%), maintained Ct.vTMD (-0.7%, +0.2%) compared with D-PTH, increased Ct.Th (+0.6%, +3.6%), and increased FL (+4.9%, +4.5%). The BPs increased Tb.vBMD only in the radius (+2.0%, +0.2%), maintained Ct.vTMD (-0.6%, +0.3%), increased Ct.Th (+0.5%, +3.4%), and increased FL (+3.9%, +2.8%). CONCLUSIONS: D-PTH and W-PTH comparably increased Ct.Th, the primary endpoint. D-PTH had a strong effect on trabecular bone. Although D-PTH decreased Ct.vTMD, it increased Ct.Th and total bone strength. W-PTH had a moderate effect on trabecular bone, maintained Ct.vTMD, and increased Ct.Th and total bone strength to the same extent as D-PTH.

Aortic Agatston score correlates with the progression of acute type A aortic dissection.

Aortic calcification in the tunica media is correlated with aortic stiffness, elastin degradation, and wall shear stress. The study aim was to determine if aortic calcifications influence disease progression in patients with acute type A aortic dissection (ATAAD). We retrospectively reviewed a total of 103 consecutive patients who had undergone surgery for ATAAD at our institution between January 2009 and December 2019. Of these, 85 patients who had preoperatively undergone plain computed tomography angiography (CTA) for evaluation of their aortic calcification were included. Moreover, we assessed the progression of aortic dissection after surgery via postoperative CTA. Using a classification and regression tree to identify aortic Agatston score thresholds predictive of disease progression, the patients were classified into high-score (Agatston score ≥ 3344; n  =   36) and low-score (<3344; n  =   49) groups. Correlations between aortic Agatston scores and CTA variables were assessed. Higher aortic Agatston scores were significantly correlated with the smaller distal extent of aortic dissection (p < 0.001), larger true lumen areas of the ascending (p  =  0.009) and descending aorta (p =   0.002), and smaller false lumen areas of the descending aorta (p =  0.028). Patients in the high-score group were more likely to have DeBakey type II dissection (p =  0.001) and false lumen thrombosis (p  =  0.027) than those in the low-score group, thereby confirming the correlations. Aortic dissection in the high-score group was significantly less distally extended (p < 0.001). A higher aortic Agatston score correlates with the larger true lumen area of the ascending and descending aorta and the less distal progression of aortic dissection in patients with ATAAD. Interestingly, the findings before and after surgery were consistent. Hence, aortic Agatston scores are associated with aortic dissection progression and may help predict postoperative residual dissected aorta remodeling.

Successful Crossover Bypass Using a Lateral Femoral Circumflex Artery as an Outflow Vessel for Indirect Revascularization in Critical Limb Ischemia: A Case Report.

A 78-year-old man presented with severe stage 3 (Fontaine IV, Rutherford 5, W1 I3 FI0) right limb ischemia. Although his artery was completely occluded from below the right external iliac to the popliteal artery, collateral circulation from the right lateral femoral circumflex artery was well developed and supplied the lower extremity arteries. We selected an uncommon crossover bypass strategy with the left common femoral artery to the right lateral femoral circumflex artery to improve lower extremity perfusion via indirect revascularization. Bypass using the lateral femoral circumflex artery as an outflow is an option for patients with major lower extremity artery occlusions.

[Rapid Growing Thoracic Aortic Aneurysm in a Patient with Relapsing Polychondritis].

A 26-year-old man with relapsing polychondritis was admitted for the treatment of multiple thoracic aortic aneurysms in the ascending and descending aorta. Descending thoracic aortic aneurysm showed rapid expansion, therefore, the patient underwent an extended thoracic aortic repair from the ascending aorta to the descending aorta via anterolateral thoracotomy and partial sternotomy. Although postoperative course was uneventful, aortic root enlargement and severe aortic insufficiency progressed over the next two years. He and his family refused redo surgical intervention and the patient died of heart failure. Careful perioperative follow-up may be mandatory in a patient with relapsing polychondritis complicated by cardiovascular disease.

