Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 19 de 19
Filter
Add more filters











Publication year range
1.
Molecules ; 27(24)2022 Dec 07.
Article in English | MEDLINE | ID: mdl-36557797

ABSTRACT

Recently, a novel electrochemical regulation associated with a deposition/dissolution reaction on an electrode surface has been proven to show superiority in large-scale energy storage systems (ESSs). Hence, in the search for high-performance electrodes showcasing these novel regulations, we utilized a low-cost ZnO microsphere electrode to construct aqueous rechargeable batteries (ARBs) that supplied a harvestable and storable charge through electrochemical deposition/dissolution via a reversible manganese oxidation reaction (MOR)/manganese reduction reaction (MRR), respectively, induced by the inherent formation/dissolution of zinc basic sulfate in a mild aqueous electrolyte solution containing 2 M ZnSO4 and 0.2 M MnSO4.

2.
ACS Appl Mater Interfaces ; 13(45): 53877-53891, 2021 Nov 17.
Article in English | MEDLINE | ID: mdl-34743513

ABSTRACT

In this study, magnesium-ion-substituted, sodium-deficient, P3- and P2-layered manganese oxide cathodes (Na0.67Mg0.1Mn0.9O2) were synthesized through a facile polyol-assisted combustion technique for applications in sodium-ion batteries. The electrochemical reaction pathways, structural integrity, and long cycling ability at low current rates of the P3- and P2-phases of the Na0.67Mg0.1Mn0.9O2 cathodes were investigated using time-consuming techniques, such as galvanostatic titration and series cyclic voltammetry. The results obtained from these techniques were supported by those obtained from operando X-ray diffraction (XRD) analysis. Particularly, the P2-phase provided excellent structural stability owing to its intrinsic crystal structure, thereby exhibiting a reversible capacity retention of 82.6% after 262 cycles at a low rate of 0.1 C; in contrast, the P3-phase exhibited a capacity retention of 38.7% after 241 cycles at a similar current rate. The air stability of these as-prepared powders, which were stored under ambient conditions, was progressively analyzed over a period of 6 months through XRD without conducting any special experiments. The results suggest that in the P3-phase, the formation of NaHCO3 and hydrated phase impurities, resulting from Na+/H+ exchange and hydration reactions, respectively, was likely to occur more quickly, that is, within a few days, compared to that in the P2-phase.

3.
Nanomaterials (Basel) ; 11(8)2021 Jul 24.
Article in English | MEDLINE | ID: mdl-34443735

ABSTRACT

Aqueous rechargeable zinc ion batteries (ARZIBs) have gained wide interest in recent years as prospective high power and high energy devices to meet the ever-rising commercial needs for large-scale eco-friendly energy storage applications. The advancement in the development of electrodes, especially cathodes for ARZIB, is faced with hurdles related to the shortage of host materials that support divalent zinc storage. Even the existing materials, mostly based on transition metal compounds, have limitations of poor electrochemical stability, low specific capacity, and hence apparently low specific energies. Herein, NH4V4O10 (NHVO), a layered oxide electrode material with a uniquely mixed morphology of plate and belt-like particles is synthesized by a microwave method utilizing a short reaction time (~0.5 h) for use as a high energy cathode for ARZIB applications. The remarkable electrochemical reversibility of Zn2+/H+ intercalation in this layered electrode contributes to impressive specific capacity (417 mAh g-1 at 0.25 A g-1) and high rate performance (170 mAh g-1 at 6.4 A g-1) with almost 100% Coulombic efficiencies. Further, a very high specific energy of 306 Wh Kg-1 at a specific power of 72 W Kg-1 was achieved by the ARZIB using the present NHVO cathode. The present study thus facilitates the opportunity for developing high energy ARZIB electrodes even under short reaction time to explore potential materials for safe and sustainable green energy storage devices.

