Compliant Pliers

The pliers include an endless loop, a top jaw appended to the endless loop, and a bottom jaw appended to the endless loop. The endless loop includes in series a top grip handle, a spring segment, a bottom grip handle and a compliant strip interconnecting the top and bottom grip handles. A rolling surface on the top grip handle rolls on a contact portion of the bottom grip handle. The rolling action causes the compliant strip to flex which causes the top and bottom jaws to move toward one another. The endless loop provides a built-in automatic spring and enhances lateral stability

3D Engineered Peripheral Nerve: Towards A New Era of Patient-Specific Nerve Repair Solutions

Reconstruction of peripheral nerve injuries (PNIs) with substance loss remains challenging because of limited treatment solutions and unsatisfactory patient outcomes. Currently, nerve autografting is the first-line management choice for bridging critical-sized nerve defects. The procedure, however, is often complicated by donor site morbidity and paucity of nerve tissue, raising a quest for better alternatives. The application of other treatment surrogates, such as nerve guides remains questionable, and inefficient in irreducible nerve gaps. More importantly, these strategies lack customization for personalized patient therapy, which is a significant drawback of these nerve repair options. This negatively impacts the fascicle-to-fascicle regeneration process, critical to restoring the physiological axonal pathway of the disrupted nerve. Recently, the use of additive manufacturing (AM) technologies has offered major advancements to the bioengineering solutions for PNI therapy. These techniques aim to reinstate the native nerve fascicle pathway using biomimetic approaches, thereby augmenting end-organ innervation. AM-based approaches, such as 3D bioprinting, are capable of biofabricating 3D engineered nerve graft scaffolds in a patient-specific manner with high precision. Moreover, realistic in vitro models of peripheral nerve tissues that represent the physiologically and functionally relevant environment of human organs could also be developed. However, the technology is still nascent and faces major translational hurdles. In this review, we spotlighted the clinical burden of PNIs and most up-to-date treatment to address nerve gaps. Next, a summarized illustration of the nerve ultrastructure that guides research solutions is discussed. This is followed by a contrast of the existing bioengineering strategies used to repair peripheral nerve discontinuities. In addition, we elaborated on the most recent advances in 3D printing (3DP) and biofabrication applications in peripheral nerve modeling and engineering. Finally, the major challenges that limit the evolution of the field along with their possible solutions are also critically analyzed

Development of an alternative harvesting method using pH to detach adherent cells from microcarriers

Peripheral nerve injuries are common in Canada, affecting 2.8% of trauma patients treated every year. Current repair strategies are inadequate and repair is often suboptimal with only 25% of patients recovering full motor function and only 3% regaining full sensory function. Because of this, the field is turning toward regenerative medicine to develop a cellular therapy using Schwann cells to repair injured nerves. Schwann cells differentiated from skin derived precursors (SKP-SCs) are a promising cell type as they are easily obtained and allow for autologous therapy. To be able to generate clinically relevant numbers of SKP-SCs, bioreactors need to be used. Since SKP-SCs are an adherent cell type, to be expanded in suspension bioreactors, small spherical beads known as microcarriers need to be used. Our lab has previously shown that these SKP-SCs readily attach to the microcarriers and grow in stirred suspension bioreactors. We have also shown that by controlling the culture parameters, we can increase the maximum cell density compared to conventional static culture methods. One of the biggest hurdles that remains is an efficient harvesting method that can be scaled up to clinical applications. Current cell detachment protocols use enzymatic based solutions to remove the cells from the surface of the microcarriers. These methods work well in removing the cells, however, they are very labour intensive as they require many washing steps and taking the reactors offline. Therefore, we looked into an alternative method for the detachment of SKP-SCs from microcarriers that will allow for an inline detachment process. This new method is based on previous research done in our lab using high pH solutions to dissociate aggregates. First we investigated the detachment efficiency in static. Cells were cultured in 6-well plates until confluency and then harvested with solutions ranging from pH 8-9.5. With a pH of 9 and an incubation time of 30 minutes, we were able to recover 75% of cells when compared to traditional enzymatic harvesting. Following this we performed a qualitative analysis on the detachment of the SKP-SCs from the microcarriers to determine if this method has potential. Small 3mL samples were taken and solutions with pHs 8.5, 9, and 9.5 were added and incubated for 30 minutes and agitated every 5 minutes. We found that the cells detached with a high efficiency after 30 minutes with a pH of only 8.5. This was then quantified while maintaining a viability of above 90%. Following this we tested this method in harvesting full 125mL bioreactors. We evaluated different pH, agitation rates, and incubation times. We also assessed the ability of the cells to reattach to microcarriers and continue to expand over several serial passages to ensure there were no negative effects on the cells. Lastly we looked at using this method in our controlled bioreactors to increase the pH without the addition of anything else. Based on our results, increasing the pH of the culture medium can detach the SKP-SCs from microcarriers at a pH as low as 8.5 which allows for minimal cell damage while still detaching cells. We also noted that when the pH gets too high (\u3e9.5), the microcarriers begin to clump together causing large aggregates of microcarriers which could lead to clogging during the filtration steps. With increasing agitation, higher recovery efficiencies can be achieved indicating that this method of cell detachment has potential for large volume processes

