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Antimicrobial resistance presents a gigantic challenge to society. We cannot simply look for new synthetic variations of established drugs, we must look towards new, technological assassins. Mother Nature’s toolbox is full of such antimicrobial assassins and some of these pack an impressive ‘light punch’ unlike any current drug on the market.

Microwave irradiation was applied to a sequence of condensation reactions from readily available 9-chloroacridines to provide a range of novel acridine–isoalloxazine conjugates. The combination of these two moieties, both of biological interest, was achieved by a chromatography-free route.

With the recent increase in bacterial resistance to conventional antibiotics, the early-stage detection and control of infection has become imperative in the fight against opportunistic pathogens in healthcare. The traditional β-lactam wonder-drugs (e.g. penicillin and cephalosporins), are rendered inactive due to enzymatic hydrolysis by bacterial β-lactamase enzymes as a bacterial defence mechanism. However, this deactivation mechanism produces different responses in the two aforementioned drugs - with the cephalosporins showing a molecular rearrangement mechanism which could be utilised for prodrug delivery. This unique mechanism could mean that inactive forms of cephalosporin antibiotics, once used as chemotherapeutics in oncology, could once again be used in the fight against disease as sensors to detect and treat bacterial colonisation. Therefore, we hypothesize that cephalosporin-dye bandages might provide an effective method to visually detect, and subsequently control, the early stages of an infection using photoantimicrobial chemotherapy (PACT).

An investigation was carried out to identify the class characteristics of Polish people writing in English and to specifically identify those characteristics that separate Polish handwriting from English handwriting. In the first stage, 40 Polish and 40 English handwriting samples were collected and systematically examined. In total, 31 features were identified that occurred in ≥25% of the Polish handwriting samples and therefore considered class characteristics. Of these, chi-square analyses identified 21 class characteristics that occurred significantly more in Polish compared to English handwriting. Twenty-one of the class characteristics in the Polish handwriting had similar constructions to the copybook pattern thus supporting the theory that class characteristics frequently stem from the taught writing system. In the second stage, an algorithm was developed using seventeen of the class characteristics that successfully discriminated between a further 13 Polish and 12 English handwriting samples.

The results of a comprehensive investigation of the photophysical properties of the sunscreen agent menthyl anthranilate in various solvent systems are reported. Luminescence studies reveal that this ester is highly fluorescent (phi f = 0.64 +/- 0.06 in ethanol) and has a solvent-dependent emission maximum in the range of 390-405 nm. Phosphorescence has also been detected in low-temperature glasses with an emission maximum at 445 nm and a lifetime of 2.5 s. Kinetic UV-visible absorption measurements revealed a transient species with absorption maxima at 480 nm and solvent-dependent lifetimes of 26-200 microseconds that are attributed to the triplet state. The triplet state is efficiently quenched by oxygen, leading to the formation of singlet oxygen in all of the solvent systems studied. The singlet-oxygen quantum yields (phi delta) determined by time-resolved near-infrared luminescence measurements were determined to be in the range 0.09-0.12 for all systems.

A two step condensation sequence allows the synthesis of the title species (V) and (VIII) from 9-chloroacridines, phenylene diamines, and alloxan.

From each of four Arabic countries; Morocco, Tunisia, Jordan and Oman, 150 participants produced handwriting samples which were examined to assess whether national characteristics were discernible. Ten characters, which have different configurations depending upon their position in the word, along with one short word, were classified into distinguishable forms, and these forms recorded for each handwriting sample. Tests of independence showed that character forms used were not independent of country (p < 0.001) for all but one character-position (this was dropped from subsequent analyses). A correspondence analysis ordination plot and analysis of similarity (R = 0.326, p = 0.0002) showed that whole samples were discernibly grouped by country, and a tree analysis produced a classification which was 71% accurate for the original data and 83% accurate for 80 new handwriting samples that underwent ‘blind’ classification. When the countries were combined into two regions, North Africa and Middle East, the grouping was more marked. Thus, there appears to be some scope for narrowing down the nationality, and particularly the wider geographical region of an author based upon the character forms they use in Arabic handwriting.

