The synthesis of methyl-2-acetamido-3,4,6-0-triacetyl alpha-D-talosaminide

Amongst the very many different kinds of amino sugars, theones that have aroused the most interest are the 2-amino 2-deoxy hexoses which are found in such well known antibiotics as streptomycin and neomycine (2). There are so far about forty-three antibiotics which are known to contain different aminosugars (6). Aminosugars exhibit the same properties as other reducing aldohexoses, e. g. reduction of silver and cupric salts, oxidation to hexonic acids, reduction to alcohols and formation of glycosides. The object of this project is to synthesize methyl N-acetyl α-D-talosaminide which has previously been prepared by Jeanloz (3) following a different route. The path that jeanloz, Jeanloz, and Glazer (3) followed involved the preparation of methyl 2-acetamide 4, 6-benzylidene 2-deoxy α-D-idospyradoside by ammonolysis of methyl 2,3-anhydro 4,6-benzylidene α-D-idospyranoside which was converted to methyl 2-acetamido 4,6-benzylidene talopyranoaide by treatment with sodium acetate in aqueous 2-methoxyethanol. This compound was debenzylidenated with aqueous acetic acid and acetylated to obtain methyl 2-acetamido 3,4,6-tri-0-acetyl talosaminide. In short, the above route involved essentially a direct conversion from the idose series into the talose series which is illustrated in Scheme I

Fluidized bed hydrodynamics by means of electrical capacitance tomography

Fluidized bed reactors are utilized in a variety of applications from hydrocarbon cracking to drying of mineral ore to coating of pharmaceutical pills. A proper understanding of bed hydrodynamics is essential to properly design, operate and control the process. Intrusive and non-intrusive measurement techniques have been utilized to study various aspects of fluidized bed behaviour. Electrical Capacitance Tomography (ECT) has been utilized to determine the distribution of gas-solid mixture in the bed. The Digital Image Analysis Technique (DIAT) is used to determine the bubble behavior in two-dimensional beds. The bubble behavior has not been studied by ECT. The premise of this research is to test a new technique by combining ECT solid fraction maps with image processing techniques to determine the bubble characteristics in the bed. Electrical Capacitance Tomography (ECT) was used to map the relative fractions of sand-air mixture in a 14 cm ID acrylic vessel at two different static bed heights. The voids were defined as the areas of gas-solid mixture with value of less than 0.25. Afterwards simple image analysis techniques were applied to isolate bubbles from the rest of the bed. The resulting data were converted into binary images to extract hydrodynamic information. The two main parameters of interest were the bubble diameter and its rise velocity. The experimental average velocities and average diameters matched the results obtained from respective correlations in the literature. However, large spreads existed for both these parameters due to the simultaneous presence of bubbles and slugs. The experimental fluidized bed did not transition fully into the turbulent regime but has the character of a hybrid bubbling-slugging regime. This is illustrated by experimental diameters which indicate presence of bubbles and slugs simultaneously. The same information was illustrated by experimental velocity-diameter envelopes (minimum and maximum values) which overlapped for higher flow conditions. The radial solid fraction distribution illustrated the same point with an inverted “M” profile which has been associated previously with regime transition. The path of bubble rise was identified, mainly rising through the midway point between the bed’s center and its inner edge. Five different types of bubbles were identified using the two dimensional binary images of voids. However, this technique can only be used for regimes where voids/bubbles are the main source of gas transfer to the surface of the bed

Measurement of the radial mode spectrum of photons through a phase-retrieval method

We propose and demonstrate a simple and easy-to-implement projective-measurement protocol to determine the radial index 'p' of a Laguerre-Gaussian (LGlp) mode. Our method entails converting any specified high-order LG0p mode into a near-Gaussian distribution that matches the fundamental mode of a single-mode fiber (SMF) through the use of two phase-screens (unitary transformations) obtained by applying a phase-retrieval algorithm. The unitary transformations preserve the orthogonality of modes and guarantee that our protocol can, in principle, be free of crosstalk. We measure the coupling efficiency of the transformed radial modes to the SMF for different pairs of phase-screens. Because of the universality of phase-retrieval methods, we believe that our protocol provides an efficient way of fully characterizing the radial spatial profile of an optical field

Principles Employment Of An Indian Armed Force In Internal Security

A major obstacle in the way of an Indian strategy to stem militant violence is summed up in the familiar saying ‘One man’s terrorist is another man’s freedom fighter’. Insurgency, terrorism and proxy war are the main components of low intensity conflict operation. Border skirmishes on a street could also fall with in this category. In future, the major international and regional powers could pursue their ambitions through sub conventional operations.it figures at the lower end of the spectrum of conflict and is characterised by asymmetry of force levels between regular forces and irregular opposition, where in the force applied and the violence generated depends on the code of conduct and the capabilities of the weaker side, as also the laws of the land which impose restrictions on the actions of security forces

