Dual-Functional Electrochromic Smart Window Using WO3·H2O-rGO Nanocomposite Ink Spray-Coated on a Low-Cost Hybrid Electrode.

Electrochromic windows have gained growing interest for their ability to change their optical state in the visible and NIR ranges with minimal input power, making them energy-efficient. However, material processing costs, fabrication complexity, and poor electrochromic properties can be barriers to the widespread adoption of this technology. To address these issues, electrochromic material and fabrication processes are designed to realize their potential as a cost-effective and energy-efficient technology. In this work, an electrochromic composite material-based ink is synthesized consisting of WO3·H2O nanoplates supported on rGO (reduced graphene oxide) nanosheets (WH-rGO), wherein an optimized amount of rGO (0.05 to 0.5 wt %) is introduced for providing a higher conduction pathway for efficient charge transport without sacrificing the electrochromic performance of WO3·H2O nanoplates. The stable ink dispersion prepared in the study is deposited by spray coating on transparent conducting electrodes over large areas (25 cm2). The WH-rGO nanocomposite (0.4 wt %) results in 43% optical modulation at 700 nm, with bleaching and coloration times of 6 and 8 s, respectively. Interestingly, the device also possesses an electrochemical energy storage capability with an areal capacitance of 16.3 mF/cm2. The electrochromic composite material is successfully translated on tin doped indium oxide (ITO)-coated Al metal mesh hybrid electrodes (T = 80%, Rs = 40 Ω/□) to replace ITO. Finally, an electrochromic device of 5 × 5 cm2 is fabricated by spray-coating the ink on cost-effective ITO/Al-mesh hybrid electrodes. The device displays blue to colorless modulation with an excellent bleaching time of 0.43 s and a coloration time of 2.16 s, making it one among the fast-operating devices fabricated by complete solution processing. This work showcases the economical production of a dual-function electrochromic device, which can be a feasible option as an alternative to existing ITO-based devices in both automotive and infrastructure applications.

Chewing Ability and the Quality of Life: A Cross-Sectional Study to Assess the Relationship Between Tooth Wear and Oral Health.

INTRODUCTION: It is important to understand how a very common prevalent condition of tooth wear (TW) impacts a person's day-to-day oral health. An emerging concept of measuring the parameter of oral health-related quality of life (OHRQoL), which evidently impacts the daily living of a person, makes it practical to examine the correlation between TW and OHRQoL. For measuring the OHRQoL, we can apply various methods, and the most effective is the use of the Oral Health Impact Profile (OHIP) questionnaire. Accordingly, the aim of this study was to assess the correlation between TW and the OHRQoL among adult patients attending a dental college and hospital. METHODS: A cross-sectional research was performed on patients who visited the outpatient department of Teerthanker Mahaveer Dental College and Research Centre, Moradabad, India. Initially, the sociodemographic details of patients, including their oral hygiene and dietary habits, were recorded. This step was followed by the assessment of TW using the Smith and Knight TW index. Then, the translated and validated version of the OHIP questionnaire was filled up, in which the patients were asked to rate each question on a Likert scale, with five points ranging from 0 to 4, where 0 = never, 1 = hardly ever, 2 = occasionally, 3 = fairly often, and 4 = very often. RESULTS: Based on a clinical examination on 630 subjects and the OHIP questionnaire responses from the participants, a significantly remarkable association (p ≤ 0.05) was found using a chi-square test between TW and the OHRQoL. In particular, TW was linked to other sociodemographic data and various lifestyle, dietary, and drinking habits. Along with the OHRQoL, TW also showed a positive correlation with gender. Using the chi-square test, a statistically significant association between age and TW was observed, with p-value = 0.004. Meanwhile, the place of residence did not show any association with TW. Educational qualifications of patients, visits to dental clinics, and reasons for dental visits showed very significant association with TW. Oral hygiene aids, materials used, frequency of brushing, and brushing technique did not have any association with TW as per the results obtained. A highly significant association was found between consumption of fruit drinks, citric drinks, and beverages and TW in the adult patients. Among all the domains of the OHIP questionnaire, the physical pain domain was the most affected, followed by the physical disability domain. CONCLUSION: We conclude that TW has a direct association and positive correlation with the OHRQoL. As TW was increasing, so were the OHIP values, which indicated a lesser OHRQoL. The study also presents information on how to maintain a regular and healthy dietary lifestyle and oral hygiene to combat the impacts of TW.

