The negative impact of wearing personal protective equipment on communication during coronavirus disease 2019.

BACKGROUND: Coronavirus disease 2019 personal protective equipment has been reported to affect communication in healthcare settings. This study sought to identify those challenges experimentally. METHOD: Bamford-Kowal-Bench speech discrimination in noise performance of healthcare workers was tested under simulated background noise conditions from a variety of hospital environments. Candidates were assessed for ability to interpret speech with and without personal protective equipment, with both normal speech and raised voice. RESULTS: There was a significant difference in speech discrimination scores between normal and personal protective equipment wearing subjects in operating theatre simulated background noise levels (70 dB). CONCLUSION: Wearing personal protective equipment can impact communication in healthcare environments. Efforts should be made to remind staff about this burden and to seek alternative communication paradigms, particularly in operating theatre environments.

Improved nanocomposite of montmorillonite and hydroxyapatite for defluoridation of water.

A novel hydroxyapatite montmorillonite (HAP-MMT) nanocomposite system was synthesized using a simple wet chemical in situ precipitation method. Neat nano hydroxyapatite (HAP) was also synthesized for comparison. The characterization of the materials was carried out using Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) isotherms to study the functional groups, morphology, crystallinity and the surface area respectively. Batch adsorption studies and kinetic studies on fluoride adsorption were conducted for the HAP-MMT system and for neat HAP. The effect of parameters such as contact time, pH, initial concentration, temperature, and thermodynamic parameters and the effect of coexisting ions on fluoride adsorption by HAP-MMT were studied. Results of the isotherm experiments were fitted to four adsorption isotherm models namely Langmuir, Freundlich, Temkin and Dubinin Radushkevich. Fluoride adsorption over HAP-MMT fitted to the Freundlich adsorption isotherm model and showed more than two-fold improved adsorption capacity (16.7 mg g-1) compared to neat HAP. The best-fitting kinetic model for both adsorbents was found to be pseudo second order. Calculated thermodynamic parameters indicated that the fluoride adsorption by HAP-MMT is more favorable compared to that on HAP within the temperature range of 27 °C-60 °C. Improved fluoride adsorption by HAP-MMT is attributed to the exfoliated nature of HAP-MMT. Gravity filtration studies carried out using a 1.5 ppm fluoride solution, which is closer to the ground water fluoride concentrations of Chronic Kidney Disease of unknown etiology (CKDu) affected areas in Sri Lanka, resulted in a 1600 ml g-1 break through volume indicating the potential of HAP-MMT to be used in real applications.

Polyaniline/palladium nanohybrids for moisture and hydrogen detection.

Palladium nanoparticles display fascinating electronic, optical and catalytic properties, thus they can be used for various applications such as sensor fabrication. Conducting polymers such as polyaniline have also been widely used in sensor technology due to its cost effectiveness, versatility, and ease of synthesis. In this research, attention was given to unify the exceptional properties of these two materials and construct palladium nanoparticle coated polyaniline films to detect hydrogen and moisture. Electrochemical polymerization of aniline was carried out on gold sputtered epoxy resin boards. Polyaniline film was generated across a gap of 0.2 mm created by a scratch made on the gold coating prior to electrochemical polymerization. A palladium nanoparticle dispersion was prepared using sonochemical reduction method and coated on to polyaniline film using drop-drying technique. Polyaniline only films were also fabricated for comparative analysis. Sensitivity of films towards humidity and hydrogen was evaluated using impedance spectroscopy in the presence of the respective species. According to the results, polyaniline films exhibited an impedance drop in the presence of humidity and the response was significantly improved once palladium nanoparticles were incorporated. Interestingly, polyaniline only films did not respond to hydrogen. Nevertheless, palladium nanoparticle coated polyaniline films exhibited remarkable response towards hydrogen.

Metastatic gastric adenocarcinoma and synchronous carcinoid tumour mimicking appendicitis: A case report.

