MyMedR

Displaying all 9 publications

Abstract:

Sort:

Fulltext Nano-structural study of microfibrils in Acacia Mangium wood using small- angle x-ray scattering (SAXS)

Tabet, Tamer A., Fauziah Abdul Aziz, Shahidan Radiman

Journal of Nuclear and Related Technologies, 2007;2007(1):209-216.
MyJurnal

Small-angle X-ray scattering (SAXS) was used to investigate the nanostructure of the microfibrils of cell wall in Acacia Mangium wood. Parameters, such as the fibre length (L), surface area of the single fibre (S), the correspondence distance from the center of the fibre to the center of its neighbor and the shape of the fibre were determined as a function to the distance from pith towards the bark. The results indicate that the fibre length ranged from 53.44 nm to 13.72 nm from pith to bark. Surface area of the single fibre varied from 0.65 nm 2 to 4.36 nm 2 , the highest being found at the end of bark region. The mean value of the correspondence distance is 13.95 nm. Surface structure analysis from scattering graph showed a rod shape of fibre in the pith region of Acacia Mangium wood. The use of SAXS technique and scanning electron microscope (SEM) micrographs gives the most reliable dimensions values.
Fulltext Influence of microfibril angle on the thermal and dynamic-mechanical properties of Acacia mangium wood using x-ray diffraction and dynamicsmechanical test

Tabet, Tamer A., Wajir, Julynnie, Fauziah Abdul Aziz

Journal of Nuclear and Related Technologies, 2009;2009(1):0-0.
MyJurnal

The term microfibril angle, MFA in wood science refers to the angle between the direction of the helical windings of cellulose microfibrils in the secondary cell wall, S2 layer of fibres and tracheids and the long axis of the cell. In this study, the mean MFA of the cell walls were determined for thin samples of thickness 200.0 µm from pith and outwards, for eight ages of Acacia mangium wood. The determination of MFA was based on a diffraction pattern arising from cellulose crystal planes of the type 002 generated by x-ray diffraction and recorded using an electronic detector. The results show an inversely relationship between MFA and age of tree in Acacia mangium wood. MFA decreased from 26.13° at age 3 year-old to 0.20° at tree of age 15 year-old for the pith region. The most significant drop occurred from 16.14° at age 7 yearold to 11.30° at age 9 year-old. An inversely relationship between MFA and storage modulus E’ was evidence in Acacia mangium at age 10-year-old. The results showed that about 76.22% variation of loss modulus E” was attributed to the MFA, while about 66.4% of the variation of glass transition Tg was explained by MFA under the same experimental conditions.
Effectiveness of hot oil treatment on cultivated 15 year-old Acacia hybrid against Coriolus Versicolors, Gloeophyllum Trabeum and Pycnoporus Sanguineus

Razak Wahab, Izyan Khalid, Tamer A. Tabet, Aminuddin Mohamed, Othman Sulaiman, Rafid MD. Salim, et al.

Sains Malaysiana, 2012;41:163-169.

The effectiveness of the hot oil treatment process on 15 year old cultivated Acacia hybrid was studied. Accelerated laboratory durability studies were conducted on the hot oil treated Acacia hybrid inoculated with fungi Coriolus versicolors, Gloeophyllum trabeum and Pycnoporus sanguineus. The logs of Acacia hybrid were harvested, segregated into bottom, middle and top portions, and later were oil-heat treated in an organic palm oil at temperatures of 180, 200 and 220°C for the duration of 30, 60 and 90 min. The wood samples that were dried and ground into sawdust was air-dried again before undergoing accelerated laboratory durability tests. Untreated samples were used as control. The durability of the wood increases with an increase in temperature and duration of the treatment. The hot oil treated samples could reduce the attack of G. trabeum from 20.89%, 20.94% and 21.29% in the control samples to 0.88-4.07%, 1.22-4.84% and 1.28-4.22% at bottom, middle and top portions, respectively. The attack of C. versicolors were reduced from 26.59%, 30.28% and 34.79% in the control samples to 2.89-9.41%, 3.88-16.84 and 4.27-17.34% at bottom, middle and top portions. However, the attacked of P. sanguineus were least effective with 31.42%, 36.33% and 36.55% in control samples to 3.26-12.55%, 4.67-15.36% and 4.69-19.22% at bottom, middle and top portions. Massive colonization of mycelia occurs in vessels of the untreated Acacia hybrid wood in comparison to the hot oil treated wood when observed through scanning electron microscope.
An Investigation of Multidimensional Voice Program Parameters in Three Different Databases for Voice Pathology Detection and Classification

