Ultrasensitive self-powered heterojunction ultraviolet photodetector of p-GaN nanowires on Si by halide chemical vapour deposition.

In this study, we report the fabrication of quasi-aligned p-GaN nanowires (NWs) on n-Si (1 1 1) substrate by halide chemical vapour deposition (HCVD) using MgCl2precursor and followed by low-energy electron beam irradiation to activate the Mg acceptor doping in GaN NWs. We aimed to attain a comprehensive understanding of p-doping in GaN NWs growth, extensive characterizations and fabrication of UV photodetector (PDs) based on p-GaN NWs/n-Si heterojunction. To realize the efficient UV photodetectors, we measure the current-voltage (I-V) characteristics of heterojunction PDs under dark and illuminated conditions and theI-Vcurve demonstrates good rectifying behaviours with 0.2 V turn-on voltage. At zero bias, the heterojunction PDs show a reverse photocurrent of 1.27 × 10-6A with a very low dark current of 2.35 × 10-9A under 325 nm UV illumination. Besides, the significance of the self-powered operation of UV PDs and the charge transfer mechanism are discussed with the aid of the energy band diagram. The substantial photocurrent increment with varying applied potential leads to narrowing the photo potential in the interface. The excitonic bound states present in p-GaN NWs/n-Si heterojunction is further elucidated. As a result, the heterojunction PDs demonstrate the high responsivity, detectivity, and external quantum efficiency of 134 mA W-1, 3.73 × 1013Jones, and 51% respectively, at 0.1 V low applied potential under the reverse bias condition. The proposed work provides an archetype for Mg doping in GaN NWs ensembles, which will help to facilitate the heterojunction with n-Si to unleash the potential of self-powered UV PDs.

GaN nanowires grown by halide chemical vapour deposition as photoanodes for photo-electrochemical water oxidation reactions.

Manifold morphologies of GaN nanowires (NWs) were fabricated using halide chemical vapour deposition (HCVD) on an n-Si (111) substrate and demonstrated to be a promising photoelectrode for photo-electrochemical (PEC) water splitting applications. We report a substantial enhancement in the photocurrent for vertically-grown GaN NWs on a buffer layer as compared to other counterparts such as GaN whiskers, tapered nanostructures and thin films. GaN NWs grown on Si have advantages due to the absorption of photons in a wide spectral range from ultraviolet to infrared and thus are directly involved in PEC reactions. A GaN NW photoanode was demonstrated with a saturation photocurrent density of 0.55 mA cm-2 under 1 sun of illumination, which is much greater than its counterparts. The role of the buffer layer and the carrier density on the PEC performance of vertically-grown GaN NW photoanodes is further elucidated. Photo-electrochemical impedance spectroscopy and Mott-Schottky characterizations were employed to further explain the PEC performance of GaN NW embedded photoanodes. Here, photoanodes based on diverse GaN nanostructures were examined for a better PEC evaluation in order to support the conclusion. The results may pave the way for the fabrication of efficient photoelectrodes and GaN as a protective layer against corrosion for improved photo-stability in an NaOH electrolyte for enhancing the efficiency of water splitting.

ABCC3 genetic variants are associated with postoperative morphine-induced respiratory depression and morphine pharmacokinetics in children.

Respiratory depression (RD) is a serious side effect of morphine and detrimental to effective analgesia. We reported that variants of the ATP binding cassette gene ABCC3 (facilitates hepatic morphine metabolite efflux) affect morphine metabolite clearance. In this study of 316 children undergoing tonsillectomy, we found significant association between ABCC3 variants and RD leading to prolonged postoperative care unit stay (prolonged RD). Allele A at rs4148412 and allele G at rs729923 caused a 2.36 (95% CI=1.28-4.37, P=0.0061) and 3.7 (95% CI 1.47-9.09, P=0.0050) times increase in odds of prolonged RD, respectively. These clinical associations were supported by increased formation clearance of morphine glucuronides in children with rs4148412 AA and rs4973665 CC genotypes in this cohort, as well as an independent spine surgical cohort of 67 adolescents. This is the first study to report association of ABCC3 variants with opioid-related RD, and morphine metabolite formation (in two independent surgical cohorts).

