Studies on certain yeasts associated with animals

The objectives of this study were to investigate the significance of yeasts as animal disease agents in the West of Scotland, to study the commensal association of yeasts with animals and, in particular, to assess the possibility of applying serological tests in the diagnosis of feline cryptococcosis. Examination of pathological specimens from various animal sources revealed that animal diseases attributable to yeasts were not common in this area. Apart from otitis externa in dogs, with which Pityrosporum pachydermatis was associated, other disease conditions were only sporadically encountered. Candida albicans was associated with 2 cases of oral thrush in adult guinea-pigs and with 3 cases of gastrointestinal ailments in puppies. Torulopsis pintolopesii was incriminated in causing a fatal gastrointestinal and systemic infection in a racing pigeon. No previous systematic studies have been done to investigate the commensal existence of yeasts on and in dogs and cats. In this study, cultural surveys were undertaken to investigate the prevalence of yeasts in those hosts. It was established that yeasts might occur as commensals on normal canine skin and in the nasal cavities of apparently normal dogs and cats. Besides its association with canine otitis externa, Pit, pachydermatis was found in association with skin infections in dogs. The association of C . albicans with oral infection in 2 guinea-pigs prompted a cultural study to see if this and other yeasts were prevalent in the oral cavity of healthy guinea-pigs. Candida albicans and Saccharomyces telluris were found to exist as normal inhabitants in this site . The value of serological methods in the diagnosis of animal cryptococcosis has not previously been determined. A serological survey owas undertaken to test sera from apparently normal cat and dog populations for the presence of antibody to Cryptococcus neoformans. Three tests, namely, counterimmunoelectrophoresis, immunodiffusion and agglutination tests were employed. Counterimmunoelectrophoresis proved more sensitive than the other tests. Using it, precipitating cryptococcal antibody was demonstrated in a proportion of cats and dogs. The antibody response was thought to have resulted from exposure to the yeast in the environment. The use of serology in the diagnosis of feline cryptococcosis was evaluated in experimentally infected cats. The 3 tests were used to examine sera and other body fluids from experimental cats for the presence of antibody and/or antigen. It was established that the presence of serum cryptococcal antigen was proof of active cryptococcosis in the cat. On the other hand, the presence of circulating cryptococcal antibody alone could not be regarded as evidence of such disease. Its presence, however, may suggest early or past infection, or simply exposure to the organism. The role of black yeasts as disease agents in domestic animals is not known and has not previously been investigated. In this study, 3 black yeast isolates from animal sources were identified and their pathogenicity for mice determined. One isolate, a Cladosporium species, was found to be non-pathogenic. Two isolates of Fonsecaea dermatitidis were highly virulent to mice and had a marked neurotropic affinity. Although not yet determined, the possibility that this species is pathogenic to domestic animals, could not be dismissed. The literature on diseases caused by yeasts in animals is reviewed

Electrochemically stable tunnel-type α-MnO2-based cathode materials for rechargeable aqueous zinc-ion batteries

The purpose of this study is the synthesis of α-MnO2-based cathode materials for rechargeable aqueous zinc ion batteries by hydrothermal method using KMnO4 and MnSO4 as starting materials. The aim is to improve the understanding of Zn2+ insertion/de-insertion mechanisms. The as-prepared solid compounds were characterized by spectroscopy and microscopy techniques. X-ray diffraction showed that the hydrothermal reaction forms α-MnO2 and Ce4+-inserted MnO2 structures. Raman spectroscopy confirmed the formation of α-MnO2 with hexagonal MnO2 and Ce-MnO2 structures. Scanning electron microscopy (SEM) confirmed the formation of nanostructured MnO2 (nanofibers) and Ce-MnO2 (nanorods). The electrochemical performance of MnO2 was evaluated using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) tests in half-cells. CV results showed the reversible insertion/de-insertion of Zn2+ ions in MnO2 and Ce-MnO2. GCD cycling tests of MnO2 and Ce-MnO2 at 2500 mA/g demonstrated an impressive electrochemical performance, excellent cycling stability throughout 500 cycles, and high rate capability. The excellent electrochemical performance and the good cycling stability of MnO2 and Ce-MnO2 nanostructures by simple method makes them promising cathode materials for aqueous rechargeable zinc-ion batteries.This work was funded by Qatar University through its Collaborative Grants Funding Program with project number QUCG-CAS-21/23-602