Exploring the Synergistic Association Between Oral Health Status and Oral Health Literacy Among College Students: A Cross-Sectional Study.

INTRODUCTION: Oral health is often viewed as a significant component for an indication of good general health or for good well-being together with a decent quality of life. Health literacy is considered a crucial factor in improvising a good life or excellent health. Oral health literacy (OHL) is the ability necessary for people to identify the factors that lead to poor oral health, learn and put into practice the essentials of effective oral self-care behaviors, and communicate with oral healthcare professionals in order to schedule appointments, put their names on waiting lists for dental care, and locate the dentist's office. AIM AND OBJECTIVES: To evaluate students' oral health, their OHL, to determine the relationship between their oral health status and OHL, and finally to suggest preventive measures for the benefit of public health. MATERIALS AND METHOD: At Teerthanker Mahaveer University, a cross-sectional study involving 1500 participants, ages 18 to 25, was conducted on students studying nursing, physiotherapy, paramedicine, engineering, and law. Their informed consent was obtained. The Rapid Estimate of Adult Literacy in Dentistry (REALD-99) was used to gauge OHL levels, and the WHO's 1997 Oral Health Survey was used for their clinical evaluation. RESULTS: The mean REALD score was significantly higher in nursing students (88.32±6.46), followed by physiotherapy college (82.46±9.11), paramedical college (70.54±10.95), law college (46.52±7.74), and least in engineering college (38.80±10.65). The difference in the REALD score based on college was statistically significant. Along with this, the REALD score showed a correlation with gender and location too. Except for fluorosis, all the clinical parameters of dental caries, gingival bleeding, and pockets, loss of attachment, dental fluorosis, and dental enamel were associated with OHL. CONCLUSION: The results of the current study showed a relationship between educational attainment, clinical parameters examined, and OHL, leading to the conclusion that higher OHL is related to better oral health. So, we can conclude that maintaining good oral health requires OHL.

Fabrication of Large-Area, Affordable Dual-Function Electrochromic Smart Windows by Using a Hybrid Electrode Coated with an Oxygen-Deficient Tungsten Oxide Ultrathin Porous Film.

Electrochromic (EC) devices are not commercialized extensively owing to their high cost. The best large-area devices in the market suffer from not reaching a distinct dark-colored state. These devices appear more like a blue tinted glass. While a better performance demands the use of appropriate components, the cost-effectiveness of such components is crucial for commercialization. Specifically, the utilization of cost-effective electrodes, thin WO3 coatings, and inexpensive electrolytes are essential for reducing the cost of EC devices. Here, we report a high-performing porous WO3 thin film (∼130 nm) achieved by optimizing the DC sputtering process parameters. This way, an affordable dual-function EC energy-storage device was fabricated, showing 84% transmittance modulation and a high power density of 3036 mW/m2, thus functioning simultaneously as a transparency switching energy-storage device. With a large-area (900 cm2) device, we have demonstrated that the need for expensive ITO electrodes and Li+ ion-based electrolytes can be eliminated by using a hybrid electrode (ITO/Al-mesh) and multivalent Al3+ ion-based electrolytes while not compromising the device performance. The findings of this study may revolutionize the EC device industry and their commercialization owing to inexpensive ingredients and scalable processing.

Cost-Effective Smart Window: Transparency Modulation via Surface Contact Angle Controlled Mist Formation.