[Revascularization of the Right Common Carotid Artery Prior to Central Repair for Stanford Type A Acute Aortic Dissection with Brain Malperfusion:Report of a Case].

A 67-year-old woman had sudden loss of consciousness and chest and back pain. She was transported by ambulance about two hours later. Computed tomography (CT) showed dissection of the aorta, the brachiocephalic artery and the right common carotid artery (RCCA). RCCA was completely obstructed. Emergency surgery was conducted one hour later. RCCA's blood flow was reestablished prior to hemi-arch replacement. Postoperative CT revealed diminishment of the false lumen and recovery of the blood flow of RCCA, and she was discharged on foot without any complications.

Physical activities and surgical outcomes in elderly patients with acute type A aortic dissection.

OBJECTIVE: Although elderly patients undergoing surgery for acute type A aortic dissection (ATAAD) is increasing, their physical activities are not fully understood. We report the physical activities and surgical outcomes in elderly patients who underwent ATAAD. METHODS: From 2009 to 2019, 103 consecutive patients underwent surgery for ATAAD at our institution. Surgical outcomes along with pre- and postoperative physical activities in 52 elderly patients (≥70 years old) were compared with those in 51 younger patients (<70 years old). Postoperative walking difficulty was defined as taking ≥30 days to regain the ability to walk 200 m postoperatively or as the inability to walk at discharge. RESULTS: It took longer for elderly patients to regain the ability to walk 100 or 200 m postoperatively. ROC analysis revealed the AUC of the duration for walking 200 m postoperatively as a prognostic indicator for late deaths was 0.878, with the highest accuracy at 30 days (sensitivity = 83.3%, specificity = 91.8%). Hospital mortality within 30 days was 3.8%, and 1-, 3-, and 5-years survival rates were 92%, 84.7%, 84.7%, respectively, for elderly patients, with no significant differences between groups. Cox proportional hazard analysis showed postoperative walking difficulty was an independent risk factor for late mortality in all cohorts (p = .017). CONCLUSIONS: Elderly patients undergoing surgical ATAAD repair showed acceptable surgical outcomes. However, they were more likely to decrease their physical activities postoperatively. Postoperative difficulty in walking was an independent risk factor for the late mortality in patients with ATAAD.

[Patch Repair by Anterolateral Thoracotomy with Partial Sternotomy for Saccular Aortic Arch Aneurysm with Severe Thoracic Deformity:Report of a Case].

An 87-year-old male was referred to our hospital for surgery of saccular aortic arch aneurysm. As he had a history of thoracoplasty on his left side due to pulmonary tuberculosis, his aortic arch adhered to the apex of the left thorax. Total arch replacement(TAR) via median sternotomy was considered difficult, and anterolateral thoracotomy with partial sternotomy (ALPS) was performed. During surgery, we considered TAR difficult even with ALPS approach. Taking account of his age, aneurysmectomy and patch repair were chosen instead of TAR to shorten operation time. Although he suffered from diffuse cerebral infarction, he was discharged without neurological deficit at 39 days after operation.

Forced expression of miR-143 and -145 in cardiomyocytes induces cardiomyopathy with a reductive redox shift.

