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.

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.

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.

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.

[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.

[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.

[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.

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.

[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.

[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.

[Total Aortic Arch Replacement by Minimally Invasive Approach in a Patient with Permanent Tracheostomy;Report of a Case].

Standard full median sternotomy for total aortic arch replacement in patients with tracheostomy has higher risks for mediastinitis and graft infection. To avoid surgical site infection, it is necessary to keep a sufficient distance between the tracheostomy and the site of surgical skin incision. We herein report a case of a 74-year-old man with permanent tracheostomy after total laryngectomy, who underwent total aortic arch replacement for an aneurysm. Antero-lateral thoracotomy in the 2nd intercostal space with lower partial sternotomy( ALPS approach) provided an enough distance between the tracheostomy and the surgical field. It also provided a good view for surgical procedure and enabled the standard setup of cardiopulmonary bypass with ascending aortic cannulation, venous drainage from the right atrium and the left ventricular venting through the upper right pulmonary vein. The operation was completed in 345 minutes and the patient was discharged on the 11th postoperative day without any complications.

[Mitral Valve Replacement under Ventricular Fibrillation through Right Thoracotomy for Severe Mitral Regurgitation with Low Left Ventricular Function after Coronary Artery Bypass Grafting；Report of a Case].

A 64-year-old woman had undergone coronary artery bypass grafting (CABG:left internal thoracic artery-left anterior descending artery, right internal thoracic artery-1st diagonal branch, saphenous vein graft-posterior descending artery) 5 years before. However, she was referred to us due to worsening of dyspnea. Severe mitral regurgitation with tethering and tricuspid regurgitation were observed by echocardiography, and low left ventricular function with ejection fraction of 32.6% was noted. Coronary artery computed tomography revealed patency of all grafts, and the right internal thoracic artery ran across the front of the ascending aorta. To avoid injuring the patent grafts, mitral valve replacement under ventricular fibrillation and tricuspid annuloplasty were performed with a right thoracotomy approach. The postoperative course was uneventful, and she was discharged in an improved state on hospital day 28. This method appears safe and useful for avoiding secondary injuries in patients with severe mitral regurgitation with low left ventricular function after CABG.

[Valve replacement after omentum flap for medicastinitis;report of a case].

A 71-year-old woman presented with heart failure due to aortic and mitral valve regurgitation. She had developed midiastinitis and graft infection, 15 months before, following replacement of the ascending aorta for acute aortic dissection. Omentum flap operation had been performed and the infection had been controlled. This time, she underwent re-thoracotomy, and replacement of ascending aorta, aortic valve replacement and mitral valve plasty were performed. The omenal tissue was exfoliated without any damage to the heart or the great vessels by using an ultrasonic scalpel. As the omental tissue was viable, it was placed back in the mediastinal space.

Reduced adult hippocampal neurogenesis and working memory deficits in the Dgcr8-deficient mouse model of 22q11.2 deletion-associated schizophrenia can be rescued by IGF2.

DiGeorge syndrome chromosomal region 8 (Dgcr8), a candidate gene for 22q11.2 deletion-associated schizophrenia, encodes an essential component for microRNA (miRNA) biosynthesis that plays a pivotal role in hippocampal learning and memory. Adult neurogenesis is known to be important in hippocampus-dependent memory, but the role and molecular mechanisms of adult neurogenesis in schizophrenia remain unclear. Here, we show that Dgcr8 heterozygosity in mice leads to reduced cell proliferation and neurogenesis in adult hippocampus, as well as impaired hippocampus-dependent learning. Several schizophrenia-associated genes were downregulated in the hippocampus of Dgcr8(+/-) mice, and one of them, insulin-like growth factor 2 (Igf2), rescued the proliferation of adult neural stem cells both in vitro and in vivo. Furthermore, IGF2 improved the spatial working memory deficits in Dgcr8(+/-) mice. These data suggest that defective adult neurogenesis contributes to the cognitive impairment observed in 22q11.2 deletion-associated schizophrenia and could be rectified by IGF2.

GABA type B receptor signaling in proopiomelanocortin neurons protects against obesity, insulin resistance, and hypothalamic inflammation in male mice on a high-fat diet.

There is evidence suggesting that the GABA system in the arcuate nucleus, where orexigenic neuropeptide Y and agouti-related peptide as well as anorexigenic proopiomelanocortin (POMC) are expressed, plays an important role in energy balance. In this study, we generated POMC-specific GABAB receptor-deficient [knock-out (KO)] mice. Male KO mice on a high-fat diet (HFD) showed mild increases in body weight (BW) at the age of 9 weeks compared to wild-type (WT) mice, and the differences remained significant until 16 weeks old. However, there was no difference in BW in females between genotypes. While food intake was similar between genotypes, oxygen consumption was significantly decreased in the male KO mice. The insulin tolerance test revealed that the male KO mice were less insulin sensitive compared to WT mice at the age of 8 weeks, when there was no significant difference in BW between genotypes. Despite increased BW, POMC mRNA expression in the arcuate nucleus was significantly decreased in the KO mice compared to WT mice at the age of 16 weeks. Furthermore, the expression of TNFα as well as IL-6, proinflammatory markers in the hypothalamus, was significantly increased in the KO mice on a HFD compared to WT mice. This demonstrates that the deletion of GABAB receptors in POMC neurons in the male mice on a HFD results in obesity, insulin resistance, and hypothalamic inflammation. Furthermore, the decreased POMC expression in the obese KO mice suggests that the regulation of POMC expression through GABAB receptors is essential for proper energy balance.

