Crosslinking Collagen Constructs: Achieving Cellular Selectivity Through Modifications of Physical and Chemical Properties

Collagen-based constructs have emerged in recent years as ideal candidates for tissue engineering implants. For many biomedical applications, collagen is crosslinked in order to improve the strength, stiffness and stability of the construct. However, the crosslinking process may also result in unintended changes to cell viability, adhesion or proliferation on the treated structures. This review provides a brief overview of some of both the most commonly used and novel crosslinkers used with collagen, and suggests a framework by which crosslinking methods can be compared and selected for a given tissue engineering application

COMPARISON OF ANTIBACTERIAL ACTIVITY OF EXTRACT OF PROSOPIS JULIFLORA SEEDS AGAINST AEROBIC AND ANAEROBIC BACTERIA

Objective: To compare the antibacterial activity of prosopisjuliflora seed extract against aerobic and anaerobic bacteria. Methods: A cross sectional study was conducted for 6 mo in the clinical microbiology laboratory of SMCH. Agar cup diffusion technique is used to isolate the strains of Clostridium perfringens ATCC 3624, Staphylococcus aureus ATCC 25923 and Escherechiacoli ATCC 25922. The prosopisjulifloraseeds are collected from the saveetha medical college. Results: By performing the research with proper guidance it is observed that all the three bacterias–Staphylococcus aureus, Escherechia coli, Clostridium perfringens showed sensitivity to prosopisjulifloraseed extract. Conclusion: Due to its vast antibacterial activity it can be used along with other antibiotics to increase its efficacy. This is used for the treatment of infectious diseases

Indian psychiatric interview schedule (IPIS)

The paper discusses the advantages of the structured interview in psychiatric research and goes on to describe the details of development of a structured interview Schedule (IPIS) suitable for an Indian setting. The Schedule is described, as well as the results of interinvestigator reliability tests. Possible uses of the instrument and the necessary further developments are outlined

Indian psychiatric survey schedule (IPSS)

The paper describes the development of Indian Psychiatric Survey Schedule (IPSS) which is designed to inquire about the presence of 124 psychiatric symptoms and 10 items of historical information in the general population. The symptoms as well as the items of historical information are the same as those in IPIS (Kapur et al., 1974) but because of a multi-stage procedure adopted with IPSS, the inquiry takes much less time than that for IPIS. - A "preliminary interview schedule" which is meant for all members of the population can be used by a nonpsychiatrist after a short period of training. The other sections in IPSS, that is "detailed inquiry with the subject", "detailed inquiry with an informant" and "observations during interview" are completed when necessary by a trained psychiatrist who also gives a physical examination when somatic symptoms are reported. - The paper describes the reasons why a multi-stage procedure was designed, a pilot study which helped reach certain decisions regarding the construction of the schedule and the results of a study carried out to test the level of agreement obtained when three non-psychiatrists (after a short period of training) and a psychiatrist used the preliminary interview schedule with 40 hospital patients and 40 members of the general population

COMPARISON OF ANTIBACTERIAL ACTIVITY OF HONEY AGAINST AEROBIC AND ANAEROBIC BACTERIA

Objective: To compare the antibacterial activity of honey against aerobic and anaerobic bacteria. Methods: Honey is extracted from the honey comb by trained persons. Antimicrobial activity of honey is performed by Agar Cup Diffusion technique for 3 bacteria Staphylococcus aureus, E. coli and Clostridium perfringens. Results: By performing the technique with proper guidance, it is observed that the Staphylococcus aureus specimen shows sensitivity to honey whereas the other two specimens Escherichia coli and clostridium perfringens doesn’t show any sensitivity to honey. Conclusion: Due to its vast antibacterial activity of honey, it can be used along with other antibiotics to increase its efficiency

COMPARISON OF ANTIBACTERIAL ACTIVITY OF GARLIC AGAINST AEROBIC AND ANAEROBIC BACTERIA

Objective: To compare the antibacterial activity of garlic against aerobic and anaerobic bacteria. Methods: Antimicrobial activity of garlic is performed by Agar cup diffusion technique for 3 bacteria Staphylococcus aureus, E. coli and clostridium perfringens. Results: By performing the technique with proper guidance, it is observed that the Staphylococcus aureus specimen shows sensitivity to garlic whereas the other two specimens Escherichia coli and clostridium perfringens doesn’t show any sensitivity to garlic. Conclusion: Due to its vast antibacterial activity of garlic, it can be used along with other antibiotics to increase its efficiency

Feature importance in multi-dimensional tissue-engineering datasets: random forest assisted optimization of experimental variables for collagen scaffolds

