Influence of Sn4+ ion on band gap tailoring, optical, structural and dielectric behaviors of ZnO nanoparticles

II-VI semiconductors are being attracted due to excellent optical and electronic behaviors when they utilize for device fabrication. Among II-VI semiconductors, Zinc oxide finds cutting-edge results for various applications with a lack of toxicity. Sn⁴⁺ ion incorporated ZnO nanoparticles have been synthesized using a soft chemical route and characterized for the investigation of properties like structural, morphological, elemental, optical and dielectric responses. The prepared ZnO had a hexagonal structure and the particles size reduces by the influence of Sn⁴⁺ ion: this reduction rate increases for the increase of doping ratio. The average particles size was estimated within 24-34 nm. TEM, HRTEM and SEM results corroborate the structural aspects noticed using XRPD study. UV-vis study results showed that a blue shift on the optical band gap was received for high doping concentration (10 at.%) of Sn⁴⁺. PL peaks were observed in the UV region for 0 at.% and 2 at.% Sn⁴⁺ doped ZnO nanoparticles, and the peak position was shifted from UV to violet and blue region for 10 at.% Sn⁴⁺ doped ZnO nanoparticles. The dielectric permittivity was reduced due to the addition of Sn⁴⁺ ions. The AC conductivity was increased for higher doping concentrations. The Sn⁴⁺ ion incorporated ZnO nanoparticles shall be useful for various applications including LED fabrication for blue emission and also it is suitable to act as a buffer material in solar panel.

Investigations of ZnO Nanorod Films Grown by Hydrothermal Method for Ethanol Gas Sensor

Rod-structured ZnO has grown hydrothermally on the seed layer by varying growth time. The growth mechanism of rod-structured ZnO thin films is studied extensively with the help of characterizing tools. The preferred orientation and c/a ratio are studied with Grazing Incidence X-ray diffraction (GIXRD). The growth mechanism of ZnO rod structure is studied in detailed manner with Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscopy (FESEM). The optical absorption and emission properties of ZnO rods are studied with respect to growth morphology. Ethanol sensing measurements are carried out at room temperature (RT). The nanostructured ZnO films show good response and sensitivity to ethanol gas at RT.

Synthesis of green marine algal-based biochar for remediation of arsenic(V) from contaminated waters in batch and column mode of operation

The sorption behavior of biochar derived from green seaweed (Ulva reticulata) toward arsenic(V) ions was explored in both batch and continuous modes. The pH edge experiments indicated optimum arsenic(V) sorption observed at pH 4, with maximum sorptional capacity of 7.67 mg/g through isotherm experiments. The kinetic experimental trials indicated that arsenic(V) sorption onto biochar was a fast electrostatic attraction process, with maximum removal occurred within 30 min. The sorption isotherms were modeled using the Toth, Redlich-Peterson, Langmuir and Freundlich isotherm models while the adsorption kinetics was modeled using the pseudo-first- and pseudo-second-order kinetic equations. The three-parameter models (Redlich-Peterson and Toth) better described the isotherm data, whereas pseudo-first-order model represented kinetic data well with low error and high correlation coefficient values. Among the different alkaline and acidic elutants investigated, the solution of 0.01 M NaOH effectively desorbed arsenic(V) from spent biochar. The feasibility of the biochar in continuous remediation of arsenic(V) from contaminated waters was explored in an up-flow fixed column. The biochar exhibited arsenic(V) removal efficiency and sorptional uptake of 59.5% and 8.12 mg/g, respectively. The biochar-loaded column was effectively desorbed using NaOH (0.01 M), with desorption efficiency of 99.5%.

Green alga-mediated treatment process for removal of zinc from synthetic solution and industrial effluent

