Nanofibrillar self-organization of regioregular poly(3-hexylthiophene) and [6,6]-phenyl C(61)-butyric acid methyl ester by dip-coating: a simple method to obtain efficient bulk heterojunction solar cells

In this paper the dip-coating technique has been investigated as a method for the production of regioregular poly(3-hexylthiophene) (RR-P3HT):[6,6]-phenyl C(61)-butyric acid methyl ester (PCBM)-based solar cells. We found that the utilization of the dip-coating technique for the RR-P3HT:PCBM system can facilitate its self-assembly into a nanofibrillar lamellar structure after evaporation of the solvent. The condition for the formation of the nanofibrillar structures leads to a power conversion efficiency of 3.6% by using only this approach without thermal treatment.

Clinical relevance of measuring colonic permeability

BACKGROUND

Gastroduodenal and small intestinal permeability are increased in patients with Crohn's disease (CD) and intensive care patients. The relevance of colonic permeability has not yet been adequately investigated. The aim of this study was to investigate the clinical value of sucralose excretion as indicator for colonic permeability in these patient groups.

DESIGN

After oral administration of four sugars and subsequent analysis of urinary excretion, gastroduodenal and intestinal permeability were calculated from saccharose excretion and lactulose/mannitol (L/M) ratio over 5 h, and sucralose excretion from 5 to 26 h in 100 healthy controls, 29 CD and 35 patients after coronary surgery (CABG).

RESULTS

In controls, sucralose excretion was highly variable (0.67+/-0.92%) and not related to small intestinal permeability. In CD and CABG, L/M ratio was increased (0.054+/-0.060; 0.323+/-0.253 vs. 0.018+/-0.001 in controls). Sucralose excretion was increased in 77% of CABG but only in 7% of CD. There was an association between gastroduodenal and intestinal permeability in CD and CABG (r=0.72, and r=0.51), but sucralose excretion was not related to either one of these two parameters. Other than a weak association between sucralose and length of stay in intensive care in CABG patients (P=0.099), sucralose excretion was not related to clinical outcome.

CONCLUSIONS

The proposed cut-off for normal sucralose excretion is 2.11%, but its high variability and lack of association to gastrointestinal permeability or clinical outcome leave it open, if it can provide information beyond established permeability tests.

Realization of porous poly(methyl methacrylate) films filled with electrodeposited carbon nanotubes

A deposition process on a conducting surface, in which water acted as the dispersed phase and a mixture of poly(methyl methacrylate) and chloroform as the continuous phase, was applied to prepare poly(methyl methacrylate) films. The influence of relative humidity during the film preparation on the surface morphology was investigated by field emission scanning microscopy. High-humidity preparation conditions lead to porous poly(methyl methacrylate) films. These films were then used as templates to perform the selective deposition into the pores of single-walled carbon nanotubes by an electrophoretic method. The attractive properties of carbon nanotubes combined with the versatile properties of poly(methyl methacrylate) open up new opportunities for these nanocomposites to achieve novel architectures in nanodevices and microdevices.

Plasma homocysteine levels in cycling, pregnant, and spayed bitches

The aim of this study was to evaluate the physiological range of homocysteine (Hcy) exhibited by bitches during the follicular (pro-oestrus), luteal (dioestrus) and anoestrus phases of cycling animals, and in pregnant and spayed bitches. The lowest concentrations of Hcy were observed during dioestrus (3.2+/-1.27micromol/L) and in pregnant bitches (3.9+/-1.72micromol/L), and the highest concentrations during anoestrus (7.8+/-0.6micromol/L) and in spayed bitches (12.1+/-5.16micromol/L).

[ESPEN guidelines on enteral nutrition--summary]

Under the auspices of the European Society for Clinical Nutrition and Metabolism (ESPEN) clinical practice guidelines were systematically developed by 88 experts from 20 different countries between spring 2004 and winter 2005 in a predefined evidence and consensus based process. Evidence was gathered by a structured literature search, and the quality and strength of the evidence was graded according to published standards. On this basis recommendations were formulated which were then finalised in a consensus conference. The recommendations and their grades were summarized in table form. The German translation of these tables is now published for the following chapters: Intensive care, surgery including organ transplantation, non-surgical oncology, gastroenterology, pancreas, liver disease, adult renal failure, cardiology and pulmonology, wasting in HIV and chronic infectious diseases, geriatrics. The full text and the comments are available in ,,Clinical Nutrition" as well as on the internet under www.espen.org and www.dgem.de. The ESPEN guidelines enteral nutrition reflect the current medical knowledge in the field of enteral nutrition therapy and may help to decide when enteral nutrition is indicated and which therapeutic goals can be reached.

Ozone adsorption on carbon nanotubes: the role of Stone-Wales defects

First-principles calculations within the density functional theory have been performed in order to investigate ozone adsorption on carbon nanotubes. Particular emphasis is placed on the effects of Stone-Wales-like defects on the structural and electronic properties of (i) ideal tubes and (ii) tubes in the presence of ozone. Our results show that structural deformations induced on the pure carbon nanotubes by Stone-Wales defects are similar, as expected, to those induced on graphite; for the (10,0) tube, the semiconducting character is kept, though with a small reduction of the band gap. As for the ozone adsorption, the process on ideal nanotubes is most likely physisorption, though slightly stronger if compared to other previously studied molecules and consistent with the strong oxydizing nature of O(3). However, when ozone adsorbs on Stone-Wales defects, a strong chemisorption occurs, leading to relevant structural relaxations and to the formation of a CO covalent bond; this is consistent with experimental observations of CO functional groups, as well as of the liberation of CO gas phase and of the formation of C vacancies, thus explaining the consumption of the nanotube film upon ozone exposure.