Synergistic antimicrobial activity of Boswellia serrata Roxb. ex Colebr. (Burseraceae) essential oil with various azoles against pathogens associated with skin, scalp and nail infections.

Antimicrobials from natural sources have gained immense importance in recent times to combat the global challenge of antibiotic resistance. Essential oils are implicated in antimicrobial action against several species. Here, we have screened nine commercially available essential oils for their antimicrobial activity against organisms associated with skin, scalp and nail infections mainly Propionibacterium acnes, Malassezia spp., Candida albicans and Trichophyton spp. Among nine essential oils, Boswellia serrata essential oil demonstrated superior antimicrobial activity against all the micro-organisms and surprisingly it showed maximum activity against Trichophyton spp. The gas chromatography-mass spectrometry analysis of B. serrata oil indicates a major composition of α thujene, ρ cymene and sabinene. Additionally, B. serrata oil was found to inhibit Staphylococcus epidermidis biofilm, and its combination with azoles has shown synergistic activity against azole-resistant strain of C. albicans. These broad-spectrum antimicrobial activities of B. serrata oil will make it an ideal candidate for topical use. SIGNIFICANCE AND IMPACT OF THE STUDY: Eradication of skin and nail infections still remain a challenge and there are serious concerns regarding the recurrence of the diseases associated with these infections. Antimicrobials from plant sources are gaining importance in therapeutics because they encounter minimal challenges of emergence of resistance. We have demonstrated the antimicrobial activity of Boswellia serrata essential oil against micro-organisms involved in skin, scalp and nail infections, especially if it has shown favourable synergistic antifungal activity in combination with azoles against the azole-resistant Candida albicans strain. Thus, B. serrata oil can be one of the plausible therapeutic agents for management of skin, scalp and nail infections.

Association of OPRM1 A118G variant with risk of morphine-induced respiratory depression following spine fusion in adolescents.

The µ1 opioid receptor (OPRM1) genetic variant A118G results in decreased µ-receptor binding potential in the brain and increases morphine requirement. We hypothesized that OPRM1 A118G polymorphism will affect morphine-induced respiratory depression (MIRD) risk in children receiving morphine. A prospective genotype-blinded study was conducted in 88 healthy adolescents (11-18 years; 67% female, 85% Caucasian) who underwent spine fusion for scoliosis. They were followed for 48 h postoperatively for MIRD, pain scores, morphine consumption and use of analgesic adjuvants. Patients were genotyped for OPRM1 A118G variant-76% were wild type (AA) and 24% heterozygous/homozygous for variant (AG/GG). Multivariable logistic regression showed that the risk of MIRD in patients with AA genotype was significantly higher (odds ratio 5.6, 95% CI: 1.4-37.2, P=0.030). Presence of G allele was associated with higher pain scores (effect size 0.73, P=0.045). This novel association is an important step toward predicting MIRD susceptibility and personalizing morphine use.

Opioid-induced respiratory depression: ABCB1 transporter pharmacogenetics.

Opioid-related respiratory depression (RD) is a serious clinical problem as it causes multiple deaths and anoxic brain injuries. Morphine is subject to efflux via P-glycoprotein transporter encoded by ABCB1, also known as MDR1. ABCB1 polymorphisms may affect blood-brain barrier transport of morphine and therefore individual response to its central analgesic and adverse effects. This study aimed to determine specific associations between common ABCB1 genetic variants and clinically important outcomes including RD and RD resulting in prolonged stay in hospital with intravenous morphine in a homogenous pediatric surgical pain population of 263 children undergoing tonsillectomy. Children with GG and GA genotypes of ABCB1 polymorphism rs9282564 had higher risks of RD resulting in prolonged hospital stays; adding one copy of the minor allele (G) increased the odds of prolonged hospital stay due to postoperative RD by 4.7-fold (95% confidence interval: 2.1-10.8, P=0.0002).