INTRODUCTION: Silent metastatic gastric adenocarcinoma presenting as appendicitis is very rare. Rare pathologies may be encountered during common operations such as appendicectomy and an awareness of possible alternative pathological entities would be helpful in a surgeon's wealth of knowledge. PRESENTATION OF CASE: A 63-year-old man presented with a three-day history of acute abdominal pain suggestive of appendicitis. Intra-operatively, a macroscopically inflamed and perforated appendix was found. There were however some atypical features, which included multiple inflamed ulcerated lesions throughout the small bowel mesentery and along the terminal ileum. Appendicectomy was performed and biopsies of these lesions were taken. Subsequent histopathology revealed that there were metastatic deposits of poorly differentiated adenocarcinoma in the appendix and mesenteric biopsies, as well as a neuroendocrine (carcinoid) tumour of the appendix. Upper endoscopy confirmed a gastric primary leading to peritoneal dissemination. The patient was scheduled to undergo a course of palliative chemotherapy. DISCUSSION: Metastatic gastric adenocarcinomas with peritoneal dissemination have a very poor prognosis and often the first choice of treatment is chemotherapy as a complete cure through surgery is often not feasible. As for classical carcinoid tumours smaller than 2 cm towards the tip of the appendix with low proliferative index and without angiolymphatic or mesoappendiceal extension, then appendicectomy alone is indicated. Synchronous neoplastic pathologies presenting as appendicitis is largely unknown. CONCLUSION: To our knowledge, this is the first report in the literature of synchronous carcinoid tumour and metastatic gastric cancer co-existing within an inflamed appendix.

Facile Synthesis of Colored and Conducting CuSCN Composite Coated with CuS Nanoparticles.

Conductivity-tunable, different colored CuS nanoparticle-coated CuSCN composites were synthesized in a single pot using a mixture of copper sulfate and sodium thiosulfate in the presence of triethyl amine hydrothiocyanate (THT) at the ambient condition. When these reagents are mixed in 1:1:1 molar ratio, white-gray-colored CuSCN was produced. In the absence of THT, microsized dark blue-colored CuS particles were produced. However, when THT is present in the solution mixture by different amounts, colored conducting CuS nanoparticle-coated CuSCN composite was produced. CuS nanoparticles are not deposited on CuSCN soon after mixing these regents, but it takes nearly overnight to see the color change (CuS production) in the white CuSCN dispersed mixture. TEM analysis shows that composite consists of hexagonal CuS nanoparticles in the range of ~ 3-10 nm in size. It is interesting to note that CuS-coated CuSCN possesses higher conductivity than neat CuS or CuSCN. Moreover, strong IR absorption was observed for CuS-coated CuSCN composite compared to neat CuS (absence of THT) or CuSCN. Lowest resistivity of 0.05 Ω cm was observed for annealed (250 °C) CuS-coated CuSCN particles (adding 10 ml of THT) under nitrogen atmosphere. Also, this simple method could be extended to be used in the synthesis of CuS-coated composites on the other nanomaterials such as metal oxides, polymers, and metal nanoparticles.

Magnesium Oxide Nanoparticles Reinforced Electrospun Alginate-Based Nanofibrous Scaffolds with Improved Physical Properties.

