Comb‐like copolymers based on a polyolefin backbone of poly(10‐undecene‐1‐ol) (PUol) with poly(ε‐caprolactone) (PCL) side chains are synthesized in two steps. After synthesis of PUol by metallocene‐catalyzed polymerization, the side‐chain hydroxyl functionalities of this polar polyolefin are used as an initiator for the ring‐opening polymerization (ROP) of ε‐caprolactone (CL). In this context, copolymers with different lengths of PCL grafts are prepared. The chemical structure and the composition of the synthesized copolymers are characterized by 1H and 13C NMR spectroscopy. It is shown that the hydroxyl end groups of PUol act effectively as initiating sites for the CL ROP. Size‐exclusion chromatography (SEC) measurements confirm the absence of non‐attached PCL and the expected increase in molar mass after grafting. The thermal and decomposition behaviors are investigated by DSC and thermogravimetric analysis (TGA). The effect of the length of the PCL grafts on the crystallization behavior of the comb‐like copolymers is investigated by DSC and wide‐angle X‐ray scattering (WAXS).
Japanese yew is a widely used ornamental plant. However, most people are unaware that it is also a poisonous plant. It has potent cardiac toxicities that can lead to sudden cardiac death. A 37-year-old female patient presented to the emergency room with altered mental status and sustained ventricular tachycardia (VT). Electrocardiogram (ECG) after cardioversion showed profound QRS prolongation and ST-segment elevation suggestive of either hyperkalaemia, acute myocardial ischaemia, or Brugada syndrome. Her electrolytes and coronary angiography were normal. After improvement of the patient's mental status, she admitted that she has been consuming Japanese yew from her yard for several months. Few hours later, QRS duration normalised, but mild ST-segment elevation persisted in the right pre-cordial leads, making it more suspicious for Brugada syndrome. However, a procainamide challenge test and electrophysiology study failed to induce typical Brugada pattern ECG and VT. The absence of coronary artery disease and electrolytes disturbances points toward the fact that her arrhythmia and ECG changes are secondary to yew intoxication. The patient was monitored for a few days. She was haemodynamically stable and has not had any arrhythmia. This case highlights the importance of public awareness of severe toxicity from Japanese yew or other yew plants. Yews contain taxines that are responsible for the ECG abnormalities due to its inhibitory effect on the cardiac sodium and calcium channels. They cause conduction abnormalities, VT, and ST-segment elevation that can resemble acute myocardial infarction, hyperkalaemia, and Brugada syndrome. 相似文献
Our objective was to find out if the extraction of deciduous teeth at the sites of clefts 3-8 weeks before alveolar bone grafting (ABG) would reduce the number of postoperative complications. Chart reviews were reviewed retrospectively of patients who had had ABG from March 2006 to June 2009. To reduce variables only healthy, non-syndromic, cooperative patients were included. Eleven patients had had their deciduous teeth extracted at the cleft sites 3-8 weeks before ABG and 10 patients had had the extractions done intraoperatively at the same time as ABG. There was a single case of postoperative infection and no wound dehiscence in the preoperative extraction group, and there were no delays in postoperative orthodontic treatment. In the intraoperative group there were 3 cases of local wound infection and 6 cases of minor dehiscence, and orthodontic treatment was delayed for 3-6 months in all patients with complications. All patients had successful ABG, eruption of teeth, and orthodontic treatment; but patients who had their deciduous teeth at the cleft sites extracted preoperatively had fewer wound complications than patients whose extractions were done at the same time as the ABG. 相似文献
Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemoperfusion (HIPEC) for peritoneal carcinomatosis (PC) of colorectal origin increases survival (OS) compared to systemic chemotherapy alone. Signet ring histology demonstrates aggressive behavior with poor survival. We sought to determine whether CRS/HIPEC increases survival in this subset of patients.
Methods
We reviewed 67 patients with PC of appendiceal (AP, n = 37) or colorectal origin (CRC, n = 30) with signet cell histology from a prospective database between May 2001 and August 2011. Survival analysis and multivariate Cox regression were used to determine prognostic factors for survival.
Results
Complete CRS (CC-0/1) was achieved in 77 % (CRC) and 73 % (AP) of patients. Progression-free survival (PFS) and OS were 9 and 12 months in CRC and 12 and 21 months in AP patients. In the CRC group, univariate predictors of poor survival included female gender, age, American Society of Anesthesiologists score, preoperative albumin, completeness of cytoreduction, and morbidity. In a multivariate Cox regression model, incomplete cytoreduction (CC-2/3) and female gender were joint significant predictors of poor survival. In the AP group, significant univariate predictors of poor survival included higher EBL and PCI score. In a multivariate Cox regression model, blood loss of >500 ml and a body mass index of <25 kg/m2 were joint significant predictors of poor survival.
Conclusions
AP signet cell tumors demonstrate a more favorable outcome than CRC signet cell tumors after CRC/HIPEC for carcinomatosis, suggesting an underlying difference in biology. CRS/HIPEC does not confer survival benefit in colorectal signet ring carcinomatosis unless complete cytoreduction can be achieved, whereas appendiceal signet ring carcinomatosis may benefit, regardless of resectability. 相似文献
Background and aimsThe incidence of diabetes mellitus (DM) is increasing worldwide, and there is growing appreciation for the impact of limited physical activity on the disease. This study aimed to determine whether the current research on DM in Ethiopia has sufficiently identified and focused on the importance of limited physical activity according to the Global Physical Activity Questionnaire (GPAQ) in the disease etiology.MethodsThis was a systematic review, performed according to the PRISMA checklist. We searched primary studies of diabetes, diabetes-related complications, determinants, and magnitude of related morbidities in Ethiopia in PubMed, Medline, and ISI Web of Science databases. Reviews, editorial communications, reports, and letters were excluded.ResultsAmong 363 articles that were identified from all databases, 28 were included. It was found that 39% of the studies measured and included limited physical activity as a predisposing lifestyle factor in diabetes, while 17.86% either did not report or did not include this variable at all. Although 42.86% of the studies identified limited physical activity as an etiological factor in diabetes, it was not measured according to the GPAQ guidelines.ConclusionsThese data suggest that Ethiopian researchers do not give sufficient attention to the role of physical activity and its definition per GPAQ as a preventative factor for reducing the severity of diabetes symptoms. We suggest that physical activity research and promotion should be advocated in Ethiopia, and that researchers should seek advice on how to re-frame their work in the future. 相似文献