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1.
J Hosp Infect ; 137: 24-34, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37044283

ABSTRACT

Following recent viral outbreaks, there has been a significant increase in global demand for gloves. Biomedical research focuses increasingly on antimicrobial gloves to combat microbial transmission and hospital-acquired infections. Most antimicrobial gloves are manufactured using antimicrobial chemicals such as disinfectants, biocides and sanitizers. The design of antimicrobial gloves incorporates advanced technologies, including colloidal particles and nanomaterials, to enhance antimicrobial effectiveness. A category of antimicrobial gloves also explores and integrates natural antimicrobial benefits from animals, plants and micro-organisms. Many types of antimicrobial agents are available; however, it is crucial that the selected agent exhibits a broad spectrum of activity and is not susceptible to promoting resistance. Additionally, future research should focus on the potential effect of antimicrobial gloves on the skin microbiota and irritation during extended wear. Careful integration of the antimicrobial agent is essential to ensure optimal effectiveness without compromising the mechanical properties of the gloves.


Subject(s)
Anti-Infective Agents , Cross Infection , Disinfectants , Humans , Gloves, Surgical , Anti-Infective Agents/pharmacology , Technology , Gloves, Protective
2.
Heliyon ; 6(6): e04077, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32529073

ABSTRACT

In this research, Friction stir spot welding (FSSW) is extensively employed to join dissimilar metals consisting of AA6061-T6 Aluminium Alloy and Commercial Copper Alloy. These alloys were friction stir spot welded using process parameters with the major impact, such as Dwell Time (DT), Rotational Speed (RS), Plunge Rate (PR) and Tool Diameter Ratio (D/d). Trail experiments have been carried out using Design of Experiments. Sound welded joints exhibiting a maximum shear fracture load of 4.79 kN were obtained at a RS of 2000 rpm, PR of 7 mm/min, DT of 25 s and D/d of 3.5, Balanced material flow around the pin was also observed at this condition, and it is evident that the superior metallurgical properties and geometric features at this condition results in the higher strength. Moreover, the joint also exhibited higher load-bearing capabilities due to an optimal hook height of 0.89 mm, hook width of 1.3 mm and hook initiation distance of 1.4 mm. The continuous formation of intermetallic compound such as ɤ2-Cu9Al4 in the Cu zone and ɳ2-CuAl in the Al zone may also enhance the shear fracture load.

3.
RSC Adv ; 10(9): 5399-5411, 2020 Jan 29.
Article in English | MEDLINE | ID: mdl-35498297

ABSTRACT

Catharanthus roseus (Apocynaceae family) extract is rich in organic phytochemicals such as alkaloids, polyphenolic compounds, and flavonoids. It contains several functional entities such as fused heterocycles, and hydroxyl and carbonyl groups, which could be useful for corrosion inhibition of mild steel in NaCl environments. In the present work, ultrasonic energy was used to obtain the ethanolic extracts of root and stem which were then tested as corrosion inhibitors for mild steel in the presence of 3.5% NaCl. The corrosion inhibition process was studied by UV-visible spectroscopy, Fourier transform infrared spectroscopy, atomic force microscopy, weight loss, and electrochemical methods. After immersing in the corrosive medium, the microstructures of mild steel were investigated by scanning electron microscopy, X-ray diffraction, and ellipsometry. The extract of C. roseus showed excellent adsorption on mild steel surface as confirmed by DFT calculations. The results indicate that the extract of C. roseus acts as a mixed type corrosion inhibitor, where the stem extract is the most efficient inhibitor in 3.5% NaCl solution possibly due to the higher active area of stem phytochemicals.