Novel associations between FAAH genetic variants and postoperative central opioid-related adverse effects.

Opioid effects are potentiated by cannabinoid agonists including anandamide, an endocannabinoid. Inter-individual variability in responses to opioids is a major clinical problem. Multiple deaths and anoxic brain injuries occur every year because of opioid-induced respiratory depression (RD) in surgical patients and drug abusers of opioids and cannabinoids. This study aimed to determine specific associations between genetic variants of fatty acid amide hydrolase (FAAH) and postoperative central opioid adverse effects in children undergoing tonsillectomy. This is a prospective genotype-blinded observational study in which 259 healthy children between 6 and 15 years of age who received standard perioperative care with a standard anesthetic and an intraoperative dose of morphine were enrolled. Associations between frequent polymorphisms of FAAH and central postoperative opioid adverse effects including, RD, postoperative nausea and vomiting (PONV) and prolonged stay in Post Anesthesia Recovery Room (postoperative anesthesia care unit, PACU) due to RD and PONV were analyzed. Five specific FAAH single nucleotide polymorphisms (SNPs) had significant associations with more than twofold increased risk for refractory PONV (adjusted P<0.0018), and nominal associations (P<0.05) with RD and prolonged PACU stay in white children undergoing tonsillectomy. The FAAH SNP, rs324420, is a missense mutation with altered FAAH function and it is linked with other FAAH SNPs associated with PONV and RD in our cohort; association between PONV and rs324420 was confirmed in our extended cohort with additional 66 white children. Specific FAAH polymorphisms are associated with refractory PONV, opioid-related RD, and prolonged PACU stay due to opioid adverse effects in white children undergoing tonsillectomy.

Application of carbon nanotubes layered on silicon wafer for the detection of breast cancer marker carbohydrate antigen 15-3 by immuno-polymerase chain reaction.

A highly sensitive detection of breast cancer marker, carbohydrate antigen 15-3 (CA 15-3) by carbon nanotube (CNT) based immuno-polymerase chain reaction was reported. The study was aimed to develop a precise and sensitive method to diagnose breast cancer and its recurrence. The hydrofluoric acid (HF) treated silicon wafer layered with bundled CNT was used as the substrate. The surface was treated with HNO3/H2SO4 to graft carboxyl groups on the tips of CNT. Subsequently, polyoxyethylene bis-amine was grafted to conjugate anti human CA 15-3 antibodies. Water contact angle measurement, scanning electron microscope, Fourier transform infrared spectrometer, Raman spectrometer and sodium dodecyl sulfate polyacrylamide gel electrophoresis were employed to confirm the surface modification. The captured antibodies on the CNT were used to capture the target antigen CA 15-3 and the biotinylated secondary antibodies were subsequently bound with the target antigen. A bi-functional streptavidin was used to link biotinylated DNA to the biotinylated detection antibodies. The biotinylated target DNA was amplified by PCR, and then analyzed by agarose gel electrophoresis. The lower limit of detection of CA 15-3 by the proposed immuno-PCR system was 0.001 U/mL, which is extremely sensitive than the other bioanalytical techniques.

Obstructive sleep apnoea in children: perioperative considerations.

Obstructive sleep apnoea (OSA) has become a major public health concern as its incidence and severity have increased in tandem with the obesity epidemic. In children, OSA is now recognized as a common disorder and can be associated with significant morbidity. OSA belongs to a spectrum of diagnoses known as sleep-related breathing disorders in which the airway is completely (apnoea) or partially (hypopnoea) occluded during sleep despite continued respiratory efforts. This airway obstruction can cause abnormal gas exchange leading to hypoxaemia, hypercapnia, sleep fragmentation, and their attendant physiological and behavioural consequences. The degrees of hypercapnia, hypoxaemia, and upper airway airflow reduction are the primary factors determining the severity of OSA. In young children, adenotonsillar hypertrophy is the most common anatomical abnormality associated with OSA, and adenotonsillectomy is, therefore, the most common surgical intervention. Perioperative complications associated with adenotonsillectomy are more common in children with severe OSA. A thorough understanding of the pathophysiology of OSA, careful and complete preoperative assessment, meticulous intraoperative and postoperative management, and early recognition of potential perioperative complications are essential to optimization of outcomes. The safe anaesthetic management of a child with OSA requires an anaesthetic technique tailored to the underlying aetiology and severity of OSA and the surgical procedure. This review focuses on the epidemiology, pathogenesis, and diagnosis of OSA, and the state-of-the-art and future directions in the perioperative management of children with OSA.