Al-Nasheri A, Muhammad G, Alsulaiman M, Ali Z, Mesallam TA, Farahat M, et al.

J Voice, 2017 Jan;31(1):113.e9-113.e18.
PMID: 27105857 DOI: 10.1016/j.jvoice.2016.03.019

BACKGROUND AND OBJECTIVE: Automatic voice-pathology detection and classification systems may help clinicians to detect the existence of any voice pathologies and the type of pathology from which patients suffer in the early stages. The main aim of this paper is to investigate Multidimensional Voice Program (MDVP) parameters to automatically detect and classify the voice pathologies in multiple databases, and then to find out which parameters performed well in these two processes.
MATERIALS AND METHODS: Samples of the sustained vowel /a/ of normal and pathological voices were extracted from three different databases, which have three voice pathologies in common. The selected databases in this study represent three distinct languages: (1) the Arabic voice pathology database; (2) the Massachusetts Eye and Ear Infirmary database (English database); and (3) the Saarbruecken Voice Database (German database). A computerized speech lab program was used to extract MDVP parameters as features, and an acoustical analysis was performed. The Fisher discrimination ratio was applied to rank the parameters. A t test was performed to highlight any significant differences in the means of the normal and pathological samples.
RESULTS: The experimental results demonstrate a clear difference in the performance of the MDVP parameters using these databases. The highly ranked parameters also differed from one database to another. The best accuracies were obtained by using the three highest ranked MDVP parameters arranged according to the Fisher discrimination ratio: these accuracies were 99.68%, 88.21%, and 72.53% for the Saarbruecken Voice Database, the Massachusetts Eye and Ear Infirmary database, and the Arabic voice pathology database, respectively.
Intra- and Inter-database Study for Arabic, English, and German Databases: Do Conventional Speech Features Detect Voice Pathology?

Ali Z, Alsulaiman M, Muhammad G, Elamvazuthi I, Al-Nasheri A, Mesallam TA, et al.

J Voice, 2017 May;31(3):386.e1-386.e8.
PMID: 27745756 DOI: 10.1016/j.jvoice.2016.09.009

A large population around the world has voice complications. Various approaches for subjective and objective evaluations have been suggested in the literature. The subjective approach strongly depends on the experience and area of expertise of a clinician, and human error cannot be neglected. On the other hand, the objective or automatic approach is noninvasive. Automatic developed systems can provide complementary information that may be helpful for a clinician in the early screening of a voice disorder. At the same time, automatic systems can be deployed in remote areas where a general practitioner can use them and may refer the patient to a specialist to avoid complications that may be life threatening. Many automatic systems for disorder detection have been developed by applying different types of conventional speech features such as the linear prediction coefficients, linear prediction cepstral coefficients, and Mel-frequency cepstral coefficients (MFCCs). This study aims to ascertain whether conventional speech features detect voice pathology reliably, and whether they can be correlated with voice quality. To investigate this, an automatic detection system based on MFCC was developed, and three different voice disorder databases were used in this study. The experimental results suggest that the accuracy of the MFCC-based system varies from database to database. The detection rate for the intra-database ranges from 72% to 95%, and that for the inter-database is from 47% to 82%. The results conclude that conventional speech features are not correlated with voice, and hence are not reliable in pathology detection.
Fulltext Thermal Properties and Drying Shrinkage Performance of Palm Kernel Shell Ash and Rice Husk Ash-Based Geopolymer Concrete

