596 research outputs found
Kesinai (Streblus Asper) Protease as a Potential Milk Coagulating Enzyme
Leaf extract of plant kesinai (Streblus asper) contains a milk coagulating
protease, which could be a potential rennet substitute. However, its potential has not
been investigated and the protease has not been purified and characterised. Preparation
of the crude leaf extract results in an undesirable, very dark brown colour and inhibition
of this browning may enhance the use of the leaf extract.
The browning inhibitors, citric acid, ascorbic acid, L-cysteine and sodium
metabisulphite were used for prevention of browning and to obtain a crude extract with
an acceptable colour. Metabisulphite was found to be an effective inhibitor of the
enzymatic browning of the leaf extract. At 2 mM concentration it has inhibited browning
and the extract obtained resulted in a white milk coagulum compared to the brown
coloured coagulum of the brown extract. It is thermostable up to 85°C, with an optimum
temperature at 70°C and its optimum pH is 7.2. Six mM added calcium chloride was
optimum for its milk coagulation activity.Microstructure, texture and syneresis of the milk coagulum of the crude extract
were assessed by Scanning electron microscopy (SEM), Transmission electron
microscopy (TEM), the Texture Analyser, and measurement of whey volume,
respectively and were compared with that of calf rennet and Fromase. Kesinai coagulum
appeared as a sponge-like when examined under SEM, while calf rennet and Fromase
coagulum appeared as a fibrous network. Quantification results showed that porosity of
kesinai coagulum is low, and significantly different from both of calf rennet and
Fromase coagulum (P<0.05) and (P<0.01), respectively. Kesinai coagulum was soft,
and its strength is significantly lower than that of calf rennet and Fromase coagulum (P<
0.01). Syneresis of its coagulum was low, and the whey volume as per cent of milk
volume was 34.75% compared to 46.75% and 48.79%, for calf rennet and Fromase,
respectively.
The ratio of milk coagulation activity to proteolytic activity of the extract was
very low (0.02) and the protein profile of the milk coagulum and whey on sodium
dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed that the
protease was more proteolytic than calf rennet, and Fromase.The protease was purified by ultrafiltration (UF), Fast protein Liquid
Chromatography (FPLC) gel filtration with Superose 6, FPLC ion exchange using
MonoQ HR 5/5 and lsoelectric Focusing (IEF) using the Rotofor system, with a
puritification fold of 25, and 18% recovery. The purified protease appeared as a single
band on SDS-P AGE with a molecular weight of 31.3 kDa. Characterisation of the purified protease showed that it could be a serine protease with optimum pH of 7.2,
stable in the pH range 5.0 -9.5, and its pI is 5.2. It is thermostable up to 85°C, with
optimum temperature at 70°C. Zymogram analysis showed that protease activity is
associated with milk coagulation activity.
It is concluded that kesinai protease could be used in the production of short
ripened cheese varieties
Assessment of infection control in public dental clinics in Khartoum State, Sudan
Magister Scientiae Dentium - MSc(Dent)The unique nature of dental procedures, instrumentation and patient care settings
require specific strategies directed at the prevention of transmission of diseases
among oral health care workers and their patients.
Aim: The aim of the present study was to assess the knowledge, attitude and practice
of infection control among dentists and dental auxiliaries in public dental clinics in
Khartoum State, Sudan.
Materials and Methods: A cross-sectional survey using a structured administered
questionnaire was carried out. The questionnaire consisted of 38 closed-ended
questions that included the key areas of infection control including hand hygiene,
personal protection, sterilization and disinfection and environmental infection control.
There were also questions to elicit perceptions regarding the treatment of HBV and
HIV/AIDS patients.
Results: All except one (n=125) of the oral health personnel in Khartoum State
participated in the study. 68 dentists and 57 dental assistants were interviewed. The
majority were female (60.8%) and 31-40 year olds the predominant age group (44%)
for both genders.
