Metal complexes of oxygen-, nitrogen-, and sulphur-containing macrocyclic ligands; synthetic and structural studies

It was at the turn of this century, within the area of co-ordination chemistry that the interdependence of structure and reactivity was first realised. The understanding of interactions between metal and ligand has become more complex progressing from simple unidentate to the more complicated multidentate systems and in some instances, ligand designs have imposed unusual co-ordination geometrics around metal atoms. Such offsets are particularly evident in macrocyclic ligands. Their intrinsic properties as ligands gives them the potential to behave as catalysts, semiconductors and sequestering agents for use in pollution control and hydrometallurgy. In addition, they have impinged on the biomedical field, where they have become likely candidates for therapeutic reagents required for the treatment of metal intoxication, or used as diagnostic agents in the form of radio-labelled macrocycle-conjugated antibodies for better tumor imaging while their specificity and efficacy prove excellent for enzyme modelling. In 1987, achievements in this expanding field culminated in the form of a Nobel prize, awarded to C. J. Pedersen, J. M. Lehn and D. J. Cram and marked the scientific world's recognition of the importance of macrocyclic chemistry. Having briefly outlined the wealth of research associated with macrocyclic ligands currently being undertaken, one aspect is of special interest to this work. The objective of this project has been to design new selective complexing agents for the toxic heavy metal ions cadmium(II), mercury(II) and lead(II). Resulting observations on the properties of such systems should provide a better insight of how and why certain ligands 'discriminate' or appear selectively to complex with only certain metal ions. In addition, the project supplements an ongoing study of related work which forms part of a series within a matrix of similar macrocyclic ligands

On the noncentral distribution of the ratio of the extreme roots of wishart matrix

The distribution of the ratio of the extreme latent roots of the Wishart matrix is useful in testing the sphericity hypothesis for a multivariate normal population. Let X be a p×n matrix whose columns are distributed independently as multivariate normal with zero mean vector and covariance matrix ∑. Further, let S=XX′ and let 11>…>1p>0 be the characteristic roots of S. Thus S has a noncentral Wishart distribution. In this paper, the exact distribution of fp=1−1p/11 is derived. The density of fp is given in terms of zonal polynomials. These results have applications in nuclear physics also

Propofol Sedation for ERCP Procedures: A Dilemna? Observations from an Anesthesia Perspective

Propofol sedation for endoscopic retrograde cholangiopancreatography (ERCP) procedures is a popular current technique that has generated controversy in the medical field. Worldwide, both anesthetic and nonanesthetic personnel administer this form of sedation. Although the American and Canadian societies of gastroenterologists have endorsed the administration of propofol by nonanesthesia personnel, the US Food and Drug Administration (FDA) has not licensed its use in this manner. There is some evidence for the safe use of propofol by nonanesthetic personnel in patients undergoing endoscopy procedures, but there are few randomized trials addressing the safety and efficacy of propofol in patients undergoing ERCP procedures. A serious possible consequence of propofol sedation in patients is that it may result in rapid and unpredictable progression from deep sedation to general anesthesia, and skilled airway support may be required as a rescue measure. Potential complications following deep propofol sedation include hypoxemia and hypotension. Propofol sedation for ERCP procedures is an area of clinical practice where discussion and mutual cooperation between anesthesia and nonanesthesia personnel may enhance patient safety

Cytological and cultural evaluation of abnormal vaginal discharge in pregnancy and its co-relation with maternal and neonatal outcome

Background: Pregnancy represents a risk factor in the occurrence of vaginal infection. This study was undertaken to define the persistence of vaginal flora in 280 pregnant women at 14 to 34 weeks' gestation and to evaluate the role of cytology in diagnosis of vaginal infections. It aims to study the maternal and neonatal outcome in pregnancy with vaginal discharge.Methods: High vaginal swab samples and data on epidemiological characteristics were collected from 280 pregnant women between 14-34 weeks with complaints of abnormal vaginal discharge at booking clinic of Indira Gandhi Government Medical College, Nagpur. Vaginal swab was collected and sent to laboratory for further investigation to establish etiological diagnosis. After diagnosis by vaginal swab report, subjects were treated with the specific treatment to individual infection. Subjects were followed up during antenatal period for complications. A birth weight of delivered baby was noted. The data was analysed using software Graph Pad in stat 3.Results: The incidence of abnormal vaginal discharge in pregnancy was 23.9% in one year. The frequency of abnormal discharge was 53% among those aged 20-24 years (97/183), 49.2% in primigravida (65/132). Pain in lower abdomen and back was the most common symptoms i.e. 88.19% in Cases, while 17.36% had vulval pruritus and 14.58% had dysuria.Conclusions: This study recommend that women complaining of vaginal discharge in pregnancy should be evaluated for infections. this study supports CDC-P recommendation as all women who have symptomatic vaginitis, should be treated regardless of pregnancy status

Modeling the Input Variables and Setting on the Static System Model at Using the Genetic Algorithm for Fault Location in the Power Transmission Grid