4.
Indian J Orthop ; 55(3): 708-713, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33995877

ABSTRACT

BACKGROUND: Scapular fractures are uncommon injuries of upper extremity resulting mostly from high-energy trauma. Extra-articular fractures form the majority of them. Un-displaced fractures can be managed conservatively with good results. But displaced fracture does not yield satisfactory results and needs surgical fixation. In this case series, we report our experience about such fractures. METHODS: This was a retrospective study of 12 patients with displaced scapular body and neck fractures treated between 2015 and 2018. Scapular fractures were exposed by modified Judet approach and fixed with either 3.5 mm T buttress or recon locking plate and screws. One case had associated clavicle fracture which was fixed along with scapula. Patients were put on structured rehabilitation and followed up regularly. Functional outcome and range of motion were analyzed. RESULTS: The patients included 10 males and two females. Mean age was 42 years. Average follow-up was 33 months. Average constant and Murley score was 80. Excellent results were seen in four patients, good results in seven patients and one patient has got fair result. The mean post-operative range of motion of the shoulder at the time of final follow-up was 140° of forward flexion, 136° of abduction, and 34° of external rotation. CONCLUSION: Displaced extra-articular scapular fractures managed by internal fixation using T buttress locking plates and reconstruction plates give good functional outcome.

5.
J Clin Orthop Trauma ; 11(2): 332-338, 2020.
Article in English | MEDLINE | ID: mdl-32099307

ABSTRACT

Pycnodysostosis is a rare inherited disorder of autosomal recessive trait causing cathepsin K deficiency, leading to failure of osteoclastic activity. Brittle and sclerotic bones which are prone for frequent fractures is the characteristic feature of this congenital disorder. Despite good healing potential there are few issues in the management of fractures in pycnodysostosis patients. In this article we report the challenges faced in managing a fracture of the femoral shaft in a 12 year old girl with pycnodysostosis. For early rehabilitation and to avoid deformity and shortening, we opted for surgical fixation over conservative treatment. Narrow medullary canal ruled out the option for titanium elastic nail fixation. 4.5mm dynamic compression plate was used to fix the fracture. Sclerotic bone made drilling extremely difficult. Deformed femoral shaft allowed plating over the anterior surface only, instead of the routine lateral surface plating. Postoperative fracture healing was satisfactory. Implant was removed after 18 months.

6.
Chem Commun (Camb) ; 55(26): 3793-3796, 2019 Mar 26.
Article in English | MEDLINE | ID: mdl-30864605

ABSTRACT

We explore NaV6O15 (NVO) nanorod cathodes prepared by a sol-gel method for aqueous rechargeable zinc-ion battery applications for the first time. The NVO cathode delivers a high capacity of 427 mA h g-1 at 50 mA g-1 current density. Furthermore, based on the mass of the active materials, it exhibits a high energy density of 337 W h kg-1.

7.
Knee Surg Relat Res ; 30(4): 341-347, 2018 Dec 01.
Article in English | MEDLINE | ID: mdl-30466254

ABSTRACT

PURPOSE: Tunnel widening following anterior cruciate ligament (ACL) reconstruction is commonly observed. Graft micromotion is an important contributing factor. Unlike fixed-loop devices that require a turning space, adjustable-loop devices fit the graft snugly in the tunnel. The purpose of this study is to compare tunnel widening between these devices. Our hypothesis is that the adjustable-loop device will create lesser tunnel widening. MATERIALS AND METHODS: Ninety-eight patients underwent ACL reconstruction from January 2013 to December 2014. An adjustable-loop device was used in 54 patients (group 1) and a fixed-loop device was used in 44 patients (group 2). Maximum tunnel widening at 1 year was measured by the L'Insalata's method. Functional outcome was measured at 2-year follow-up. RESULTS: The mean widening was 4.37 mm (standard deviation [SD], 2.01) in group 1 and 4.09 mm (SD, 1.98) in group 2 (p=0.511). The average International Knee Documentation Committee score was 78.40 (SD, 9.99) in group 1 and 77.11 (SD, 12.31) in group 2 (p=0.563). The average Tegner-Lysholm score was 87.25 (SD, 3.97) in group 1 and 87.29 in group 2 (SD, 4.36) (p=0.987). There was no significant difference in tunnel widening and functional outcome between the groups. CONCLUSIONS: The adjustable-loop device did not decrease the amount of tunnel widening when compared to the fixed-loop device. There was no significant difference in outcome between the two fixation devices. LEVEL OF EVIDENCE: Level 3, Retrospective Cohort.