Агрессивная форма ювенильной макромастии

ПОДРОСТКИМОЛОЧНЫЕ ЖЕЛЕЗЫ ЧЕЛОВЕКА /АНОМАЛБОЛЕЗНИ РЕДКИЕМАКРОМАСТИЯГИПЕРТРОФИЯМОЛОЧНОЙ ЖЕЛЕЗЫ ПЛАСТИКАХИРУРГИЧЕСКИЕ ОПЕРАЦИИ ВОССТАНОВИТЕЛЬНЫЕМОЛОЧНОЙ ЖЕЛЕЗЫ БОЛЕЗНИ /ТЕР /ХИ

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

A Techno-Economic Study of Catalytic Decarboxylation Process for Naphthenic Acids Utilizing Protonic Zeolite Socony Mobil Type 5 (HZSM-5) Catalyst

This paper represents a detailed techno-economic analysis of a typical commercial-scale catalytic decarboxylation process of naphthenic acids over HZSM-5 zeolite. Simulation of the process has been performed in ASPEN Plus®. The performance of the modeled unit was compared to experimental results data from a similar plant. Two models were developed for the proposed industrial plant based on continuous flow reactors; the first is based on a fluidized bed reactor, and it was modeled as a continuous stirred tank reactor (CSTR) unit, and the second is a semi-regenerative process that consists of three fixed-bed reactors with intermediate preheaters and are modeled as three plug flow reactors (PFR). The outcome of the economic analysis of the two proposed commercial scale reactors of a decarboxylation process of a capacity of 11,000 bbl/day showed that the CAPEX, including the total equipment cost for the fluidized bed reactor plant and semi-regenerative process plant, was $44,319,362 and$4,447,919, respectively. The annual operating cost for the fluidized bed plant and semi-regenerative process plant is 45,269,180 $/year and 1,771,839$/year, respectively. Our results demonstrated that catalytic decarboxylation over HZSM-5 zeolite is economically feasible using a semi-regenerative process, and is a promising method for removing naphthenic acid. The insight obtained from this work can be used as a basis for more comprehensive future financial and risk modeling of the process. The cost estimated in this work was compared to the Khartoum refinery cost for the naphthenic acid corrosion mitigation system, with a saving of $29,459,528

Aerobic bacteria and fungi from skin lesions of fish in Khartoum state

Objective: This cross-sectional study was conducted from April to July 2014 in Khartoum state, the Sudan, to investigate aerobic bacteria and fungi of skin lesions of fish in 3 different areas in Khartoum. Material and methods: A total of 50 samples were collected from the skin lesions of different types of fish including Synodontis species (n=17), Tilapia niloticus (n=15), Labeo niloticus (n=10), Hydrocynus species (n=4), and Clarias species (n=4). Liquid, semi-solid, and solid culture media like nutrient broth, blood agar, MacConkey agar, sabouraud dextrose agar (SDA), and Simmons citrate medium were used for the isolation and identification of bacteria and fungi. Besides, Gram staining and biochemical characterization were also conducted. Results: Culturing of the collected samples revealed growth of bacteria from all (100%), and growth of fungi could be found from 32% samples. A number of 188 bacteria were isolated, mainly Staphylococcus species, Bacillus species, Aeromonas species, Pseudomonas species, and Vibrio species. Besides, 16 fungi could be identified containing Aspergillus niger, A. flavus, A. fumigatus, and Phycomycete. Conclusion: Fishes with skin lesions are harboring many pathogenic bacteria and fungi and may act as a source of zoonotic infections and can transmit several pathogens to workers in fish industry and consumers. Therefore, thorough and strict routine inspection of fish is recommended to ensure safety and that there are no serious risks to consumers. [J Adv Vet Anim Res 2016; 3(4.000): 375-385

Kinetics of Catalytic Decarboxylation of Naphthenic Acids over HZSM-5 Zeolite Catalyst