Synergistic binding of DnaJ and DnaK chaperones to heat shock transcription factor σ32 ensures its characteristic high metabolic instability: implications for heat shock protein 70 (Hsp70)-Hsp40 mode of function.

Escherichia coli heat shock transcription factor σ(32) is rapidly degraded by ATP-dependent proteases, such as FtsH and ClpYQ. Although the DnaK chaperone system (DnaK, DnaJ, and GrpE) promotes σ(32) degradation in vivo, the precise mechanism that is involved remains unknown. Our previous results indicated that σ(32) mutants containing amino acid substitution in the N-terminal half of Region 2.1 are markedly stabilized in vivo. Here, we report the further characterization of these mutants by examining purified σ(32) mutants in vitro. Surprisingly, I54A σ(32), a very stable mutant, is more susceptible to ClpYQ and FtsH proteases than wild-type σ(32), indicating that the stability of σ(32) does not always reflect its susceptibility to proteases. Co-precipitation and gel filtration analyses show that purified σ(32) mutants exhibit a reduced affinity for DnaJ, leading to a marked decrease in forming a complex with DnaK in the presence of DnaJ and ATP. Other mutants with modestly increased stability (A50S σ(32) and K51E σ(32)) show an intermediate efficiency of complex formation with DnaK, suggesting that defects in binding to DnaK and DnaJ are well correlated with metabolic stability; effective interaction with DnaK promotes σ(32) degradation in vivo. We argue that the stable and effective interaction of heat shock protein 70 (Hsp70) with a substrate polypeptide may generally require the simultaneous binding of heat shock protein 40 (Hsp40) to distinct sites on the substrate.

Reduction of mitral valve leaflet tethering by procedures targeting the subvalvular apparatus in addition to mitral annuloplasty.

BACKGROUND: Ischemic mitral regurgitation (IMR) with ischemic cardiomyopathy (ICM) was treated with surgical procedures, and mitral leaflet tethering was assessed. Twenty-two patients with both ICM (left ventricular ejection fraction <0.35) and IMR (>2) underwent coronary artery bypass grafting (CABG), mitral annuloplasty (MAP) with or without surgical ventricular restoration (SVR) and procedures targeting the subvalvular apparatus. METHODS AND RESULTS: Fourteen patients (group 1) underwent CABG and MAP, and the remaining 8 (group 2) underwent CABG, MAP, SVR, papillary muscle approximation (PMA), and papillary muscle suspension (PMS). PMA joined the entire papillary muscles with 3 mattress sutures. For PMS, 2 ePTFE sutures were placed between papillary muscle tips and fibrous annuli. Anterior and posterior mitral leaflet tethering angles (ALA and PLA) relative to the line connecting annuli, posterior and apical displacement of coaptation, and IMR grade were measured on echocardiography. Although preoperative ALA and PLA in group 2 were significantly larger than in group 1, there was no significant difference between groups at 1 month after surgery. At 1 year after surgery, however, the situation reversed: ALA and PLA in group 1 were significantly larger than in group 2. CONCLUSIONS: In addition to MAP, procedures targeting the subvalvular apparatus including PMA and PMS achieved persistent reduction of mitral valve leaflet tethering, which might lead to the improvement of long-term outcome.

[Brain protection during operation for aortic arch aneurysms].

Aortic arch replacement has been safely performed by moderate hypothermic circulatory arrest, and antegrade selective cerebral perfusion. To prevent permanent neurological deficit, it is important to precisely evaluate brain, neck vessels and atherosclerotic thoracic aorta by computed tomography(CT), magnetic resonance imaging (MRI)and intraoperative epiaortic echography, which can lead the safest cannulation site, careful manipulation of cerebral perfusion catheters. It is also important to make good exposure of surgical site, especially in distal anastomosis, and irrigate and flush atheromatous debris. Since 1991 to 2013, our consecutive 410 cases of total and hemi arch replacement of aorta, including 57 emergency cases, result in 22 cases( 5.4%) of mortality( 3.1% of elective, 19.3% of emergency) and 10 cases( 2.4%) of stroke( 2.3% of elective, 3.5% of emergency). Mortality and morbidities are more likely be occurred in emergency cases. It is possible to keep good operative results with reliable brain protection of selective antegrade cerebral perfusion which gives enough time for secure open distal anastomosis to every surgeon, but atheroemborism from shaggy aorta remains as a problem yet to be solved.