The development of iron-free partially stabilized cement for use as dental root-end filling material.

AIM: To determine the effect of increasing the proportion of zinc on partially stabilized cement (PSC) produced using a one-step sol gel process. METHODOLOGY: A one-step sol-gel process of Portland cement-based PSC with Zn was synthesized by replacing iron nitrate. The crystalline phases of the PSC-Zn powder were analysed by using X-ray diffraction (XRD). The experimental groups [i.e., MTA, PSC-Fe (control), PSC with 1% Zn, PSC with 3% Zn, and PSC with 5% Zn] were immersed in simulated body fluid for 3 h, 1 and 3 days to evaluate the hydration product formation. The microstructure and surface morphology were analysed using scanning electron microscopy (SEM). Initial and final setting times of the materials were determined using an ASTM Vicat needle testing machine. To evaluate the cytotoxicity of PSC-Zn system, primary osteoblasts cell lines were used. RESULTS: The addition of increased weight percentages of Zn, resulted in a more unstable phase which favoured the formation of a monoclinic structure of C3 S with an increased hydration reaction of PSC and reduced setting time. The cytotoxicity testing of PSC with Zn revealed that the material was not toxic. CONCLUSIONS: The newly synthesized PSC-Zn material had short setting time and was biocompatible.

Perceived stress, resilience, well-being, and COVID 19 response in Isha yoga practitioners compared to matched controls: A research protocol.

OBJECTIVES: The COVID-19 pandemic has been a significant stressor worldwide and reports of psychological distress, depression, sedentary lifestyles, and overall decreased wellbeing are increasing. Yoga practices have been found to improve mental and physical health. The purpose of this randomized controlled trial is to compare Isha yoga practitioners to controls on perceived stress, resilience, wellbeing, and protection and recovery from COVID-19. Trial Design. In this prospective randomized control trial, the effects of yoga practices are being compared between seasoned yoga practitioners with two controls who are age (±3 years), gender matched, and living in the same neighborhood. METHODS: Participants will be asked to complete a series of web-based surveys at baseline, six weeks, and 12 weeks. These surveys include validated scales and objective questions on COVID-19 infection and medical history. The validated questionnaires assess stress, mood states, resilience, and overall wellbeing. Questionnaires, weekly activity diaries, and medical history, will be collected using REDCap. RESULTS: We hypothesize that routine yoga practice during the COVID-19 pandemic will reduce stress, enhance well-being, and provide protective effects against COVID-19. CONCLUSION: With the growing concern about the physical and mental impacts of COVID-19 and increased interest in alternative practices such as yogic practices, this study will contribute to the growing body of evidence about the safety and efficacy of yoga for emotional, mental, and physical health conditions.

Complicated appendicitis--is the laparoscopic approach appropriate? A comparative study with the open approach: outcome in a community hospital setting.