Flash photolysis of bis[4.5-di(methylsulfanyl) 1,3-dithiol-2-ylidene]-9,10(-dihydroanthracene (1) in chloroform leads to formation of the transient radical cation species 1.+ which has a diagnostic broad absorption band at lambdamax approximately 650 nm. This band decays to half its original intensity over a period of about 80 micros. Species 1.+ has also been characterised by resonance Raman spectroscopy. In degassed solution 1.+ disproportionates to give the dication 1(2+), whereas in aerated solutions the photodegradation product is the 10-[4,5-di(methylsulfanyl) 1,3-dithiol-2-ylidene]anthracene-9(10 H)one (2). The dication 1(2+) has been characterised by a spectroelectrochemical study [lambdamax (CH2Cl2) = 377, 392, 419, 479 nm] and by an X-ray crystal structure of the salt 1(2-) (ClO4)2, which was obtained by electrocrystallisation. The planar anthracene and 1,3-dithiolium rings in the dication form a dihedral angle of 77.2 degrees; this conformation is strikingly different from the saddle-shaped structure of neutral 1 reported previously.

Formation of a spermatozoa ('sperm') reservoir in the mare is thought to occur through lectin-mediated sperm attachment to the oviductal epithelium. Once attached, prefertilization sperm survival is supported by oviductal factors. Cryopreservation of stallion sperm decreases the number of sperm attaching to oviduct epithelial cells (OEC) and the length of time these sperm survive. Quantification of in vitro interactions between sperm and OEC in a co-culture system may provide an assay for functional integrity of cryopreserved or fresh sperm samples. Additionally, superior additives for in vitro handling of stallion sperm may be isolated from OEC secretory products. Experiment 1 compared first service conception (FSC) rates resulting from the use of cryopreserved sperm of seven stallions, with sperm function in co-culture such as attachment to OEC and subsequent survival time. Stallions were grouped by cumulative FSC rates observed over three seasons as having average (44 +/- 3%) or high (65 +/- 2%) fertility over a total of 217 first services (31 +/- 9 per stallion). Samples from stallions in the high fertility group had more (P = 0.04) sperm attached to OEC and longer subsequent sperm survival in co-culture (P = 0.05) as compared with those from the average fertility group. FSC rates correlated with numbers of sperm attaching to OEC and their survival time in co-culture (r > or = 0.71). In Experiment 2, the function of cryopreserved stallion sperm was evaluated in culture with OEC secretory products from three different sources. After 5 h of culture, sperm incubated with medium conditioned by bovine OEC which had been 'bioactivated' (e.g. previously exposed to sperm in culture) were found to be more (P < or = 0.05) motile and capacitated as compared to sperm in basal TALP medium alone. Sperm in this conditioned medium also survived longer (P = 0.05; 27 +/- 5 h vs. 17 +/- 4 h) than did those in control medium.

An investigation was carried out to identify the class characteristics of Polish people writing in English and to specifically identify those characteristics that separate Polish handwriting from English handwriting. In the first stage, 40 Polish and 40 English handwriting samples were collected and systematically examined. In total, 31 features were identified that occurred in ≥25% of the Polish handwriting samples and therefore considered class characteristics. Of these, chi-square analyses identified 21 class characteristics that occurred significantly more in Polish compared to English handwriting. Twenty-one of the class characteristics in the Polish handwriting had similar constructions to the copybook pattern thus supporting the theory that class characteristics frequently stem from the taught writing system. In the second stage, an algorithm was developed using seventeen of the class characteristics that successfully discriminated between a further 13 Polish and 12 English handwriting samples.

The results of a comprehensive investigation of the photophysical properties of the sunscreen analogue, N -acetyl menthyl anthranilate (NAMA), in various solvent systems are reported. Luminescence studies reveal that this compound is fluorescent ( Φ f =0.16±0.01) in toluene and has a solvent dependent emission maximum in the range 363–370 nm. Phosphorescence has also been detected in low temperature glasses with an emission maximum at 420 nm in EPA, and a lifetime of 1.3 s; the triplet energy was found to be 311±3 kJ mol −1 . Kinetic UV–visible absorption measurements revealed a transient species with absorption maxima at 450 nm and solvent dependent lifetimes of 120–240 μs which are attributed to the triplet state. The triplet state is efficiently quenched by oxygen, leading to the formation of singlet oxygen in all of the solvent systems studied. The singlet oxygen quantum yields ( Φ Δ ), determined by time-resolved near-infrared luminescence measurements, were in the range 0.19–0.21.