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1.
J Cardiothorac Surg ; 19(1): 493, 2024 Aug 24.
Article in English | MEDLINE | ID: mdl-39182148

ABSTRACT

BACKGROUND: PPHN is a common cause of neonatal respiratory failure and is still a serious condition and associated with high mortality. OBJECTIVES: To compare the demographic variables, clinical characteristics, and treatment outcomes in neonates with PHHN who underwent ECMO and survived compared to neonates with PHHN who underwent ECMO and died. METHODS: We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline and searched ProQuest, Medline, Embase, PubMed, CINAHL, Wiley online library, Scopus and Nature for studies on the development of PPHN in neonates who underwent ECMO, published from January 1, 2010 to May 31, 2023, with English language restriction. RESULTS: Of the 5689 papers that were identified, 134 articles were included in the systematic review. Studies involving 1814 neonates with PPHN who were placed on ECMO were analyzed (1218 survived and 594 died). Neonates in the PPHN group who died had lower proportion of normal spontaneous vaginal delivery (6.4% vs 1.8%; p value > 0.05) and lower Apgar scores at 1 min and 5 min [i.e., low Apgar score: 1.5% vs 0.5%, moderately abnormal Apgar score: 10.3% vs 1.2% and reassuring Apgar score: 4% vs 2.3%; p value = 0.039] compared to those who survived. Neonates who had PPHN and died had higher proportion of medical comorbidities such as omphalocele (0.7% vs 4.7%), systemic hypotension (1% vs 2.5%), infection with Herpes simplex virus (0.4% vs 2.2%) or Bordetella pertussis (0.7% vs 2%); p = 0.042. Neonates with PPHN in the death group were more likely to present due to congenital diaphragmatic hernia (25.5% vs 47.3%), neonatal respiratory distress syndrome (4.2% vs 13.5%), meconium aspiration syndrome (8% vs 12.1%), pneumonia (1.6% vs 8.4%), sepsis (1.5% vs 8.2%) and alveolar capillary dysplasia with misalignment of pulmonary veins (0.1% vs 4.4%); p = 0.019. Neonates with PPHN who died needed a longer median time of mechanical ventilation (15 days, IQR 10 to 27 vs. 10 days, IQR 7 to 28; p = 0.024) and ECMO use (9.2 days, IQR 3.9 to 13.5 vs. 6 days, IQR 3 to 12.5; p = 0.033), and a shorter median duration of hospital stay (23 days, IQR 12.5 to 46 vs. 58.5 days, IQR 28.2 to 60.7; p = 0.000) compared to the neonates with PPHN who survived. ECMO-related complications such as chylothorax (1% vs 2.7%), intracranial bleeding (1.2% vs 1.7%) and catheter-related infections (0% vs 0.3%) were more frequent in the group of neonates with PPHN who died (p = 0.031). CONCLUSION: ECMO in the neonates with PPHN who failed supportive cardiorespiratory care and conventional therapies has been successfully utilized with a neonatal survival rate of 67.1%. Mortality in neonates with PPHN who underwent ECMO was highest in cases born via the caesarean delivery mode or neonates who had lower Apgar scores at birth. Fatality rate in neonates with PPHN who underwent ECMO was the highest in patients with higher rate of specific medical comorbidities (omphalocele, systemic hypotension and infection with Herpes simplex virus or Bordetella pertussis) or cases who had PPHN due to higher rate of specific etiologies (congenital diaphragmatic hernia, neonatal respiratory distress syndrome and meconium aspiration syndrome). Neonates with PPHN who died may need a longer time of mechanical ventilation and ECMO use and a shorter duration of hospital stay; and may experience higher frequency of ECMO-related complications (chylothorax, intracranial bleeding and catheter-related infections) in comparison with the neonates with PPHN who survived.


Subject(s)
Extracorporeal Membrane Oxygenation , Humans , Extracorporeal Membrane Oxygenation/methods , Infant, Newborn , Persistent Fetal Circulation Syndrome/therapy , Persistent Fetal Circulation Syndrome/mortality , Treatment Outcome
2.
Bioresour Technol ; 401: 130707, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38663636

ABSTRACT

This study aimed to improve biochar's quality for arid land applications by using elemental sulfur as a pH reducer agent co-applied with compost or vermicompost as biological activators. Biochar pH was decreased by the addition of elemental sulfur, with the highest reduction from 8.1 to 7.2 occurring when co-amended with vermicompost. Elemental sulfur increased the water-soluble concentrations of calcium, magnesium, and many other elements, and stimulated substrate-induced respiration, especially when co-amended with vermicompost. The bacterial diversity community structure were significantly affected by all treatments. The Shannon index significantly increased in response to compost and sulfur treatments, while the vermicompost treatments showed higher microbial evenness and equitability diversity indices. Multivariate analyses indicated that elemental sulfur oxidation was associated with specific sulfur-oxidizing bacterial clusters. Integrating biochar with sulfur and (vermi)compost was found to be a promising sustainable technology for managing excessive biochar alkalinity, increasing its fertility and potential for application in aridlands.


