Structures and Reactivity Patterns of Group 9 Metallocorroles

Group 9 metallocorroles 1-M(PPh_3) and 1-M(py)_2 [M = Co(III), Rh(III), Ir(III); 1 denotes the trianion of 5,10,15-tris-pentafluorophenylcorrole] have been fully characterized by structural, spectroscopic, and electrochemical methods. Crystal structure analyses reveal that average metal−N(pyrrole) bond lengths of the bis-pyridine metal(III) complexes increase from Co (1.886 Å) to Rh (1.957 Å)/Ir (1.963 Å); and the average metal−N(pyridine) bond lengths also increase from Co (1.995 Å) to Rh (2.065 Å)/Ir (2.059 Å). Ligand affinities for 1-M(PPh_3) axial coordination sites increase dramatically in the order 1-Co(PPh_3) < 1-Rh(PPh_3) < 1-Ir(PPh_3). There is a surprising invariance in the M(+/0) reduction potentials within the five- and six-coordinate corrole series, and even between them; the average M(+/0) potential of 1-M(PPh_3) is 0.78 V vs Ag/AgCl in CH_2Cl_2 solution, whereas that of 1-M(py)_2 is 0.70 V under the same conditions. Electronic structures of one-electron-oxidized 1-M(py)_2 complexes have been assigned by analysis of electron paramagnetic resonance spectroscopic measurements: oxidation is corrole-centered for 1-Co(py)_2 (g = 2.008) and 1-Rh(py)_2 (g = 2.003), and metal-centered for 1-Ir(tma)_2 (g_(zz) = 2.489, g_(yy) = 2.010, g_(xx) = 1.884, g_(av) = 2.128) and 1-Ir(py)_2 (g_(zz) = 2.401, g_(yy) = 2.000, g_(xx) = 1.937, g_(av) = 2.113)

Cutaneous Squamous Cell Carcinoma, an Immunohistological Analysis

Background: To detect the presence of keratin in apparently non-keratinizing squamous cell carcinomas by immunoperoxidase staining. This is important because keratinizing tumours are less radiosensitive and non-keratinizing are more radio responsive. Methods: This prospective study was conducted at King Edward Medical College and Post Graduate Medical Institute, Lahore over six months, A total of 45 patients suffering from squamous cell carcinomas of skin were included in the study.Both H and E and immunoperoxidase stainings were performed. Positive and negative controls were set up. The results of both types of staining were compared for each case. Results: Four groups were identified. Nineteen cases showed obvious keratinization on both H and E and immunoperoxidase staining.Eight cases had doubtful keratinization on H and E but showed more obvious keratinization on immunoperoxidase staining. Seven cases were non-keratinizing on H and E staining but revealed keratin on immunoperoxidase analysis.Eleven cases were non-keratinizing on H and E as well as on immunoperoxidase analysis. Conclusion: Immunohistological technique can help us in revising and modifying our H and E impression of a squamous cell carcinoma. It can help us in better diagnosis of squamous cell cancers on basis of keratinizatio

Processing melt blended polymer nanocomposites using a novel laboratory mini-mixer. Development of polymer nanocomposites in the melt phase using a novel mini-mixer.

Research into the processing conditions and parameters of polymeric nanocomposites has always been challenging to scientists and engineers alike. Many have developed tools and procedures to allow materials to be exploited and their properties improved with the addition of nanofillers to achieve the desired end material for various applications. Initial trials are mostly conducted using conventional small scale experiments using specialised equipment within the laboratory that can replicate the larger industrial equipment. This is a logical approach as it could save time and costs as many nanocomposites are relatively expensive to produce. Experiments have previously been done using the likes of the Haake twin screw extruder to manufacture nanocomposites within the laboratory but this research project has used a novel minimixer specifically developed to replicate mixing like large twin screw extrusion machines. The minimixer uses a twin paddle system for high shear mixing in conjunction with a single screw thus theoretically allowing an infinitely long recirculation. It is this ability to mix intensely whilst allowing for as long as desired recirculation which enables the replication in this very small mixer (10-30g capacity) of the mixing conditions in a large twin screw extruder. An added feature of the minimixer is that it can undertake inline data analysis in real time. The main experiments were conducted using a comprehensive DOE approach with several different factors being used including the temperature, screw speed, residence time, clay and compatibiliser loading and two polymer MFI¿s. The materials used included PP, Cloisite 20A, Polybond 3200, PET, Somasif MTE, Polyurethane 80A and Single / Multi-walled Carbon nanotubes. Detailed experimental results highlighted that rheological analysis of the nanocomposite materials as an initial testing tool were accurate in determining the Elastic and Loss modulus values together with the Creep and Recovery, Viscosity and Phase Angle properties in the molten state. This approach was also used in an additional set of experiments whereby the temperature, speed, residence time and compatibiliser were kept constant but the clay loading was increased in 1% wt. increments. These results showed that the G¿ & G¿¿ values increased with clay loading. Another important finding was the bi-axial stretching step introduced after the processing stage of the nanocomposite materials which highlighted a further improvement in the modulus values using rheological testing. Other tests included using inline monitoring to look into both the viscosity and ultrasound measurements in real time of the molten polymer nanocomposite through a slit die attachment to the minimixer.EPSR

