The folded conformation of phage P22 coat protein is affected by amino acid substitutions that lead to a cold-sensitive phenotype

Three cold-sensitive mutants in phage P22 coat protein have been characterized to determine the effects of the amino acid substitutions that cause cold sensitivity on the folding pathway and the conformation of refolded coat protein. Here we find that the three cold-sensitive mutants which have the threonine residue at position 10 changed to isoleucine (T10I), the arginine residue at position 101 changed to cysteine (R101C), or the asparagine residue at position 414 changed to serine (N414S) were capable of folding from a denatured state into a soluble monomeric species, but in each case, the folded conformation was altered. Changes in the kinetics of folding were observed by both tryptophan and bisANS fluorescence. In contrast to the temperature-sensitive for folding coat protein mutants which can be rescued at nonpermissive temperatures in vivo by the overproduction of molecular chaperones GroEL and GroES [Gordon, C. L., Sather, S. K., Casjens, S., & King, J. (1994) J. Biol. Chem. 269, 27941-27951], the folding defects associated with the cold-sensitive amino acid substitutions were not recognized by GroEL and GroES.     

Grinding-Induced Texture in Ferroelastic Tetragonal Zirconia

Ceria- and yttria-doped tetragonal polycrystalline zirconia ceramics were ground at temperatures as high as 1100°C. X-ray diffraction revealed that the intensity ratio I ₍₀₀₂₎/ I ₍₂₀₀₎ increased (to as high as ∼4.5) compared with that from the as-sintered surfaces (∼0.55). The enhancement in I ₍₀₀₂₎/ I ₍₂₀₀₎ at temperatures well above the m → t transition temperature shows that it is not related to transformation, reversible or otherwise, but can be explained by ferroelastic domain switching.     

Recycling Bacteria for the Synthesis of LiMPO4 (M = Fe,Mn) Nanostructures for High‐Power Lithium Batteries

In this work, a novel waste‐to‐resource strategy to convert waste bacteria into a useful class of cathode materials, lithium metal phosphate (LiMPO₄; M = Fe, Mn), is presented. Escherichia coli (E. coli) bacteria used for removing phosphorus contamination from wastewater are harvested and used as precursors for the synthesis of LiMPO₄. After annealing, LiFePO₄ and LiMnPO₄ nanoparticles with dimensions around 20 nm are obtained. These particles are found to be enveloped in a carbon layer with a thickness around 3–5 nm, generated through the decomposition of the organic matter from the bacterial cell cytoplasm. The battery performance for the LiFePO₄ is evaluated. A high discharge capacity of 140 mAh g^?1 at 0.1 C with a flat plateau located at around 3.5 V is obtained. In addition, the synthesized particles display excellent stability and rate capabilities. Even under a high C rate of 10 C, a stable discharge capacity of 75.4 mAh g^?1 can still be achieved.     

Morphological Stabilization by Supramolecular Perfluorophenyl‐C60 Interactions Leading to Efficient and Thermally Stable Organic Photovoltaics

A new PC₆₁BM‐based fullerene, [6,6]‐phenyl‐C₆₁ butyric acid pentafluorophenyl ester (PC₆₁BP^F) is designed and synthesized. This new n‐type material can replace PC₆₁BM to form a P3HT:PC₆₁BP^F binary blend or serve as an additive to form a P3HT:PC₆₁BM:PC₆₁BP^F ternary blend. Supramolecular attraction between the pentafluorophenyl group of PC₆₁BP^F and the C₆₀ cores of PC₆₁BP^F/PC₆₁BM can effectively suppress the PC₆₁BP^F/PC₆₁BM materials from severe aggregation. By doping only 8.3 wt% PC₆₁BP^F, device PC₆₁BP^F651 exhibits a PCE of 3.88% and decreases slightly to 3.68% after heating for 25 h, preserving 95% of its original value. When PC₆₁BP with non‐fluorinated phenyl group is used to substitute PC₆₁BP^F, the stabilizing ability disappears completely. The efficiencies of PC₆₁BP651 and PC₆₁BP321 devices significantly decay to 0.44% and 0.11%, respectively, after 25 h isothermal heating. Most significantly, this strategy is demonstrated to be effective for a blend system incorporating a low band‐gap polymer. By adding only 10 wt% PC₆₁BP^F, the PDTBCDTB: PC₇₁BM‐based device exhibits thermally stable morphology and device characteristics. These findings demonstrate that smart utilization of supramolecular interactions is an effective and practical strategy to control morphological evolution.     