8.
Orthop J Sports Med ; 6(9): 2325967118794367, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30246039

ABSTRACT

BACKGROUND: The knee dislocation-3 (KD3) injury pattern is the most common form of multiligamentous injury. Medial KD3 (KD3-M) and lateral KD3 (KD3-L) are 2 anatomically different varieties of this injury. PURPOSE: To compare the surgical outcomes of KD3-M and KD3-L multiligamentous knee injury patterns and to determine the factors that could influence the outcomes after single-stage reconstruction. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A cohort of 45 patients with multiligamentous knee injuries (31 KD3-M, 14 KD3-L) who were operated on between 2011 and 2015 were compared. The cruciate ligaments were reconstructed, and the collateral ligaments were managed either conservatively or surgically depending on intraoperative laxity, tissue condition, injury site, and chronicity. The mean follow-up was 36 months (range, 24-72 months). The International Knee Documentation Committee (IKDC) score, Lysholm score, knee flexion range of motion (ROM), and laxity on stress radiographs were compared. Various factors likely to influence the outcomes were also analyzed. RESULTS: The mean IKDC score, Lysholm score, and knee flexion ROM for the 45 patients were 74.74, 87.66, and 126.78°, respectively. There was no significant difference between the KD3-M and KD3-L groups in terms of the postoperative IKDC score (P = .768), Lysholm score (P = .689), knee flexion ROM (P = .798), and laxity on stress radiographs (P = .011). Patients with a transient dislocation had better outcomes (76.51, 89.41, and 128.61°, respectively) than those with a frank dislocation (67.62, 80.66, and 119.44°) (P = .037, .007, and .043). The acute group had better outcomes (77.00, 89.51, and 127.86°) when compared with the subacute (66.26, 86.00, and 121.00°) and chronic groups (67.40, 76.40, and 125.00°) (P = .045, .006, and .486). Regression analysis showed the influence of these factors on outcomes. The presence or absence of dislocations, time frame in which surgery was performed, and follow-up duration were found to influence the outcome. All other factors had no bearing on outcomes. Two patients had knee stiffness and underwent arthrolysis. CONCLUSION: Despite anatomic and biomechanical differences between KD3-M and KD3-L injuries, single-stage management did not produce any significant difference in results. The presence of a frank dislocation, delay in surgery, and duration of follow-up were found to influence outcomes.

9.
Nanoscale ; 10(13): 5938-5949, 2018 Mar 29.
Article in English | MEDLINE | ID: mdl-29542744

ABSTRACT

Pyrite (FeS2) is a promising electrode material for lithium ion batteries (LIBs) because of its high natural availability, low toxicity, cost-effectiveness, high theoretical capacity (894 mA h g-1) and high theoretical specific energy density (1270 W h kg-1, 4e-/FeS2). Nevertheless, the use of FeS2 in electrochemical capacitors was restricted due to fast capacity fading as a result of polysulfide (S/Sn2-) formation during the initial electrochemical cycling. In order to avoid the formation of polysulfides, we employed the strategy of utilizing an ether based electrolyte (1.0 M lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)/diglyme (DGM)). Herein, we introduce FeS2/C as the Faradaic electrode for a non-aqueous hybrid electrochemical capacitor (NHEC) in combination with activated carbon (AC) as a non-Faradaic electrode, and 1.0 M LiTFSI/DGM as a non-aqueous electrolyte. Specifically, FeS2/C nanoparticles have been prepared via the sulfidation of a room temperature synthesized Fe-based MOF (metal organic framework) precursor. The fabricated FeS2/C∥AC NHEC, operating within the chosen voltage window of 0-3.2 V, delivered energy densities in the range of 63-9 W h kg-1 at power densities of 152-3240 W kg-1. Remarkable cycling stability with stable energy density retention for 2500 cycles at high power densities (729, 1186 and 3240 W kg-1) was observed.

