Improving the Coke Resistance of Ni-Ceria Catalysts for Partial Oxidation of Methane to Syngas: Experimental and Computational Study.

The synthesis of syngas (H2 : CO=2) via catalytic partial oxidation of methane (CPOM) is studied over noble metal doped Ni-CeO2 bimetallic catalysts for CPOM reaction. The catalysts were synthesized via a controlled deposition approach and were characterized using XRD, BET-surface area analysis, H2 -TPR, TEM, Raman and TGA analysis. The catalysts were experimentally and computationally studied for their activity, selectivity, and long-term stability. Although the pure 5Ni/CeO2 catalyst showed high initial activity (∼90%) of CH4 conversion, it rapidly deactivates around 20% of its initial activity within 140 hours of TOS. Doping of Ni/CeO2 catalyst with noble metal was found to be coke resistant with the best-performing Ni-Pt/CeO2 catalyst showed ∼95% methane conversion with >90% selectivity at a temperature of 800 °C, having exceptional stability for about 300 hours of time-on-stream (TOS). DFT studies were performed to calculate the activation barrier for the C-H activation of methane over the Ni, Ni3 Pt, Ni3 Pd, and Ni3 Ru (111) surfaces showed nearly equal activation energy over all the studied surfaces. DFT studies showed high coke formation tendency of the pure Ni (111) having a very small C-C coupling activation barrier (14.2 kJ/mol). In contrast, the Ni3 Pt, Ni3 Pd, and Ni3 Ru (111) surfaces show appreciably higher C-C coupling activation barrier (∼70 kJ/mol) and hence are more resistant against coke formation as observed in the experiments. The combined experimental and DFT study showed Ni-Pt/CeO2 as a promising CPOM catalyst for producing syngas with high conversion, selectivity and long-term stability suited for future industrial applications.

Charge Stability and Charge-State-Based Spin Readout of Shallow Nitrogen-Vacancy Centers in Diamond.

Spin-based applications of the negatively charged nitrogen-vacancy (NV) center in diamonds require an efficient spin readout. One approach is the spin-to-charge conversion (SCC), relying on mapping the spin states onto the neutral (NV0) and negative (NV-) charge states followed by a subsequent charge readout. With high charge-state stability, SCC enables extended measurement times, increasing precision and minimizing noise in the readout compared to the commonly used fluorescence detection. Nanoscale sensing applications, however, require shallow NV centers within a few nanometers distance from the surface where surface related effects might degrade the NV charge state. In this article, we investigate the charge state initialization and stability of single NV centers implanted ≈5 nm below the surface of a flat diamond plate. We demonstrate the SCC protocol on four shallow NV centers suitable for nanoscale sensing, obtaining a reduced readout noise of 5-6 times the spin-projection noise limit. We investigate the general applicability of the SCC for shallow NV centers and observe a correlation between the NV charge-state stability and readout noise. Coating the diamond with glycerol improves both the charge initialization and stability. Our results reveal the influence of the surface-related charge environment on the NV charge properties and motivate further investigations to functionalize the diamond surface with glycerol or other materials for charge-state stabilization and efficient spin-state readout of shallow NV centers suitable for nanoscale sensing.

Star-topology registers: NMR and quantum information perspectives.

Quantum control of large spin registers is crucial for many applications ranging from spectroscopy to quantum information. A key factor that determines the efficiency of a register for implementing a given information processing task is its network topology. One particular type, called star-topology, involves a central qubit uniformly interacting with a set of ancillary qubits. A particular advantage of the star-topology quantum registers is in the efficient preparation of large entangled states, called NOON states, and their generalized variants. Thanks to the robust generation of such correlated states, spectral simplicity, ease of polarization transfer from ancillary qubits to the central qubit, as well as the availability of large spin-clusters, the star-topology registers have been utilized for several interesting applications over the last few years. Here we review some recent progress with the star-topology registers, particularly via nuclear magnetic resonance methods.

Tendon Transfer for Persistent Radial Nerve Palsy Using Single-Split FCU Technique and Re-Routing of Extensor Pollicis Longus: A Prospective Study of 25 Cases.