Implementing simple and inexpensive energy-saving smart technologies in households is quite effective to accomplish on-demand privacy control and reduction in energy consumption. Conventional smart glasses face difficulty in making inroads into the consumer market due to utilizing expensive active layers, electrolytes, and transparent electrodes. Thus, the need of the hour is to develop an unconventional smart window, which should be cost-effective, power-efficient, and simple to fabricate. Against this backdrop, we report the fabrication of a new class of smart partition windows termed "mist-driven transparency switching glass". The fabrication protocol includes surface energy modification of two glass panes, followed by assembling them into a square or rectangular-shaped narrow cell with appropriate inlets and outlets for mist. In its pristine state, the device is transparent, as expected of two plain glasses forming a cell. Insertion of cool mist into the device produces tiny droplets onto the inner walls due to condensation enabling scattering of light, thereby producing the translucent state. The optimized device shows a transmittance modulation of as much as ∼65% at 550 nm, allowing it to reduce the indoor temperature by more than 30% compared to a regular glass windowpane. To realize commercial viability, a large area device (30 × 30 cm2) was fabricated, which could be operated wirelessly through a cellphone application paving the way for incorporating the Internet of Things into the technology.

Charge storage mechanism in vanadium telluride/carbon nanobelts as electroactive material in an aqueous asymmetric supercapacitor.

A novel one-step method for fabricating vanadium telluride nanobelt composites for high-performance supercapacitor applications is reported. The nanobelts are realized by direct tellurization of vanadium oxide in-situ formed via decomposition of ammonium metavanadate in argon atmosphere. Use of melamine as precursor helps in forming graphitic carbon layers during pyrolization on which the nanobelts are grafted. Morphological analysis suggests interconnected nanobelts of ∼23.0 nm width coming out of carbon structure. As pseudocapacitive electrode, vanadium telluride/carbon (C) composite exhibits interesting electrochemical performance within a potential window of 0-1.0 V in 1.0 M sodium sulfate electrolyte along with excellent capacitance retention during 5000 cycles. In-depth analysis suggests that the charge storage mechanism in the composite is governed by both diffusion-controlled and diffusion-independent processes with the former dominating at slower scan rates and later at faster scan rates. The asymmetric supercapacitor assembled using vanadium telluride/C and activated charcoal (AC) as respective positive and negative electrodes exhibited an energy/power combination of 19.3 Wh/kg and 1.8 kW/kg within a potential window of 0-1.8 V in aqueous electrolyte. This strategy to improve capacitance along with potential window in an aqueous electrolyte would facilitate development of high-performance energy storage devices with metal chalcogenides.

Simple but Significant Modifications of High-Flow Nasal Cannula.

High-flow nasal cannula (HFNC) is one of the most commonly used devices for oxygen therapy during the coronavirus disease 2019 (COVID-19) pandemic in different hospital settings. Multiple alternative options include non-invasive and invasive ventilation. But non-invasive ventilation is very uncomfortable for patients, and weaning from invasive ventilation in a patient with lung pathology is challenging. Hence, HFNC has come up as a safe alternative that averts invasive ventilation. However, its widespread application is difficult in patients with nasal deformities. We discuss two patients, one with caudal dislocation of the nasal septum with a crooked nose and the other patient with septal hypertrophy. In both cases, invasive ventilation was deferred, and target oxygen saturation was achieved after a simple dispositive modification.

Clinicoepidemiological Features and Mortality Analysis of Deceased Patients with COVID-19 in a Tertiary Care Center.