Transmittance behaviour of curtain fabrics under natural lighting conditions

The light transmittance behaviour of four different coloured curtain fabrics has been studied under natural lightingconditions (morning, afternoon and evening). The intensity of incident sunlight and transmitted light from the samples aremeasured using Luxmeter, in an enclosed black chamber. The percentage of transmitted light is calculated with reference tothe incident sunlight, to study the influence of colour and number of fabric layers. It is observed that the transmittancebehaviour of curtain fabrics is highly influenced by its colour due to the spectrum of colours, which is followed by theinfluence of number of layers and sunlight conditions. Further, the transmittance % of curtain is also influenced by thewavelength of incident sunlight

Thyroid profile in newly diagnosed male HIV patients: a study from North Western part of India

Background: The aim of this study was to determine proportion of newly diagnosed male HIV cases with thyroid dysfunction at different levels of CD4 counts.Methods: 195 newly diagnosed male HIV patients attending medical OPD, ART centre and medical wards of SMS Medical College and Hospital, during a period of May 2012 to April 2013 were enrolled in the study. These patients were divided in three groups on the basis of CD4 cell counts. Group A: CD4 counts 500/mm3.Results: We concluded a negative correlation between the CD4 counts and serum TSH level (r = -0.382) which was significant (p-value <0.05). Overall 32 (16.41%) patients had increased TSH, 4 (2.05%) patients had decreased and 159 (81.53%) patients had normal TSH level. Plasma TSH values in group A were higher than group B and C and they were highly significant (p<.001). Mean plasma TSH values in patients of group A, B and C was 4.56±3.60 µIU/mL (range: 1.10-17.74), 2.20±1.02 µIU/mL (range:0.24-4.22) and 2.23±1.06 µIU/mL (range:0.28-4.25) respectively. (Reference normal value = 0.4-4.0 µIU/mL). There was significantly positive correlation (p-value < 0.01) found between the CD4 counts and serum free T4 levels (r = +0.378).Conclusions: This study has demonstrated a high prevalence of thyroid dysfunction in HIV infected patients of this part of country. High prevalence of thyroid dysfunction may contribute to the morbidity of the patients and have a bearing on quality of life of the HIV infected patients. Severity of hypothyroidism was correlated with decreasing CD4 cell count

Influence of trichloroacetic acid-methylene chloride on structure of polyester fabrics

341-348In this study, polyethylene terephthalate (PET) fabric has been treated with trichloroacetic acid–methylene chloride (TCA-MC) to modify its functional properties by altering the structure. TCA-MC interacts with both amorphous and crystalline regions of PET and alters the structure (solvent-induced-polymer modification), which directly affects the functional properties of PET fabrics. Five different concentrations (0.5, 1, 3, 5 and 10%) of TCA-MC at 1, 3 and 5 min are used to treat two fabric structures, viz 100% micro polyester fabric and 100 % texturized polyester fabric. The physical properties and wettability of the treated samples are investigated, and the results are statistically analyzed. The results reveal that TCA-MC alters the structure of polyester, with the degree of modification determined by TCA-MC concentration and treatment time

Recent Developments and Characterization Techniques in 3D printing of Corneal Stroma Tissue

