262 research outputs found
Synthesis and characterization of divalent metal complexes of the macrocyclic ligand derived from isatin and 1,2-diaminobenzene
A novel series of complexes of the type [M(C28H18N6)X2], where M=Co(II), Ni(II), Cu(II) or Zn(II) and X = Cl-, NO3- or CH3COO-, were synthesized by template condensation of isatin and 1,2-diaminobenzene in methanolic medium. The complexes were characterized with the help of various physico–chemical techniques, such as elemental analyses, molar conductance measurements, magnetic measurements, and NMR, infrared and far infrared spectral studies. The low value of molar conductance indicates them to be non-electrolytes. Based on various studies, a distorted octahedral geometry may be proposed for all the complexes. All the synthesized macrocyclic complexes were also tested for their in vitro antibacterial activity against some pathogenic bacterial strains. The MIC values shown by the complexes against these bacterial strains were compared with those of the standard antibiotics linezolid and cefaclor. Some of the complexes showed good antibacterial activities
A comparative study between dynamic hip screw and intramedullary nail fixation in trochanteric fractures
Background: The trochanteric fractures are one of the commonest fractures in elderly population. Incidence of these fractures is increasing due to better life expectancy, growing number of population, industrialization and the road traffic accidents. Variety of implants are available but still there is no consensus for single implant.Methods: A prospective randomized control study was conducted on total 60 patients of intertrochanteric fractures which were randomized into 2 groups of 30 each, treated with dynamic hip screw (DHS) and proximal femoral nail (PFN). All the patients were followed up for a maximum of 6 months. Outcomes were reviewed and compared such as mode of injury, complications, functional and radiological outcomes.Results: There was no significant difference between two groups of patients as regards to mean age and sex. The mode of injury by slip and fall was main cause. The most common type of fracture as per AO-orthopaedic trauma association (OTA) classification was 31-A2 (65%) and 31-A3 (5%) being the least common type. Mean surgical time of DHS group and PFN group was 125.17 minutes and 89.93 minutes respectively. Mean blood loss in DHS group and PFN group was 251.67 ml and 158.67 ml respectively. Mean radiological union time of fracture in DHS group and PFN group was 12.3 and 9.5weeks respectively. Mean Harris hip score at six month in DHS group and PFN group was 80.77 and 85.47 respectively.Conclusions: We conclude that though both the implants can achieve comparable union rates but PFN are better than DHS as of better Harris hip score, shorter surgical time and less intra operative blood loss
Evaluation of bacteriological contamination pattern of open fractures of extremities in tertiary care hospital
Background: Open fractures and associated complications like infection are fairly common in developing countries due to rising incidence of high velocity trauma. Primary goal of study is to evaluate the pattern of bacteriological contamination of open fractures of extremities in tertiary care hospital.Methods: A total of 316 patients of all the age group, both the sexes with open fractures of extremities presented within 6 hours were taken in to study. 1st swab taken at the time of primary wound examination followed by 2nd culture swab on just after debridement followed by 3rd culture swab on the day of 1st aseptic dressing followed by 4th culture swab if infection continues or asepsis score is more than 20 till the duration of 4 days. Culture and sensitivity reports were collected for studying pattern of bacterial isolates and their sensitivity.Results: Infection developed in 22.5% of the patients with open fractures of extremities in whom most of bacterial infections were caused by gram-negative organisms (80.3%). Cultures on admission were positive in 41 patients, out of which 11 patients had developed infection in the final cultures but with different flora. While cultures taken at 1st aseptic dressing were found to be positive in 51 cases, out of which 31 had developed infection with prognostic value of 57%.Conclusions: We concluded that cultures obtained at 1st aseptic dressing are far more predictive than pre and post-debridement cultures in management of patients with open fractures of extremities and are important in formulating an antibiotic policy
Mechanisms of Action of Human Mesenchymal Stem Cells in Tissue Repair Regeneration and their Implications
Cell replacement therapy holds a promising future in the treatment of degenerative diseases related to neuronal, cardiac and bone tissues. In such kind of diseases, there is a progressive loss of speciï¬c types of cells. Currently the most upcoming and trusted cell candidate is Mesenchymal Stem Cells (MSCs) as these cells are easy to isolate from the tissue, easy to maintain and expand and no ethical concerns are linked. MSCs can be obtained from a number of sources like bone marrow, umbilical cord blood, umbilical cord, dental pulp, adipose tissues, etc. MSCs help in tissue repair and regeneration by various mechanisms of action like cell differentiation, immunomodulation, paracrine effect, etc. The future of regenerative medicine lies in tissue engineering and exploiting various properties to yield maximum output. In the current review article, we have targeted the repair and regeneration mechanisms of MSCs in neurodegenerative diseases, cardiac diseases and those related to bones. Yet there is a lot to understand, discover and then understand again about the molecular mechanisms of MSCs and then applying this knowledge in developing the therapy to get maximum repair and regeneration of concerned tissue and in turn the recovery of the patient
Protein-Specific Features Associated with Variability in Human Antibody Responses to Plasmodium falciparum Malaria Antigens