BACKGROUND AND OBJECTIVE: A large number of studies describing the clinicoepidemiological features of coronavirus disease-2019 (COVID-19) patients are available but very few studies have documented similar features of the deceased. This study was aimed to describe the clinicoepidemiological features and the causes of mortality of COVID-19 deceased patients admitted in a dedicated COVID center in India. METHODOLOGY: This was a retrospective study done in adult deceased patients admitted in COVID ICU from April 4 to July 24, 2020. The clinical features, comorbidities, complications, and causes of mortality in these patients were analyzed. Pediatric deceased were analyzed separately. RESULTS: A total of 654 adult patients were admitted in the ICU during the study period and ICU mortality was 37.7% (247/654). Among the adult deceased, 65.9% were males with a median age of 56 years [interquartile range (IQR), 41.5-65] and 94.74% had one or more comorbidities, most common being hypertension (43.3%), diabetes mellitus (34.8%), and chronic kidney disease (20.6%). The most common presenting features in these deceased were fever (75.7%), cough (68.8%), and shortness of breath (67.6%). The mean initial sequential organ failure assessment score was 9.3 ± 4.7 and 24.2% were already intubated at the time of admission. The median duration of hospital stay was 6 days (IQR, 3-11). The most common cause of death was sepsis with multi-organ failure (55.1%) followed by severe acute respiratory distress syndrome (ARDS) (25.5%). All pediatric deceased had comorbid conditions and the most common cause of death in this group was severe ARDS. CONCLUSION: In this cohort of adult deceased, most were young males with age less than 65 years with one or more comorbidities, hypertension being the most common. Only 5% of the deceased had no comorbidities. Sepsis with multi-organ dysfunction syndrome was the most common cause of death. HOW TO CITE THIS ARTICLE: Aggarwal R, Bhatia R, Kulshrestha K, Soni KD, Viswanath R, Singh AK, et al. Clinicoepidemiological Features and Mortality Analysis of Deceased Patients with COVID-19 in a Tertiary Care Center. Indian J Crit Care Med 2021; 25(6):622-628.

Check Central Venous Catheter Set thoroughly or Bite the Bullet!

How to cite this article: Singh AK, Kumar S, Aggarwal R, Trikha A. Check Central Venous Catheter Set thoroughly or Bite the Bullet! Indian J Crit Care Med 2021;25(7):832-833.

Degradation of Carbon Electrodes in the All-Vanadium Redox Flow Battery.

The charge-discharge operation of the vanadium redox flow battery degrades the electrodes over time and results in a performance and efficiency decay. The impact of extended charge-discharge cycling operation on carbon electrodes is investigated using carbon paper as a model electrode. Electrode degradation along with 70 % degradation of charge-discharge capacity was observed after 100 charge-discharge cycles of a single cell vanadium redox flow battery operating at a current density of 80 mA cm-2 at room temperature (23 °C). Raman mapping of the electrodes shows a decrease in structural defects in the negative electrode, and an increase in defects in the positive electrode, indicating differences in the degradation mechanism at each electrode. Electrochemical investigation reveals an increase in the activation overpotential at both the positive and negative electrodes. However, the negative electrode showed a higher activation overpotential indicating a higher impact of electrode degradation on the negative side. X-ray photoelectron spectroscopy shows around an eightfold increase in surface oxygen functional groups after degradation in both positive and negative electrodes. The composition of oxygen functional groups was also observed to change significantly after degradation from dominantly carbonyl-based to a combination of carbonyl- and carboxyl-based groups. This study provides insight into the electrode degradation mechanism and highlights the differences in the mechanism for the positive and negative electrodes.

Outcome of Conservative Therapy in Coronavirus disease-2019 Patients Presenting With Gastrointestinal Bleeding.