Abdullah MN, Mustapha F, Yusof N', Khan T, Sebaey TA

Materials (Basel), 2024 Mar 11;17(6).
PMID: 38541452 DOI: 10.3390/ma17061298

This study aims to develop suitable formulations of geopolymer concrete (GPC) by varying the percentages of the geopolymer with aggregates and evaluating the performances in thermal and mechanical properties of palm kernel shell ash (PKSA)-GPC compared to rice husk ash (RHA)-GPC and ordinary Portland cement concrete (OPCC). Preliminary tests were conducted to select the best mix design ratios before casting the specimens. Then, the performance of the PKSA-GPC, RHA-GPC and OPCC specimens was evaluated based on their thermal performance and drying shrinkage. The mix designs of PKSA-GPC 70:30, PKSA-GPC 60:40, PKSA-GPC 50:50 and PKSA-GPC 66.6:33.3 were found to produce an acceptable consistency, rheological and thixotropic behaviour for the development of the GPC. PKSA-GPC showed a better thermal performance than the RHA-GPC and OPCC due to their strong and dense intumescent layers and slow temperature increment upon exposure to a high flame temperature from ambient temperature to 169 °C. The low molar ratio of the Si/Al present in the PKSA-GPC created a thermally stable intumescent layer. In the drying shrinkage test, PKSA-GPC 60:40 and RHA-GPC 60:40 shared an equal drying shrinkage performance (5.040%) compared to the OPCC (8.996%). It was observed that microcrack formation could significantly contribute to the high shrinkage in the PKSA-GPC 50:50 and RHA-GPC 70:30 specimens. The findings of this study show that PKSA could be incorporated into GPC as a fire-retardant material due to its capability of prolonging the spread of fire upon ignition and acting as an alternative to the conventional OPCC.
Phage-Resistant Streptomyces abietis and its Telomycin Bioactive Metabolite as a Possible Alternative to Antibiotics

Abdelaziz R, Abd El-Hamid MI, El-Wafaei N, Ghaly MF, Askora A, El-Didamony G, et al.

Microb Pathog, 2024 Jul 22.
PMID: 39047802 DOI: 10.1016/j.micpath.2024.106822

Multidrug-resistant pathogens are now thought to be the primary global causes of disease and death. Therefore, it is imperative to develop new effective bioactive compounds from microbial sources, such as Streptomyces species. Nevertheless, the pharmaceutical industry suffered financial losses and low-quality end products as a result of Streptomyces bacteriophage contamination. To reduce the likelihood of phage-induced issues in the medical industry, it is crucial to develop a method for finding phage-resistant strains. Hence, we aimed to isolate and characterize Streptomyces spp. and Streptomyces phages from various rhizospheric soil samples in Egypt and to investigate their antibacterial activities. Moreover, we targeted development of a Streptomyces phage-resistant strain to extract its active metabolites and further testing its antibacterial activity. Herein, the antibacterial activities of the isolated 58 Streptomyces isolates showed that 10 (17.2%) Streptomyces isolates had antibacterial activities against the tested bacteria including Listeria monocytogenes, E. coli O157, Acinetobacter baumannii, methicillin resistant-vancomycin-intermediate Staphylococcus aureus (MRSA-VISA) and Micrococcus luteus. Three lytic bacteriophages (ϕPRSC1, ϕPRSC2, and ϕPRSC4) belonging to the families Siphoviridae and Podoviridae were obtained from the rhizospheric soil samples using the most potent S. abietis isolate as the host strain. The three isolated Streptomyces phages were thermostable, ultraviolet stable, infectious, and had a wide range of hosts against the 10 tested Streptomyces isolates with antibacterial activities. The DNA of the ϕPRSC1 and ϕPRSC4 phages were resistant to digestion by EcoRI and HindIII, but the DNA of ϕPRSC2 was resistant to digestion by EcoRI and sensitive to digestion by HindIII. Of note, we developed a S. abietis strain resistant to the three isolated phages and its antibacterial activities were twice that of the wild strain. Finally, telomycin was recognized as an antibacterial metabolite extracted from phage-resistant S. abietis strain, which was potent against the tested Gram-positive bacteria including L. monocytogenes, MRSA-VISA, and M. luteus. Thus, our findings open new horizons for researching substitute antimicrobial medications for both existing and reemerging illnesses.
Fulltext International survey on complications of religious fasting after metabolic and bariatric surgery

Kermansaravi M, Husain FA, Bashir A, Valizadeh R, Abbas SI, Abouzeid T, et al.