4.
Int J Biol Macromol ; 129: 615-633, 2019 May 15.
Article in English | MEDLINE | ID: mdl-30753877

ABSTRACT

Biopolymers have become very attractive as they are degradable, biocompatible, non-toxic and renewable. Due to the intrinsic reactive amino groups, chitosan is vibrant in the midst of other biopolymers. Using the versatility of these amino groups, various structural modifications have been accomplished on chitosan through certain chemical reactions. Chemical modification of chitosan via imine functionalization (RR'CNR″; R: alkyl/aryl, R': H/alkyl/aryl and R″: chitosan ring) is significant as it recommends the resultant chitosan-based Schiff bases (CSBs) for the important applications in the fields like biology, catalysis, sensors, water treatment, etc. CSBs are usually synthesized by the Schiff condensation reaction between chitosan's amino groups and carbonyl compounds with the removal of water molecules. In this review, we first introduce the available synthetic approaches for the preparation of CSBs. Then, we discuss the biological applications of CSBs including antimicrobial activity, anticancer activity, drug carrier ability, antioxidant activity and tissue engineering capacity. Successively, the applications of CSBs in other fields such as catalysis, adsorption and sensors are demonstrated.


Subject(s)
Biocompatible Materials/chemistry , Chitosan/chemistry , Schiff Bases/chemistry , Animals , Biocompatible Materials/pharmacology , Catalysis , Humans , Schiff Bases/pharmacology
5.
RSC Adv ; 9(15): 8537-8545, 2019 Mar 12.
Article in English | MEDLINE | ID: mdl-35518658

ABSTRACT

Ti6Al4V alloy is light weight and is used in construction, oil industries and airbus, automobile, and bio implant materials. The native oxide layers of the alloy are not stable at high temperatures and strong mineral acid environments. The conventional epoxy-based layers are porous and the alloy finally fails in the harsh environment in the long term. Therefore, the carbon-based functional materials are being proposed as coating materials to overcome the alloy degradation. In the present contribution, we have used the neodymium-decorated graphene oxide as the corrosion inhibiting barrier for the Ti6Al4V alloy. As a novelty, we found that the few-layer graphene decorated with neodymium acts as a self-cleaning coating. The Nd-decorated graphene oxide were studied by XRD, TEM, FESEM, FTIR, UV, and Raman spectroscopy. The corrosion inhibition efficiency was studied by electrochemical methods.

6.
3 Biotech ; 8(11): 479, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30456013

ABSTRACT

Thirty-four Xanthomonas citri pv. malvacearum (Xcm) isolates collected from three cotton-growing zones of India were subjected for virulence and race documentation and further correlated with genetic diversity as revealed by repetitive elements [repetitive extragenic palindromic (REP), enterobacterial repetitive intergenic consensus (ERIC) and BOX elements] and intersimple sequence repeat (ISSR)-PCR analyses. Among the 34 isolates tested for virulence on susceptible cultivar LRA 5166, 7 were recorded as highly virulent (HV), 16 were moderately virulent (MV) and 11 were less virulent (LV). Eight different races were recorded by using ten cotton host differentials. Twenty-two isolates (65%) belonged to race 18. Twelve isolates (35%) pertained to races 3, 5, 6, 7, 8, 11 and 13. REP, ERIC, BOX, combined repetitive elements, and ISSR analyses revealed the presence of 7, 10, 9, 11, and 8 clusters, respectively, at similarity coefficient of 0.70 in dendrograms. Principal coordinate analysis (PCoA) exhibited 76.4% and 77.5% cumulative variability for combined repetitive elements and ISSR analyses. ERIC produced the highest polymorphic information content (PIC) value (0.928). A lot of intra-pathovar variability was observed in virulence and genomic fingerprinting among Xcm isolates. Many of the isolates grouped based on geographical origin irrespective of virulence or race. The spread of the pathogen races in India might be due to the transport of germplasm lines and seed materials from one place to others.