10.
Nano Lett ; 18(4): 2402-2410, 2018 04 11.
Article in English | MEDLINE | ID: mdl-29570307

ABSTRACT

Owing to their safety and low cost, aqueous rechargeable Zn-ion batteries (ARZIBs) are currently more feasible for grid-scale applications, as compared to their alkali counterparts such as lithium- and sodium-ion batteries (LIBs and SIBs), for both aqueous and nonaqueous systems. However, the materials used in ARZIBs have a poor rate capability and inadequate cycle lifespan, serving as a major handicap for long-term storage applications. Here, we report vanadium-based Na2V6O16·3H2O nanorods employed as a positive electrode for ARZIBs, which display superior electrochemical Zn storage properties. A reversible Zn2+-ion (de)intercalation reaction describing the storage mechanism is revealed using the in situ synchrotron X-ray diffraction technique. This cathode material delivers a very high rate capability and high capacity retention of more than 80% over 1000 cycles, at a current rate of 40C (1C = 361 mA g-1). The battery offers a specific energy of 90 W h kg-1 at a specific power of 15.8 KW kg-1, enlightening the material advantages for an eco-friendly atmosphere.

11.
J Colloid Interface Sci ; 501: 133-141, 2017 Sep 01.
Article in English | MEDLINE | ID: mdl-28448833

ABSTRACT

In the present study, a metal-organic framework (MOF) derived from a facile water-assisted green precipitation technique is employed to synthesize phase-pure cobalt vanadate (Co3V2O8, CVO) anode for lithium-ion battery (LIB) application. The material obtained by this eco-friendly method is systematically characterized using various techniques such as powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and N2 adsorption-desorption measurements. By using as an anode, an initial discharge capacity of 1640mAhg-1 and a reversible capacity of 1194mAhg-1 are obtained at the applied current densities after the 240th cycle (2Ag-1 for 200 cycles followed by 0.2Ag-1 for 40 cycles). Moreover, a reversible capacity as high as 962mAhg-1 is retained at high current densities even after 240 cycles (4Ag-1 for 200 cycles followed by 2Ag-1 for 40 cycles), revealing the long life stability of the electrode. Significantly, CVO anode composed of fine nanoparticles (NPs) registered a substantial rate performance and reversible specific capacities of 275, 390, 543 and 699mAhg-1 at high reversibly altered current densities of 10, 5, 2, and 1Ag-1, respectively.

12.
ACS Appl Mater Interfaces ; 8(13): 8546-53, 2016 Apr 06.
Article in English | MEDLINE | ID: mdl-26983348

ABSTRACT

Metal-organic framework (MOF)-based synthesis of battery electrodes has presntly become a topic of significant research interest. Considering the complications to prepare Co3V2O8 due to the criticality of its stoichiometric composition, we report on a simple MOF-based solvothermal synthesis of Co3V2O8 for use as potential anodes for lithium battery applications. Characterizations by X-ray diffraction, X-ray photoelectron spectroscopy, high resolution electron microscopy, and porous studies revealed that the phase pure Co3V2O8 nanoparticles are interconnected to form a sponge-like morphology with porous properties. Electrochemical measurements exposed the excellent lithium storage (∼1000 mAh g(-1) at 200 mA g(-1)) and retention properties (501 mAh g(-1) at 1000 mA g(-1) after 700 cycles) of the prepared Co3V2O8 electrode. A notable rate performance of 430 mAh g(-1) at 3200 mA g(-1) was also observed, and ex situ investigations confirmed the morphological and structural stability of this material. These results validate that the unique nanostructured morphology arising from the use of the ordered array of MOF networks is favorable for improving the cyclability and rate capability in battery electrodes. The synthetic strategy presented herein may provide solutions to develop phase pure mixed metal oxides for high-performance electrodes for useful energy storage applications.

