Structural, thermal and optical properties of TeO2-ZnO-CdO-BaO glasses doped with VO(2+)

The glasses with composition 64TeO2-15ZnO-(20-x)CdO-xBaO-1V2O5 (0⩽x⩽20 mol%) were prepared by conventional melt quenching technique. X-ray diffraction analysis was used to confirm the amorphous nature of the glasses. The optical absorption studies revealed that the cut-off wavelength (λα) decreases while optical band gap energy (Eopt) and Urbach energy (ΔE) values increase with an increase of BaO content. Refractive index (n) evaluated from Eopt was found to decrease with an increase of BaO content. The physical parameters such as density (ρ), molar volume (Vm), oxygen packing density (OPD), optical basicity (Λ), molar refraction (Rm), and metallization criterion (M) evaluated and discussed. FTIR and Raman spectroscopic studies showed that the glass network consists of TeO4, TeO3+1/TeO3 and ZnO4 units as basic structural units. The glass transition temperature (Tg) of glass sample, onset crystallization temperature (To) and thermal stability ΔT were determined from Differential Scanning Calorimetry (DSC). Using electron paramagnetic resonance (EPR) spectra of vanadium glasses the spin Hamiltonian parameters and dipolar hyperfine coupling parameters of VO(2+) ions were calculated. It was found that V(4+) ions in these glasses exist as VO(2+) in octahedral coordination with a tetragonal distortion and have C4V symmetry with ground state dxy. Tetragonality (Δg∥/Δg⊥) of vanadium ion sites exhibited non-linear variation with BaO content.

Clinico-microbiological profile and outcomes of nosocomial sepsis in an Indian tertiary care hospital--a prospective cohort study

BACKGROUND

Nosocomial infections are linked to rising morbidity and mortality worldwide. We sought to investigate the pattern of nosocomial sepsis, device usage, risk factors for mortality and the antimicrobial resistance pattern of the causative organisms in medical intensive care units (ICUs) in an Indian tertiary care hospital.

METHODS

We conducted a single-centre based prospective cohort study in four medical ICUs and patients who developed features of sepsis 48 hours after admission to the ICUs were included. Patients' demographics, indwelling device usage, microbiological culture reports, drug resistance patterns and the outcomes were recorded. The Acute Physiology and Chronic Health Evaluation (APACHE) III score and the relative risk of variables contributing towards non recovery were calculated.

RESULTS

Pneumonia (49%) was the commonest nosocomial infection resulting in sepsis, followed by urosepsis (21.8%), bloodstream infection (BSI) (10.3%) and catheter-related bloodstream infection (CRBSI) (5%). Sixty three percent of the Acinetobacter baumannii and 64.4% of the Pseudomonas aeruginosa were multidrug-resistant (MDR). Seventy percent of the Klebsiella pneumoniae were extended spectrum beta-lactamase producers and 7.4% were resistant to carbapenems. Forty three percent of the Staphylococcus aureus were methicillin-resistant S. aureus. Resistance to carbapenems was 35.2% in this study. High APACHE III scores (P = 0.006 by unpaired t-test) and chronic kidney disease (P = 0.023) were significantly associated with non-recovery.

CONCLUSIONS

A high degree of multidrug resistance was observed among both Gram-positive and -negative organisms in nosocomial sepsis patients. Carbapenem resistance was a common occurrence. Chronic kidney disease and high APACHE III scores were significantly associated with non-recovery. Male gender and sepsis leading to cardiovascular failure were the independent predictors of mortality.

Polymer electrolyte membranes based on sulfonated polysulfone and functionalized layered silicate for direct methanol fuel cell applications

Polymer electrolyte membranes (PEMs) of sulfonated polysulfone (SPSf) and sulfonated montmorillonite (SMMT) have been developed. Sodium montmorillonite (NaMMT) has been sulfonated with 4-sulfophthalic acid and incorporated into the SPSf matrix for further enhancement of proton conductivity. Sulfonation of NaMMT has been confirmed using Fourier transform infrared spectroscopy and X-ray diffraction (XRD) analysis. The XRD patterns proved that the SMMT layers were completely exfoliated within the SPSf matrix. The performances of the PEM in terms of their liquid uptake, oxidative stability, and proton conductivity were investigated. The morphological characterizations have been carried out using scanning electron microscopy and atomic force microscopy. SPSf/SMMT membrane with 5 wt% of SMMT loading showed adequate thermal stability and an improved proton conductivity. The reduction in methanol permeability from 8.9 ×10−5 cm2 s−1 to 2.4 × 10−5 cm2 s−1 has been observed when SMMT loading content increased from 1 wt% to 5 wt%. Direct methanol fuel cell (DMFC) performance showed a power density value of 49 mW cm−2for SPSf/SMMT membrane, indicating its candidature for DMFC applications.