Donor Heart Allocation

The limited number of donor hearts is one of the greatest and persistent challenges to heart transplantation. Allocation of this precious resource requires the integration of objective data, clinical intuition, and moral fairness. Institution of an allocation system by UNOS has provided important structure to the allocation methodology. The system must be periodically reviewed and reorganized to ensure it is reflective of current patient disease and clinical practice and builds upon the previous knowledge paradigms. Since the establishment of the 2006 allocation system, not only has there been a dramatic increase in the number of heart transplant candidates, but also a dramatic increase in the number of patients qualifying as high-priority candidates. To address these changes, UNOS Thoracic Organ Transplantation Committee was tasked with providing a revised allocation system. The resulting system aims to improve waitlist mortality and post-transplant outcomes by better prioritizing the highest acuity patients while improving the geographic distribution of organ offers

Resource optimization through process re-engineering of inhalational therapy unit at a tertiary care public hospital

Background: Salaries, supplies and machinery account for bulk of public funding necessitating efficient utilisation. Studies suggest that process re-engineering helps improve cost, quality, service, and speed. Disbanded once and re-commissioned, a centralized Inhalational Therapy Unit (ITU) banked and provided portable mechanical ventilators to the inpatient wards. A demand for new ventilators from ITU led to the present study involving its critical review and cost analysis.Methods: An interventional study was conducted at a large tertiary care public hospital in India from April 2015 to June 2015. Critical review of process of providing portable ventilators and cost analysis were conducted. Review of records of and interview with ITU personnel and nursing staff were carried out. Fundamental rethinking and radical redesign of the process was done with attention to human resource, costs, space and actual medical equipment utilization. Two fundamental questions of process re-engineering were deliberated upon: “Why do we do what we do?” “And why do we do it the way we do?” Fundamental rethinking for new process was organized around the outcome.Results: Average utilization coefficient was 6.2% (3.3% to 12.1%). Ventilators utilized per day were 1.43. Expenditure on salaries was INR 315000 per month and INR 10500 per day. Low utilization offered low value for expenses incurred. All activities in ITU focused on “provision of ventilators” (outcome) and the old rule was, “If one needed a ventilator one must contact ITU”. Since nurses were using the “outcome” and performed activities of arranging, they were handed-over the ventilators (based on utilisation patterns). ITU was disbanded, human resource and space were re-allocated to various hospital areas (costs tied were done away with) with no adverse effect on hospital functioning.Conclusions: Process re-engineering led to improved healthcare delivery, curtailed delays in hospital processes, optimised costs involved in human resources and medical equipment

Cheiradone: a vascular endothelial cell growth factor receptor antagonist

<p>Abstract</p> <p>Background</p> <p>Angiogenesis, the growth of new blood vessels from the pre-existing vasculature is associated with physiological (for example wound healing) and pathological conditions (tumour development). Vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2) and epidermal growth factor (EGF) are the major angiogenic regulators. We have identified a natural product (cheiradone) isolated from a <it>Euphorbia </it>species which inhibited <it>in vivo </it>and <it>in vitro </it>VEGF- stimulated angiogenesis but had no effect on FGF-2 or EGF activity. Two primary cultures, bovine aortic and human dermal endothelial cells were used in <it>in vitro </it>(proliferation, wound healing, invasion in Matrigel and tube formation) and <it>in vivo </it>(the chick chorioallantoic membrane) models of angiogenesis in the presence of growth factors and cheiradone. In all cases, the concentration of cheiradone which caused 50% inhibition (IC₅₀) was determined. The effect of cheiradone on the binding of growth factors to their receptors was also investigated.</p> <p>Results</p> <p>Cheiradone inhibited all stages of VEGF-induced angiogenesis with IC₅₀values in the range 5.20–7.50 μM but did not inhibit FGF-2 or EGF-induced angiogenesis. It also inhibited VEGF binding to VEGF receptor-1 and 2 with IC₅₀values of 2.9 and 0.61 μM respectively.</p> <p>Conclusion</p> <p>Cheiradone inhibited VEGF-induced angiogenesis by binding to VEGF receptors -1 and -2 and may be a useful investigative tool to study the specific contribution of VEGF to angiogenesis and may have therapeutic potential.</p

Frequency and predisposing factors of pharyngocutaneous fistula after total laryngectomy

