In quest to synthesize high quality carbon nanotubes in bulk, different routes have been proposed and established over the last two decades. Arc discharge is the oldest and among the best techniques ...to produce high quality carbon nanotubes. Though this synthesis technique has been explored for a long time, the nanotube growth mechanism is still unclear and the growth conditions lack strong correlation with the synthesized product. In this review, we attempt to present the mechanism of nanotube growth in arc discharge and the factors affecting its formation. In order to understand the physics of this mechanism, the effect of experimental parameters such as setup modification, power supply, arc current, catalyst, pressure, grain size, electrode geometry and temperature on size and yield of the nanotubes has been detailed. The variation in synthesis parameters employed in literature has been presented along with challenges and gaps that persist in the technique.
Summary
Background
Clostridium difficile infection (CDI) is the commonest nosocomial cause of diarrhoea. Faecal microbiota transplantation (FMT) is an approved treatment for recurrent or refractory ...CDI but there is uncertainty about its use.
Aim
To evaluate the efficacy of FMT in treating recurrent and refractory CDI and investigate outcomes from modes of delivery and preparation.
Methods
A systematic review and meta‐analysis was performed. MEDLINE, EMBASE, CINAHL, Cochrane Library, trial registers and conference proceedings were searched. Studies on FMT in recurrent and refractory CDI were included. The primary outcome was clinical resolution with subgroup analyses of modes of delivery and preparation. Random effects meta‐analyses were used to combine data.
Results
Thirty seven studies were included; seven randomised controlled trials and 30 case series. FMT was more effective than vancomycin (RR: 0.23 95%CI 0.07‐0.80) in resolving recurrent and refractory CDI. Clinical resolution across all studies was 92% (95%CI 89%‐94%). A significant difference was observed between lower GI and upper GI delivery of FMT 95% (95%CI 92%‐97%) vs 88% (95%CI 82%‐94%) respectively (P=.02). There was no difference between fresh and frozen FMT 92% (95%CI 89%‐95%) vs 93% (95%CI 87%‐97%) respectively (P=.84). Administering consecutive courses of FMT following failure of first FMT resulted in an incremental effect. Donor screening was consistent but variability existed in recipient preparation and volume of FMT. Serious adverse events were uncommon.
Conclusion
Faecal microbiota transplantation is an effective treatment for recurrent and refractory Clostridium difficile infection, independent of preparation and route of delivery.
In this paper, a novel technique on a multiscale energy and eigenspace (MEES) approach is proposed for the detection and localization of myocardial infarction (MI) from multilead electrocardiogram ...(ECG). Wavelet decomposition of multilead ECG signals grossly segments the clinical components at different subbands. In MI, pathological characteristics such as hypercute T-wave, inversion of T-wave, changes in ST elevation, or pathological Q-wave are seen in ECG signals. This pathological information alters the covariance structures of multiscale multivariate matrices at different scales and the corresponding eigenvalues. The clinically relevant components can be captured by eigenvalues. In this study, multiscale wavelet energies and eigenvalues of multiscale covariance matrices are used as diagnostic features. Support vector machines (SVMs) with both linear and radial basis function (RBF) kernel and K-nearest neighbor are used as classifiers. Datasets, which include healthy control, and various types of MI, such as anterior, anteriolateral, anterioseptal, inferior, inferiolateral, and inferioposterio-lateral, from the PTB diagnostic ECG database are used for evaluation. The results show that the proposed technique can successfully detect the MI pathologies. The MEES approach also helps localize different types of MIs. For MI detection, the accuracy, the sensitivity, and the specificity values are 96%, 93%, and 99% respectively. The localization accuracy is 99.58%, using a multiclass SVM classifier with RBF kernel.
High precision optical angular sensors are extensively used for detection and control of position and velocity in payload rotating mechanisms and spacecraft actuators. The accuracy and thus the ...performance of the encoder are significantly affected due to installation eccentricity. In this paper, a comprehensive study of the causes of installation eccentricity is done. The apportionment of the resultant eccentricity is attributed to variations in diametrical clearances, doweling error, gluing error of the glass disc and bearing wobble. The effect of eccentricity changes during rotation. A new 3-center variable eccentricity model is introduced which improves upon the existing 2-centered one in previous literature. This new 3-centered model is able to better predict the deviations in the fine angle signals in a practical system due to variable eccentricity effect. The efficacy of the mathematical model was validated through two independent experiments- 1) by analyzing the electrical signals from opposite read-heads and 2) by performing mechanical measurements- both done on an actual sensor assembly. The eccentricity value calculated from the maximum and minimum phase difference of the fine angle signals is able to exactly match with the total phase difference variation over one complete rotation. It is observed that the variation in the phase difference between the fine angle sinusoidal signals given by two opposite read-heads varies as a shifted sine over one complete rotation and not as a symmetric sine as shown in previous literature. The eccentricity value obtained from mechanical measurement and that computed using the 3-centered model was matching within 0.1 µm. Both the experimental results support the effectiveness of the 3-centered model.