PURPOSE: Optimal treatment of persistent radial nerve palsy is controversial. However, most authors agree that tendon transfers lead to satisfactory result in majority of patients. Triple tendon transfer using flexor carpi radialis, pronator teres, and palmaris longus is the most preferred tendon transfer. The aim of this study was to evaluate the results of a split flexor carpi ulnaris (FCU) as a single transfer in such patients and compare our results with other transfers from the available literature. MATERIALS AND METHODS: A total of 25 patients (20 males and 5 females: mean age: 30.9 years) were selected for FCU split transfer in persistent radial nerve palsy injury from April 2014 to May 2015. All patients were followed up with a mean followup of 1 year. Clinical outcomes were assessed using Bincaz score. RESULTS: Using Bincaz score, 68% of our patients had good-to-excellent result, while 32% patients had fair and none had bad results. Wrist extension was comparatively less in high radial nerve palsy as compared to low radial nerve palsy patients, but all patients were functionally independent. Power grip was assessed using a jammer dynamometer. All patients had adequate grip strength and good active extension of the wrist and fingers. CONCLUSION: Single transfer using split FCU can be a preferred alternative in patients of low radial nerve palsy, it can be considered for high radial nerve patients in whom multiple donors are absent due to the nature of injury, for example, brachial plexus injury.

Results of Rodding and Impact on Ambulation and Refracture in Osteogenesis Imperfecta: Study of 21 Children.

INTRODUCTION: Delay in presentation and surgical intervention is quite usual in osteogenesis imperfecta (OI) because of various local and cultural beliefs. The purpose of this study is to review the results of 21 children who had intramedullary rodding and its effect on ambulation and refracture. METHODS: We reviewed 21 children with a clinical diagnosis of OI. The mean age of children at presentation was 8.74 years (3-21 years). All children had recurrent fractures of long bones. Twenty eight femurs and 21 tibiae were stabilized with intramedullary rodding. Ambulatory status was assessed by the Hoffers and Bullock's (H and B) grading, and muscle power was recorded using the Medical Research Council, U. K., grade. Ten children had received intravenous bisphosphonates preoperatively. Postoperatively, the children were assessed for ambulatory status, pain, and ability for independent self-care. RESULTS: The mean followup period was 34 months (24-48 months). Rush rods were used in 20 femurs, the Fassier-Duval (FD) rods in 6 femurs, and in two cases, with narrow intramedullary canals, Kirshner (K) wires were used. For the tibiae, 15 children received rush rods and in 6 cases, an FD rod was used. The mean time to fracture union was 8 weeks (6-12 weeks). Before surgery, 13 children were in H and B Grade 4 (wheel-chair independent or carried by parents usually in a developing country), four were able to ambulate with a walking aid (H and B Grade 3b), and four children were able to walk about in the house without aids (H & B Grade 2). After the rodding procedure, the ambulatoty status improved in 11 (50%) children. Seven children (33%) became household physiologic walkers (H & B Grade 3b), three achieved independent ambulation with orthosis (H & B Grade 1b), and one child with mild OI could walk unaided (H & B Grade 1a). No child had deterioration in ambulatory status. Only two children had refractures at the distal end of the rod due to continual growth of bones. CONCLUSIONS: Intramedullary rodding treatment for recurrent fractures in children with OI improves their mobility potential. It also and prevents repeated cast application, disuse wasting, and osteopenia which can lead to deterioration in the quality of the long bones.

Effect of various parameters on Quadriceps angle in adult Indian population.

BACKGROUND: The purpose of this study was to compare the values of quadriceps angle (Q angle) in relation to age, weight, height, gender, bilateral and postural variations, and strenuous activities on the weight bearing limbs in order to observe its variability. MATERIALS AND METHODS: A total of 450 adult healthy volunteers (150 male students, 150 female students and 150 male labourers) were enrolled in this cross sectional study. Each volunteer had its height, weight and Q angles measured. Q angle was measured in all subjects bilaterally in both supine and standing position with the same goniometer. Comparison of Q angles and various parameters and groups were studied and tabulated. Correlation between age, weight, height and Q angles was determined by Karl Pearson's correlation coefficient. RESULTS: Females had statistically significant higher Q angles in both knees than males of either group, and difference between males of two groups was insignificant. It was more often greater on left side (42.36%) as compared to right, both in males and females. Majority of subjects showed an increase in angle from supine to standing position. There was negative correlation between height and Q angle with both standing and supine position all three groups. Weight and age did not show significant correlation with Q angle. Physical activity did not show any significant effect on the angle. CONCLUSION: Q angle is an important parameter to assess quadriceps muscle's function and its effect on knee. An increase in the angle is clearly associated with patellofemoral problems. Higher Q angle among females may predispose them to sports related injuries. It is important to take into consideration of such factors like sex, height, posture, side, foot rotation and muscle's relaxation while measuring and comparing the angle.

Bang-bang optimal control of large spin systems: Enhancement of 13C-13C singlet-order at natural abundance.