Pain patterns in patients with polycystic kidney disease

Pain patterns in patients with polycystic kidney disease.BackgroundPain is a common problem in patients with polycystic kidney disease (PKD), but patterns have not been characterized as to frequency and severity. Physicians should be aware of pain problems so an approach to chronic pain management can be pursued.MethodsOne hundred seventy-one completed questionnaires out of 300 distributed to PKD patients whose renal function ranged from normal to end-stage renal disease (ESRD) were analyzed. Age at diagnosis of PKD was documented, and patients noted how the diagnosis was made. Location, severity, and frequency of pain were characterized. The Visual Analogue Scale (VAS) was used to measure pain intensity.ResultsThere were 94 females and 77 male respondents, with a mean age of 47.4 years. Initial diagnosis of PKD occurred at a mean age of 31.6 years. Caucasians comprised 92.2% of the respondents. Patients' symptoms, a family history of PKD, and discovery of PKD during evaluation for hypertension or hematuria were the most frequent factors that led to the diagnosis. Order of frequency of pain was: low back pain, abdominal pain, headache, chest pain, and leg pain. Severity of pain, documented by the VAS intensity, was 4 to 5/10 in the majority of patients.ConclusionPain, which can be diffuse, is the most frequent symptom that led to the diagnosis of PKD in patients who responded to this questionnaire, and occurs with greater frequency than generally appreciated. Physicians need to obtain a detailed history about pain in their PKD population so as to allow an approach to pain management

Highly efficient 5\u27 capping of mitochondrial RNA with NAD+ and NADH by yeast and human mitochondrial RNA polymerase

Bacterial and eukaryotic nuclear RNA polymerases (RNAPs) cap RNA with the oxidized and reduced forms of the metabolic effector nicotinamide adenine dinucleotide, NAD+ and NADH, using NAD+ and NADH as non-canonical initiating nucleotides for transcription initiation. Here, we show that mitochondrial RNAPs (mtRNAPs) cap RNA with NAD+ and NADH, and do so more efficiently than nuclear RNAPs. Direct quantitation of NAD+- and NADH-capped RNA demonstrates remarkably high levels of capping in vivo: up to ~60% NAD+ and NADH capping of yeast mitochondrial transcripts, and up to ~15% NAD+ capping of human mitochondrial transcripts. The capping efficiency is determined by promoter sequence at, and upstream of, the transcription start site and, in yeast and human cells, by intracellular NAD+ and NADH levels. Our findings indicate mtRNAPs serve as both sensors and actuators in coupling cellular metabolism to mitochondrial transcriptional outputs, sensing NAD+ and NADH levels and adjusting transcriptional outputs accordingly. © 2018, Bird et al

Time Control or Size Control? Reducing Complexity and Improving Accuracy of Genetic Programming Models

Complexity of evolving models in genetic programming (GP) can impact both the quality of the models and the evolutionary search. While previous studies have proposed several notions of GP model complexity, the size of a GP model is by far the most researched measure of model complexity. However, previous studies have also shown that controlling the size does not automatically improve the accuracy of GP models, especially the accuracy on out of sample (test) data. Furthermore, size does not represent the functional composition of a model, which is often related to its accuracy on test data. In this study, we explore the {\em evaluation time} of GP models as a measure of their complexity; we define the evaluation time as the time taken to evaluate a model over some data. We demonstrate that the evaluation time reflects both a model’s size and its composition; also, we show how to measure the evaluation time reliably. To validate our proposal, we leverage four well-known methods to size-control but to control evaluation times instead of the tree sizes; we thus compare size-control with time-control. The results show that time-control with a nuanced notion of complexity produces more accurate models on 17 out of 20 problem scenarios. Even when the models have slightly greater times and sizes, time-control counterbalances via superior accuracy on both training and test data. The paper also argues that time-control can differentiate functional complexity even better in an identically-sized population. To facilitate this, the paper proposes Fixed Length Initialisation (FLI) that creates an identically-sized but functionally-diverse population. The results show that while FLI particularly suits time-control, it also generally improves the performance of size-control. Overall, the paper poses evaluation-time as a viable alternative to tree sizes to measure complexity in GP