Display omitted
•Effect of eccentricity on fine angle signals of angle sensors is studied.•Causes of installation eccentricity is studied and its apportionment is illustrated.•Established relationship between eccentricity and phase difference of fine angle signals.•The results of the mathematical model are verified using two independent experiments.
MicroRNAs (miRNAs) are short, non-coding, conserved, oligonucleotides that are regulatory in nature and are often dysregulated in many cancers including prostate cancer. Depending on the level of ...complementarity between the miRNA and mRNA target, they can either inhibit translation or degrade the target mRNA. MiRNAs expression is specific to the type of cancer, its stage and level of metastasis, making miRNAs potential stage-specific biomarkers of cancer. Recent research has shown that these miRNAs have the potential to be a diagnostic and prognostic non-invasive biomarker for various cancers including prostate cancer. Various miRNAs have been reported as novel biomarkers for prostate cancer therapy. However, there is inconsistency in the data reported and no overlapping expression pattern could be found. In this review, we have highlighted the most consistently reported dysregulated miRNAs in prostate cancer from the existing literature and discussed the currently available data on their role in regulating the hallmarks of prostate cancer. These four most consistently reported dysregulated miRNAs viz. miRNA-141, miRNA-375, miRNA-221 and miRNA-21 need to be further validated in terms of their regulatory potential in regulating various pathways important for prostate cancer management.
ZnCo2O4 has been synthesized by the low‐temperature and cost‐effective urea combustion method. X‐ray diffraction (XRD), HR‐TEM and selected area electron diffraction (SAED) studies confirmed its ...formation in pure and nano‐phase form with particle size ∼ 15–20 nm. Galvanostatic cycling of nano‐ZnCo2O4 in the voltage range 0.005–3.0 V versus Li at 60 mA g–1 gave reversible capacities of 900 and 960 mA h g–1, when cycled at 25 °C and 55 °C, respectively. These values correspond to ∼ 8.3 and ∼ 8.8 mol of recyclable Li per mole of ZnCo2O4. Almost stable cycling performance was exhibited in the range 5–60 cycles at 60 mA g–1 and at 25 °C with ∼ 98 % coulombic efficiency. A similar cycling stability at 55 °C, and good rate‐capability both at 25 and 55 °C were found. The average discharge‐ and charge‐potentials were ∼ 1.2 V and ∼ 1.9 V, respectively. The ex‐situ‐XRD, ‐HRTEM, ‐SAED and galvanostatic cycling data are consistent with a reaction mechanism for Li‐recyclability involving both de‐alloying‐alloying of Zn and displacement reactions, viz., LiZn ↔ Zn ↔ ZnO and Co ↔ CoO ↔ Co3O4. For the first time we have shown that both Zn‐ and Co‐ions act as mutual beneficial matrices and reversible capacity contribution of Zn through both alloy formation and displacement reaction takes place to yield stable and high capacities. Thus, nano‐ZnCo2O4 ranks among the best oxide materials with regard to Li‐recyclability.
Nanophase ZnCo2O4 has been synthesized, characterized and tested for Li‐recyclability. It exhibited reversible capacities of 900 mAh/g (8.3 moles of Li) in the voltage range 0.005–3.0V vs Li at 60 mA/g up to 60 cycles with excellent rate capability.
Now days, breast cancer is the most frequently diagnosed life-threatening cancer in women and the leading cause of cancer death among women. Since last two decades, researches related to the breast ...cancer has lead to extraordinary progress in our understanding of the disease, resulting in more efficient and less toxic treatments. Increased public awareness and improved screening have led to earlier diagnosis at stages amenable to complete surgical resection and curative therapies. Consequently, survival rates for breast cancer have improved significantly, particularly in younger women. This article addresses the types, causes, clinical symptoms and various approach both non- drug (such as surgery and radiation) and drug treatment (including chemotherapy, gene therapy etc.) of breast cancer.
PDF