Corneal stroma has a significant function in normal visual function. The corneal stroma is vulnerable because of being the thickest part of the cornea, as it can be affected easily by infections or injuries. Any problems on corneal stroma can result in blindness. Donor shortage for corneal transplantation is one of the main issues in corneal transplantation. To address this issue, the corneal tissue engineering focuses on replacing injured tissues and repairing normal functions. Currently, there are no available, engineered corneal tissues for widely accepted routine clinical treatment, but new emerging 3D printing applications are being recognized as a promising option. Recent in vitro researches revealed that the biocompatibility and regeneration possessions of 3D-printed hydrogels outperformed conventional tissue engineering approaches. The goal of this review is to highlight the current developments in the characterization of 3D cell-free and bioprinted hydrogels

Parasitic nematodes exert antimicrobial activity and benefit from microbiota-driven support for host immune regulation

Intestinal parasitic nematodes live in intimate contact with the host microbiota. Changes in the microbiome composition during nematode infection affect immune control of the parasites and shifts in the abundance of bacterial groups have been linked to the immunoregulatory potential of nematodes. Here we asked if the small intestinal parasite Heligmosomoides polygyrus produces factors with antimicrobial activity, senses its microbial environment and if the anti-nematode immune and regulatory responses are altered in mice devoid of gut microbes. We found that H. polygyrus excretory/secretory products exhibited antimicrobial activity against gram(+/-) bacteria. Parasites from germ-free mice displayed alterations in gene expression, comprising factors with putative antimicrobial functions such as chitinase and lysozyme. Infected germ-free mice developed increased small intestinal Th2 responses coinciding with a reduction in local Foxp3(+)RORγt(+) regulatory T cells and decreased parasite fecundity. Our data suggest that nematodes sense their microbial surrounding and have evolved factors that limit the outgrowth of certain microbes. Moreover, the parasites benefit from microbiota-driven immune regulatory circuits, as an increased ratio of intestinal Th2 effector to regulatory T cells coincides with reduced parasite fitness in germ-free mice

Stem‐cell–based therapies to enhance peripheral nerve regeneration

Peripheral nerve injury remains a major cause of morbidity in trauma patients. Despite advances in microsurgical techniques and improved understanding of nerve regeneration, obtaining satisfactory outcomes after peripheral nerve injury remains a difficult clinical problem. There is a growing body of evidence in preclinical animal studies demonstrating the supportive role of stem cells in peripheral nerve regeneration after injury. The characteristics of both mesoderm‐derived and ectoderm‐derived stem cell types and their role in peripheral nerve regeneration are discussed, specifically focusing on the presentation of both foundational laboratory studies and translational applications. The current state of clinical translation is presented, with an emphasis on both ethical considerations of using stems cells in humans and current governmental regulatory policies. Current advancements in cell‐based therapies represent a promising future with regard to supporting nerve regeneration and achieving significant functional recovery after debilitating nerve injuries.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154610/1/mus26760.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154610/2/mus26760_am.pd

Studies on serviceability of jute geotextiles in unpaved roads at different rainfall conditions

Geotekstili u cestama osiguravaju bolje pojačanje i funkcije odvodnjavanja. Za potrebe ispitivanja, čiji rezultati su objavljeni u ovom radu, položeno je jutenog geotekstila/geojute površinske mase 760 g/m2 u neasfaltiranim cestama s pješčanim slojem i bez pješčanog sloja, u trajanju od 30, 60 i 90 dana koji su bili izloženi simuliranoj kiši 50 i 100 mm/h. Uočeno je da na prekidnu čvrstoću, prekidno istezanje i otpornost na probijanje, koji utječu na funkciju pojačavanja jutenim tekstilom, značajno utječe prisutnost pješčanog sloja u konstrukciji ceste. Zatim su ispitani utjecaj intenziteta kiše i vrijeme upotrebe. Pješčani sloj i intenzitet kiše su značajno utjecali na prosječnu veličinu pora koja utječe na funkciju drenaže jutenog tekstila.Geotextiles in roads provide better reinforcement and drainage functions. In this paper, 760 g/m2 grade jute geotextiles/geojute were laid in unpaved road designs with and without sand layer, for durations of 30, 60 and 90 days, and were subjected to 50 and 100 mm/hour simulated rainfall. It was observed that the tensile strength, breaking elongation and puncture resistance properties, which influence the reinforcement function of jute geotextiles are significantly influenced by the presence of sand layer in road design, which was followed by rainfall intensity and duration of usage. The average pore size which influences the drainage function of jute geotextiles was highly influenced by the sand layer and rainfall intensity