The present work explored biosorption of Zn(II) ions from aqueous and zinc-bearing factory effluent using marine seaweed Ulva lactuca. The batch pH edge experiments using aqueous zinc solution indicated that Zn(II) uptake by U. lactuca was found to be maximum at pH 4.5 and the batch isotherm trials performed at pH 4.5 resulted in maximum uptake capacity of 128.0 mg Zn(II)/g. With 0.1 M CaCl₂ (pH 3.5, HCl) as elutant, the elution of Zn(II) ions from Zn(II)-laden U. lactuca biosorbent was effective with possible regeneration and reuse for three cycles. The zinc industrial effluent was found to comprise of 87.8 mg/L of zinc ions along with excess co-ions and high total dissolved solids (838.1 mg/L). Owing to this, Zn(II) uptake from electroplating effluent by U. lactuca was suppressed due to competition from other ions. Continuous-flow sorption trials were conducted at flow rate of 5 mL/min in an up-flow fixed column. The existence of surplus competing ions in zinc wastewater influenced the Zn(II) biosorption by U. lactuca. U. lactuca-loaded packed column exhibited uptakes of 78.3 and 70.8 mg Zn(II)/g for aqueous solution and effluent, respectively. The results of three continuous sorption-desorption cycles demonstrated that reuse of U. lactuca biosorbent in remediation of zinc-containing wastewaters was practical and economical.

The design of novel visible light driven Ag/CdO as smart nanocomposite for photodegradation of different dye contaminants

In this paper, we report a novel visible light driven Ag/CdO photocatalyst, fabricated for the first time via one pot hydrothermal method and further applied for the photodegradation of two important exemplar water contaminants, Malachite green and Acid Orange 7. The microstructure, composition and optical properties of Ag/CdO nanocomposites were thoroughly investigated by various techniques. Scanning electron microscopy clearly shows that Ag NPs were strongly embedded between the CdO nanoparticles. Among the series of synthesized Ag/CdO nanocomposites, (5%) Ag/CdO nanocomposite possesses enhanced photocatalytic activity. This result was attributed to the synergistic effect between Ag and CdO, and mainly Ag NPs can act as an electron trap site, which could reduce the recombination of the electron-hole and induce the visible light absorption. The active species trapping experiments implicate OH and O₂^- radicals as the respective primary and secondary reactive species responsible for oxidative photodegradation of organic pollutants. On the basis of the results, a possible photocatalytic mechanism has also been proposed.

Breast Cancer Detection using Image Processing Techniques

Breast Cancer is one of the significant reasons for death among ladies. Many research has been done on the diagnosis and detection of breast cancer using various image processing and classification techniques. Nonetheless, the disease remains as one of the deadliest disease. Having conceive one out of six women in her lifetime. Since the cause of breast cancer stays obscure, prevention becomes impossible. Thus, early detection of tumour in breast is the only way to cure breast cancer. Using CAD (Computer Aided Diagnosis) on mammographic image is the most efficient and easiest way to diagnosis for breast cancer. Accurate discovery can effectively reduce the mortality rate brought about by using mamma cancer. Masses and microcalcifications clusters are an important early symptoms of possible breast cancers. They can help predict breast cancer at it’s infant state. The image for this work is being used from the DDSM Database (Digital Database for Screening Mammography) which contains approximately 3000 cases and is being used worldwide for cancer research. This paper quantitatively depicts the analysis methods used for texture features for detection of cancer. These texture featuresare extracted from the ROI of the mammogram to characterize the microcalcifications into harmless, ordinary or threatening. These features are further decreased using Principle Component Analysis(PCA) for better identification of Masses. These features are further compared and passed through Back Propagation algorithm (Neural Network) for better understanding of the cancer pattern in the mammography image.

Novel hydrothermal synthesis of MoS2nanocluster structure for sensitive electrochemical detection of human and environmental hazardous pollutant 4-aminophenol

A trace level electrochemical detection platform for the determination of environmentally hazardous pollutant 4-aminophenol at MoS₂nanoclusters is reported.

Constructing novel Ag nanoparticles anchored on MnO2 nanowires as an efficient visible light driven photocatalyst

We report the first construction of novel Ag nanoparticles anchored on MnO₂ nanowires as an efficient visible light driven photocatalyst.

Lumbar Zygapophyseal (Facet) Joint Pain

Lumbar zygapophyseal joints act as primary pain generators in at least 10-15% of patients with chronic low back pain.Diagnostic nerve blocks are the most reliable way to diagnose lumbar zygapophyseal joint pain.IASP recommends either controlled or comparative blocks for diagnosis of zygapophyseal joint pain as there is a significant incidence of false positives with single blocks.Management should be multimodal comprising education, exercises, analgesics and procedural interventions to achieve functional restoration.There is a need for further RCTs with standardised diagnostic criteria and outcome measures as well as long-term data to determine the efficacy of radiofrequency denervation.