Ethical and legal aspects of enteral nutrition

European ethical and legal positions with regard to EN vary slightly from country to country but are based on a common tradition derived from Graeco Roman ideas, religious thought and events of the 20th century. The Hippocratic tradition is based on 'beneficience' (do good) and 'non-maleficience' (do no harm). Religious thinking is based upon the presumption of providing food and drink by whatever means unless burden outweighs benefit. The concept of 'autonomy' (the patients right to decide) arose following in the decades after the Second World War and is enshrined in Human Rights law. The competent patient has the right to participate in decision making and to refuse treatment although the doctor is not obliged to give treatment which he or she considers futile or against the patient's interests. The incompetent patient is protected by law. The fourth principle is that of 'justice' i.e. equal access to healthcare for all. The law regards withholding and withdrawing treatment as the same. It also defines the provision of food and drink by mouth as basic care and feeding by artificial means as a medical treatment. It requires doctors to act in the best interests of the patient.

ESPEN Guidelines on Enteral Nutrition: Gastroenterology

Undernutrition as well as specific nutrient deficiencies have been described in patients with Crohn's disease (CD), ulcerative colitis (UC) and short bowel syndrome (SBS). The present guideline gives evidence-based recommendations for the indication, application and type of formula of enteral nutrition (EN) (oral nutritional supplements (ONS) or tube feeding (TF)) in these patients. It was developed in an interdisciplinary consensus-based process in accordance with officially accepted standards and is based on all relevant publications since 1985. ONS and/or TF in addition to normal food is indicated in undernourished patients with CD or CU to improve nutritional status. In active CD EN is the first line therapy in children and should be used as sole therapy in adults mainly when treatment with corticosteroids is not feasible. No significant differences have been shown in the effects of free amino acid, peptide-based and whole protein formulae for TF. In remission ONS is recommended only in steroid dependent patients in CD. In patients with SBS TF should be introduced in the adaptation phase and should be changed with progressing adaptation to ONS in addition to normal food.

Review article: anorexia and cachexia in gastrointestinal cancer

In patients with gastrointestinal malignancies, i.e. cancers of the stomach, colon, liver, biliary tract or pancreas, progressive undernutrition can be regularly observed during the course of illness. Undernutrition significantly affects the patients' quality of life, morbidity and survival. Pathogenetically, two different causes are relevant in the development of undernutrition in patients with gastrointestinal cancer. One cause is reduced nutritional intake. This condition is referred to as anorexia and can be worsened by the side effects of cancer therapy. The other cause is the release of endogenous transmitters and/or other products of the tumour leading to the cachexia syndrome, which is characterized by loss of body weight, negative nitrogen balance and fatigue. Cancer anorexia and cancer cachexia may have synergistic negative effects in affecting the patients' status. In this review, current nutritional support strategies with respect to different clinically relevant situations are described. An algorithm of the treatment strategies, including dietetic counselling, oral supplements, enteral and parenteral nutritional support is given. One focus is the approach of nutrition-focused patient care, which shows promising results. In addition, the possibilities of pharmacological intervention are discussed.

Soft-x-ray photoemission spectroscopy and ab initio studies on the adsorption of NO2 molecules on defective multiwalled carbon nanotubes

The adsorption of NO(2) molecules on defective multiwalled carbon nanotubes has been studied by soft-x-ray photoemission. The valence band and carbon core-level spectra have been acquired before, during, and after NO(2) exposure. The spectra show a reversible decrease of the density of states at the top of the valence band when NO(2) molecules are adsorbed on the (carbon nanotubes) CNTs. No shift of the C 1s spectra has been observed. Theoretical calculations, using density-functional theory, have been performed on the CNT + NO(2) system, considering semiconducting nanotubes with different diameters and introducing a Stone-Wales [Chem. Phys. Lett. 128, 501 (1986)] defect. The calculation confirms the decrease of the density of states at the top of the valence band in the CNT + NO(2) system, while close to the adsorption site new states appear very close to the Fermi level.

Acute effects of insulin-like growth factor I on interorgan glucose and lactate flux in protein-catabolic dogs

Insulin-like growth factor-I (IGF-I) is a potent protein-anabolic hormone with a glucose-lowering effect and is therefore a possible agent for treating catabolic patients. In this study we investigated the effect of recombinant human (rh) IGF-I on the interorgan flux of glucose under hypo- and normoglycemic conditions in catabolic, anaesthetized, and catheterized dogs. We administered a primed (40 micrograms/kg) continuous (1.5 micrograms.kg-1.min-1) infusion of rhIGF-I (Kabi Biopharma, Stockholm, Sweden) for 180 min together with either a saline (0.9% NaCl) or an amino acid solution (2.2 mg AA.kg-1.min-1 solution of Vamin, Kabi Nutrition, Stockholm, Sweden). RhIGF-I administration lowered plasma glucose levels for approximately 50% of the baseline (P < 0.001) and stimulated glucose uptake from skeletal muscle about twofold (P < 0.01), but did not modify glucose balances across the gut and liver. The same effects were found when infusing rhIGF-I together with AA. A co-infusion of rhIGF-I and glucose to maintain normoglycemic conditions stimulated glucose uptake from skeletal muscle by about fivefold (P < 0.001) and glucose uptake across the gut by about 50%, but reduced the hepatic glucose liberation (-65%; P < 0.01). The rhIGF-I infusion did not alter arterial lactate levels, but stimulated lactate release from skeletal muscle (P < 0.05) and lactate uptake across the liver (P < 0.05). We conclude that rhIGF-I reduces plasma glucose levels mainly by stimulating glucose uptake across skeletal muscle.(ABSTRACT TRUNCATED AT 250 WORDS)