Study of polymeric nanocomposite membrane made from sulfonated polysulfone and nanoclay for fuel cell applications

In the present study, sulfonated polysulfone (SPSU (T)) was prepared from PSU using trimethyl silyl chlorosulfonate as a sulfonating agent. Volumetric analytic studies revealed 58% degree of sulfonation and 1.15 meq g−1 ion-exchange capacity of SPSU (T). Fourier transform infrared spectra also confirmed the occurrence of sulfonation reaction in SPSU (T). Subsequently, nanocomposite membranes were prepared by incorporating variable quantities of Cloisite 30B (C30B) within the SPSU (T) in N-methyl-2-pyrrolidone employing solution casting method. All the membranes were characterized for thermal analysis, liquid uptake, swelling behavior, and proton conductivity measurements. Thermogravimetric analysis revealed that incorporation of C30B increased the thermal stability of the membranes. Morphological study of the nanocomposite membranes was also evaluated using scanning electron microscopy and atomic force microscopy. The x-ray diffraction patterns of nanocomposite membranes confirmed exfoliation of C30B clay galleries within the SPSU (T) matrix.

Polymer electrolyte membranes from Cloisite 30B-based solid proton conductor and sulfonated polyether ether ketone/polyvinylidene fluoride-co-hexafluoro propylene blends for direct methanol fuel cells

The improved fuel cell performance of polymer electrolyte membranes from C 30B-filled sulfonated polyether ether ketone/polyvinylidene fluoride-co-hexafluoro propylene blends indicates their candidature for DMFC applications.

Role of cyanoacrylate glue therapy in enteral SEMS bleeding - A nightmare

Over the past century, the use of stents has evolved to a point where they are now used extensively throughout the gastrointestinal tract. Endoscopic stenting has become widely used for treatment of gastrointestinal and hepatobiliary strictures. Metallic stents are deployed in malignant strictures as a palliative procedure. Adverse events of stenting include perforation, migration, bleeding, occlusion, and pain. Finally, the use of multidisciplinary teams which include endoscopists, interventional radiologists, and surgeons allows for the exchange of ideas and procedural planning necessary for successful innovation. We present a case of successful cessation of bleeding by using cyanoacrylate glue therapy in post-enteral self-expandable metallic stent bleeding. In conclusion, glue therapy may also be considered as a mode of treatment other than conservative approach and angiographic coil embolization.

Primary headache disorders in children under 7 years of age

Background and aim

Research on headache disorders in young children is limited. This study aims to determine causes and clinical presentations of headache in young children attending a specialist clinic.

Methods and results

All children attending the headache clinic over 9-year period were included. Data were collected prospectively on demography and clinical presentations of headache at every attendance. The diagnosis of headache disorders was based on the International Classification of Headache Disorders-II (2004). Of the 921 children (491 male) who attended the clinic, 73 children (8%) were under 7 years of age at presentation; 34 children had migraine, 11 had tension-type headache (4 chronic), 4 had mixed types of headache and 16 children had unclassified headaches. Anorexia, nausea, vomiting, light intolerance and noise intolerance were common during migraine attacks and forehead was the most common site of maximal pain.

Conclusions

Migraine is the most common headache disorder in young children attending a specialist clinic. Headache presentation is often atypical and in 20% of young children headache disorders are unclassified. Chronic tension-type headache, often considered a disease of adolescents and adults, is shown to present in early age.

Molecular profile of head and neck squamous cell carcinomas bearing p16 high phenotype

BACKGROUND

We sought to determine biomarker expression differences in head and neck squamous cell cancers (HNSCCs) based on p16/human papillomavirus (HPV) classification. In addition, our aim was to explore how expression of biomarkers is modulated after E6/E7 repression in HPV16⁺ oropharyngeal cancer cells.

METHODS

HPV16⁺ and HPV⁻ HNSCC cells were infected with retroviruses expressing short hairpin RNA targeting HPV16 E6/E7. Components of the epidermal growth factor receptor (EGFR) pathway before and after E6/E7 gene silencing were analyzed by immunoblotting and qRT-PCR. Protein expression of 13 biomarkers was analyzed using AQUA on a tissue microarray (TMA). The HPV16 status was determined using HPV16 in situ hybridization (ISH).

RESULTS

In HPV16⁺ cells, E6/E7 silencing was associated with PTEN upregulation and reduction of phosphorylated EGFR. Tumors were classified into four categories based on the HPV and p16 status. HPV⁺/p16⁺ tumors expressed significantly higher levels of E-cadherin (P = 0.003), PTEN (P = 0.004), lower levels of PI3Kp110 and β-catenin (P = 0.07). There was a significant difference in overall survival (OS, P = 0.016) among the four subsets. The median OS was 24.83 months for p16⁻/HPV⁻ patients, 11.63 for p16⁻/HPV⁺ patients and was not reached for p16⁺/HPV⁻ and p16⁺/HPV⁺ groups.

CONCLUSIONS

Aberrant EGFR signaling contributes to malignant conversion of HPV16⁺ HNSCC cells. These results validate β-catenin as a distinct biomarker in HPV⁺/p16⁺ HNSCC. Wnt signaling inhibitors merit exploration in HPV⁺/p16⁺ HNSCC.