Naphthenic acids are naturally occurring carboxylic acids in crude oil with cyclic or aromatic rings in their structure. These carboxylic acids are responsible for the acidity of crude oil, leading to corrosion problems in refinery equipment and the deactivation of catalysts while creating a continuous need for maintenance. Therefore, removing naphthenic acids has become an important requirement in refining acidic crude oil. In this paper, experiments are conducted to investigate the use of HZSM-5 zeolite catalyst to reduce the total acid number (TAN) of a typical acidic crude oil obtained from Al-Fula blocks in Western Sudan. TAN is an important metric signifying the acidity of crude oil. A full factorial design of the experiment (DOE) framework enabled a better understanding of the efficacy of the catalyst at three parametric levels (reaction temperature: 250-270-300 °C, reaction time: 2-3-4 h, and oil:catalyst weight ratio: 20-22-25 g/g). The results demonstrate that the HZSM-5 zeolite catalyst provides up to 99% removal of naphthenic acids via the decarboxylation route. Additionally, the removal efficiency increases with increasing temperature and residence time. The acidity of the crude oil was shown to decrease after treatment with the catalyst for four hrs.; from 6.5 mg KOH/g crude to 1.24; 0.39 and 0.17 mg KOH/g at 250; 270 and 300 °C, respectively. A sharp decrease of TAN was observed at the oil catalyst mass ratio of 20 g/g at 250 °C, and almost complete conversion of acids was achieved after 4 hrs. Another experiment at 270 °C showed a converse relationship between the oil:catalyst ratio and acid removal; suggesting the activation of side reactions at higher temperature conditions catalyzed by excess acid. Finally; a Langmuir–Hinshelwood (LH) kinetic model has been developed to enable rapid prediction of the performance of the HZSM-5 zeolite catalyst for decarboxylation reaction. The model has also been validated and tested in ASPEN® software for future simulation and scalability studies

Effects of Combined Calcium Hypochlorite and Chlorine Dioxide on Drinking Water Quality in Qatar and Disinfection by Products Formation

Chlorite, chlorate, bromate and trihalomethane's (THMs) are included in WHO guidelines for drinking water quality. This study examined dosing different chlorine concentrations as calcium hypochlorite (Ca(ClO)2) to water containing chlorine dioxide to evaluate the control of water quality in storage and the distribution system in Qatar with emphasis on chlorite, chlorate, bromate, pH and other parameters. Seven water samples were collected from the Ras Laffan-Q Power desalination plant outlet in amber bottles having a chlorine dioxide concentration of 0.3 mg/l in 1 liter. The bottles were spiked with Ca(ClO)2 in sequence to give concentration of 0.2, 0.4, 0.6, 0.8, 1.0, and 1.2 mg/l as free chlorine. The mixtures were stored for 7 days at 25°C in the dark then heated to 45°C for two days more, and analyzed daily for physical and chemical parameters. A total of 312 sub-samples were analyzed for chlorite, chlorate, bromate, bromide, chloride, nitrate, nitrite, sulfate, THMs, temperature, pH, electrical conductivity, and chlorine and chlorine dioxide residuals. Chlorite concentration reductions were observed from the first day forward as 59, 65, 68, 94, 100, and 100%, and 17.4, 22.1, 39.2, 63.9, 66.0, 68.9% (from 0.157 to 0.049 mg/l) respectively based on observed means for seven days the commensurate respective chlorate concentrations increases were 196, 344, 516, 602, 703, 787% (from 0.035 to 0.313 mg/l) based on observed mean values for seven days. These data were statistically analyzed by multivariate regression. There were no significant changes in THMs concentrations and the reductions in chlorite and increases in chlorate concentration are chlorine dosage dependent. No bromate formation was observed. Chlorine dioxide levels decrease as the free chlorine residual levels increased. This study demonstrates that hypochlorite/chlorine can be used as an operational tool to control the chlorite levels, and slow the disappearance of the chlorine dioxide over time during distribution, that is usually faster than chlorine disappearance. The original chlorine dioxide dosage will determine the ultimate chlorate concentration, which must also be managed.qscienc