Good outcome has been reported with the laparoscopic approach in uncomplicated appendicitis, but a higher incidence of postoperative intraabdominal abscesses has been reported after laparoscopic appendectomy in complicated appendicitis. This retrospective comparative study compares outcome after laparoscopic (LA) and open appendectomy (OA) in complicated appendicitis. All patients who had LA or OA for complicated appendicitis between January 2003 and February 2006 were included in the study. Data collection included demographics, operative time, estimated blood loss, length of stay (LOS), complications, readmission, and reoperative rates. The primary end points for analysis were postoperative intraabdominal abscess and complication rates and secondary end points were LOS and operative time. All data were analyzed on an intent-to-treat basis. Of 104 patients, 43 patients underwent LA and 61 had OA. The mean age (24.8 +/- 16.5 versus 31.3 +/- 18.9, P = 0.08) in the LA group was lower than the OA group because there was a significantly higher proportion of pediatric patients (34.8% versus 14.8%, P = 0.02) who had LA. There was no significant difference in gender (female/male, 14/29 versus 27/34, P = 0.3) or American Society of Anesthesiologists class distribution (American Society of Anesthesiologists 1/2/3/4/, 35/7/1/0 versus 45/12/3/1, P = 0.68) between the two groups. The operative time (100.5 +/- 36.2 versus 81.5 +/- 29.5 minutes, P = 0.03) was significantly longer and the estimated blood loss (21 mL versus 33 mL, P = 0.01) was lower in LA when compared with OA, but there was no significant difference in the number of patients with preoperative peritonitis versus abscesses (7/36 versus 13/48, P = 0.6) in both groups. There was no difference in the median LOS (6 [interquartile range 5-9] versus 6 [interquartile range 4-8], P = 0.7) in the two groups. The conversion rate in LA was 18.6% (n = 8). There was also no significant difference in the complication (17/43 [39.5%] versus 21/61 [34.4%], P = 0.54), reoperative (3/43 [7%] versus 0/61 [0%], P = 0.07), and 30-day readmission (5/41 [11.6%] versus 3/61 [4.9%], P = 0.23) rates between the two groups. The rate of postoperative intraabdominal abscesses was significantly higher in the LA group when compared with the OA group (6/43 [14%] versus 0/61 [0%], P = 0.04) and the wound infection (1/43 [2.3%] versus 5/61 [8.2%], P = 0.4) and pulmonary complication (0/43 [0%] versus 3/61 [4.9%], P = 0.26) rate was higher in the OA group. There was no mortality in the LA group, but there was one mortality in the OA group resulting from postoperative myocardial infarction. Laparoscopic appendectomy can be performed in patients with complicated appendicitis with a comparative operative time, LOS, and complication rates but results in a significantly higher intraabdominal abscess rate and lower wound infection rate when compared with OA.

Characterization of Contributing Factors to Variability in Morphine Clearance Through PBPK Modeling Implemented With OCT1 Transporter.

Morphine shows large interindividual variability in its pharmacokinetics; however, the cause of this has not been fully addressed. The variability in morphine disposition is considered to be due to a combination of pharmacogenetic and physiological determinants related to morphine disposition. We previously reported the effect of organic cation transporter (OCT1) genotype on morphine disposition in pediatric patients. To further explore the underlying mechanisms for variability arising from relevant determinants, including OCT1, a physiologically based pharmacokinetic (PBPK) model of morphine was developed. The PBPK model predicted morphine concentration-time profiles well, in both adults and children. Almost all of the observed morphine clearances in pediatric patients fell within a twofold range of median predicted values for each OCT1 genotype in each age group. This PBPK modeling approach quantitatively demonstrates that OCT1 genotype, age-related growth, and changes in blood flow as important contributors to morphine pharmacokinetic (PK) variability.

Predicting the pain continuum after adolescent idiopathic scoliosis surgery: A prospective cohort study.