Part 14: Energy DistributionInternational audienceIn the paper is presented a method for fault location in the power grid through waveform matching of the recorded wave from failure with simulation from the static system model wave failure. The basis of the approach is comparing of the phase of the waves. The search process to find the best waveform match is actually an optimization problem. The genetic algorithm is used to find the optimal solution. The proposed method is suitable in cases where data from digital fault recorders are scarce. In these circumstances, the proposed approach provides more accurate results compared to the other known techniques. But for the correct operation of this method for fault locating in the system exercise influence both the form of the acquired form from digital fault recorders input data thus the correlation between the power transmission system and the static system model. Namely these issues are the subject of this paper

The Bootstrap Method for the Selection of a Shrinkage Factor in Two-stage Estimation of the Reliability Function of an Exponential Distribution

An application of a bootstrap method for selecting a suitable shrinkage factor for the two-stage shrinkage estimator of a reliability function for the exponential distribution is discussed. The estimator obtained here has higher efficiency as compared to the one where the shrinkage factor is not subjected to bootstrapping

High-resolution esophageal manometry in children

Functional disorders of the esophagus are known as esophageal dysmotility disorders. Esophageal manometry can be used to study swallowing disorders, feeding problems, nonobstructive dysphagia, and lower esophageal dysfunction. This paper discusses the recent advances in and reviews the use of high-resolution esophageal manometry in children. The Chicago 4.0 classification should be used judiciously in children. Manometric studies can guide the proper management of dysmotility in children

Challenges and Opportunities for Developing Countries from Medical Tourism

Wikipedia defines “Medical Tourism” as the act of traveling to other countries to obtain medical, dental and surgical care. Rapid expansion of facilities for patients abroad has helped to spur this industry’s growth. Regardless of the destination, U.S. citizens are increasingly embracing the benefits of medical tourism due to dramatically rising U.S. healthcare costs. Medical care in countries such as India, Mexico, Thailand and Singapore can cost as little as ten percent of the cost of comparable care in the U.S. for some procedures. Statistical analysis revealed the costs to be significantly lower for many of these countries. Currently, patients from U.S., Canada, Europe, Australia and the Middle East appear to be traveling to destinations in Asia such as India and in Central America such as Mexico for medical care. Medical tourism can offer opportunities to developing countries to make improvements in their country and the host country can enjoy the economic benefit from medical tourism. However, there are also some challenges they may face from medical tourism. This paper discusses the opportunities and the challenges resulting from medical tourism for developing countries

Broad ligament pregnancy - a rare form of ectopic

Ectopic pregnancy in the broad ligament is a serious form of extrauterine pregnancy which is very rare. The diagnosis is very difficult to establish especially in acute cases leading to many complications and maternal morbidity and mortality. We present the case of 22-weeks-old abdominal pregnancy who underwent emergency laparotomy for acute symptoms before her complete diagnostic evaluation. Ruptured broad ligament pregnancy was noted with hemoperitoneum. The patient recovered completely after surgery and was discharged in a stable condition. The diagnosis of broad ligament pregnancy is difficult to establish and challenging to manage because of its rarity, varied presentation and intra-operative complications. High chances of morbidity and mortality in both mother and foetus prompts increased awareness among both obstetricians and patients

Low serum sodium is associated with protein energy wasting and increased interdialytic weight gain in haemodialysis patients.

BACKGROUND: Low serum sodium (Na) has been associated with decreased body mass index and increased cardiovascular mortality in haemodialysis (HD) patients. We examined the relationship between serum Na and selected nutritional parameters of protein energy wasting that are not affected from the hydration status in a cohort of HD patients. METHODS: Triceps skinfold thickness (TSF), mid-arm circumference (MAC), mid-arm muscle circumference (MAMC), handgrip strength (HGS) and subjective global assessment (SGA) were assessed in maintenance HD patients using standard techniques. MAMC was calculated with the formula MAMC (cm) = MAC (cm) -3.142 × TSF cm. Pre-dialysis serum Na values from routine monthly laboratory measurements were averaged for the last 6 months prior to the nutritional assessment. RESULTS: Altogether 172 patients with anthropometric data were included in the final analysis. Mean age was 66 ± 14, females 62 (36%) and diabetics 48 (28.9%). Patients with pre-dialysis serum Na below the mean value (136.2 mEq/L) had lower MAMC, HGS, SGA scores and albumin levels (23.50 ± 3.16 cm versus 24.58 ± 3.71 cm, P = 0.048; 21.7 ± 13.6 kg versus 28.0 ± 12.4 kg, P = 0.030; 5.1 ± 1.2 versus 5.7 ± 1.0, P = 0.012 and 31.65 ± 4.73 mg/L versus 32.25 ± 3.91 mg/L, P = 0.022, respectively) and higher interdialytic weight gains. Pre-dialysis serum Na correlated positively with MAMC, handgrip and SGA (Pearson's correlation r = 0.165, P = 0.031, r = 0.237, P = 0.022 and r = 0.195, P = 0.011, respectively). CONCLUSION: This study demonstrates that low serum sodium is associated with protein energy wasting and increased interdialytic weight gain in HD patients