Mechanically robust alginate-based nanofibrous scaffolds were successfully fabricated by electrospinning method to mimic the natural extracellular matrix structure which benefits development and regeneration of tissues. Alginate-based nanofibres were electrospun from an alginate/poly(vinyl alcohol) (PVA) polyelectrolyte complex. SEM images revealed the spinnability of the complex composite nanofibrous scaffolds, showing randomly oriented, ultrafine, and virtually defects-free alginate-based/MgO nanofibrous scaffolds. Here, it is shown that an alginate/PVA complex scaffold, blended with near-spherical MgO nanoparticles (⌀ 45 nm) at a predetermined concentration (10% (w/w)), is electrospinnable to produce a complex composite nanofibrous scaffold with enhanced mechanical stability. For the comparison purpose, chemically cross-linked electrospun alginate-based scaffolds were also fabricated. Tensile test to rupture revealed the significant differences in the tensile strength and elastic modulus among the alginate scaffolds, alginate/MgO scaffolds, and cross-linked alginate scaffolds (P < 0.05). In contrast to cross-linked alginate scaffolds, alginate/MgO scaffolds yielded the highest tensile strength and elastic modulus while preserving the interfibre porosity of the scaffolds. According to the thermogravimetric analysis, MgO reinforced alginate nanofibrous scaffolds exhibited improved thermal stability. These novel alginate-based/MgO scaffolds are economical and versatile and may be further optimised for use as extracellular matrix substitutes for repair and regeneration of tissues.

Nano-MgO reinforced chitosan nanocomposites for high performance packaging applications with improved mechanical, thermal and barrier properties.

Chitosan nanocomposite thin films were fabricated by incorporating MgO nanoparticles to significantly improve its physical properties for potential packaging applications. A novel in-situ method was developed to synthesise spherical shaped MgO nanoparticles by heat-treating magnesium carbonate/poly(methyl methacrylate) (PMMA) composite precursor. Optimum mechanical properties of chitosan composites were yielded at 5 (w/w%) of MgO concentration, where tensile stress and elastic modulus significantly improved by 86% and 38%, respectively, compared to those of pure chitosan films. These improvements are due to the interaction of hydroxyl and amine groups of chitosan with MgO as confirmed by FTIR spectroscopy. Fracture surface morphology indicated the interplay between MgO dispersion and aggregation on the mechanical properties at different MgO concentrations. Furthermore, the chitosan/MgO nanocomposites displayed remarkable thermal stability, flame retardant properties (satisfied V0 rating according to the UL-94 standards), UV shielding and moisture barrier properties, which could certainly add value to the packaging material.

Identification and characterisation of a biosynthetic locus for Moraxella bovis lipo-oligosaccharide.

Moraxella bovis is a Gram-negative gammaproteobacterium and is one of the causative agents of infectious bovine keratoconjunctivitis. The structure of lipooligosaccharide (LOS) from strain Epp63 was recently elucidated. In the present study a genetic locus of seven encoding genes with high similarity to glycosyltransferases has been identified. Mutation of these putative glycosyltransferase genes resulted in M. bovis mutant bacteria that expressed truncated LOS structures. The structures of the oligosaccharide (OS) expressed by the mutant strains were elucidated and demonstrated the role of the glycosyltransferase enzymes in the LOS biosynthesis of M. bovis. The glycosyltransferase genes designated lgt1, lgt3, and lgt6 are highly similar to the genes in the related bacterium M. catarrhalis. In addition, there are syntenic similarities with the corresponding LOS biosynthesis locus in M. catarrhalis and other members of Moraxellaceae.

Could an underlying hearing loss be a significant factor in the handicap caused by tinnitus?

There have been several studies that have demonstrated a link between the hearing loss of subjects and tinnitus. However, there has been no systematic evaluation of the link between perceived tinnitus distress and an underlying hearing loss. The purpose of the current study is to explore this association, and ascertain whether a subject's hearing loss contributes to the handicap caused by tinnitus. A group of 96 adults were evaluated with Pure Tone Audiometry and a questionnaire that included the Tinnitus Handicap Inventory (THI). In 58% of the subjects, the side of the unilateral or worse tinnitus corresponded with the ear with poorer hearing thresholds. A subset of the THI, the Two Question Mean (TQM) that was related to questions with regard to communication, correlated significantly with the hearing thresholds in the better hearing ear ( P < 0.01). There was also a significant correlation between the THI and TQM scores ( P < 0.01). These results suggested that in tinnitus subjects with impaired hearing, the underlying hearing loss may be a significant factor in the perceived distress.

Effects of Icon, a pyrethroid insecticide on early pregnancy of rats.