7.
J Appl Microbiol ; 125(3): 876-887, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29786938

ABSTRACT

AIM: Lignolytic (lignin degrading) enzyme, from oil palm pathogen Ganoderma boninense Pat. (Syn G. orbiforme (Ryvarden)), is involved in the detoxification and the degradation of lignin in the oil palm and is the rate-limiting step in the infection process of this fungus. Active inhibition of lignin-degrading enzymes secreted by G. boninense by various naturally occurring phenolic compounds and estimation of efficiency on pathogen suppression was aimed at. METHODS AND RESULTS: In our work, 10 naturally occurring phenolic compounds were evaluated for their inhibitory potential towards the lignolytic enzymes of G. boninense. Additionally, the lignin-degrading enzymes were characterized. Most of the peholic compounds exhibited an uncompetitive inhibition towards the lignin-degrading enzymes. Benzoic acid was the superior inhibitor to the production of lignin-degrading enzymes, when compared between the 10 phenolic compounds. The inhibitory potential of the phenolic compounds towards the lignin-degrading enzymes are higher than that of the conventional metal ion inhibitor. The lignin-degrading enzymes were stable in a wide range of pH but were sensitive to higher temperature. CONCLUSION: The study demonstrated the inhibitor potential of 10 naturally occurring phenolic compounds towards the lignin-degrading enzymes of G. boninense with different efficacies. SIGNIFICANCE AND IMPACT OF THE STUDY: The study has shed a light towards a new management strategy to control basal stem rot disease in oil palm. It serves as a replacement for the existing chemical control.


Subject(s)
Cellulases , Fungal Proteins , Ganoderma/enzymology , Lignin/metabolism , Phenols/pharmacology , Cellulases/antagonists & inhibitors , Cellulases/metabolism , Fungal Proteins/antagonists & inhibitors , Fungal Proteins/metabolism , Ganoderma/drug effects , Kinetics
8.
J Appl Microbiol ; 124(6): 1544-1555, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29405525

ABSTRACT

AIM: Ganoderma sp, the causal pathogen of the basal stem rot (BSR) disease of oil palm, secretes extracellular hydrolytic enzymes. These play an important role in the pathogenesis of BSR by nourishing the pathogen through the digestion of cellulose and hemicellulose of the host tissue. Active suppression of hydrolytic enzymes secreted by Ganoderma boninense by various naturally occurring phenolic compounds and estimation of their efficacy on pathogen suppression is focused in this study. METHODS AND RESULTS: Ten naturally occurring phenolic compounds were assessed for their inhibitory effect on the hydrolytic enzymes of G. boninense. The enzyme kinetics (Vmax and Km ) and the stability of the hydrolytic enzymes were also characterized. The selected compounds had shown inhibitory effect at various concentrations. Two types of inhibitions namely uncompetitive and noncompetitive were observed in the presence of phenolic compounds. Among all the phenolic compounds tested, benzoic acid was the most effective compound suppressive to the growth and production of hydrolytic enzymes secreted by G. boninense. The phenolic compounds as inhibitory agents can be a better replacement for the metal ions which are known as conventional inhibitors till date. The three hydrolytic enzymes were stable in a wide range of pH and temperature. CONCLUSION: These findings highlight the efficacy of the applications of phenolic compounds to control Ganoderma. SIGNIFICANCE AND IMPACT OF THE STUDY: The study has proved a replacement for chemical controls of G. boninense with naturally occurring phenolic compounds.


Subject(s)
Cellulases , Cellulose/metabolism , Ganoderma/enzymology , Phenols/pharmacology , Polysaccharides/metabolism , Cellulases/antagonists & inhibitors , Cellulases/chemistry , Cellulases/metabolism , Fungal Proteins/antagonists & inhibitors , Fungal Proteins/chemistry , Fungal Proteins/metabolism , Hydrolysis , Kinetics
9.
Article in English | MEDLINE | ID: mdl-25983056

ABSTRACT

Chitosan (a biopolymer) anchored Cu(II) and Ni(II) Schiff base complexes, [M(OIAC)Cl2] (M: Cu/Ni and OIAC: ([2-oxo-1H-indol-3-ylidene]amino)chitosan) were electron beam irradiated by different doses (100 Gy, 1 kGy and 10 kGy). The electron beam has shown potential impact on biopolymer's support, in detail chain linking and chain scissoring, as evidenced by viscosity studies, FT-IR and X-ray diffraction spectroscopic techniques. Due to these structural changes, thermal properties of the complexes were found to be changed. The surface of these heterogeneous complexes was also effectually altered by electron beam. As a consequence, pores and holes were created as probed by SEM technique. The catalytic activity of both non-irradiated and irradiated complexes was investigated in the aerobic oxidation of cyclohexane using hydrogen peroxide oxidant. The catalytic ability of the complexes was enhanced significantly after irradiation as the result of surface changes. The reusability of the complexes was also greatly affected because of the structural variations in polymeric support. In terms of both better catalytic activity along with the reusability, 1 kGy is suggested as the best dose to attain adequate increase in catalytic activity and good reusability.