An Algorithm for Symbolic Reliability Computation with Path-sets or Cut-sets

An algorithm obtains a symbolic expression for system reliability, given a set of events (path-sets or cut-sets) as input. The algorithm is simple in structure and uses few probability laws. The resultant symbolic expression is compact and requires relatively few arithmetic operations in its evaluation.     

Crystal structure and functional analysis of the HERG potassium channel N terminus: a eukaryotic PAS domain

More and more elderly subjects are offered for pulmonary resection. The object of this study was to review the results of excision for cancer in octogenarians. PATIENTS: 51 consecutive patients (44 men, 7 women) with a mean age of 82 years (80-91) were operated on. 31 lobectomies, 2 bilobectomies, 13 pneumonectomies, 1 segmental resection and 4 exploratory thoracotomies were carried out. 17 tumours were classed as stage I, 15 as stage II and 15 as stage III. RESULTS: 38 patients (75%) had uncomplicated post-operative periods; the predicted factors for complication were the existence of weight loss and alteration of respiratory function. 2 patients (4%) died in the post-operative phase. Neither the type of operation, the staging or the existence of cardiovascular dysfunction had any influence on the post-operative phase. The level of the survival at 3 and 5 years was 39% and 16% respectively. 30% of the late deaths were related to intercurrent events. CONCLUSIONS: Pulmonary excision may be envisaged in an octogenarian who is in good physical and intellectual state with a limited tumour. This surgery in general is applied to a population which probably only marginally consists of octogenarians but the results here justify their inclusion in the indications for selection.     

Morbillivirus downregulation of CD46

There is evidence that CD46 (membrane cofactor protein) is a cellular receptor for vaccine and laboratory-passaged strains of measles virus (MV). Following infection with these MV strains, CD46 is downregulated from the cell surface, and consequent complement-mediated lysis has been shown to occur upon infection of a human monocytic cell line. The MV hemagglutinin (H) protein alone is capable of inducing this downregulation. Some wild-type strains of MV fail to downregulate CD46, despite infection being prevented by anti-CD46 antibodies. In this study we show that CD46 is also downregulated to the same extent by wild-type, vaccine, and laboratory-passaged strains of rinderpest virus (RPV), although CD46 did not appear to be the receptor for RPV. Expression of the RPV H protein by a nonreplicating adenovirus vector was also found to cause this downregulation. A vaccine strain of peste des petits ruminants virus caused slight downregulation of CD46 in infected Vero cells, while wild-type and vaccine strains of canine distemper virus and a wild-type strain of dolphin morbillivirus failed to downregulate CD46. Downregulation of CD46 can, therefore, be a function independent of the use of this protein as a virus receptor.     

Primary nonampullary/periampullary adenocarcinoma of the duodenum

Primary duodenal adenocarcinoma not involving the ampullary region is rare. Our aim was to review the outcome of these patients and determine the factors that affect survival. We performed a retrospective review of all patients with primary, nonampullary duodenal adenocarcinoma at the Cleveland Clinic Foundation from January 1986 through December 1996. Twenty-six patients with primary, nonampullary duodenal malignancies were identified. There were 16 adenocarcinomas, 3 gastrinomas, 3 stromal tumors, 3 leiomyosarcomas, and 1 carcinoid tumor. Patients with adenocarcinoma had symptoms present an average of 6.1 months. Tumors were identified by upper gastrointestinal contrast study and esophagogastroduodenoscopy in 90 per cent and 87 per cent of patients, respectively. Twelve of 13 (93%) cancers found in the third or fourth portion of the duodenum were adenocarcinomas. Seven of the 16 adenocarcinomas were resectable on exploration. Those that were contained within the serosa have not recurred (mean, 6 years); one of the two patients with locally invasive adenocarcinoma remains disease free. The average survival for patients with unresectable disease was 6.7 months. The 5-year survival rates were: all adenocarcinoma, 38 per cent; resectable, 86 per cent; and unresectable, 0 per cent. All patients presenting with weight loss or obstructive symptoms died of disease; those with melena survived long term. Patients with tumors other than adenocarcinoma had a 90 per cent 5-year survival. We conclude that patients typically present with a long history of symptoms. Distal duodenal malignancies are most frequently adenocarcinomas. Upper gastrointestinal contrast study or endoscopy is often diagnostic. Patients with weight loss and/or obstructive symptoms had invasive disease and a morbid prognosis. Aggressive surgery is warranted, and most with resectable disease (86%) had long-term survival.