Icon is a water miscible type II synthetic pyrethroid insecticide based on active ingredient lambda cyhalothrin (10% w/w). It is used in Sri Lanka as an adulticidal indoor spray against malaria vector mosquitoes. The goal of this study was to assess the effects of Icon on pregnancy outcome of rats when exposed during early pregnancy (days 1-7). Icon was gavaged daily for 7 consecutive days in three different doses; 63, 83, or 125 mg/kg/day (active ingredient; lambda cyhalothrin; 6.3, 8.3, 12.5 mg/kg/day), respectively. Several parameters of reproduction and pre- and post-natal development were monitored. The results show that Icon is detrimental to pregnancy outcome (in terms of quantal pregnancy, number of uterine implants, implantation index and foetal deaths) but induced no detectable developmental defects. The anti-reproductive effects of Icon were mainly due to increased pre-implantation losses. Enhancement of post-implantation losses played a subsidiary role. These effects resulted from multiple mechanisms: maternal toxicity, stress, uterotropic activity and embryo-foetotoxicity. Further progesterone had a protective effect against Icon induced anti-reproductive actions. Overall, the results suggest that exposure to Icon during early gestation may result in a threat to pregnancy.

Effects of pyrethroid insecticide ICON (lambda cyhalothrin) on reproductive competence of male rats.

AIM: To assess the effect of ICON (trade name of lambda-cyhalothrin) on sexual competence and fertility of male rats. METHODS: Male rats were gavaged daily for 7 consecutive days with different doses of ICON (63 mg/kg and 100 mg/kg) or vehicle (distilled water). Their sexual behaviour and fertility were evaluated at different time points during treatment and post-treatment using receptive females. RESULTS: Treatment had no effect on fertility, but sexual competence was seriously impaired: libido (assessed in terms of pre-coital sexual behaviour, and numbers of mounting, intromission and ejaculation), sexual arousability/motivation (in terms of latencies for mounting, intromission and ejaculation), sexual vigour (judged by frequencies of mounting and intromission or copulatory efficiency). In addition, ICON suppressed intromission ratio, indicating erectile dysfunction. These effects on sexual function had a rapid onset and was reversible. ICON-induced sexual dysfunction was mediated by multiple mechanisms, mainly toxicity, stress, sedation and possibly via GABA and dopaminergic systems. CONCLUSION: Exposure to ICON may cause sexual dysfunction in male rats.

Purification and characterization of a cytotonic protein expressed In vitro by the live cholera vaccine candidate CVD 103-HgR.

Cholera vaccines developed by the deletion of CTX genes from Vibrio cholerae induce a residual reactogenicity in up to 10% of vaccinees. A novel cytotonic agent named secreted CHO cell elongating protein (S-CEP) was purified from culture supernatants of CVD 103-HgR (Levine et al., Lancet ii:467-470, 1988). Five fractionation steps yielded electrophoretically pure S-CEP with an M(r) of 79,000. A partially purified preparation caused fluid accumulation in the sealed infant mouse model. The amino terminus bore a unique sequence with strong homology to a cytotonic toxin of El Tor V. cholerae.

Erythema nodosum in pregnant patients with coccidioidomycosis.

Pregnant patients with coccidioidomycosis develop dissemination and serious disease more frequently than do the general population. To assist in prognosis and management, we analyzed the significance of erythema nodosum in pregnant patients with coccidioidomycosis. Sixty-one pregnant patients (mean age +/- SD, 26.4 +/- 6.3 years) were evaluated. Seventy percent of the patients were Hispanic; 15%, African American; 13%, Caucasian; and 2%, unknown race. Of the 30 patients (49%) who developed erythema nodosum, 0 had disseminated disease (P = .001), 1 (3%) with pulmonary involvement required therapy for > 1 year, and 29 (97%) recovered (P = .0008). Of the 31 patients (51%) without erythema nodosum, 11 (35%) had disseminated disease, 12 (39%) required therapy for > 1 year, 17 (55%) recovered, 1 (3%) died, and 1 (3%) had an outcome that was unknown. Erythema nodosum appears to be a salient marker of a positive outcome for pregnant patients, more so than for the general population.

