Surface Modification and Adhesion Mechanism of Isotactic Polypropylene with Low-Energy Electron-Beam Treatments.

Recently, smaller-size electron-beam (EB) accelerators have offered EB irradiation in laboratory systems. Therefore, polymer surface treatments with low-energy EB have been developed in the past years. For high adhesion strength, low-energy EB treatment is also a promising method in comparison to plasma surface treatment. In the plasma treatment, the mechanism of the effect on the adhesion properties has been proved and the excess treatments led to the formation of a weak boundary layer and reduction of adhesion strength. In contrast, the low-energy EB possesses high penetration ability. In this work, we focused on the surface treatments of isotactic polypropylene (it.PP) with low-energy EB irradiation for adhesion. The dependence of adhesion strength on the absorbed dose of electron beam was evaluated, and the mechanism of electron beam on the adhesion properties was investigated from various perspectives of surface properties and morphology. Compared to that of plasma-treated it.PP, the adhesion strength of it.PP with electron-beam irradiation increased drastically. We proved that the radical was generated in the substrates after electron-beam treatments and would form covalent bonds between adhesives and substrates, which achieved higher adhesion than plasma treatments. In addition, the electron beam reached effectively a deep region from the top surface of the substrates and provided larger adhesion strength.

Comparison of Long-Term Clinical Outcomes after Drug-Eluting Stent Implantation in Patients with Coronary Artery Disease with and without Prior Cerebral Infarction.

OBJECTIVE: To compare the clinical and angiographic outcomes after implantation of drug-eluting stents (DESs) in patients with coronary artery disease (CAD) with or without prior cerebral infarction. MATERIALS AND METHODS: Ninety-eight consecutive patients (130 lesions) who underwent successful coronary DES implantation were prospectively classified into two groups: those with a clinical history of symptomatic cerebral infarction (cerebral infarction group, 49 patients, 69 lesions) and those without a clinical history of symptomatic cerebral infarction (noncerebral infarction group, 49 patients, 61 lesions). The primary endpoint was defined as death, nonfatal myocardial infarction, and cerebrovascular events. RESULTS: The Kaplan-Meier method was used to create a primary endpoint curves to determine the time-dependent cumulative primary endpoint-free rate, which were compared using the log-rank test. The incidence of primary endpoints was higher in the cerebral infarction group than in the noncerebral infarction group (p = 0.0075). The Cox proportional hazards regression model for primary endpoint identified prior cerebral infarction (p = 0.0331, hazard ratio = 2.827) and patients with peripheral artery disease (p = 0.0271, hazard ratio = 2.757) as explanatory factors. CONCLUSION: The results showed that clinical outcomes were poorer in patients with CAD who had prior cerebral infarctions than in those who did not have infarction.

Progression of pneumoconiosis in coal miners after cessation of dust exposure: a longitudinal study based on periodic chest X-ray examinations in Hokkaido, Japan.

BACKGROUND: The progression rate of pneumoconiosis in retired coal miners over ten years has not been studied in Japan. METHODS: A retrospective longitudinal study was undertaken using chest X-rays of 1091 pneumoconiosis subjects in Hokkaido, Japan between 1985 and 2005. RESULTS: The final numbers of subjects were 207 (19% of the entry) after 1 decade and 85 (8%) after 2 decades. Sixty-two percent of 207 subjects after 1 decade and 29% of 85 showed progression in 2 decades. Thirty-one percent of ILO category 1 and 55% of category 2 subjects showed progression to complicated pneumoconiosis after 1 decade, and 6% (4 of 64) of category 1 and 6% (5 of 77) of category 2 subjects progressed to complicated pneumoconiosis during 2 decades. CONCLUSION: The progression of pneumoconiosis was observed after the cessation of dust exposure, especially during the first 10 years.

[Central hyperthermia suspected of malignant hyperthermia in a patient undergoing radical neck clipping for cerebral aneurysm].

