Lower pole of patella fractures treated with non-absorbable trans-osseous sutures: an effective surgical method to avoid implant related complications

Background: The treatment option for inferior pole of patella fracture is still being debated. Although tension‑band wiring is the most widely used technique to treat patellar fractures, metal implant‑related complications such as implant failure, palpable hardware are very common and additional procedures are often necessary to treat the complications. The aim of the study was to evaluate the functional results in patients with inferior pole of patella fracture treated by trans-osseous non-absorbable suture fixation.Methods: Patients who underwent trans-osseous suture fixation by no. 5 Ethibond for post-traumatic distal pole patella fracture were included in the study. This was a prospective study conducted at a tertiary care Government Hospital in Kolkata, between December 2018 to May 2020. All patients were followed up at an interval of 2 weeks, 6 weeks, 12 weeks, 6 months and 9 months. Bostman score was used to assess the functional outcomes of the patients.Results: Outcome at final follow-up was assessed with Bostman scoring system. In a total of 11 patients, 8 (72.8%) patients showed excellent and 3 (27.2%) patients had good results during the final follow-up. None of the patients demonstrated unsatisfactory result. At the end of 9 months, the average Bostman score for 11 patients was 27.9.Conclusions: The trans-osseous suturing with non-absorbable sutures is a safe and effective fixation technique for the treatment of distal pole patella fractures. It allows for rapid recovery with minimal implant‑related complications. It also reduces the re-surgery rates significantly

Surgical fixation of posterior cruciate ligament avulsion fracture from tibial attachment using cannulated cancellous screw: a clinical, radiological and functional outcome evaluation

Background: PCL (posterior cruciate ligament) is the main posterior stabilizer of the knee and plays a role in central axis controlling and imparting rotational stability to the knee. Injury to PCL presents commonly with avulsion fractures from its tibial attachment. An avulsion fracture of the PCL, if not surgically fixed, may lead to secondary changes in the knee joint. The aim of the study was to evaluate the clinical and functional results in patients with PCL tibial avulsion fractures treated by CC (cannulated cancellous) screw fixation.Methods: This was a prospective study conducted at a tertiary care government hospital in Kolkata, between December 2018 to July 2020 on patients who underwent CC screw fixation for post-traumatic PCL avulsion fracture from tibial site. All patients were followed up for 9 months. Lysholm knee score was used to assess the functional outcomes of the patients.Results: In a total of 10 patients, 9 (90%) patients showed excellent and 1 (10%) patient had good result during the final follow-up. 80% patients did not develop any complications. At the end of 9 months, the mean Lysholm score was 95.6. 8 (80%) patients achieved almost full knee ROM post-operatively by the end of final follow-up.Conclusions: Surgical fixation using CC screws is a simple, easy, safe and reproducible method without requiring significant expertise for achieving good stability in PCL tibial site avulsion fractures, where early intervention prevents significant late disability as it provides an excellent clinical, functional and radiographic outcome along with good joint function.

Fabrication of novel transparent Co3O4-TiO2 nanowires p-n heterojunction diodes for multiband photodetection applications

Axial Co3O4 - TiO2 heterojunction nanowires (NWs) were synthesized by glancing angle deposition (GLAD) technique. The p-n heterojunction showed excellent rectification ratio of 2.26 × 102 at ± 3.4 V. The forward turn on voltage of 1.5 V in the dark was reduced to 1 V under white light excitation on the device. The diode showed a maximum half-wave rectification efficiency of 7.77% at 200 Hz frequency operated with maximum ±10 V. The device showed maximum peak responsivity of 4.01 A/W and internal gain of 13.1 at 380 nm wavelength. The detectivity was calculated to be 2.82 × 1011 and 1.69 × 1011 Jones and the noise equivalent power was estimated to be 14.9 and 24.8 pW at 380 and 620 nm wavelength, respectively. The device spatial response showed sharp transition with rise and fall time of ∼0.17s and 0.21s, respectively

Investigation of optical and electrical properties of erbium-doped TiO2 thin films for photodetector applications

We have investigated the electrical and optical properties of erbium (Er3+) doped TiO2 thin films (Er:TiO2 TFs) grown by sol–gel technique on glass and silicon substrates. The samples were characterized by field emission gun–scanning electron microscopes (FEG–SEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), X-ray diffraction (XRD), photoluminescence (PL) and current–voltage measurement techniques. FEG–SEM and AFM images showed the morphological change in the structure of Er:TiO2 TFs and EDX analysis confirmed the Er3+ doped into TiO2 lattice. Broad PL emissions in visible and infrared regions were observed in undoped TiO2 samples and associated to different mechanisms due to the anatase and rutile phases. PL spectra revealed sharp peaks at 525 nm, 565 nm, 667 nm and 1.54 µm which are related to Er3+ emissions in Er:TiO2 samples. The undoped TiO2 and Er:TiO2 TFs based UV-photodetectors were fabricated, and various device parameters were investigated. The doped devices exhibit high photoresponse upon illuminating 350 nm UV light at 2 V bias with faster response time compared to undoped device