Maternal dietary fat and fatty acid intake during lactation and the risk of asthma in the offspring

AIM

To explore the association between maternal dietary fat and fatty acid (FA) intake during lactation, and the risk of asthma in the offspring by the age of 5 years.

METHODS

The subjects comprised 1798 mother-child pairs from the Type 1 Diabetes Prediction and Prevention (DIPP) Nutrition Study. Dietary intake was assessed by a validated 181-item food frequency questionnaire, which covered the third month of lactation. The cumulative incidence of asthma was assessed at the age of 5 years with a questionnaire modified from the International Study of Asthma and Allergies in Childhood (ISAAC). Cox proportional hazards regression was used for statistical analysis.

RESULTS

The maternal use of margarines during lactation was associated with a marginally increased risk of asthma [hazard ratio (HR) for user vs. nonuser 1.96, 95% confidence interval (CI) 1.01-3.82, p = 0.047] after adjusting for putative confounders. The maternal intakes of n-3 polyunsaturated FA (PUFA) and fish during lactation were not associated with the risk of asthma.

CONCLUSION

Maternal use of margarines during lactation was weakly associated with an increased risk of asthma in the offspring at the age of 5 years. Other fats or FAs during lactation were not associated with the risk of asthma. However, the nonadherence to dietary recommendations regarding especially fats of our study population may restrict the generalizability of our results.

Glycosaminoglycan chain of dentin sialoprotein proteoglycan

Dentin sialophosphoprotein (DSPP) is processed into dentin sialoprotein (DSP) and dentin phosphoprotein. A molecular variant of rat DSP, referred to as "HMW-DSP", has been speculated to be a proteoglycan form of DSP. To determine if HMW-DSP is the proteoglycan form of DSP and to identify the glycosaminoglycan side-chain attachment site(s), we further characterized HMW-DSP. Chondroitinase ABC treatment reduced the migration rate for portions of rat HMW-DSP to the level of DSP. Disaccharide analysis showed that rat HMW-DSP contains glycosaminoglycan chains made of chondroitin-4-sulfate and has an average of 31-32 disaccharides/mol. These observations confirmed that HMW-DSP is the proteoglycan form of DSP (renamed "DSP-PG"). Edman degradation and mass spectrometric analyses of tryptic peptides from rat DSP-PG, along with substitution analyses of candidate Ser residues in mouse DSPP, confirmed that 2 glycosaminoglycan chains are attached to Ser(241) and Ser(253) in the rat, or Ser(242) and Ser(254) in the mouse DSPP sequence.

Key proteolytic cleavage site and full-length form of DSPP

It is known that dentin sialophosphoprotein (DSPP) is processed into NH(2)- and COOH-terminal fragments, but its key cleavage site has not been identified, nor has its full-length form been discovered. The objectives of this study were to identify the key cleavage site during DSPP processing and to search for full-length DSPP in vivo. We generated a construct encoding DSPP, in which Asp(452), a cleavage site residue, was replaced by Ala(452). The pulp-odontoblast complex and dentin were extracted, chromatographically separated, and assessed by Stains-All staining, Western immunoblotting, and mass spectrometry. These studies showed that the substitution of Asp(452) by Ala(452) completely blocks the cleavage of mouse DSPP in the transfected cells, indicating that the NH(2)-terminal peptide bond of Asp(452) is essential for the initiation of DSPP proteolytic processing. The results of this study revealed the presence of full-length DSPP and its processed fragments in extracts from the pulp/odontoblast and dentin.

Distribution of small integrin-binding ligand, N-linked glycoproteins (SIBLING) in the condylar cartilage of rat mandible

The Small Integrin-Binding LIgand, N-linked Glycoprotein (SIBLING) family is one category of non-collagenous proteins closely related to osteogenesis. In this study, the authors systematically evaluated the presence and distribution of four SIBLING family members, dentin sialophosphoprotein (DSPP), dentin matrix protein 1 (DMP1), bone sialoprotein (BSP) and osteopontin (OPN), in rat mandibular condylar cartilage using protein chemistry and immunohistochemistry. For protein chemistry, SIBLING proteins in the dissected condylar cartilage were extracted with 4M guanidium-HCl, separated by ion-exchange chromatography, and analyzed by Western immunoblotting. Immunohistochemistry was employed to assess the distribution of these four SIBLING proteins in the condylar cartilage of 2-, 5- and 8-week-old rats. Results from both approaches showed that all four members are expressed in the condylar cartilage. DSPP, unlike that observed in dentin and bone, exists as a full-length form (uncleaved) in the condylar cartilage. The NH(2)-terminal fragment of DMP1 is mainly detected in the matrix of the cartilage while the COOH-terminal fragment is primarily localized in the nuclei of cells in the chondroblastic and hypertrophic layers. The data obtained in this investigation provide clues about the potential roles of these SIBLING proteins in chondrogenesis.