BACKGROUND/OBJECTIVE: There is a paucity of data on the management of gastrointestinal (GI) bleeding in patients with Coronavirus disease -2019 (COVID-19) amid concerns about the risk of transmission during endoscopic procedures. We aimed to study the outcomes of conservative treatment for GI bleeding in patients with COVID-19. METHODS: In this retrospective analysis, 24 of 1342 (1.8%) patients with COVID-19, presenting with GI bleeding from 22nd April to 22nd July 2020, were included. RESULTS: The mean age of patients was 45.8 ± 12.7 years; 17 (70.8%) were males; upper GI (UGI) bleeding: lower GI (LGI) 23:1. Twenty-two (91.6%) patients had evidence of cirrhosis- 21 presented with UGI bleeding while one had bleeding from hemorrhoids. Two patients without cirrhosis were presumed to have non-variceal bleeding. The medical therapy for UGI bleeding included vasoconstrictors-somatostatin in 17 (73.9%) and terlipressin in 4 (17.4%) patients. All patients with UGI bleeding received proton pump inhibitors and antibiotics. Packed red blood cells (PRBCs), fresh frozen plasma (FFPs) and platelets were transfused in 14 (60.9%), 3 (13.0%) and 3 (13.0%), respectively. The median PRBCs transfused was 1 (0-3) unit(s). The initial control of UGI bleeding was achieved in all 23 patients and none required an emergency endoscopy. At 5-day follow-up, none rebled or died. Two patients later rebled, one had intermittent bleed due to gastric antral vascular ectasia, while another had rebleed 19 days after discharge. Three (12.5%) cirrhosis patients succumbed to acute hypoxemic respiratory failure during hospital stay. CONCLUSION: Conservative management strategies including pharmacotherapy, restrictive transfusion strategy, and close hemodynamic monitoring can successfully manage GI bleeding in COVID-19 patients and reduce need for urgent endoscopy. The decision for proceeding with endoscopy should be taken by a multidisciplinary team after consideration of the patient's condition, response to treatment, resources and the risks involved, on a case to case basis.

Scalable Fabrication of Scratch-Proof Transparent Al/F-SnO2 Hybrid Electrodes with Unusual Thermal and Environmental Stability.

Fabrication protocols of transparent conducting electrodes (TCEs), including those which produce TCEs of high values of figure of merit, often fail to address issues of scalability, stability, and cost. When it comes to working with high-temperature stable electrodes, one is left with only one and that too, an expensive choice, namely, fluorine-doped SnO2 (FTO). It is rather difficult to replace FTO with a low-cost TCE due to stability issues. In the present work, we have shown that an Al nanomesh fabricated employing the crack template method exhibits extreme thermal stability in air even at 500 °C, compared with that of FTO. In order to fill in the non-conducting island regions present in between the mesh wires, a moderately conducting material SnO2 layer was found adequate. The innovative step employed in the present work relates to the SnO2 deposition without damaging the underneath Al, which is a challenge in itself, as the commonly used precursor, SnCl2 solution, is quite corrosive toward Al. Optimization of spray coating of the precursor while the Al mesh on a glass substrate held at an appropriate temperature was the key to form a stable hybrid electrode. The resulting Al/SnO2 electrode exhibited an excellent transparency of ∼83% at 550 nm and a low sheet resistance of 5.5 Ω/□. SnO2 coating additionally made the TCE scratch-proof and mechanically stable, as the adhesion tape test showed only 8% change in sheet resistance after 1000 cycles. Further, to give FTO-like surface finish, the SnO2 surface was fluorinated by treating with a Selectfluor solution. As a result, the Al/F-SnO2 hybrid film exhibited one order higher surface conductivity with negligible sensitivity toward humidity and volatile organics, while becoming robust toward neutral electrochemical environments. Finally, a custom-designed projection lithography technique was used to pixelate the Al/SnO2 hybrid film for optoelectronic device applications.

Correction of preexisting astigmatism by penetrating arcuate keratotomy in femtosecond laser-assisted cataract surgery.

Purpose: To evaluate the astigmatism correcting effect of penetrating arcuate keratotomy (AK) done during femtosecond laser-assisted cataract surgery (FLACS). Methods: In this nonrandomized prospective study, 80 eyes of 70 patients were studied. The study included patients who underwent combined FLACS and AK, with corneal astigmatism ranging from 0.4 to 1.5 diopters (D). Femtosecond laser-assisted penetrating arcuate keratotomies were created at 8 mm optical zone at 80% depth and were centered at the limbus. Keratometric astigmatism was measured prior to and 3 months post-surgery. Vector analysis was performed using Power vector analysis method. Results: The mean preoperative keratometric astigmatism without accounting for axis was 0.85 ± 0.27 D, which reduced significantly to 0.47 ± 0.27 D at 3-month follow-up. The mean astigmatism correction attained without accounting for axis was 0.38 ± 0.32 D. The vector corrected mean preoperative astigmatism was 0.85 ± 0.27 D which reduced significantly to 0.50 ± 0.31 D postoperatively (P < 0.001, 95% CI). Vector corrected mean astigmatism correction attained was 0.35 ± 0.38 D. There were no significant intraoperative or postoperative complications. Conclusion: Preexisting astigmatism can be tackled effectively with penetrating AK during FLACS although under correction is observed with present nomograms. Further refinements may achieve better correction.