The magnitude of antibody responses varies across the individual proteins that constitute any given microorganism, both in the context of natural infection and vaccination with attenuated or inactivated pathogens. The protein-specific factors underlying this variability are poorly understood. In 267 individuals exposed to intense seasonal malaria, we examined the relationship between immunoglobulin G (IgG) responses to 861 Plasmodium falciparum proteins and specific features of these proteins, including their subcellular location, relative abundance, degree of polymorphism, and whether they are predicted to have human orthologs. We found that IgG reactivity was significantly higher to extracellular and plasma membrane proteins and also correlated positively with both protein abundance and degree of protein polymorphism. Conversely, IgG reactivity was significantly lower to proteins predicted to have human orthologs. These findings provide insight into protein-specific factors that are associated with variability in the magnitude of antibody responses to natural P. falciparum infection-data that could inform vaccine strategies to optimize antibody-mediated immunity as well as the selection of antigens for sero-diagnostic purposes
Validation of a noninvasive aMMP-8 point-of-care diagnostic methodology in COVID-19 patients with periodontal disease
Objectives: The aim of this study was to validate an active matrix metalloproteinase (MMP-8) point-of-care diagnostic tool in COVID-19 patients with periodontal disease. Subjects, Materials, and Methods: Seventy-two COVID-19-positive and 30 COVID-19-negative subjects were enrolled in the study. Demographic data were recorded, periodontal examination carried out, and chairside tests run for evaluating the expression of active MMP-8 (aMMP-8) in the site with maximum periodontal breakdown via gingival crevicular fluid sampling as well as via a mouth rinse-based kit for general disease activity. In COVID-19-positive patients, the kits were run again once the patients turned COVID-19 negative. Results: The overall (n = 102) sensitivity/specificity of the mouthrinse-based kits to detect periodontal disease was 79.41%136.76% and that of site-specific kits was 64.71%/55.88% while adjusting for age, gender, and smoking status increased the sensitivity and specificity (82.35%/76.47% and 73.53%/88.24, respectively). Receiver operating characteristic (ROC) analysis for the adjusted model revealed very good area under the ROC curve 0.746-0.869 (p < .001) and 0.740-0.872 (p < .001) (the aMMP-8 mouth rinse and site-specific kits, respectively). No statistically significant difference was observed in the distribution of results of aMMP-8 mouth rinse test (p = .302) and aMMP-8 site-specific test (p = .189) once the subjects recovered from COVID-19. Conclusions: The findings of the present study support the aMMP-8 point-of-care testing (PoCT) kits as screening tools for periodontitis in COVID-19 patients. The overall screening accuracy can be further increased by utilizing adjunctively risk factors of periodontitis. The reported noninvasive, user-friendly, and objective PoCT diagnostic methodology may provide a way of stratifying risk groups, deciding upon referrals, and in the institution of diligent oral hygiene regimens.Peer reviewe
Phenylalanine-Rich Peptides Potently Bind ESAT6, a Virulence Determinant of Mycobacterium tuberculosis, and Concurrently Affect the Pathogen's Growth
BACKGROUND:The secretory proteins of Mycobacterium tuberculosis (M. tuberculosis) have been known to be involved in the virulence, pathogenesis as well as proliferation of the pathogen. Among this set, many proteins have been hypothesized to play a critical role at the genesis of the onset of infection, the primary site of which is invariably the human lung. METHODOLOGY/PRINCIPAL FINDINGS:During our efforts to isolate potential binding partners of key secretory proteins of M. tuberculosis from a human lung protein library, we isolated peptides that strongly bound the virulence determinant protein Esat6. All peptides were less than fifty amino acids in length and the binding was confirmed by in vivo as well as in vitro studies. Curiously, we found all three binders to be unusually rich in phenylalanine, with one of the three peptides a short fragment of the human cytochrome c oxidase-3 (Cox-3). The most accessible of the three binders, named Hcl1, was shown also to bind to the Mycobacterium smegmatis (M. smegmatis) Esat6 homologue. Expression of hcl1 in M. tuberculosis H37Rv led to considerable reduction in growth. Microarray analysis showed that Hcl1 affects a host of key cellular pathways in M. tuberculosis. In a macrophage infection model, the sets expressing hcl1 were shown to clear off M. tuberculosis in much greater numbers than those infected macrophages wherein the M. tuberculosis was not expressing the peptide. Transmission electron microscopy studies of hcl1 expressing M. tuberculosis showed prominent expulsion of cellular material into the matrix, hinting at cell wall damage. CONCLUSIONS/SIGNIFICANCE:While the debilitating effects of Hcl1 on M. tuberculosis are unrelated and not because of the peptide's binding to Esat6-as the latter is not an essential protein of M. tuberculosis-nonetheless, further studies with this peptide, as well as a closer inspection of the microarray data may shed important light on the suitability of such small phenylalanine-rich peptides as potential drug-like molecules against this pathogen
Open X-Embodiment:Robotic learning datasets and RT-X models
Large, high-capacity models trained on diverse datasets have shown remarkable successes on efficiently tackling downstream applications. In domains from NLP to Computer Vision, this has led to a consolidation of pretrained models, with general pretrained backbones serving as a starting point for many applications. Can such a consolidation happen in robotics? Conventionally, robotic learning methods train a separate model for every application, every robot, and even every environment. Can we instead train "generalist" X-robot policy that can be adapted efficiently to new robots, tasks, and environments? In this paper, we provide datasets in standardized data formats and models to make it possible to explore this possibility in the context of robotic manipulation, alongside experimental results that provide an example of effective X-robot policies. We assemble a dataset from 22 different robots collected through a collaboration between 21 institutions, demonstrating 527 skills (160266 tasks). We show that a high-capacity model trained on this data, which we call RT-X, exhibits positive transfer and improves the capabilities of multiple robots by leveraging experience from other platforms. The project website is robotics-transformer-x.github.io
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