Subject(s)
Biopolymers/chemistry , Copper/chemistry , Electrons , Nickel/chemistry , Catalysis , Differential Thermal Analysis , Microscopy, Electron, Scanning , Spectroscopy, Fourier Transform Infrared , Time Factors , Viscosity , X-Ray Diffraction
10.
J Appl Microbiol ; 113(4): 925-39, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22805053

ABSTRACT

AIMS: To investigate the antifungal activity of conventional chitosan and chitosan-loaded nanoemulsions against anthracnose caused by Colletotrichum spp. isolated from different tropical fruits. METHODS AND RESULTS: In vitro results illustrated that conventional chitosan onwards 1·5% concentration inhibited radial mycelial growth, conidial germination, sporulation and dry weight of mycelia for Colletotrichum musae (Berk. & Curt) Arx. isolated from banana, Colletotrichum gloeosporioides (Penz.) Penz and Sacc. isolated from papaya and dragon fruits. For further investigations, chitosan-loaded nanoemulsions were prepared, and chitosan at 2·0% concentration with 200 nm droplet size gave the best results in terms of all the in vitro parameters tested for C. musae and at the same concentration with 600 nm droplet size for both the isolates of C. gloeosporioides. However, the results obtained at 2·0% chitosan concentration with different droplet sizes were nonsignificantly different with 1·0 and 1·5% concentrations. Therefore, for in vivo studies, only 1·0% chitosan with different droplet sizes was used. In terms of fungicidal effects and maintaining postharvest quality of banana, papaya and dragon fruits, chitosan at 1·0% concentration with a droplet size of 200 nm in banana and 600 nm in papaya and dragon fruits showed the best results in delaying the onset of anthracnose and maintaining quality of all the fruits for up to 28 days of cold storage. CONCLUSION: Chitosan used in a conventional form showed good results but not as effective as in the form of nanoemulsions. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this study suggest that instead of applying chitosan in a conventional form, chitosan in the form of nanoemulsions could be more effective as a biofungicide for controlling anthracnose of fresh fruits. Moreover, it could be cost-effective as the amount of chemical used is reduced when applied in the form of nanoemulsions.


Subject(s)
Chitosan/pharmacology , Colletotrichum/drug effects , Food Contamination/prevention & control , Food Microbiology , Fruit/microbiology , Fungicides, Industrial/pharmacology , Carica/microbiology , Colletotrichum/growth & development , Emulsions/pharmacology , Musa/microbiology , Nanostructures , Spores, Fungal/drug effects , Spores, Fungal/growth & development
11.
Indian J Nephrol ; 20(3): 137-41, 2010 Jul.
Article in English | MEDLINE | ID: mdl-21072153

ABSTRACT

Renal biopsy is an integral part of the nephrologists' diagnostic armamentarium. Usually it is performed by radiologists or nephrologists with radiologist's assistance. Our aim was to assess the efficacy and safety of percutaneous ultrasound-guided renal biopsy performed solely by nephrologists. We performed real-time ultrasound-guided renal biopsy on 37 patients (N group). The results were then compared with those of a similar number of biopsies done with radiologist's support (NR group) immediately prior to these. In the N group, 36 biopsies (97.3%) were successful and were histopathologically adequate, whereas in the NR group, all biopsies were successful but only 28 were adequate (75.68%). Eighteen patients required only a single attempt in the N group, whereas majority (34 patients) in the NR group required two or more attempts. The average attempt per bit of renal tissue was 1.22 in both the groups. The average number of passes per patient was 1.77 in the N group and 2.32 in the NR group. The mean size of renal tissue obtained was 1.41 ± 0.47 cm in the N group and 1.19 ± 0.42 cm in the NR group. The average number of glomeruli was 15.62 ± 5.26 and 13.7 ± 7.38 in the N and NR groups, respectively (P<0.05). In the N group, there were no complications except two cases of post procedural hematuria that was managed conservatively. There was no need for blood transfusion and both of them were discharged after 48 hours. No patient had peri-renal collection or hematoma on repeat ultrasonography of the abdomen at 24 hours. However, in the NR group, five patients developed complications and one patient required laparotomy. Our study shows that percutaneous ultrasound-guided renal biopsy can be safely and successfully performed entirely by nephrologists without outside assistance. In our series, nephrologists who performed solely took fewer attempts, had better yield and fewer complications when compared to biopsies performed with radiologist's assistance. More and more nephrologists should take up this simple yet vital procedure.