BACKGROUND: Animal model studies show that reductive stress is involved in cardiomyopathy and myopathy, but the exact physiological relevance remains unknown. In addition, the microRNAs miR-143 and miR-145 have been shown to be upregulated in cardiac diseases, but the underlying mechanisms associated with these regulators have yet to be explored. METHODS: We developed transgenic mouse lines expressing exogenous miR-143 and miR-145 under the control of the alpha-myosin heavy chain (αMHC) promoter/enhancer. RESULTS: The two transgenic lines showed dilated cardiomyopathy-like characteristics and early lethality with markedly increased expression of miR-143. The expression of hexokinase 2 (HK2), a cardioprotective gene that is a target of miR-143, was strongly suppressed in the transgenic hearts, but the in vitro HK activity and adenosine triphosphate (ATP) content were comparable to those observed in wild-type mice. In addition, transgenic complementation of HK2 expression did not reduce mortality rates. Although HK2 is crucial for the pentose phosphate pathway (PPP) and glycolysis, the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG) was unexpectedly higher in the hearts of transgenic mice. The expression of gamma-glutamylcysteine synthetase heavy subunit (γ-GCSc) and the in vitro activity of glutathione reductase (GR) were also higher, suggesting that the recycling of GSH and its de novo biosynthesis were augmented in transgenic hearts. Furthermore, the expression levels of glucose-6-phosphate dehydrogenase (G6PD, a rate-limiting enzyme for the PPP) and p62/SQSTM1 (a potent inducer of glycolysis and glutathione production) were elevated, while p62/SQSTM1 was upregulated at the mRNA level rather than as a result of autophagy inhibition. Consistent with this observation, nuclear factor erythroid-2 related factor 2 (Nrf2), Jun N-terminal kinase (JNK) and inositol-requiring enzyme 1 alpha (IRE1α) were activated, all of which are known to induce p62/SQSTM1 expression. CONCLUSIONS: Overexpression of miR-143 and miR-145 leads to a unique dilated cardiomyopathy phenotype with a reductive redox shift despite marked downregulation of HK2 expression. Reductive stress may be involved in a wider range of cardiomyopathies than previously thought.

Risk factors for spinal cord injury in patients undergoing frozen elephant trunk technique for acute aortic dissection.

BACKGROUND: The purpose of this study was to evaluate the risk factors for spinal cord injury (SCI) in patients with acute aortic dissection undergoing surgery with frozen elephant trunk technique (FET). METHODS: From December 2014 to February 2018, 17 patients with acute aortic dissection underwent surgical treatment of the aortic arch with FET. SCI occurred in 3 patients. Risk factors for SCI were evaluated. RESULTS: Mean age of the patients was 56 years and 88.2% were male. The ratio of true lumen to total aortic diameter at the level of carina (before: 0.48 vs. after: 0.75, P < 0.001), aortic valve (before: 0.47 vs. after: 0.67, P = 0.001), and celiac artery (before: 0.48 vs. after: 0.68, P = 0.003) increased after surgery. There were no significant differences in perioperative minimum hemoglobin level and postoperative mean arterial pressure between patients with and without SCI. However, patients with SCI had higher creatinine level before surgery (SCI: 1.32 mg/dL vs. no SCI: 0.81 mg/dL, P = 0.023). Although there was no difference in number of patent intercostal arteries before surgery, those originating from the true lumen were fewer in patients with SCI (SCI: 2.7 vs. no SCI: 8.6, P = 0.021). Furthermore, with entry closure, significant decrease in patency was observed in intercostal arteries originating from the false lumen (before: 3.1 vs. after: 1.0, P < 0.001). CONCLUSION: FET was useful in entry closure. However, FET in patients with higher creatinine level and those who may have significant spinal cord perfusion from the false lumen could be a risk factor for postoperative SCI.

Off-pump coronary artery bypass grafting via left anterior thoracotomy from the 4th costal space in a patient with total laryngectomy and a permanent tracheostoma.

Median sternotomy is the standard approach for coronary artery bypass grafting. Herein, we performed off-pump coronary artery bypass grafting via left anterior thoracotomy from the 4th costal space in an unstable angina pectoris patient with total laryngectomy and a permanent tracheostoma. In this patient, median sternotomy had high risks of surgical-site infection and tracheal injury. To avoid these risks, we selected left anterior thoracotomy. Initially, it was difficult to expose the ascending aorta and postdescending branch. With extension of the skin incision to the median area and division of the 5th and 6th ribs and costal arch, we could expose the anastomotic sites, including the ascending aorta and postdescending branch, without median sternotomy conversion. We performed multiple coronary artery bypass graft procedures safely. This approach might be an additional surgical option in patients with total laryngectomy and a permanent tracheostoma.

[Pseudoaneurysm with Infective Endocarditis Ten Years After the Resection of Pseudoaneurysm Complicated with Myocardial Infarction;Report of a Case].

