Development of the Regenerative Glycosylation Approach for Manual and Automated Oligosaccharide Synthesis

It has been recognized that carbohydrates are involved in all phases of life beginning with the embryonic development and cell growth. However, it is the involvement of carbohydrates in the progression of various deadly diseases that gave these natural compounds significant roles in diagnostics and as pharmaceuticals. Although carbohydrates are highly desirable to the biological and medical communities, these molecules are still very challenging targets for chemists. Functionalization, derivatization, controlling anomeric stereoselectivity, purification, and characterization are all existing experimental hurdles towards producing synthetic carbohydrates in large quantities and high purity. Advances in chemistry and biochemistry have certainly facilitated the synthesis and purification of carbohydrates. However, the development of practical and general methods for chemical glycosylation and expeditious oligosaccharide synthesis remain an important and challenging area of research. This topic has also become the basis for this doctoral dissertation wherein the focus was primarily placed on the development of new leaving groups for chemical glycosylation and designing novel methods and technologies for efficient oligosaccharide synthesis. One outcome of this study is the development of two new classes of building blocks for chemical glycosylation, O-benzoxazolyl (OBox) and 3,3-difluoro-3H-indol-2-yl (OFox) imidates. Based on our observation that the OFox leaving group has the same structure before its introduction and after its departure, 3,3-difluoroxindole (HOFox) aglycone, we developed a new regenerative concept for chemical glycosylation. This method allows for performing glycosylation reactions in a conceptually novel way using catalytic amounts of reagents and activators. Further application of the regenerative concept to the HPLC-assisted synthesis on polymer support, an automated technology being developed in our laboratory, was complementary for refining all chemical aspects of both methods

Effectiveness of 4D construction modeling in detecting time-space conflicts of construction sites

This research investigated whether 4D construction model effectively helps project participants on construction sites in detecting time-space conflicts in the schedule. Previous researchers on construction space management typically modeled space requirements for equipment and paths for material and focused primarily on static or dynamic layout planning. Some researchers regarded time-space conflicts as an essential aspect of construction space management. They demonstrated the use of 4D modules in time-space conflict analysis. Although these 4D prototypes have been successful in tackling time-space conflict analysis, they have been validated with only post-hoc analysis of construction projects. Also, various currently commercially available 4D visualization softwares do not take into account the workspace required during the construction of a component unless space is modeled as a separate component into the CAD application. Therefore, without modeling space as a component in the 3D model it is necessary to assess whether 4D visualization can be effectively used on construction sites to detect time-space conflicts in the schedule. In order to fulfill the research goal an experiment was conducted. A 4D construction model of an ongoing project was developed. Project participants were introduced to two different graphic representations of the schedule; namely, an overlay drawing - the conventional method used on site to detect conflicts and the 4D construction model. Analysis of the results compared the performance of the participants in detecting time-space conflicts in the schedule using the two methods. The experiment produced empirical evidence that a 4D construction model may be effective on construction sites in detecting time-space conflicts in the schedule

β‐Mannosylation through O‐Alkylation of Anomeric Cesium Alkoxides: Mechanistic Studies and Synthesis of the Hexasaccharide Core of Complex Fucosylated N‐Linked Glycans

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154903/1/ejoc202000313.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154903/2/ejoc202000313-sup-0001-SupMat.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154903/3/ejoc202000313_am.pd

A novel watermarking technique for medical image authentication

Medical images are stored in PACS (Picture Archiving and Communication Systems) that are accessed over the intranet by radiologists for diagnosis. These days the trend is shifting towards a web based interface for accessing PACS (image) data. This calls for thorough security measures in the information system of the hospital to ensure integrity of medical image data that is being transferred over the public network. The paper analyses various watermarking techniques with a perspective of applying them to medical images stored on the PACS. It discusses the applicability of invertible watermarking technique for ensuring integrity of medical images. Any modification to the watermarked DICOM (Digital Imaging and Communications in Medicine) image can be detected with high reliability using invertible fragile watermarking system. A unique content based digital signature can be generated from the image data (pixel data) which would be embedded inside the image in an imperceptible way without increasing the data size that need to be transferred. This signature can be extracted at the radiologist viewer work stations and used for the authentication while the modified pixel data is restored back to original if the image is found to be authentic. This kind of distortion free (erasable) embedding procedure would ensure image retrieval without any modification to pixel data after the authentication process that caters to the unique need of medical images for diagnosis. 1