Kinetics of Catalytic Decarboxylation of Naphthenic Acids over HZSM-5 Zeolite Catalyst

Naphthenic acids are naturally occurring carboxylic acids in crude oil with cyclic or aromatic rings in their structure. These carboxylic acids are responsible for the acidity of crude oil, leading to corrosion problems in refinery equipment and the deactivation of catalysts while creating a continuous need for maintenance. Therefore, removing naphthenic acids has become an important requirement in refining acidic crude oil. In this paper, experiments are conducted to investigate the use of HZSM-5 zeolite catalyst to reduce the total acid number (TAN) of a typical acidic crude oil obtained from Al-Fula blocks in Western Sudan. TAN is an important metric signifying the acidity of crude oil. A full factorial design of the experiment (DOE) framework enabled a better understanding of the efficacy of the catalyst at three parametric levels (reaction temperature: 250-270-300 °C, reaction time: 2-3-4 h, and oil:catalyst weight ratio: 20-22-25 g/g). The results demonstrate that the HZSM-5 zeolite catalyst provides up to 99% removal of naphthenic acids via the decarboxylation route. Additionally, the removal efficiency increases with increasing temperature and residence time. The acidity of the crude oil was shown to decrease after treatment with the catalyst for four hrs.; from 6.5 mg KOH/g crude to 1.24; 0.39 and 0.17 mg KOH/g at 250; 270 and 300 °C, respectively. A sharp decrease of TAN was observed at the oil catalyst mass ratio of 20 g/g at 250 °C, and almost complete conversion of acids was achieved after 4 hrs. Another experiment at 270 °C showed a converse relationship between the oil:catalyst ratio and acid removal; suggesting the activation of side reactions at higher temperature conditions catalyzed by excess acid. Finally; a Langmuir–Hinshelwood (LH) kinetic model has been developed to enable rapid prediction of the performance of the HZSM-5 zeolite catalyst for decarboxylation reaction. The model has also been validated and tested in ASPEN® software for future simulation and scalability studies

Enhanced adsorptive removal of rifampicin and tigecycline from single system using nano-ceria decorated biochar of mango seed kernel

Pharmaceutically active compounds (PhACs) represent an emerging class of contaminants. With a potential to negatively impact human health and the ecosystem, existence of pharmaceuticals in the aquatic systems is becoming a worrying concern. Antibiotics is a major class of PhACs and their existence in wastewater signifies a health risk on the long run. With the purpose of competently removing antibiotics from wastewater, cost-effective, and copiously available waste-derived adsorbents were structured. In this study, mango seeds kernel (MSK), both as a pristine biochar (Py–MSK) and as a nano-ceria-laden (Ce–Py–MSK) were applied for the remediation of rifampicin (RIFM) and tigecycline (TIGC). To save time and resources, adsorption experiments were managed using a multivariate-based scheme executing the fractional factorial design (FrFD). Percentage removal (%R) of both antibiotics was exploited in terms of four variables: pH, adsorbent dosage, initial drug concentration, and contact time. Preliminary experiments showed that Ce–Py–MSK has higher adsorption efficiency for both RIFM and TIGC compared to Py–MSK. The %R was 92.36% for RIFM compared to 90.13% for TIGC. With the purpose of comprehending the adsorption process, structural elucidation of both sorbents was performed using FT-IR, SEM, TEM, EDX, and XRD analyses which confirmed the decoration of the adsorbent surface with the nano-ceria. BET analysis revealed that Ce–Py–MSK has a higher surface area (33.83 m2/g) contrasted to the Py–MSK (24.72 m2/g). Isotherm parameters revealed that Freundlich model best fit Ce–Py–MSK–drug interactions. A maximum adsorption capacity (qm) of 102.25 and 49.28 mg/g was attained for RIFM and TIGC, respectively. Adsorption kinetics for both drugs conformed well with both pseudo-second order (PSO) and Elovich models. This study, therefore, has established the suitability of Ce–Py–MSK as a green, sustainable, cost-effective, selective, and efficient adsorbent for the treatment of pharmaceutical wastewater