Objective The objective of our study was to determine the frequency and predisposing factors of pharyngocutaneous fistula in postlaryngectomy patients. Materials and methods Charts of those patients who were treated with total laryngectomy for laryngeal carcinoma in our department from 2000 to 2008 were reviewed. Total 77 patients were included in the study. The variables studied for the development of pharyngocutaneous fistula (PCF) after total laryngectomy were: age and gender, diabetes mellitus, post-operative hemoglobin, ischemic heart disease, chronic obstructive pulmonary disease, tumor characteristics including tumor site, stage, differentiation and extension into pyriform sinus, pre-operative radiotherapy, pre-operative chemotherapy, pre-operative tracheostomy and positive surgical margins. Results Univariate analysis showed diabetes, pre-operative radiotherapy, pre-operative chemotherapy and pre-operative tracheostomy to be significantly associated with the formation of PCF. However, multivariate regression revealed that the only pre-operative radiotherapy was highly associated with the formation of PCF (OR = 132.923, P = 0.001). Conclusions We found 28.6% incidence of pharyngocutaneous fistula mainly because of the number of patients undergoing radiotherapy and chemotherapy as primary treatment for laryngeal cancers is increasing with current approach of organ preservation protocol

Frequency and predisposing factors of pharyngocutaneous fistula after total laryngectomy

AbstractObjectiveThe objective of our study was to determine the frequency and predisposing factors of pharyngocutaneous fistula in postlaryngectomy patients.Materials and methodsCharts of those patients who were treated with total laryngectomy for laryngeal carcinoma in our department from 2000 to 2008 were reviewed. Total 77 patients were included in the study. The variables studied for the development of pharyngocutaneous fistula (PCF) after total laryngectomy were: age and gender, diabetes mellitus, post-operative hemoglobin, ischemic heart disease, chronic obstructive pulmonary disease, tumor characteristics including tumor site, stage, differentiation and extension into pyriform sinus, pre-operative radiotherapy, pre-operative chemotherapy, pre-operative tracheostomy and positive surgical margins.ResultsUnivariate analysis showed diabetes, pre-operative radiotherapy, pre-operative chemotherapy and pre-operative tracheostomy to be significantly associated with the formation of PCF. However, multivariate regression revealed that the only pre-operative radiotherapy was highly associated with the formation of PCF (OR=132.923, P=0.001).ConclusionsWe found 28.6% incidence of pharyngocutaneous fistula mainly because of the number of patients undergoing radiotherapy and chemotherapy as primary treatment for laryngeal cancers is increasing with current approach of organ preservation protocol

Awareness regarding causes of infertility among out-patients at a tertiary care hospital in Karachi, Pakistan

Introduction: Infertility is the inability of a couple to achieve pregnancy within 12 months of sexual intercourse without the use of contraceptives. The Pakistani population, belonging to a low-middle income country, has a high prevalence of infertility due to a low knowledge and awareness regarding its causes, and lack of healthcare-seeking behavior for this medical issue. The prevalence of infertility in Pakistan is reported as 22%, with primary infertility accounting for 4% of the total cases. This leads to psychological trauma among women as societal norms equate infertility with failure on a personal, emotional, and social level. In this study, we aimed to assess among this population the general awareness regarding infertility and its causes; and identify any key knowledge gaps pertaining to the subject.Methods: A cross-sectional study was carried out between June 2019 and November 2019, at a public hospital (Civil Hospital Karachi) in Karachi, Pakistan. Convenience sampling technique was used to collect data from adult participants (older than 18 years) via an interview-administered questionnaire. The questionnaire was based on the Cardiff Fertility Knowledge Scale (CFKS) and assessed the knowledge regarding causes of infertility such as smoking, healthy lifestyle, contraceptives, genital tract infections among others. We also determined the association between socio-demographic variables with mean knowledge scores. Data were analyzed using Statistical Package for Social Sciences (SPSS), version 20.0.Results: The majority of the participants were married (n=342, 68.8%) and more than half were unemployed (n=259, 52.1%). Approximately, two-quarters (n=250, 50.3%) did not believe that equal proportions of males and females contribute to infertility. The mean knowledge score of our study population was 12.95 ± 2.48 points. An overwhelming proportion of the participants (n=326, 65.6%) falsely believed that the usage of the intra-uterine device contributes to infertility. Additionally, more than half of the responders (n=278, 55.9%) incorrectly believed that a male achieving erection is an indication of fertility. Education (p=0.019), vehicle ownership (p=0.018), and marital status (p=0.031) were the only demographic factors that showed significant differences with mean knowledge scores.Conclusion: Awareness regarding the causes of infertility among the general population was found to be inadequate. Emphasis on targeted fertility education, in association with general public awareness programs regarding its causes and risk factors may help mitigate this problem by potentially reducing the prevalence of this condition, and increasing the number of affected individuals who seek medical care in a timely fashion