First Report of Phomopsis longicolla Infection of Cowpea Pods and Seeds in Mississippi.

Mature cowpea (Vigna unguiculata (L.) Walp.) pods with scattered, irregular black spots, similar in appearance to those found on mature soybean (Glycine max (L.) Merr.) pods infected with Phomopsis longicolla T. W. Hobbs, were observed in three fields in Oktibbeha County, MS, in September 1994. In a delayed harvest sample of pods and seeds from one field, a fungus identified as P. longicolla (1) was isolated from more than 60% of surface-disinfested, excised pod disks and from 42% of surface-disinfested seeds. Average frequencies of isolation from seeds harvested at the normal time from the other two fields were 27 and 9%. When surface-disinfested soybean seeds (cv. Avery) were placed along the margins of P. longicolla colonies on potato dextrose agar, the radicals from most germinating seeds became necrotic and many seeds did not germinate. Koch's postulates were completed by reisolating the fungus from diseased tissue. Reference: (1) T. W. Hobbs et al. Mycologia 77:535, 1985.

First Report of Colletotrichum capsici on Bell Pepper in Mississippi.

Anthracnose (ripe rot) of bell pepper (Capsicum annuum L.), caused by Colletotrichum capsici (Syd.) E. J. Butler & Bisby, was observed in seven home gardens in Copiah, DeSoto, and Oktibbeha counties in Mississippi in 1994. Falcate conidia measuring 20.5 × 4.0 µm were produced on lesions of fruits in moist chambers. Conidial size and other distinguishing features agreed with the description of C. capsici (1). Pure cultures of the pathogen were obtained by aseptic transfer of conidia to agar. Occurrence of symptomatic fruits in gardens ranged from 15% in Starkville to 3% near Crystal Springs, MS, but nine of the gardens inspected had no fruit rot. The most severe disease occurred on ripening fruits. Lesions similar to those observed were produced by inoculating sterilized toothpick tips infested with C. capsici into fruits, followed by incubation in a moist chamber. Koch's postulates were completed by reisolation of the fungus from inoculated fruits. Reference: (1) J. E. M. Mordue. 1971. No. 317 in: Descriptions of Pathogenic Fungi and Bacteria. Commonw. Mycol. Inst., Kew, England.

Structural studies of the enterotoxigenic Escherichia coli (ETEC) O153 O-antigenic polysaccharide.

The O-specific side-chain of the lipopolysaccharide from Escherichia coli O153 has been investigated using methylation analysis, Smith degradation, partial hydrolysis, FABMS, and NMR spectroscopy as the principal methods. It is concluded that the polysaccharide is composed of pentasaccharide repeating-units having the following structure.

Structural studies of the Escherichia coli O90 O-antigen polysaccharide.

The O-specific side-chain of the lipopolysaccharide from Escherichia coli O90 has been investigated using methylation analysis, partial hydrolysis, and NMR spectroscopy as the principal methods. It is concluded that the polysaccharide is composed of tetrasaccharide repeating-units having the following structure. [formula: see text] The polysaccharide contains approximately one mole of O-acetyl groups per repeating unit, located on the fucose residue.

Structural studies of the extracellular polysaccharide from Butyrivibrio fibrisolvens strain X6C61.

The capsular polysaccharide from Butyrivibrio fibrisolvens strain X6C61 has been investigated using NMR spectroscopy, mass spectrometry, methylation analysis, and partial acid hydrolysis as the main methods. The polysaccharide is composed of hexasaccharide repeating units having the following structure. [formula: see text] The polysaccharide also contains O-acetyl groups, of which approximately 70% are substituted to O-3 of the beta-D-Glc pA residue.