Hand washing before and after treating each patient was reported by 89.6%. Among
dentists, 84.8% reported that they take the medical history of every patient. A quarter
of the dentists and 36.8% of dental assistants reported using both hands to recap the
used needles. 84%were vaccinated against hepatitis B. With regard to personal
protection, the highest adherence was reported for glove use (99.2%), and the least for
eye protection (45.6%). None of the study participants used plastic barriers to cover
the clinical contact surfaces, 61.6% did not high vacuum suction and 97.6% did not
use the rubber dam. All respondents used autoclaves for sterilization, but only
7.2%sterilized hand pieces. 72.8%reported that they did not mind treating HIV/AIDS
and hepatitis B patients; however, dental assistants were more willing to treat them
than the dentists
Effect of planting date and sowing method on yield and grain quality of soybean (Glycine max L.) under North Sudan conditions
This study aimed to assess the effect of different planting dates and sowing methods on yield and grain quality of soybean. A split plot arrangement using randomized complete block with three replications was used to layout the experiment. The studied traits determining yield and grain quality, included height to first pod, no of pods/plant, 100-seed weight, harvest index, straw yield, seed yield, grain protein and oil contents. The results showed significant differences between planting dates in height to first pod, 100-seed weight, harvest index, grain yield and grain protein. Planting date in the 1st July produced 72% more grain yield than delaying planting date (15th July). Early planting date (15th June) and mid-planting date (1st July) increased grain protein of soybean by 5% than delaying planting date (15th July). Results revealed that soybean yield components were not affected by sowing methods except that of straw yield. Interaction between planting date and sowing method was significant for grain oil content.
Keywords: Soybean, planting date, sowing method, grain protein, grain yield, oil conten
In-vitro anti-microbial and brine-shrimp lethality potential of the leaves extract of nahar (Mesua ferrea) plant
The growing interest in human health and increasing
bacterial resistance to antibiotics among other reasons have
resulted into an increasing need for the exploration of both the essential oils and other plant extracts in the food and pharmaceutical industries. This work, as part of on-going work on the leaves of Nahar (Mesua ferrea) plant, was aimed at evaluating the antimicrobial activity, minimum inhibitory concentration as well as the cytotoxicity of the leaves extract. The dry leaves were grinded and extracted in an oven shaker set at 37°C and 200rpm for 24 hours using ethanol and methanol as solvents. The agar disc diffusion method was used for the evaluation of antibacterial property of the leaves extract, micro broth dilution was employed for the determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), while Brine shrimp (Artemia salina) lethality bioassay was made use of for the cytotoxicity assay.
Ethanol gave higher extract’s yield (6.20%) than methanol. The extract showed a remarkable antibacterial property against all the selected microbes (Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus) with the inhibition zones ranging from 16.0±0.5mm to 18.0±0.5mm for all the tested bacteria. The MIC range of 2.5- 0.625 mg/ml with MBC value of 5mg/ml was obtained for the gram-negative bacteria while MIC rangeof 1.3- 0.313mg/ml with MBC value of 2.5mg/ml was
obtained for the gram-positive bacteria. The leaves extract was found to be toxic to the Brine shrimps with LC50 of 500ppm (μg/ml) suggesting that the extracts may contain bioactive compounds of potential the therapeutic and prophylactic significance
Comparison of bone regenerative capacity of donor-matched human adipose–derived and bone marrow mesenchymal stem cells
Adipose-derived stem cells (ASC) have been used as an alternative to bone marrow mesenchymal stem cells (BMSC) for bone tissue engineering. However, the efficacy of ASC in bone regeneration in comparison with BMSC remains debatable, since inconsistent results have been reported. Comparing ASC with BMSC obtained from different individuals might contribute to this inconsistency in results. Therefore, this study aimed to compare the bone regenerative capacity of donor-matched human ASC and BMSC seeded onto poly(L-lactide-co-ε-caprolactone) scaffolds using calvarial bone defects in nude rats. First, donor-matched ASC and BMSC were seeded onto the co-polymer scaffolds to evaluate their in vitro osteogenic differentiation. Seeded scaffolds and scaffolds without cells (control) were then implanted in calvarial defects in nude rats. The expression of osteogenesis-related genes was examined after 4 weeks. Cellular activity was investigated after 4 and 12 weeks. Bone formation was evaluated radiographically and histologically after 4, 12, and 24 weeks. In vitro, ASC and BMSC demonstrated mineralization. However, BMSC showed higher alkaline phosphatase activity than ASC. In vivo, human osteogenesis–related genes Runx2 and collagen type I were expressed in defects with scaffold/cells. Defects with scaffold/BMSC had higher cellular activity than defects with scaffold/ASC. Moreover, bone formation in defects with scaffold/BMSC was greater than in defects with scaffold/ASC, especially at the early time-point. These results suggest that although ASC have the potential to regenerate bone, the rate of bone regeneration with ASC may be slower than with BMSC. Accordingly, BMSC are more suitable for bone regenerative applications.publishedVersio
Membrane fouling in a submerged membrane bioreactor treating high strength municipal wastewater
Studying the influence of the operating parameters on membrane fouling is important in fouling control. This paper presents the interaction effects of the sludge retention time (SRT), organic loading rate (OLR) and feed temperature (Tf) on membrane fouling. A submerged membrane bioreactor (SMBR) was operated under a constant flux (11.1 l/m2 h), with different SRT, Tf and OLR. A synthetic
wastewater representative of high strength municipal wastewater was fed to the bioreactor. Three different levels (low, medium and high) of SRT, Tf and OLR were studied. These were 25, 30 and 35 days for SRT, 20, 30 and 40°C for Tf and OLR of 1.73, 4.03 6.82 kg COD/m3.d. The sustainable time (tsus) was defined as the time at which the rate of suction pressure started to increase rapidly.