13.
Stud Health Technol Inform ; 84(Pt 1): 643-7, 2001.
Article in English | MEDLINE | ID: mdl-11604816

ABSTRACT

Development and usage of Case Based Reasoning (CBR) driven medical diagnostic system requires a large volume of clinical cases that depict the problem-solving methodology of medical experts. Successful usage of CBR based systems in healthcare is constrained by the need for a continuous supply of current and correct clinical cases (in an electronic medium) from medical experts. To address this constraint we present a strategy to pro-actively transform generic Electronic Patient Records (EPR) to Operable CBR-oriented Cases (OCC) that are compliant to specialised CBR-based medical systems. EPR-OCC transformation methodology is based on XML parse-trees, Unified Medical Language Source (UMLS) meta-thesauri and medical knowledge ontologies. The featured work involves the implementation of a Java-based computer system for the automatic transformation of XML-based EPR-originating from heterogeneous EPR repositories accessible over the Internet/WWW-to specialised OCC that can then be seamlessly incorporated within Intelligent CBR-based Medical Diagnostic Systems.


Subject(s)
Diagnosis, Computer-Assisted , Medical Records Systems, Computerized/organization & administration , Humans , Internet , Programming Languages , Unified Medical Language System
14.
Stud Health Technol Inform ; 77: 709-13, 2000.
Article in English | MEDLINE | ID: mdl-11187645

ABSTRACT

Electronic patient records (EPR) can be regarded as an implicit source of clinical behaviour and problem-solving knowledge, systematically compiled by clinicians. We present an approach, together with its computational implementation, to pro-actively transform XML-based EPR into specialised Clinical Cases (CC) in the realm of Medical Case Base Systems. The 'correct' transformation of EPR to CC involves structural, terminological and conceptual standardisation, which is achieved by a confluence of techniques and resources, such as XML, UMLS (meta-thesaurus) and medical knowledge ontologies. We present below the functional architecture of a Medical Case-Base Reasoning Info-Structure (MCRIS) that features two distinct, yet related, functionalities: (1) a generic medical case-based reasoning system for decision-support activities; and (2) an EPR-CC transformation system to transform typical EPR's to CC.


Subject(s)
Artificial Intelligence , Medical Informatics Computing , Medical Records Systems, Computerized , Unified Medical Language System , Decision Support Systems, Clinical , Humans , Logic
15.
Biomed Mater Eng ; 6(2): 113-21, 1996.
Article in English | MEDLINE | ID: mdl-8761521

ABSTRACT

The finite element analysis method was used to obtain values of the von Mises equivalent stress (SEQV) at selected locations within the adhesive layer of two-dimensional models of bonded orthodontic brackets. In all, 39 model cases were analyzed involving 4 overall bracket configurations, 3 combinations of materials of fabrication of the bracket, 3 types of debonding forces and 4 adhesives. The results are presented to show the sensitivity of SEQV to each of the parameters studied. Comments are made on the usefulness of the results in the development of a standard protocol for experimental determination of the bond strength of adhesives used in securing orthodontic brackets.


Subject(s)
Dental Debonding/methods , Dentin-Bonding Agents/chemistry , Orthodontic Brackets , Computer Simulation , Humans , Materials Testing , Reproducibility of Results , Sensitivity and Specificity , Stress, Mechanical , Tensile Strength
16.
Biomed Mater Eng ; 6(1): 33-45, 1996.
Article in English | MEDLINE | ID: mdl-8727501

