A hybrid state-space approach to sampled-data feedback control

This paper develops a state-space theory for the study of linear shift-invariant finite-dimensional hybrid dynamical systems. By hybrid systems, we mean an input-output operator relating hybrid signals, that is, signals which consist of two parts: a continuous-time part and a discrete-time part. We first introduce the hybrid state-space model and show the closedness properties under the fundamental operations. We next investigate the standard basic issues associated with this formalism: reachability, observability, and internal stability. We define the notion of H2-norm of the hybrid system and show how to evaluate it. Since the analysis result can be applied to any hybrid system with the proposed hybrid state-space model, we apply the analysis result to the optimal digital control problem for standard four-block configuration with H2-norm performance measure. The solution, with computational algorithm, is derived for the time-delay case.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31483/1/0000405.pd

Crystallization characteristics of amorphous trehalose dried from alcohol

Trehalose forms a glass that can be used to preserve labile substances under desiccation. The crystallization characteristics, namely crystallization temperature (Tcry) and isothermal crystallization behavior of amorphous trehalose, dried from alcohol (methanol, ethanol), was analyzed and the results were compared with those for the amorphous trehalose freeze-dried from water. The use of alcohol as a solvent lowered the Tcry from 184 ± 6 °C for the case of an aqueous solvent to 103 ± 5 °C/methanol and 120 ± 8 °C/ethanol. The formation of multiple forms of crystals and partial melting were suggested by the thermal analysis. Isothermal crystallization experiments showed that the alcohol-originated amorphous trehalose was eventually exclusively converted into β-form crystals. The induction period (tind) before the start of isothermal crystallization was markedly shortened when alcohol was used as the solvent compared to water. The tind values for various amorphous sugar samples including the alcohol-originated ones could be correlated with difference between Tcry and the sample temperature

食道痛細胞におけるWntのベータカテ二ンTCF経路の活性化の検討

Although, accumulation of nuclear and cytoplasmic beta-catenin has been observed in ESCCs, mutation of APC and beta-catenin are not found in ESCCs. Therefore, another mechanism for cytoplasmic beta- catenin accumulation might exist in ESCCs. Materials and Methods: Human ESCCs cell lines and the 293 stable transfectants expressing Wnt-1, Wnt-5A, and Wnt-7A were cultured under standard conditions. The TOPFlash or FOPFlash reporter plasmids were transfected. Results: Transfected mutant beta-catenin as well as an axin fragment harbing the GSK3 beta interaction domain, the latter a potent GSK3 beta inhibitor. both robustly activated pTOPFlash in ESCCs cells. When pTOPFlash/pFOPFlash reporters were transfected in ESCCs cell lines followed by cocultivation with 293 cells that stably express Wnt -1, all cell lines except one demonstrated TCF mediated transcriptional. But, cells were co- cultured, Wnt - 7A or Wnt - 5A did not activate TCF mediated transcription in a cell number dependent fashion. Discussion; We report the activation of TCF promoter gene by extemal Wnt stimuli in ESCCs cells.背景:食道癌細胞にベータカテニンの蓄積があることは報告されているが,大腸癌とことなり,ベータカテニン,Axin,APC変異の報告がなく,そのメカニズムは不明である｡ 方法:8種類の食道癌細胞株において,3種類のWntの刺激によるベータカテニンTCF系の活性化への影響をTCFプロモーターを持つルシュフフェラーゼプラスミドを癌細胞にトランスフェクションして検討した｡ 結果:代表的な食道癌細胞は変異ベータカテニン,変異APC,変異Axinのいずれも,TCFの活性化をおこした｡8種類中7種類の癌細胞はWnt1により量依存性のTCFの活性化が認められたが,Wnt5A,Wnt7Aでは活性化が認められなかった｡ 結語:食道癌の進展にWnt1の関与が示唆された

Risk factors for sternal wound infection

Background Although the utility of flaps for the treatment of sternal wound infections following median sternotomy has been reported for 30 years, there have been few reports on the risk factors for complications after reconstruction. The objective of this investigation was to identify factors related to complications after the reconstruction of sternal wound infections. Methods A retrospective analysis of 74 patients with reconstructive surgery after sternal wound infection over a 5-year period was performed. Clinical data including age, sex, body mass index (BMI), comorbidities, bacterial culture, previous cardiac surgery, wound depth, mortality rate, type of reconstructive procedure, and complication rate were collected. Results The patients' BMI ranged from 15.2 to 33.6 kg/m2 (mean, 23.1±3.74 kg/m2). Wound closure complications after reconstructive surgery were observed in 36.5% of the cases. The mortality rate was 2.7%. Diabetes mellitus significantly affected the rate of wound closure complications (P=0.041). A significant difference in the number of complications was seen between Staphylococcus aureus (S. aureus) and coagulase-negative Staphylococci (P=0.011). There was a correlation between harvesting of the internal thoracic artery and postoperative complications (P=0.048). The complication rates of the pectoralis major flap, rectus abdominis flap, omentum flap, a combination of pectoralis major flap and rectus abdominis flap, and direct closure were 23.3%, 33.3%, 100%, 37.5%, and 35.7%, respectively. Conclusions Diabetes mellitus, S. aureus, harvesting of the internal thoracic artery, and omentum flap were significant factors for complications after reconstruction. The omentum flap volume may be related to the complications associated with the omentum flap transfer in the present study