tsus was found to increase with low SRT and high Tf. A higher OLR resulted in higher mixed liquor suspended solids (MLSS), however it did not cause a faster membrane fouling. Applying higher aeration rate enabled a longer sustainable time to be obtained. Sustainable time tsus was found to
be well correlated with MLVSS/MLSS with an r2 of 0.995. The range of MLVSS/MLSS tested varied from 74.3 to 82.3% at which tsus decreased 2.9-fold (from 175 to 60.5 h)
Primary School Teachers’ Perspectives on ADHD in Alkadrow, Khartoum, Sudan
Background: Attention deficit hyperactivity disorder, which is a prevalent neurodevelopmental condition, commonly manifests during early childhood and has the potential to adversely affect an individual’s social, academic, and occupational performance in multiple settings. Students with ADHD may struggle with attention, focus, listening, and completing schoolwork. Additionally, they may exhibit restless or disruptive behavior in class and may have learning disabilities that affect their academic performance. The aim of this study was to explore the perspectives of primary school teachers on ADHD in Alkadrow, Khartoum, Sudan.
Methods: A descriptive cross-sectional study was conducted in Alkadrow-Bahri locality, Sudan, over a period of three to six months in 2022. The study population included primary school teachers who had taught for at least one year and encountered at least one student with ADHD. A convenience sampling technique was used to select a minimum of 59 participants, and data were collected using a self-administered questionnaire with closed-ended questions. SPSS version 23 was used to analyze the data, including descriptive statistics and inferential statistics such as chi-square tests and logistic regression analysis.
Results: The study had 59 participants, with the majority being female and in the age group of 41–45 years. The participants were mostly married and had obtained psychology courses, with a bachelor’s degree being the most common level of education. Many participants had over 20 years of teaching experience. Regarding the attitude toward attention deficit hyperactivity, most participants strongly agreed that they did have a negative/positive attitude toward it, and a majority agreed or were neutral toward ADHD. However, in the case of attention deficit hyperactivity, a significant percentage of participants disagreed or strongly disagreed with the statement.
Conclusion: The study found that most participants had a negative attitude toward student referrals for medical care and believed that most symptoms of ADHD can be lowered by aging. Additionally, more than half strongly disagreed that punishment has a positive effect on ADHD
COVID-19 clinical presentations: the modern mimic of other conditions
The coronavirus pandemic (COVID-19) has placed enormous challenges on the health sector. Diagnosis is one of these challenges, where a clinical presentation may suggest a disease other than COVID-19. In this review we describe many presentations unrelated to the respiratory system. The ACE2 receptor is present in a wide variety of body tissues and it appears that this may be a link with the clinical pathology. To find these data we searched the major academic research engines, Google Scholar, and Pubmed, as well as the most recent case reports and original research published in specialized journals. An awareness of these uncommon presentations helps health workers to recognize and treat the disease early and appropriately.
Keywords: COVID-19, coronavirus, pandemic, ACE2, unusual symptoms, revie
New norfloxacin/nitric oxide donor hybrids: Synthesis and nitric oxide release measurement using a modified Griess colorimetric method
Oximes and nitrate esters are considered as important nitric oxide (NO) donors with diverse biological activities. Herein, we report the synthesis and characterization of new oxime and nitrate ester derivatives of norfloxacin as potential NO donor hybrids with expected synergistic antimicrobial activity. The release of NO from those hybrids was measured by a modified Griess method in which p-nitroaniline was employed instead of sulfanilamide. The increased electrophilicity of the intermediate 4-nitroaniline diazonium salt accelerated the coupling process and shortened the overall assessment time. The improved detection limits and enhanced sensitivity would pave the way for the future application of this method in nitrite determination in biological or non-biological systems
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