A facile approach for preparing densely-packed individual p-NiO/n-Fe2O3 heterojunction nanowires for photoelectrochemical water splitting.

Innovative design of electrode materials is crucial for efficient conversion of solar energy into chemical fuel through photoelectrochemical (PEC) water splitting. Herein, we report the development of a p-n heterojunction nanowire (NW) based photoanode made of low cost earth-abundant materials. Densely-packed and freestanding individual p-NiO/n-Fe2O3 heterojunction NWs are fabricated through consecutive electrodeposition of Fe and Ni NWs inside the pores of the anodic alumina template followed by controlled oxidation. Heterojunction formation in individual NWs is confirmed through energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM), along with elemental mapping on individual NWs through electron energy loss spectroscopy (EELS). An inverted 'V' shape nature of the Mott-Schottky curve suggests p-n diode like characteristics of the heterojunction NWs. These p-n heterojunction NWs demonstrate a significantly enhanced photocurrent density (∼24 times at a potential of 1.23 V vs. RHE) and a cathodic shift (∼0.4 V) of the photocurrent onset potential compared to the pristine Fe2O3 NW electrode, which can be attributed to the synergistic combination of n-Fe2O3 with the co-catalyst p-NiO facilitating the generation and transfer of photogenerated holes into the electrolyte for water oxidation. This study validates the feasibility of developing Fe2O3 based heterojunction photoelectrodes for efficient PEC water splitting.

Intra-ocular medulloepithelioma as a masquerade for PHPV and Panophthalmitis: a Diagnostic Dilemma.

A previously diagnosed child of persistent hyperplastic primary vitreous (PHPV) with painless blind eye remained clinically silent for about 3 years follow-up. The child suddenly presented as a case of orbital cellulitis and panopthalmitis with meningitis. No definite mass lesion was detected on ultrasonography, magnetic resonance imaging (MRI) and positron emission tomography (PET) scan. Histopathology of the enucleated eye revealed intra-ocular medulloepithelioma as the culprit of sterile panophthalmitis and orbital inflammation.

Surface functionalized H2Ti3O7 nanowires engineered for visible-light photoswitching, electrochemical water splitting, and photocatalysis.

This article demonstrates comprehensive studies on different visible-light driven photoelectrochemical and photocatalytic aspects of a hydrothermally synthesized n-type H2Ti3O7 (HTO) nanowire mesh and its carbon and nitrogen functionalized counterparts, namely C-HTO and N-HTO. It was found that the presence of various defect states within the band gap of HTO, C-HTO and N-HTO nanowires, make them photoactive under visible-light. The photo-conversion efficiencies of HTO, C-HTO, and N-HTO nanowire electrodes are about 0.066, 0.129, and 0.076%, respectively, at around 1 V vs. Ag/AgCl. Carbon functionalization of HTO nanowires has been found to be most beneficial in increasing the charge carrier density, resulting in the highest current density, high photo conversion efficiency, remarkable photoelectrochemical water splitting performance and enhanced photocatalytic activity. The photocurrent density of the C-HTO NWs was found to be 0.0562 mA cm-2 at 1 V vs. Ag/AgCl, which is almost two times that of the pristine HTO NWs (0.029 mA cm-2). Although nitrogen functionalization increases the charge carrier density of the HTO nanowires, nitrogen incorporation produces lots of recombination centres in the nanowires, which are found to play a detrimental role in the photoelectrochemical and photocatalytic performance of N-HTO nanowires, limiting the expected performance. Therefore, the present study demonstrates a suitable surface engineering technique for nanostructures to maximize the utilization of green solar light.