Patient Satisfaction after Endoscopic Thoracic Sympathectomy for Palmar Hyperhidrosis

Endoscopic thoracic sympathectomy (ETS) for palmar hyperhidrosis was performed using a 3-mm small endoscope at our hospital, and we conducted a questionnaire for the purpose of studying the conditions and satisfaction after surgery. The subjects were comprised of 50 patients, of which 35 patients (75%) answered the survey. The average age of the respondents was 27 years old (range: 12?62 years old) including 13 males and 22 females and the average postoperative observation period was 33 months (1?114 months). The results showed the good effects of surgery in all of the patients for palmar sweating while patient satisfaction was 79.4 points, which concluded that ETS was sufficiently accepted as treatment for palmar hyperhidrosis. However, compensatory sweating (CS) developed in 97.1% of the patients, and 82.9% answered that they were disturbed because it was more than they had expected. This result makes us realize further the importance of preoperative informed consent for CS. The problem of palmar hyperhidrosis is very serious for patients, and hence it is important to give treatment with a thorough understanding of the effectiveness and problems of ETS for palmar hyperhidrosis according to the analytical results of this questionnaire

Bilateral Multiple Pulmonary Sclerosing Hemangioma in a Young Male Patient

The patient was a 24-year-old male who visited our University Hospital complaining of chest pain, and chest computed tomography revealed multiple bilateral nodules. The chest pain disappeared almost immediately, but the tumor underwent no changes during the 3 years of follow-up observations. We used a thoracoscope to perform a partial lung resection of a nodule that reached a maximum diameter of 9 mm for the purpose of obtaining a definite diagnosis. From the pathological findings, the patient was diagnosed to have pulmonary sclerosing hemangioma in which circular tumor cells lacking nuclear atypia rose to papillary hyperplasia. The mindbomb homolog-1 positive rate (MIB-1 index) of the tumor cells was less than 1%, and it is believed to have a poor proliferation activity. Pulmonary sclerosing hemangioma is predominantly found in cases of middle-aged female patients and occurs unilaterally. Cases of bilateral multiple forms in young males are extremely rare. Some cases of enlargement, metastasis and relapse have also been reported, so in the future, careful follow-up is required

Histopathologically Proven Autoimmune Pancreatitis Mimicking Neuroendocrine Tumor or Pancreatic Cancer

Autoimmune pancreatitis (AIP) can be difficult to distinguish from pancreatic cancer. We report a case of histopathologically proven AIP mimicking neuroendocrine tumor (NET) or pancreatic cancer in a 53-year-old man. He was referred to our hospital for further evaluation of a pancreatic mass detected on ultrasonography at a medical check-up. Abdominal ultrasonography showed a 15-mm hypoechoic mass located in the pancreatic body. Computed tomography revealed a tumor without any contrast enhancement, and magnetic resonance imaging demonstrated the mass to be hyperintense on diffusion-weighted image. Endoscopic retrograde cholangiopancreatography revealed slight dilatation of a branch of the pancreatic duct without stricture of the main pancreatic duct. The common bile duct seemed intact. Under suspicion of a non-functioning NET or malignant neoplasm, laparotomy was performed. At laparotomy, an elastic firm and well-circumscribed mass was found suggestive of a non-functioning NET, thus enucleation was performed. Histopathologically, the lesion corresponded to AIP

Thoracoscopic Resection of an Anterior Mediastinal Bronchogenic Cyst

We report a very rare case of anterior mediastinal bronchogenic cyst, successfully resected by thoracoscopic surgery. A 78-year-old female was noted as having an abnormal shadow on her chest X-ray during a routine medical checkup. Chest CT revealed a cystic tumor in the anterior mediastinum. A thymic cyst was suspected after a detailed examination and thoracoscopic surgery was performed. A cystic tumor containing yellowish-white mucus measuring 46 × 33 × 19 mm in size was successfully removed. Calcification was also observed in the cyst wall. Pathologically, the tumor was characterized by a ciliated columnar epithelial lining, and was subsequently diagnosed as a bronchogenic cyst. Although they may be rare, bronchogenic cysts should also be considered in the evaluation of cystic tumors in the anterior mediastinum