A 45-year-old woman underwent radical neck clipping for cerebral aneurysm under isoflurane anesthesia. Her preoperative examination revealed elevated body temperature which had been normal on admission. Her body temperature increased up to 40.3 degrees C during anesthesia and surgery, and it showed a downward trend at the end of surgery. Malignant hyperthermia was excluded because the patient did not have metabolic acidosis, hypercarbia, hyperpotassemia or abnormal sweating anesthesia. The patient received intravenous dantrolene postoperatively since there was a suspicion of malignant hyperthermia on the basis of hyperthermia and increases in serum creatine kinase (CK) and myoglobin (Mb) levels. Her body temperature and serum CK and Mb levels decreased for a while after administration of dantrolene, but they increased again thereafter. The patient was aggressively cooled with a cooling blanket and hyperthermia and increases in serum CK and Mb levels disappeared in postoperative two weeks. She was discharged on foot without any neurological deficit on the forty-third hospital day. According to the diagnostic criteria for malignant hyperthermia by Larach and his colleague, malignant hyperthermia was somewhat less than likely in our case. The clinical course of the patient also suggested that a possibility of malignant hyperthermia was considerably low. The authors conclude that perioperative hyperthermia in our case must have derived from central hyperthermia following subarachnoid hemorrhage, and that postoperative increases in serum CK and Mb levels might have resulted from acceleration of sympathetic nervous system by subarachnoid hemorrhage.

[Anesthetic management of the surgical patients with complete left bundle branch block].

For last ten years twenty three cases of anesthesia were performed in twenty surgical patients with complete left bundle branch block (CLBBB) ranging in ages from 58 to 82 years. The CLBBB in these patients included 16 cases of permanent block, 6 cases of transient block and one case of alternative block. Two of these patients had no past history of heart disease, but the remaining patients had hypertension, ischemic heart disease, cardiomegaly, cardiac hypertrophy or others. Transient episodes of CLBBB were detected on the preoperative examination, on arrival at operating room or after the emergence from anesthesia at a recovery room, and some of which were provoked by elevated blood pressure or increased heart rate. A transient CLBBB in the patient changed to permanent CLBBB two years later. Complete atrioventricular (A-V) block appeared suddenly in the patient with alternative CLBBB four months after the surgery. Complete A-V block did not develop during anesthesia and surgery in our patients with CLBBB. Therefore we consider a routine prophylactic temporary pacemaker is not necessary during anesthesia and surgery in patients with asymptomatic CLBBB. However, a temporary pacemaker equipment should be at hand in case of complete A-V block. Appropriate perioperative management of circulatory system is important for the patients with CLBBB because most of these patients have underlying heart disease.

[Anesthetic management of elderly patients aged 90 years or older].

The authors experienced 55 cases of anesthetic management in 52 elderly surgical patients, 14 men and 38 women, aged 90 to 101 years with an average of 92.1 +/- 2.1 years for the past ten years. Surgical procedures included 38 cases of orthopedic, 14 cases of general surgical and 3 cases of ophthalmic operations. Thirteen cases out of them were emergency. General, epidural, spinal, and local anesthesia were applied in 34 cases, 18 cases, 2 cases, and one case out of these elderly patients, respectively. These general anesthesia consisted of total intravenous anesthesia with propopol, fentanyl and ketamine in 27 cases, sevoflurane with nitrous oxide in 4 cases, isoflurane with nitrous oxide or air in 2 cases, and thiopental anesthesia in one case. The elderly patients had past history of heart disease, dementia, hypertension, cerebral infarction/hemorrhage, diabetes mellitus and others. Their preoperative examinations revealed anemia, hypoproteinemia, renal hypofunction, serum electrolytes imbalance, and others. Vasopessors were given to 42% of the patients during anesthesia and surgery. Their postoperative complications included myocardial infarction, paroxysmal atrial fibrillation, hypotension following anemia, transient hemiparesis, delirium and so on. Two patients developed myocardial infarction postoperatively and died thereafter. The authors suggest that appropriate anesthetic management for elderly patients aged 90 years or older requires proper preoperative evaluation, sufficient vigilance of hemodynamics with direct arterial pressure measurement, reliable preparation of medical agents, and awareness of impairment of circulatory function and others by aging.