A 76-year-old female was referred to our hospital for fever and chillness. She was diagnosed with pneumonia and sepsis, and methicillin-resistant Staphylococcus aureus (MRSA)was detected by the sputum culture. Echocardiography showed mobile vegetation and left ventricular pseudoaneurysm at the apex. As she had a history of ventricular pseudoaneurysmectomy 10 years before, we considered the patient had developed infective endocarditis at the surgical site. Surgical treatment was needed because of the rapidly growing pseudoaneurysm despite the use of antibacterial agents. She successfully underwent resection of the pseudoaneurysm and MRSA was also detected in the culture of the previous vascular graft patch. Antibacterial agents were administrated for 6 weeks, and she was discharged at 53 days after operation.

Redo Descending Aortic Replacement via Direct Anastomosis to J Graft Open Stent Graft.

A 64-year-old man with prior history of total arch replacement with frozen elephant trunk was admitted for an enlarging descending thoracic aortic aneurysm. Preoperative computed tomography revealed previously implanted J graft open stent graft, a frozen elephant trunk device approved in Japan, with enlarged dissected aortic aneurysm from distal anastomosis site to the level of the diaphragm. The patient underwent descending aortic replacement. Proximal anastomosis was directly performed at the distal end of the previously implanted J graft open stent graft. Hemostasis at the anastomosis site was uneventful and the patient was discharged from the hospital without any aneurysm-related complication.

Surgical outcomes of acute type A aortic dissection in dialysis patients.

BACKGROUND: Acute type A aortic dissection (ATAAD) is relatively uncommon in dialysis patients, and characteristics and repair outcomes are not fully understood. PATIENTS AND METHODS: Patients with ATAAD (n = 960) were divided into a dialysis group (n = 19) and non-dialysis group (n = 941), depending on whether they required dialysis for preoperative end-stage renal disease (ESRD). Hospital charts and imaging data were reviewed, and characteristics and outcomes were compared between the groups. Segmental aortic wall or intima/media flap calcification in the thoracic and abdominal aorta was assessed in the dialysis patients. RESULTS: The leading primary causes of ESRD were polycystic kidney disease (n = 5) and chronic glomerulonephritis (n = 5). There were no significant differences (dialysis group vs. non-dialysis group) in age (60.5 vs. 64.5 years), preoperative hemodynamics, or organ ischemia. Dialysis patients were more likely to have an entry tear in the aortic arch (42% vs. 15%, p = 0.003). These patients showed moderate-to-severe calcification (multiple focal or single focal calcification > 10 mm) in the ascending aorta (17%), aortic arch (61%), descending aorta (67%), and abdominal aorta (83%). Arch replacement was common in this group (37% vs. 18%, p = 0.030). Although in-hospital mortality was increased in this group (21% vs. 7%, p = 0.059), morbidities did not differ significantly. Six-year survival was 60.3 ± 13.4% and 78.8 ± 1.6%, respectively (p = 0.01). CONCLUSIONS: Dialysis patients tend to have aortic calcification and a primary tear in the aortic arch. Outcomes are acceptable.

[Combined Thoraco-abdominal Aortic Aneurysm Repair and Coronary Artery Bypass Grafting through a Left Thoracotomy].

Approximately 40% of the patients with aortic aneurysm have coronary artery disease(CAD), which is an important factor contributing to early mortality associated with aneurysm surgery. Combined coronary artery bypass grafting (CABG)and aortic aneurysm repair of the ascending aorta to the aortic arch is often performed through a median sternotomy due to a good surgical exposure. However, treatment strategy of thoraco-abdominal aortic aneurysm(TAAA) combined with CAD is often controversial. We report a successful case of a 69-year-old man who underwent TAAA repair and CABG through a left thoracotomy. Left thoracotomy via the 5th intercostal space with para-rectal incision provides a good surgical exposure of the thoraco-abdominal aorta and the left anterior descending artery(LAD). LAD was revascularized with a saphenous vein graft which was anastomosed to the descending aorta, followed by TAAA repair. The postoperative course was uneventful and the patient was discharged on 13th postoperative day without any complications.