Using a bang-bang optimal control technique, we transfer polarization from a set of abundant high-γ nuclei directly to singlet order of a low-γ spin-pair. This approach is analogous to algorithmic cooling (AC) procedure used in quantum state purification. Specifically, we apply this method for enhancing the singlet order in a natural abundant 13C- 13C spin pair by exploiting nine equivalent protons of an 11-spin system. Compared to the standard method not involving polarization transfer, we find an enhancement of singlet order by about 3.4 times. In addition, since the singlet magnetization is contributed by the faster relaxing protons, the recycle delay is halved. Thus effectively we observe a reduction in the overall experimental time by a factor of 23. We also discuss a possible extension of AC, known as heat-bath algorithmic cooling (HBAC).

Schwannoma of the Median Nerve at Mid Forearm Level.

INTRODUCTION: Schwannomas are also known as neurilemmoma that usually originate from Schwann cells located in the peripheral nerve sheaths. It usually occurs in the age group of 20 to 70 years. These are the commonest tumors of the peripheral nerves, 5% of which occur in the adults and 19% of the tumors occur in upper extremities. Schwannomas are generally presented as an asymptomatic mass. Discomfort may be the only presenting complaint of the patient. Paresthesia may be elicited on tapping the swelling. Magnetic resonanceimaging, and ultrasound are helpful in the diagnosis. Surgical removal is usually curative. CASE PRESENTATION: A 28-year-old male came to our hospital for a lump located at the volar side of the right mid forearm for 10 years with discomfort and paresthesia in median nerve distribution of hand which appeared in last two years. Total excision was performed for the lesion. Histopathological examination of the mass revealed typical features of schwannoma. At two months follow-up, the patient was symptom free with mild paresthesia in his index and middle fingers. CONCLUSION: Benign tumours involving peripheral nerves of the upper extremity are uncommon. Schwannomas are theoretically removable because they repulse fascicular groups without penetrating them, thus allowing their enucleation while preserving nerve continuity, as reported in our patient.

Enhanced transdermal delivery of luteolin via non-ionic surfactant-based vesicle: quality evaluation and anti-arthritic assessment.

Luteolin (LUT) is a promising molecule with potential anti-arthritic activity. This investigation presents formulation and evaluation of niosomal transgel for enhanced transdermal delivery of LUT. Different non-ionic surfactants and vesicle compositions were employed for preparation of niosomes. The vesicle size analysis showed that all vesicles were in the range from 534.58 to 810.22 nm which favoured efficient transdermal delivery. The entrapment of LUT in vesicle was found to be higher in all surfactant. The developed formulation was proved significantly superior in terms of amount of drug permeation with an enhancement ratio of 2.66 when compared to a control formulation. The in vivo bioactivity studies revealed that the prepared niotransgel formulation of LUT was able to provide good anti-arthritic activity and the results were comparable to standard (diclofenac gel for anti-arthritic and analgesic). Finally, the results were confirmed through radiological analysis which proved that the prepared niotransgel was effectively able to treat arthritis and results were comparable with the standard formulation.

Comparative study of high tibial osteotomy using dynamic axial fixator and locked low-profile plate in medial osteoarthritis of knee.

PURPOSE: The purpose of this study was to evaluate the role of medial opening wedge high tibial osteotomy (HTO) in medial unicompartmental osteoarthritis (MCOA) of knee and to compare between the two methods of osteotomy using either dynamic axial fixator (DAF) or locking compression plate (LCP). METHODS: A total of 20 patients with medial osteoarthritis of knee were enrolled in this prospective study who were divided into two groups of 10 each. First group comprising of two males and eight females were treated by HTO using DAF. Second group comprising of five males and five females were treated by HTO using LCP. We assessed various radiological parameters including hip knee ankle angle (HKA), tibiofemoral angle (TFA), weight-bearing line on tibia, Insall Salvati index and tibial slope. Functional outcome of knee at final follow-up was assessed by Oxford knee score (OKS) and visual analogue scale. RESULTS: In first group, mean HKA angle changed from 187° to 178.30° (p = 0.006), mean TFA from 182.40° to 172° (p = 0.003), average position of weight-bearing line from 11.24 to 59.54 % (p = 0.004), and mean OKS 43.3-16.9 (p = 0.004). In second group, mean HKA angle changed from 186° to 178.80° (p = 0.004), mean TFA from 180.90° to 173.60° (p = 0.004), average position of weight-bearing line from 14 to 61.3 % (p = 0.004), and mean OKS 43.2-16.5 (p = 0.002). CONCLUSION: HTO is an established treatment for patients with symptomatic MCOA knee with significant improvement in the clinical and radiographic parameters. There is no significant difference between the two methods; however, external fixator has the complication of pin tract infections. LEVEL OF EVIDENCE: II.