High-Performance Supercapacitor Electrode Based on Cobalt Oxide-Manganese Dioxide-Nickel Oxide Ternary 1D Hybrid Nanotubes.

We report a facile method to design Co3O4-MnO2-NiO ternary hybrid 1D nanotube arrays for their application as active material for high-performance supercapacitor electrodes. This as-prepared novel supercapacitor electrode can store charge as high as ∼2020 C/g (equivalent specific capacitance ∼2525 F/g) for a potential window of 0.8 V and has long cycle stability (nearly 80% specific capacitance retains after successive 5700 charge/discharge cycles), significantly high Coulombic efficiency, and fast response time (∼0.17s). The remarkable electrochemical performance of this unique electrode material is the outcome of its enormous reaction platform provided by its special nanostructure morphology and conglomeration of the electrochemical properties of three highly redox active materials in a single unit.

Growth and Magnetic Characterization of 1D Permalloy Nanowires Using Self Developed Anodic Aluminium Oxide Templates.

1D Permalloy refers to arrays of nanowires (NWs) made of an alloy of Ni and Fe with 80 and 20 at% composition respectively. In the present work 1 D Permalloy NWs arrays were fabricated into the pores of self engineered Anodic Aluminium Oxide (AAO) templates by a simple electrodeposition technique (EDT). By varying the anodization voltage and parameters of the electrolyte solutions we developed AAO templates with different average pore diameters (40 nm to 70 nm) and developed 1D Permalloy NWs within them. Structural characterization of AAO templates and 1D Permalloy NWs were performed by Transmission and Scanning Electron Microscopy (TEM and SEM respectively). X-ray diffraction (XRD) studies of 1D Permalloy NWs showed their fcc crystalline structure and the AAO template was found to be amorphous in nature. Magnetic studies showed the 1D Permalloy NWs arrays to have strong shape anisotropy, and the easy axis was found to be parallel to the NWs axis. We studied the angular dependence of magnetic properties of the NWs. Coercivity (Hc) and remanence (Mr/Ms) measured along the NWs axis were found to be higher than those measured in a direction perpendicular to the NWs axis. 1D Permalloy NWs developed in this work have the potential to be used in magnetic recording devices.

In vitro comparison of resistance to implant failure in unstable trochanteric fractures fixed with intramedullary single screw versus double screw device.

BACKGROUND: The purpose of this study was to compare the resistance of intramedullary single screw device (Gamma nail) and double screw device proximal femoral nail (PFN) in unstable trochanteric fractures in terms of the number of cycles sustained, subsidence and implant failure in an axial loading test in cadaveric femora. MATERIALS AND METHODS: The study was conducted on 18 dry cadaveric femoral specimens, 9 of these were implanted with a Gamma nail and 9 with PFN. There was no significant difference found in average dual energy X-ray absorptiometry value between both groups. The construct was made unstable (AO type 31A3.3) by removing a standard sized posteromedial wedge. These were tested on a cyclic physiological loading machine at 1 cycle/s with a load of 200 kg. The test was observed for 50,000 loading cycles or until implant failure, whichever occurred earlier. Peak displacements were measured and analysis was done to determine construct stiffness and gap micromotion in axial loading. RESULT: It was observed that there was statistically significant difference in terms of displacement at the fracture gap and overall construct stiffness of specimens of both groups. PFN construct group showed a mean subsidence of 1.02 mm and Gamma nail construct group showed mean subsidence of 2.36 mm after cycling. The average stiffness of Gamma nail group was 62.8 ± 8.4 N/mm which was significantly lower than average stiffness of the PFN group (80.4 ± 5.9 N/mm) (P = 0.03). In fatigue testing, 1 out of 9 PFN bone construct failed, while 5 of 9 Gamma nail bone construct failed. CONCLUSION: When considering micromotion (subsidence) and incidence of implant/screw failure, double screw device (PFN) had statistically significant lower micromotion across the fracture gap with axial compression and lower incidence of implant failure. Hence, double screw device (PFN) construct had higher stability compared to single screw device (GN) in an unstable trochanteric fracture femur model.