Self-optimisation and model-based design of experiments for developing a C-H activation flow process.

A recently described C(sp3)-H activation reaction to synthesise aziridines was used as a model reaction to demonstrate the methodology of developing a process model using model-based design of experiments (MBDoE) and self-optimisation approaches in flow. The two approaches are compared in terms of experimental efficiency. The self-optimisation approach required the least number of experiments to reach the specified objectives of cost and product yield, whereas the MBDoE approach enabled a rapid generation of a process model.

Continuous-Flow Synthesis and Derivatization of Aziridines through Palladium-Catalyzed C(sp(3) )-H Activation.

A continuous-flow synthesis of aziridines by palladium-catalyzed C(sp(3) )-H activation is described. The new flow reaction could be combined with an aziridine-ring-opening reaction to give highly functionalized aliphatic amines through a consecutive process. A predictive mechanistic model was developed and used to design the C-H activation flow process and illustrates an approach towards first-principles design based on novel catalytic reactions.

Identification of xylem occlusions occurring in cut clematis (Clematis L., fam. Ranunculaceae Juss.) stems during their vase life.

During the vase life of cut stems obstruction of xylem vessels occurs due to microbial growth, formation of tyloses, deposition of materials in the lumen of xylem vessels and the presence of air emboli in the vascular system. Such obstructions may restrict water uptake and its transport towards upwards thus lowering their ornamental value and longevity of cut flowers. Clematis is a very attractive plant material which may be used as cut flower in floral compositions. Nothing is known about the histochemical or cytological nature of xylem blockages occurring in cut stems of this plant. This study shows that in clematis, tyloses are the main source of occlusions, although bacteria and some amorphic substances may also appear inside the vessels. A preservative composed of 200 mg dm(-3) 8-HQC (8-hydroxyquinolin citrate) and 2% sucrose arrested bacterial development and the growth of tyloses. This information can be helpful in the development of new treatments to improve keeping qualities of cut clematis stems.

An uncommon location of Meckel's diverticulum or small intestine duplication? Case report and literature review.

Meckel's diverticulum is the most common congenital abnormality of alimentary tract. The antimesenteric location is one of the cardinal attribiutes of this pathology. We report case which tries to verify this dogma. The literature regarding uncommon location of Meckel's diverticulum was also reviewed.

[The ovarian hyperstimulation syndrome--diagnostic criteria, management procedures]. / Zespól hyperstymulacji jajników--kryteria rozpoznania, sposoby postepowania.

The ovarian hyperstimulation syndrome (OHSS) is still a difficult diagnostic and therapeutic problem. OHSS is associated with significant hypertrophy of the ovaries associated with the loss of the intravascular fluid to the third space which results in hypovolaemia, oliguria, electrolyte imbalance, and a rise in haematocrit. The endogenous OHSS is rare. Most often OHSS appears as a complication of induction of ovulation. The fundamental issue in pathophysiology of OHSS is an increase of capillary permeability which results in the leakage of fluid to the third space. The vascular endothelial growth factor--VEGF--is considered to be the factor directly responsible for the processes involved. The most common are the mild and moderate forms of the syndrome. The severe form of OHSS is a life-threatening condition. The following symptoms may be present: ascites, pleural and pericardial effusion, oliguria, dyspnoea with tachypnoe, tachycardia, adult respiratory distress syndrome, renal failure, venous thrombosis, ischaemic stroke, haemorrhage from a ruptured ovary. Therapy should be based on the correction of hypovolaemia, hypotension and oliguria. Antithrombotic prophylaxis is an integral part of the OHSS management. Some interesting attempts have been undertaken to re-infuse the protein-rich ascites fluid directly to the systemic circulation, so called continuous auto-transfusion system of the ascites (CATSA).

Skin reactivity to histamine and codeine in unselected 9-year-old children from Italy, Poland and Libya.

BACKGROUND: Previous studies have shown that histamine skin reactivity (the dimensions of a skin wheal elicited by a prick with histamine 10 mg/ml) in unselected school children has increased in Italy during the past two decades and is higher in Italy than in Poland. Hence this variable can probably be influenced by a changing or different lifestyle. The aim of this study was to compare skin reactivity to histamine and codeine (a marker of histamine releasability from mast cells) in schoolchildren from countries with different lifestyles. METHODS: Six previously unstudied unselected populations of 9-year-old schoolchildren (two each from Poland, Italy, and Libya; n = 863 subjects; 49.0% males) were pricked with two concentrations of histamine (10 and 1 mg/ml) and codeine (90 and 9 mg/ml). RESULTS: The higher concentrations of both pharmacologic agents tested yielded significantly different wheal areas in the three countries: Poland < Italy < Libya (histamine, 11.8, 16.1 and 20.7 mm2; codeine, 9.2, 13.2 and 16.2 mm2; p < 0.001 for all comparisons). The lower concentrations elicited almost matching results. Histamine wheal areas correlated closely with areas elicited by codeine in the same individual: angular coefficients of the histamine to codeine regression lines were 0.535, Italy; 0.551, Libya; 0.612, Poland; and 0.581 for the whole population. More histamine was needed to produce a wheal in Poland than in Libya: a 20-mm2 wheal required an injected histamine concentration of about 8.8 mg/ml in Libya, 29.5 mg/ml in Italy and 102.1 mg/ml in Poland. CONCLUSION: More studies are necessary to explain the observed international differences in skin histamine reactivity and their effect on the prevalence of positive allergen skin tests.

Efeito da hiperlipidemia experimental na farmacocinetica da procainamida e acecainida / Effect of experimental hyperlipidemia on the pharmacokinetics of procainamide and acecainide

O objetivo da experiencia foi determinar o efeito da hiperlipidemia experimental na farmacocinetica da procainamida (PA) e N-acetilprocainamida (NAPA), cujo nome oficial e acecainida. A experiencia foi realizada em um periodo de dois meses em 20 coelhos, machos, divididos aleatoriamente em dois grupos: controle e experimental (deixado em dieta rica em gorduras). Depois dos dois meses foram realizadas determinacoes farmacocineticas em todos os animais. Apos administracao estomacal (por sonda) de procainamida em dose de 40 mg/kg, foi coletado sangue para as determinacoes, durante um periodo de 12 horas. Para calculos, foi tomado o modelo de dois compartimentos para administracao extravascular. Foi observada diminuicao da concentracao da PA e NAPA no sangue, diminuicao do volume de distribuicao e aumento da depuracao total. A presente experiencia demonstrou o efeito da hiperlipidemia experimental na farmacocinetica de PA e NAPA, seguido de aumento da velocidade de eliminacao do farmaco do organismo