ABSTRACT

The finite element analysis method and a two-dimensional idealization were used to conduct a detailed parametric study of the stresses in and displacement of models of bonded edgewise "combination-materials" type of orthodontic brackets when subjected to loading and constraint conditions that are deemed to be the same as those that exist in vivo. A "combination-materials" type bracket is herein defined as one in which different materials are used in fabricating the main body and the archwire slot. The present study was conducted in three parts. In Part 1, 16 model cases were analyzed, involving 4 different combinations of materials (for the main body of the bracket and its archwire slot) and 4 different overall bracket configurations (comprising main body, base and slot). The focus of Part 2 was the model bracket configuration that was, on the basis of Part 1 results, deemed to show the "optimum performance". In this part, the parameter investigated was the value of the modulus of elasticity of the adhesive, Eadh. In Part 3, the concept of an efficiency index of the bonded bracket-archwire system, eta, was introduced and explained. The dependence of eta on stated characteristics of a rectangular archwire, for the "optimum performance" model, was explored. Part 1 results led to the conclusion that the "optimum performance" model has equally angulated buccal and lingual edges and the main body and archwire slot are fabricated from glass fiber-reinforced polycarbonate and stainless steel, respectively. Part 2 results showed that, for the aforementioned "optimum performance" model, the longitudinal displacement of the archwire slot is fairly insensitive to Eadh. Part 3 results showed that eta is intimately related to each of the wire characteristics studied (namely cross-sectional dimensions, "interbracket distance" and modulus of rigidity of the material).


Subject(s)
Dental Bonding , Orthodontic Appliance Design , Orthodontic Brackets , Adhesives/chemistry , Aluminum Oxide/chemistry , Bisphenol A-Glycidyl Methacrylate/chemistry , Elasticity , Glass/chemistry , Humans , Materials Testing , Methylmethacrylates/chemistry , Models, Theoretical , Orthodontic Wires , Polycarboxylate Cement/chemistry , Polymers , Rotation , Stainless Steel/chemistry , Stress, Mechanical , Surface Properties
17.
Am Rev Respir Dis ; 141(6): 1538-46, 1990 Jun.
Article in English | MEDLINE | ID: mdl-1972006

ABSTRACT

Respiratory tract nerves have cell bodies outside (sensory, sympathetic) and inside (parasympathetic) the organ and contain bioactive peptides. These include calcitonin gene-related peptide and tachykinins (sensory nerves), vasoactive intestinal polypeptide (parasympathetic nerves), and neuropeptide with tyrosine (sympathetic nerves). Because transplantation interrupts the extrinsic nerve supply to the tissues, we have examined transplanted human respiratory tracts (n = 11) removed at retransplantation 2 to 42 months after the primary transplant in order to determine whether any nerves and peptide synthesis persist. As controls to establish nerve distribution in human respiratory tract, tissues were obtained from 10 lung resections and five autopsies. Cryostat sections were immunostained to demonstrate the general neural marker PGP 9.5, neuropeptides, and the catecholamine-synthesizing enzyme tyrosine hydroxylase. Nerves immunoreactive for PGP 9.5 were detected in all transplanted tissues. They were fewer in number overall than in control tissue, significantly so in epithelium of trachea and bronchus where they were present sparsely in only three cases. Nerves immunoreactive for tyrosine hydroxylase were significantly fewer in the transplants. Peptide-immunoreactive nerves were also reduced in number in the transplants, except for vasoactive intestinal polypeptide, which was only significantly changed in blood vessels in the lung. Ganglion cells immunoreactive for tyrosine hydroxylase and neuropeptide with tyrosine were seen in the transplanted tissues in five cases, but never in the control tissues. We conclude that whereas some nerves and neuropeptide synthesis persist after extrinsic pulmonary denervation, potentially significant changes also occur, including the appearance in intrinsic parasympathetic neurones of immunoreactivity for a catecholamine-synthesizing enzyme and a peptide normally found in sympathetic nerves.


Subject(s)
Heart-Lung Transplantation , Respiratory System/innervation , Adult , Denervation , Female , Fluorescent Antibody Technique , Humans , Male , Nerve Fibers/metabolism , Neurons/metabolism , Neuropeptide Y/metabolism , Neuropeptides/metabolism , Phenotype , Tyrosine 3-Monooxygenase/metabolism , Ubiquitin Thiolesterase , Vasoactive Intestinal Peptide/metabolism
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