13.
Foot Ankle Spec ; 9(1): 83-7, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26864831

ABSTRACT

UNLABELLED: Glomus tumor, originally known as an angioneuromyoma, is a benign neoplasm arising from specialized structures called glomus bodies, involved in thermoregulation. Although it has been reported at a number of sites in the body, this rare tumor is most commonly seen in the subungual areas of the digits of the hand. Only a handful of lesions have been reported in the toes. Because most foot conditions are treated by podiatrists and dermatologists, orthopaedic surgeons are generally unaccustomed to making early diagnoses. The purpose of this case report is to alert the attending surgeon regarding the possibility of glomus tumor as a cause of chronic toe pain. Also it has been observed that the behavior of this tumor varies with the site of occurrence-whether digital or extradigital. So we have extensively reviewed all similar reports in the literature to analyze the behavior of this tumor at this unusual location, apart from comparing it with the more common finger variety, to ensure it possibly is not a misclassification like the chemodectomas that were earlier thought to be glomus tumors. LEVELS OF EVIDENCE: Therapeutic Level IV: Case Study.


Subject(s)
Bone Neoplasms/diagnosis , Bone Neoplasms/surgery , Glomus Tumor/diagnosis , Glomus Tumor/surgery , Toes , Diagnosis, Differential , Diagnostic Imaging , Female , Humans , Young Adult
14.
Nanoscale ; 7(33): 13935-42, 2015 Sep 07.
Article in English | MEDLINE | ID: mdl-26219927

ABSTRACT

ZnO nanorods and Mn/ZnO microflowers with nano-sized petals exhibit singly ionized oxygen vacancies, V. This is strongly supported by a green photoluminescence emission at 2.22 eV and an EPR g value of 1.953, both of which are suppressed greatly after annealing in an oxygen atmosphere. A strong red emission observed during exposure to X-rays reveals the presence of F(+) centres as a consequence of the V. Mn/ZnO displayed enhanced H2 generation with visible light exposure, when compared to pure ZnO and annealed Mn/ZnO in the visible region, which directly correlated with the oxygen vacancy concentration. There is an interesting correlation between the intensities of the EPR lines at the g-value of 1.953 due to the oxygen vacancies, the intensity of light emitted from the exposure to X-rays, the intensity of the photoluminescence due to oxygen vacancies and the quantity of H2 produced by the photocatalytic effect when comparing the three different nanomaterials, viz. pure ZnO, Mn/ZnO before and after annealing, all having been made exactly by the same methodologies.