BACKGROUND: Chronic postsurgical pain (CPSP) affects half a million children annually in the United States, with dire socioeconomic consequences, including long-term disability into adulthood. The few studies of CPSP in children are limited by sample size, follow-up duration, non-homogeneity of surgical procedure and factors evaluated. METHODS: In a prospective study of 144 adolescents undergoing a single major surgery (spine fusion), we evaluated demographic, perioperative, surgical and psychosocial factors as predictors of a continuum of postsurgical pain: immediate, pain maintenance at 2-3 months (chronic pain/CP) and persistence of pain a year (persistent pain/PP) after surgery. RESULTS: We found an incidence of 37.8% and 41.8% for CP and PP. CP and acute pain were both significant predictors for developing PP (p-value <0.001 and 0.003). Preoperative pain and higher postoperative opioid requirement was significantly associated with CP (p = 0.015, p = 0.002), while Childhood Anxiety Sensitivity Index (p = 0.002) and surgical duration (p = 0.014) predicted PP. The final regression models had reasonable predictive accuracy (c-statistic of 0.73 and 0.83 for CP and PP, respectively). Anxiety scores and catastrophizing for child and parent were found to be significantly correlated (p = 0.005, p = 0.013 respectively). Pain trajectories revealed that 65% of patients who developed PP reported CP and high pain trends; however, 33% of those who developed PP could not be identified using solely pain criteria. CONCLUSION: Persistent postsurgical pain in children is a significant problem. It can be predicted in part by combinations of psychological and clinical variables, which may provide evidence-based measures to prevent development of CPSP in the future. SIGNIFICANCE: In a homogeneous cohort of adolescents undergoing spine fusion, we report a high incidence of persistent postsurgical pain (41.8%) predicted by child anxiety, perioperative pain, and surgical duration. Our results stress timely preventive and therapeutic strategies.

Structural, thermal and optical properties of KTi(0.92)La(0.08)OPO4 and KTi(0.94)Nd(0.06)OPO4.

KTi0.92La0.08OPO4 (KTP:La) and KTi0.94Nd0.06OPO4 (KTP:Nd) single crystals are grown using high temperature top seeded flux growth technique. The strain derived from doping is calculated from Williamson-Hall relation. The packing structure and lattice parameter of the grown crystals are analyzed using single crystal X-ray diffraction. The bonding, distortion and change in inter-atomic distances by strain effects of doping are assessed by Raman spectroscopy. Thermal stabilities of grown crystals are evaluated by specific heat capacity measurement. Pronounced high specific heat capacity is recorded as 1.16 J/gK at 498 K for KTP:Nd. Second harmonic generation intensities are measured for KTP:Nd and KTP:La single crystal.

Carbon encapsulated iron oxide nanoparticles surface engineered with polyethylene glycol-folic acid to induce selective hyperthermia in folate over expressed cancer cells.

Carbon encapsulated iron oxide nanoparticles (CEIO-NPs) prepared by carbon arc method were successfully applied for in vitro magnetic hyperthermia. The CEIO-NPs were chemically oxidized and surface modified with PEG-FA for selective tumor localization in cancer cells that over expresses the folate receptors (FR(+)). The size, morphology, heating efficiency, biocompatibility and in vitro cell uptake of CEIO-PEG-FA NPs are extensively characterized. The as-prepared nanoparticles have generated quick heating (43-45°C) upon exposure to an alternating magnetic field (AMF) with the saturation magnetization of 25emu/g. The LDH cytotoxic assay demonstrated that the nanoparticle did not affect the viability of normal human fibroblast. The quantitative and cellular uptake studies by TEM confirmed the selective and increased uptake of CEIO-PEG-FA NPs when compared to the CEIO-nanoparticles. In conclusion, CEIO-PEG-FA NPs have the potential to induce magnetic hyperthermia in FR(+) cells via the receptor mediated endocytosis uptake mechanism.

Thoracic epidural anesthesia for modified radical mastectomy in a patient with cryptogenic fibrosing alveolitis: a case report.

A case of advanced cryptogenic fibrosing alveolitis (CFA) with multiple bullae and extensive pulmonary fibrosis, scheduled for modified radical mastectomy for carcinoma of breast, is presented. This patient had ischemic heart disease, corticosteroid-induced hypertension, diabetes mellitus, and a difficult airway. Thoracic epidural segmental anesthesia was successfully given to this patient. Preoperative problems, perioperative management, and alternative anesthetic techniques are discussed.

Optical, structural, thermal and dielectric spectroscopy characterizations of seeded melt grown 2-hydroxy biphenyl single crystal.

