Two series of 3-substituted polythiophenes (PTs) and poly(4-methylthiophene)~ (P4MTs) having the Substituents containing 8 atoms in the backbone with oxygen as the first atom bonded to the thiophene ring, C,H&-, C~HBOC~H~O-, and CH30C2H~OC2H~O-for the former series and having the first two substituents for the latter series were synthesized by chemical polymerization using ferric chloride as the oxidizing agent and characterized using thermal analysis, various spectroscopic methods, cyclic voltammetry, and conductivity measurement. For the first series, in comparison with poly(3-octylthiophene) (P30T; A, , = 480 nm), a replacement of the first carbon attached to the thiophene ring by an oxygen atom leads to a decreased band gap ( A, = 580 nm) due to the electron-donating nature of the oxygen. Further substitution on the 4-position of the thiophene ring with the methyl group of the 3-substituted PT with the substituent C,H&-leads to an increase in the band gap due to a decrease in conjugation caused by a steric hindrance of the methyl group as reflected in the change of A, , from 580 to 420 nm. But ita oxidation potential (0.76 V) ia lower than that of P30T (1.01 V) due to electron donation to the ?r system by the oxygen. Additional replacement of the third carbon atom by an oxygen atom in the side chain (giving CdHsOC2H40-) improves the conjugation (as reflected by an increase in A, , to 530 nm and a decrease in the oxidation potential to 0.6 V) due to a strong interaction between neighboring side chains, such that no thermochromism is observed before a decomposition of side chains.
People entrapped at different heights of floors or in differently damaged buildings could have a distinct pattern of injury. Our findings may facilitate strategic approaches of patients entrapped in damaged buildings and may contribute to future training for field searches and rescues after earthquakes.
The 81-year-old male presented with progressive headache and was diagnosed as bilateral chronic subdural hemorrhage (SDH). He has history of hypertension, coronary artery disease and hyperlipidemia. Burr-hole craniostomy for removal of SDH was performed. However, deteriorated consciousness and seizure happened after removal of bilateral external ventricular drainage (EVD) on postoperative Day 3. The brain computed tomography (CT) scan showed bilateral tension pneumocephalus with significant mass effect and Mount Fuji sign ( Figure 1).The patient underwent an emergency burr hole operation and the insertion of bilateral EVD. During the operation, the air bubbled out when the dura was opened. The patient's consciousness subsequently improved and postoperative CT imaging showed considerable reduction in the pneumocephalus with relieved mass effect. Finally, the patient discharged with recovery neurological condition on the admission Day 11. Figure 1: Bilateral tension pneumocephalus with significant mass effect and Mount Fuji sign.Tension pneumocephalus is an uncommon and life-threatening neurological condition. The incidence of tension pneumocephalus developing after the evacuation of a chronic SDH ranged 0 to 16% [1,2]. The incidence of pneumocephalus increases in the patients aged over 60 years and those presenting with a midline shift more than 5 mm [2]. In the review of literature, several contributing factors including nitrous oxide anesthesia, duration of surgery, hydrocephalus, ventriculoperitoneal shunt, and intraoperative administration of mannitol are involved in the pathogenesis of tension pneumocephalus [3].Clinically, tension pneumocephalus can cause headaches, nausea, vomiting, irritability, dizziness, and seizures. It is characteristically demonstrated on CT of the head with the Mount Fuji sign-bilateral subdural hypo-attenuation with compression of frontal gray matter and widening of the inter-hemispheric space between the frontal lobes. If tension pneumocephalus is not diagnosed early and treated properly, it can be fatal. Even after surgical intervention, the recurrence rate was 7.3% in one series [4].The present case report underlines that early diagnosis of tension pneumocephalus and emergent surgical treatment are crucial to prevent life-threatening deterioration. It also highlights the noticeable complication during post-operation care of craniotomy. References 1. Ishiwata Y, Fujitsu K, Sekino T, Fujino H, Kubokura T, et al. (1988) Subdural tension pneumocephalus following surgery for chronic subdural hematoma. J Neurosurg 68: 58-61. 2. Ihab Z (2012) Pneumocephalus after surgical evacuation of chronic subdural hematoma: Is it a serious complication? Asian J Neurosurg 7: 66-74. 3. Satapathy GC, Dash HH (2000) Tension pneumocephalus after neurosurgery in the supine position.
Metal–organic frameworks (MOFs) containing V, Cr, Mn, Fe, Co, Ni, Cu, and Zr were pyrolyzed under nitrogen flow. The products of carbonized MOFs (CMOFs) contain metal oxides and carbonaceous residues, which were characterized by powder X‐ray diffraction (PXRD), electrical conductivity (EC), and Raman spectroscopy. To remove the metallic components in CMOFs, hydrofluoric acid (HF) treatment was performed. PXRD analysis showed that only Mn, Co, Ni, and Zr, but not V, Cr, Fe, and Cu, could be completely removed from CMOFs after HF treatment. In fact, PXRD analysis also revealed that during the formation of CMOFs, not only metal oxides, but also metal carbides were formed. The change of the EC of CMOFs after HF treatment was found to be mainly contributed from the metal components, whereas the carbon (graphitic) components played minor roles. The effect of HF treatment on the structure of CMOF was not significant as verified by the Raman analysis of the intensity ratio between D band and G band.
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