Ice-templated collagen-based tissue-engineering scaffolds are ideal for controlled tissue regeneration since they mimic the micro-environment experienced in vivo. The structure and properties of scaffolds are fine-tuned during fabrication by controlling a number of experimental parameters. However, this parameter space is large and complex, rendering the interpretation of results and selection of optimal parameters to be challenging in practice. This paper investigates the impact of a cross section of this parameter space (drying conditions and solute environment) on the scaffold microstructure. Qualitative assessment revealed the previously unreported impact of drying temperature and pressure on pore wall roughness, and confirmed the influence of collagen concentration, solvent type, and solute addition on pore morphology. For quantitative comparison, we demonstrate the novel application of random forest regression to analyze multi-dimensional biomaterials datasets, and predict microstructural attributes for a scaffold. Using these regression models, we assessed the relative importance of the input experimental parameters on quantitative pore measurements. Collagen concentration and pH were found to be the largest factors in determining pore size and connectivity. Furthermore, circular dichroism peak intensities were also revealed to be a good predictor for structural variations, which is a parameter that has not previously been investigated for its effect on a scaffold microstructure. Thus, this paper demonstrates the potential for predictive models such as random forest regressors to discover novel relationships in biomaterials datasets. These relationships between parameters (such as circular dichroism spectra and pore connectivity) can therefore also be used to identify and design further avenues of investigation within biomaterials

The Case of Onboarding Process at Company X

Within an organisation, changes are endless.For an organisation to grow and flourish, changes are necessary and inevitable.Although the significance of change management and organisational development has been established, organisations always face resistance and challenges towards the same. Change interventions in an organization are of varied nature and can be classified as follows: strategic, techno structure, human resource management and human process interventions. The onboarding process is related to work design and refers to the procedure in which newly joined employees are given orientation about the company’s culture, policies and other necessary documentation that is entailed as being part of that company. This process can be viewed from two perspectives: from the employer’s point of view and the new employees’ point of view. This case study attempts to analyse the benefits and shortcomings of a temporary and permanent change of the onboarding process in companies

MicroCT analysis of connectivity in porous structures: optimizing data acquisition and analytical methods in the context of tissue engineering.

Micro-computed X-ray tomography (MicroCT) is one of the most powerful techniques available for the three-dimensional characterization of complex multi-phase or porous microarchitectures. The imaging and analysis of porous networks are of particular interest in tissue engineering due to the ability to predict various large-scale cellular phenomena through the micro-scale characterization of the structure. However, optimizing the parameters for MicroCT data capture and analyses requires a careful balance of feature resolution and computational constraints while ensuring that a structurally representative section is imaged and analysed. In this work, artificial datasets were used to evaluate the validity of current analytical methods by considering the effect of noise and pixel size arising from the data capture, and intrinsic structural anisotropy and heterogeneity. A novel 'segmented percolation method' was developed to exclude the effect of anomalous, non-representative features within the datasets, allowing for scale-invariant structural parameters to be obtained consistently and without manual intervention for the first time. Finally, an in-depth assessment of the imaging and analytical procedures are presented by considering percolation events such as micro-particle filtration and cell sieving within the context of tissue engineering. Along with the novel guidelines established for general pixel size selection for MicroCT, we also report our determination of 3 μm as the definitive pixel size for use in analysing connectivity for tissue engineering applications

Inositol Acylation of Phosphatidylinositol Mannosides: A Rapid Mass Response to Membrane Fluidization in Mycobacteria

Mycobacteria share an unusually complex, multilayered cell envelope, which contributes to adaptation to changing environments. The plasma membrane is the deepest layer of the cell envelope and acts as the final permeability barrier against outside molecules. There is an obvious need to maintain the plasma membrane integrity, but the adaptive responses of the plasma membrane to stress exposure remain poorly understood. Using chemical treatment and heat stress to fluidize the membrane, we show here that phosphatidylinositol (PI)-anchored plasma membrane glycolipids known as PI mannosides (PIMs) are rapidly remodeled upon membrane fluidization in Mycobacterium smegmatis. Without membrane stress, PIMs are predominantly in a triacylated form: two acyl chains of the PI moiety plus one acyl chain modified at one of the mannose residues. Upon membrane fluidization, we determined the fourth fatty acid is added to the inositol moiety of PIMs, making them tetra-acylated variants. Additionally, we show that PIM inositol acylation is a rapid response independent of de novo protein synthesis, representing one of the fastest mass conversions of lipid molecules found in nature. Strikingly, we found that M. smegmatis is more resistant to the bactericidal effect of a cationic detergent after benzyl alcohol pre-exposure. We further demonstrate that fluidization-induced PIM inositol acylation is conserved in pathogens such as Mycobacterium tuberculosis and Mycobacterium abscessus. Our results demonstrate that mycobacteria possess a mechanism to sense plasma membrane fluidity change. We suggest that inositol acylation of PIMs is a novel membrane stress response that enables mycobacterial cells to resist membrane fluidization