Assessment of diet diversity among working women in Mumbai and its association with diabetes risk as determined by the Indian diabetes risk score: A cross-sectional study

Aims and Objective: Diet diversity is defined as the number of food groups consumed over a reference period and the effect of diet diversity on diabetes risk is controversial in different populations. The purpose of this study was to determine an association between diet diversity and diabetes risk and identify a trend among working women in Mumbai. Materials and Methods: This was a cross-sectional study conducted among working women in Mumbai. Working women of the age 21‐50 years were eligible for participation. A self-designed questionnaire with four sections of questions on socio-demographic, anthropometric, diabetes risk determination by Indian Diabetes Risk Score and dietary data where diet diversity was determined using Modified Women’s Diet Diversity Score (MWDDS) was administered. Results: Two hundred and one working women participated and it was found that the mean diabetes risk score was 47.9 ± 18.3 with 89.5% of the population having a moderate to high risk. The mean diet diversity score was 4.2% and 94.5% of the population had a low to moderate diet diversity score. As the diet diversity increases, on the one hand the percentage of people having a high risk (31.1%, 36.6%, 45.5%) of diabetes also increases but on the other hand the percentage of those having a low risk (13.3%, 10.3%, 0%) of diabetes decreases, but this is not statistically significant (P 0.711). Conclusion: There was no significant association between diet diversity and diabetes risk; however, a significant positive association was seen between energy and nutrient consumption and diabetes risk, as well as between diet diversity and energy and nutrient consumption

Stereocontrolled 1,2-Cis Glycosylation as the Driving Force of Progress in Synthetic Carbohydrate Chemistry

Recent developments in stereoselective 1,2-cis glycosylation that have emerged during the past decade are surveyed herein. For detailed coverage of the previous achievements in the field the reader is referred to our earlier reviews: A. V. Demchenko, Curr. Org. Chem., 2003, 7, 35–79 and Synlett, 2003, 1225–1240

Organocatalytic aziridine synthesis using F salts

This paper describes a unique application of the fluoronium cation (F ) as an organocatalyst for mediating the reaction between N-substituted imines and ethyl diazoacetate affording excellent yields of N-substituted aziridines. © 2009 American Chemical Society

Epidemiological survey of neurological diseases in a tribal population cluster in Gujarat

Background: There are few community-based neuroepidemiological studies based in tribal communities. This cross-sectional community-based study explored the prevalence rates of neurological disorders in the tribal region of Kaparada in Gujarat. Methodology: A two-stage methodology was used. Door-to-door surveys were conducted in the villages of Moti Vahiyal, Arnai, and Chavshala in Kaparada taluka in the Valsad district. Trained volunteers administered a questionnaire that assessed demographic details and common neurological symptoms in children and adults. Data were obtained from 8217 individuals from 1464 households using the questionnaire in stage 1. A number of 615 individuals reported at least one symptom. In stage 2, a team of neurologists conducted a medical camp to assess those “screened in” for neurological disorders. Results: The crude prevalence rate for neurological disorders in general was found to be 2592.19/100,000. The prevalence rates for lower motor neuron diseases were highest (1010.1), and the rates of epilepsy, movement disorders, stroke, vertigo, headaches, upper motor neuron diseases, and mental and behavioral disorders were found to be 255.6, 133.9, 109.53, 170.38, 511.4, 109.53, and 292.08/100,000, respectively. Age- and sex-specific rates and patterns varied for different disorders. Conclusion: The prevalence rates of most disorders were found to be lower than those reported elsewhere, but age and sex prevalence patterns were similar to existing research. Challenges in conducting such a study in a remote population are discussed

Regenerative Glycosylation under Nucleophilic Catalysis

This article describes 3,3-difluoroxindole (HOFox)-mediated glycosylation. The uniqueness of this approach is that both the in situ synthesis of 3,3-difluoro-3<i>H</i>-indol-2-yl (OFox) glycosyl donors and activation thereof can be conducted in a regenerative fashion as is a typical reaction performed under nucleophilic catalysis. Only a catalytic amount of the OFox imidate donor and a Lewis acid activator are present in the reaction medium. The OFox imidate donor is constantly regenerated upon its consumption until glycosyl acceptor has reacted