Organic single crystal of 2-hydroxy biphenyl (2-HB) was grown by top seeded melt growth method. Scanning electron microscopy studies has been carried out on the surface of the grown crystals to investigate the nature of growth and defects. The crystalline perfection and lattice parameters of 2-HB has been determined by single crystal XRD analysis and it belongs to orthorhombic crystal system with space group Fdd2. The functional groups and molecular associations were confirmed by FT-IR. The optical characteristics such as cut-off and transmittance were carried out using UV-Vis-NIR spectra. Absence of absorption in the region between 320 and 1100 nm makes the grown crystal desirable to optical applications. Thermal stability of grown crystals was characterized by thermogravimetric (TGA), differential thermal analysis (DTA) and differential scanning calorimetric (DSC) analyses. Broadband dielectric studies reveals that dielectric constant of grown crystal is low. The resistivity of grown crystal was studied by impedance analysis. The second harmonic generation intensity of 3.8 mJ was studied. The grown crystal belongs to soft material studied by hardness test.

Fabrication of multiwalled carbon nanotubes-magnetite nanocomposite as an effective ultra-sensing platform for the early screening of nasopharyngeal carcinoma by luminescence immunoassay.

The hybrid nanocomposite that consists of multiwalled carbon nanotubes (MWCNTs) and magnetite (Fe3O4) was fabricated by chemical co-precipitation method. Briefly, CNTs were oxidized with acids to form carboxylic group and then co-precipitated with Fe3O4 to form CNT-Fe3O4 nanocomposites. The nanocomposites were characterized by SEM, HRTEM, XRD, FTIR X-ray photoelectron spectrometry (XPS) and SQUID. The XRD results indicated the high crystallinity of Fe3O4 nanoparticles with spinel structure and the transmission electron microscope images depicted the intercalated iron oxide magnetic particles on the surface of CNTs. The MWCNTs-Fe3O4 was applied as a sensing interface to perform luminescence enzyme immunoassays. Firstly, EBNA-1 antigen was immobilized onto the carboxyl group functionalized MWCNTs-Fe3O4, followed by binding with anti-EBNA-1 IgA antibodies. The diluted secondary antibodies (anti-human IgA-HRP) were then added to the CNTs/Fe3O4-PEG-EBNA-1-anti-EBV IgA ab complex and act as a catalyst to produce a visible light upon reaction with the substrate luminol. The formed RLU is proportional to the amount of IgA anti-EBV antiobodies on the MWCNTs. The detection limit of proposed CNTs/Fe3O4 based luminescence enzyme immunoassay was in the order of 0.00128 EU/mL (1:100,000 fold dilution) for the detection of anti-EBV IgA antibodies, whereas the commercial ELISA and magnetic beads' assay was accounted for up to the dilution fold of 1000 (i.e., 0.128 EU/mL). The initial findings showed that CNTs/Fe3O4 nanocomposites have a great potential in luminescent enzyme immunoassays and could be used as a sensing platform for the early screening of nasopharyngeal carcinoma.

Design and synthesis of elastin-like polypeptides for an ideal nerve conduit in peripheral nerve regeneration.

The study involves design and synthesis of three different elastin like polypeptide (ELP) gene monomers namely ELP1, ELP2 and ELP3 that encode for ELP proteins. The formed ELPs were assessed as an ideal nerve conduit for peripheral nerve regeneration. ELP1 was constructed with a small elongated pentapeptide carrying VPGVG sequence to mimic the natural polypeptide ELP. The ELP2 was designed by the incorporation of 4-penta peptide chains to improve the biocompatibility and mechanical strength. Thus, the third position in unique VPGVG was replaced with alanine to VPAVG and in a similar way modified to VPGKG, VPGEG and VPGIG with the substitution of lysine, glutamic acid and isoleucine. In ELP3, fibronectin C5 domain endowed with REDV sequence was introduced to improve the cell attachment. The ELP1, ELP2 and ELP3 proteins expressed by Escherichia coli were purified by inverse transition cycling (ITC). The purified ELPs were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting. The Schwann cell (SC) morphology and cell adhesion were assessed by fabrication of ELP membrane cross-linked with glutaraledhyde. The Schwann cell proliferation was measured by WST-1 assay. Immunofluorostaining of Schwann cells was accomplished with SC specific phenotypic marker, S100.