16.
Phys Chem Chem Phys ; 16(18): 8541-55, 2014 May 14.
Article in English | MEDLINE | ID: mdl-24671627

ABSTRACT

Silver doped zinc oxide nanoparticles are synthesized by a solution combustion method. The samples characterized by a variety of spectroscopic and other techniques clearly reveal the presence of silver nanoparticles as well as silver clusters. The silver in the two forms was identified by careful deconvolution of X-ray photoelectron spectral results. Their formation was also confirmed by the presence of plasmons, the concentration and energy of which increase on increasing silver input, indicating the presence of perpendicular excitons since aggregates of clusters are known to shift the plasmon resonances depending on their topologies. Further confirmation of clusters came from EPR (electron paramagnetic resonance), HRSEM (high resolution scanning electron microscopy) and HRTEM (high resolution transmission electron microscopy); direct proof for clusters came from matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectral measurements. The antimicrobial activity of the silver doped zinc oxide polymer nanocomposites as biomedical devices are measured by zone of inhibition. Also, samples coated on paper disk with acacia binder are evaluated by a disk diffusion method. While pure zinc oxide does not show any antimicrobial property, the activity of silver-doped zinc oxide is comparable to that of commercial antibiotics and found to be related to nanoparticulate silver. Similarly, the microbial adherence to the surface of polymer nanocomposite which mimics a biomedical device also was influenced by nanoparticles of silver. The photocatalytic water treatment was carried out using silver carrying nanoparticles with Rhodamine-B and 4-chlorophenol as model pollutants. The increased photocatalytic activity of silver containing zinc oxide as compared to pure zinc oxide nanoparticles is attributed to the synergistic display of the properties of silver nanoparticles and clusters in zinc oxide. This activity depends upon the dispersion of silver nanoparticles over the zinc oxide lattice where charge separation plays a dominant role. The mechanisms for both photocatalysis and antimicrobial activity are discussed.


Subject(s)
Metal Nanoparticles/chemistry , Silver/chemistry , Zinc Oxide/chemistry , Bacterial Adhesion/drug effects , Catalysis , Chlorophenols/chemistry , Disk Diffusion Antimicrobial Tests , Electron Spin Resonance Spectroscopy , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Kinetics , Metal Nanoparticles/toxicity , Particle Size , Photolysis , Rhodamines/chemistry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Sunlight , Ultraviolet Rays , Waste Disposal, Fluid
17.
J Clin Orthop Trauma ; 5(2): 65-73, 2014 Jun.
Article in English | MEDLINE | ID: mdl-25983473

ABSTRACT

Management of fracture distal end clavicle has always puzzled the orthopaedic surgeons. Now-a-days with a relatively active lifestyle, patients want better results both cosmetically and functionally. Despite so much literature available for the management of this common fracture, there is no consensus regarding the gold standard treatment for this fracture. In this article, we reviewed the literature on various techniques of management for this fracture, both conservative as well as surgical, and their merits and demerits.

18.
J Clin Orthop Trauma ; 4(1): 36-9, 2013 Mar.
Article in English | MEDLINE | ID: mdl-26403773

ABSTRACT

BACKGROUND: Total knee arthroplasty is associated with significant perioperative blood loss which may necessitate blood transfusion. In this prospective randomised case control study we analysed the efficacy and safety of tranexamic acid in reducing perioperative blood loss and requirement of blood transfusion in total knee arthroplasty. METHODS: Fourteen patients (group A) undergoing total knee replacement were given intravenous tranexamic acid twice, once ten minutes before tourniquet deflation and once after four hours. Thirteen patients (group B) were observed as a separate group without the administration of the drug. Total perioperative blood loss, need of blood transfusion and D-dimer assay were analysed subsequently. RESULTS: The average blood loss in the first group was 266.2 ml and in the second group was 667.5 ml (p < 0.001). average requirement of transfusion in both the groups were 0.54 and 1.6 units of blood respectively (p < 0.001). There was no case of deep vein thrombosis or any other untoward effects. CONCLUSION: Hence from these evidences it was concluded that administration of tranexamic acid during total knee replacement helps to reduce blood loss without increasing the risk of deep vein thrombosis.

19.
J Clin Orthop Trauma ; 4(4): 164-70, 2013 Dec.
Article in English | MEDLINE | ID: mdl-26403876

ABSTRACT

In orthopedics management of surgical blood loss is an important aspect which has evolved along with modern surgeries. Replacement of lost blood by transfusion alone is not the answer as was considered earlier. Complications like infection and immune reaction due to blood transfusion are a major concern. Today numerous techniques are available in place of allogenic blood transfusion which can be employed safely and effectively. In this article we have reviewed these techniques, their merits and demerits.

SELECTION OF CITATIONS
SEARCH DETAIL