Sci Rep, 2023 Nov 18;13(1):20189.
PMID: 37980363 DOI: 10.1038/s41598-023-47673-w

Religious fasting in Ramadan the 9th month of the lunar year is one of five pillars in Islam and is practiced for a full month every year. There may be risks with fasting in patients with a history of metabolic/bariatric surgery (MBS). There is little published evidence on the possible complications during fasting and needs stronger recommendations and guidance to minimize them. An international survey was sent to surgeons to study the types of complications occurring during religious fasting in patients with history of MBS to evaluate the risk factors to manage and prepare more evidence-based recommendations. In total, 21 centers from 11 countries participated in this survey and reported a total of 132 patients with complications occurring during religious fasting after MBS. The mean age of patients with complications was 36.65 ± 3.48 years and mean BMI was 43.12 ± 6.86 kg/m2. Mean timing of complication occurring during fasting after MBS was 14.18 months. The most common complications were upper GI (gastrointestinal) symptoms including [gastroesophageal reflux disease (GERD), abdominal pain, and dyspepsia], marginal ulcers and dumping syndrome in 24% (32/132), 8.3% (11/132) and 23% (31/132) patients respectively. Surgical management was necessary in 4.5% of patients presenting with complications (6/132) patients due to perforated marginal or peptic ulcer in Single Anastomosis Duodenoileostomy with Sleeve gastrectomy (SADI-S), one anastomosis gastric bypass (OAGB) and sleeve gastrectomy (SG), obstruction at Jejunojenostomy after Roux-en-Y gastric bypass (RYGB) (1/6) and acute cholecystitis (1/6). Patients after MBS should be advised about the risks while fasting including abdominal pain, dehydration, and peptic ulcer disease exacerbation, and a thorough review of their medications is warranted to minimize complications.
Fulltext COVID-19 infection in patients on long-term home parenteral nutrition for chronic intestinal failure

Pironi L, Jezerski D, Sobocki J, Lal S, Vanuytsel T, Theilla M, et al.

Clin Nutr ESPEN, 2023 Jun;55:212-220.
PMID: 37202049 DOI: 10.1016/j.clnesp.2023.03.008

BACKGROUND AND AIMS: To investigate the incidence and the severity of COVID-19 infection in patients enrolled in the database for home parenteral nutrition (HPN) for chronic intestinal failure (CIF) of the European Society for Clinical Nutrition and Metabolism (ESPEN).
METHODS: Period of observation: March 1st, 2020 March 1st, 2021.
INCLUSION CRITERIA: patients included in the database since 2015 and still receiving HPN on March 1st, 2020 as well as new patients included in the database during the period of observation. Data related to the previous 12 months and recorded on March 1st 2021: 1) occurrence of COVID-19 infection since the beginning of the pandemic (yes, no, unknown); 2) infection severity (asymptomatic; mild, no-hospitalization; moderate, hospitalization no-ICU; severe, hospitalization in ICU); 3) vaccinated against COVID-19 (yes, no, unknown); 4) patient outcome on March 1st 2021: still on HPN, weaned off HPN, deceased, lost to follow up.
RESULTS: Sixty-eight centres from 23 countries included 4680 patients. Data on COVID-19 were available for 55.1% of patients. The cumulative incidence of infection was 9.6% in the total group and ranged from 0% to 21.9% in the cohorts of individual countries. Infection severity was reported as: asymptomatic 26.7%, mild 32.0%, moderate 36.0%, severe 5.3%. Vaccination status was unknown in 62.0% of patients, non-vaccinated 25.2%, vaccinated 12.8%. Patient outcome was reported as: still on HPN 78.6%, weaned off HPN 10.6%, deceased 9.7%, lost to follow up 1.1%. A higher incidence of infection (p = 0.04), greater severity of infection (p