Mg:TiO2 alloy thin films based MOS capacitors grown on GaAs substrates

Electron beam evaporation technique is employed to synthesise TiO2, Mg0.1Ti0.9O2 and Mg0.2Ti0.8O2 thin films (TFs) grown on (100) n-type GaAs substrates. Field emission gun-scanning electron microscope (FEG-SEM) results show that the TFs have a thickness of ~ 225 nm. The non- contact atomic force microscopy (NC-AFM) images shows the pore volume of the TiO2, Mg0.1Ti0.9O2 and Mg0.2Ti0.8O2 TFs enhanced gradually. UV-Vis absorption measurements are performed on the samples to determine the main bandgap and defect level transition of the material. A unique modified Urbach theoretical model has been introduced to simulate the experimental absorption spectrum. The main bandgap energy of the TiO2, Mg0.1Ti0.9O2 and Mg0.2Ti0.8O2 samples are calculated to be ~ 3.45 eV, 3.85 eV and 4.30 eV respectively. A gradual enhancement in main bandgap transition probability and decrease in defect level transition of the material has been observed with enhanced incorporation of Mg into the TiO2 host material. X-ray diffraction (XRD) is performed, which shows a continuous change in lattice constant of TiO2 with Mg. Current (I)-voltage (V) characteristics of the TiO2, Mg0.1Ti0.9O2 and Mg0.2Ti0.8O2 Schottky devices revealed that the leakage current at -1 V was 1.28×10-6 A, 1.46×10-9 A and 2.44×10-10 A respectively. Capacitance (C) – voltage (V) measurements are performed on the devices at different frequencies. A theoretical simulation has been adopted by amending the delta depletion model at 1 MHz. The dielectric constant and the flat band voltage of the TiO2, Mg0.1Ti0.9O2 and Mg0.2Ti0.8O2 devices are found to be 100, 120 and 160 and 16.1 V, 14.7 V and 9.7 V respectively. Hill-Coleman’s method shows a gradual enhancement of the density of interface states (Dit) with Mg concentration. The calculated Dit value of the TiO2, Mg0.1Ti0.9O2 and Mg0.2Ti0.8O2 TF devices are ~ 6.16×1010 eV-1 cm-2, 6.44×1010 eV-1 cm-2 and 1.11×1011 eV-1 cm-2 respectively. The observed C-V hysteresis confirms an enhancement in the charge retention into the film with increasing Mg concentration, which in turn improves the memory window (MW) from ~ 0.36 V (at ±7 V) to ~ 0.67 V (at ±7 V) and ~ 0.87 V (at ±10 V) to ~ 1.0 V (at ±10 V) with sweeping voltage

Rectangular ZnO porous nano-plate assembly with excellent acetone sensing performance and catalytic activity

The controlled synthesis of a hierarchically assembled porous rectangular ZnO plate (2.5-3.5 mm length, 1.5-2.5 mm width and 100-150 nm thickness) from bulk ZnO without using any organic substrates, such as solvents/surfactants/structure-directing agents, is presented. The synthesized ZnO plates are single crystalline with exposed (10 (1) over bar0) facets on the flat surface, porous and formed through the calcination of a hydrozincite Zn-5(CO3)(2)(OH)(6)] intermediate. A gas sensor based on the synthesized porous ZnO architecture exhibited high sensitivity towards acetone even in low concentration (S = 3.4 in 1 ppm acetone) with good selectivity. The ZnO nanostructured material as a heterogeneous catalyst also showed excellent catalytic activity for the synthesis of 5-substituted-1H-tetrazoles (yield = 94%). Both the activities are superior than those of other reported ZnO based acetone sensors and heterogeneous catalysts. We believe that the improved properties of the synthesized ZnO nanostructure is due to the exposed (10 (1) over bar0) facets, and its porous and assembled structure, which provides a reasonably large accessible surface area, and facilitates diffusion and mass transport of gas or substrate molecules

Effect of erbium-doping concentration on the electrical, structural and morphological properties of heterostructures based on TiO2 thin films

Effect of erbium (Er) doping on the electrical, structural and morphological properties of TiO2 thin films deposited by the combination of a simple sol–gel process and spin-coating technique on p-type silicon substrates, has been investigated. A systematic study of the effect of concentration of Er on the properties of heterostructures was carried out. Raman spectroscopy and atomic force microscopy have been used to study the structural and morphology properties of devices based on Er-doped TiO2/Si heterostructures. Deep level transient spectroscopy (DLTS) has been also employed to study the electrically active defects within the band gap of Er-doped TiO2 thin films. DLTS that has proved to be a powerful tool in analysing traps in semiconductors devices showed that undoped TiO2-based devices exhibit five defects. However, three defects have been detected in the low erbium-doped TiO2 devices and only one defect was observed in the higher erbium-doped devices. These results provide strong evidence that Er doping annihilates oxygen-related defects and demonstrate the effective proof of doping process in TiO2 thin film. This finding contributes to the improved activities (e.g., photocatalytic) of TiO2 since the increase in charge traps can reduce bulk recombination and consequently, separates photogenerated electrons and holes more efficiently. Furthermore, it is found that the overall electrical properties of the devices are improved by increasing Er doping concentration. This study provides an important understanding of the deep and shallow level defects in Er-doped TiO2 thin films, which is essential for the manufacturing of future devices including UV detectors

Detailed investigation of defect states in Erbium doped In2O3 thin films

Erbium doped Indium Oxide (In2O3:Er) thin films (TFs) were synthesised by spin-on technique. Secondary Ion Mass Spectrometry confirmed that Er is incorporated into the In2O3 lattice and formed an In-O-Er layer. The current–voltage loop produced a lower loop current window of ∼3.6 × 10−4 A for In2O3:Er TF based devices. The Au/In2O3:Er/Si Schottky devices have lower ideality factor (∼6) and higher barrier height (∼0.63 eV) at 300 K than Au/In2O3/Si control samples. A blue shift in the main band-gap (∼50 nm) was calculated for In2O3:Er TFs from 10 K photoresponse. The Au/In2O3:Er/Si samples show higher photosensitivity in the temperature range 10 K–300 K and maximum (∼15 times) in the UV region at 10 K as compared to the Au/In2O3/Si devices. In addition, the Au/In2O3:Er/Si devices have better UV to visible cut-off ratio (∼3 times). Excellent temporal responses were recorded for Au/In2O3:Er/Si in the UV region as compared to Au/In2O3/Si