Influence of reverse Trendelenburg position on aortocaval compression in obese pregnant women

INTRODUCTION

Obese pregnant women are at risk of aortocaval compression and associated hypotension with neuraxial anaesthesia. We hypothesised that addition of reverse Trendelenburg tilt to the standard practice of pelvic tilt may attenuate aortocaval compression.

METHODS

After ethical approval and consent, six women with a singleton pregnancy and booking body mass index of 30-35kg/m(2) underwent magnetic resonance imaging scanning in six different positions: right lateral decubitus; left lateral decubitus; supine with pelvic tilt; and reverse Trendelenburg positions of 5°, 10° and 15°. Dimensions of the inferior vena cava and abdominal aorta at the L2-3 intervertebral disc level were obtained from axial images using medical imaging software OsiriX™.

RESULTS

Inferior vena cava dimensions were higher in left lateral decubitus position compared to supine with pelvic tilt (P=0.002). Inferior vena cava compression was noted in all participants (59±33%, 95% CI 32 to 86). Addition of 15° reverse Trendelenburg tilt to standard pelvic tilt produced a non-statistically significant increase in inferior vena cava area (10.54±9.91cm(2), 95% CI 2.61 to 18.47, P=0.06).

CONCLUSION

A non-statistically significant improvement of aortocaval compression was noted with the addition of 15° reverse Trendelenburg tilt to the supine with pelvic tilt position in obese pregnant women.

Intravenous patient-controlled analgesia for labour: a survey of UK practice

BACKGROUND

Although regional techniques offer superior analgesia during labour, many women receive other methods of pain relief. Furthermore, there is a specific need for analgesia in a small population of labouring women for whom regional techniques are contraindicated, unavailable or impossible to perform. We surveyed current UK practice of labour analgesia for such patients, with particular reference to the use of intravenous patient-controlled analgesia.

METHODS

Following approval from the Obstetric Anaesthetists' Association, a questionnaire was sent to the lead anaesthetic consultants of 243 obstetric units in the United Kingdom. The questionnaire evaluated the availability of methods of pain relief other than regional blocks. Information was sought on patient-controlled intravenous analgesia regimens and patient monitoring.

RESULTS

A total of 159 questionnaires were returned giving a response rate of 65.4%. The majority of units that responded (95.5%) used either intramuscular pethidine or diamorphine. Nearly half (49%) offered patient-controlled intravenous analgesia for labour pain. One third of units (36%) had an analgesic protocol for women in whom regional anaesthetic techniques were contraindicated. With patient-controlled intravenous analgesia, remifentanil (34.6%) was the most commonly used opioid for live births while morphine (35.5%) was used more commonly for deliveries involving intrauterine deaths.

CONCLUSION

The survey demonstrated that, when regional techniques were contraindicated, patient-controlled intravenous opioid analgesia was employed in almost half of the units responding to the questionnaire.

Obesity and obstetric anaesthesia

The prevalence of obesity continues to increase despite preventive strategies. Obese parturients are at increased risk of having either concurrent medical problems or superimposed antenatal diseases such as pre-eclampsia and gestational diabetes. Moreover, they have a tendency to labour abnormally contributing to increased instrumental delivery and Caesarean section. Obesity is a risk factor for anaesthesia related maternal mortality. Morbidly obese women must be considered as high-risk and deserve an anaesthetic consultation during their antenatal care. The significant difficulty in administering epidural analgesia should not preclude their use in labour. A more liberalised use of regional techniques may be a means to further reduce anaesthesia-related maternal mortality in the obese population. The mother's life should not be jeopardised to save a compromised fetus. Prophylactic placement of an epidural catheter when not contraindicated in labouring morbidly obese women would potentially decrease anaesthetic and perinatal complications associated with attempts at emergency provision of regional or general anaesthesia. Early mobilisation, aggressive chest physiotherapy and adequate pain control are essential components of effective postoperative care.

Delayed onset refractory dystonic movements following propofol anesthesia

Neuroexcitation is an uncommon but well recognized side effect of propofol anesthesia and sedation. We present a patient who, despite an intact mental status and without any preexisting movement disorder, experienced delayed onset of involuntary dystonic movements involving head, neck and shoulder for 11 h following emergence from propofol/nitrous oxide anesthesia.