Subject(s)
Charcoal , Composting , Soil , Sulfur , Charcoal/pharmacology , Charcoal/chemistry , Sulfur/metabolism , Hydrogen-Ion Concentration , Soil/chemistry , Composting/methods , Bacteria/metabolism , Soil Microbiology , Oxidation-Reduction
3.
Sci Rep ; 13(1): 18766, 2023 10 31.
Article in English | MEDLINE | ID: mdl-37907760

ABSTRACT

Coronavirus (COVID-19) was a pandemic disease that was affecting our medical and surgical daily practice badly. The surgical management of acute appendicitis was the gold standard, but new studies suggest the safety of antibiotic treatment alone. Non-operative treatment for simple acute appendicitis (NOTA) avoids surgery, the risks of general anesthesia, and long hospital stays. It also decreases the risk of exposure to coronavirus. We aimed to study the cost-effectiveness and outcome of NOTA during the COVID-19 pandemic and compared it to single-incision pediatric endo-surgery appendectomy (SIPESA). A prospective cohort study for NOTA of patients from 6 to 12 years old in the COVID-19 pandemic period from April 1st, 2020, to April 30th, 2021, patients were divided into two groups: Group S was managed by SIPESA, and Group N was managed by NOTA. Family education and assurance with detailed explanation were done for early detection of any complications, and we continue monitoring the patients until their complete recovery. Group S had 24 cases (40%), mean age 9.3 years. Group N had 36 cases (60%), mean age 9.1 years. Six cases (17%) in group N were converted to surgical management in the first 6 months of the study. The mean cost dropped from $2736/day to $400/day. The mean psychological stress for the children improved from 4.4 in April to 2 in September. The mean follow-up was 3.5 months. NOTA is a feasible, cost-effective approach, and we recommend it, as we have learned this lesson during the COVID-19 pandemic days.


Subject(s)
Appendicitis , COVID-19 , Humans , Child , Pandemics , Prospective Studies , Appendicitis/drug therapy , Appendicitis/surgery , Retrospective Studies , Acute Disease
4.
Cureus ; 15(10): e47928, 2023 Oct.
Article in English | MEDLINE | ID: mdl-38034265

ABSTRACT

BACKGROUND: Despite decades of studies, appendicitis in children still presents several uncertainties regarding optimal treatment. OBJECTIVES: To assess parental understanding of appendicitis, along with its risks and treatment, and to determine attitudes to operative and non-operative treatment of uncomplicated appendicitis. METHODS: This is a cross-sectional study. The current study has targeted all parents who visited the pediatric outpatient departments or clinics at three different hospitals in Makkah and Jeddah City, including Maternity and Children Hospital (MCH) in Makkah, King Fahad Armed Force Hospital (KFAFH), and Saudi German Private Hospital (SGH) in Jeddah. Data was collected via an online Google form and was analyzed by using SPSS. RESULTS: A total of 408 subjects were involved in this study. The majority of them were females (74.5%); 25.5% were males. Most of the study participants aged between 25 and 34 years. Our results found that the average knowledge score of the study population was 4.1±1.81 out of 11. Only 23.5% of them had good knowledge about appendicitis. More than half of the respondents identified the appendix as a part of the digestive system and most of the study population were aware of the current treatment for appendicitis, which is surgery (80.9%). Female participants and respondents who knew someone that has been treated for appendicitis were significantly associated with a better level of knowledge about appendicitis (P-values: 0.011 and 0.033, respectively). Moreover, we found that educational level significantly influenced preference for treatment with antibiotics and surgery if appendicitis happened again (P-value: 0.049). CONCLUSION: The study population had poor knowledge of appendicitis and its management options. The highlighted criteria of self-reported relevance to parents should be addressed in all appendicitis counseling and consent. We advocate for the establishment of national public awareness campaigns, as well as increased research and clinical trials. Understanding lay views of treatment alternatives and efficacy will influence future approaches to appendicitis therapy by analyzing the community's preference for emerging treatment modalities and identifying future directions for patient-centered clinical trials.

5.
J Taibah Univ Med Sci ; 17(4): 587-595, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35983439

ABSTRACT

Objectives: This study reports the prevalence of anemia and investigates its associated correlates and outcomes among elderly hospitalized patients in a single hospital in Bahrain. Methods: A retrospective study was conducted on 227 consecutive elderly patients admitted under general internal medicine in the biggest tertiary hospital in Bahrain. Medical records were reviewed for all patients, including clinical characteristics, laboratory results, and outcomes. Results: Anemia was highly prevalent among hospitalized elderly patients (71.6%). Males were significantly more affected than females (p = 0.031). In terms of severity, the most common type was moderate anemia (56.1%); with regards to etiology, the most common type was anemia associated with chronic disease (48.1%). Anemia was as common as other comorbidities, including hypertension (71.4%) and diabetes mellitus (53.7%). When comparing anemic to non-anemic patients, the length of hospital stay was significantly longer (p < 0.001) and inversely correlated to the level of hemoglobin; furthermore, 1-year mortality was significantly higher (p < 0.001). When compared to those with mild anemia, patients with moderate/severe anemia were more likely to die (odds ratio [OR] = 2.2, 95% confidence interval [CI]: 1.27-4.92). Conclusion: The prevalence of anemia in our study was higher than previously reported. Even so, anemia receives minimal attention and is usually seen as a minor problem. Our results reiterate the need to recognize the high importance of anemia especially when diagnosing and treating older patients. This, in turn, could positively affect a number of outcomes such as mortality, length of stay, and the functional decline of admitted individuals.

6.
Diabetol Metab Syndr ; 13(1): 120, 2021 Oct 26.
Article in English | MEDLINE | ID: mdl-34702335

ABSTRACT

BACKGROUND: One possible reason for increased mortality due to SARS-CoV-2 in patients with diabetes is from the complication of diabetic ketoacidosis (DKA). OBJECTIVES: To re-evaluate the association of SARS-CoV-2 and development of DKA and analyse the demographic and biochemical parameters and the clinical outcomes in COVID-19 patients with DKA. DESIGN: A systematic review and meta-analysis. Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement was followed. METHODS: Electronic databases (Proquest, Medline, Embase, Pubmed, CINAHL, Wiley online library, Scopus and Nature) were searched from 1 December 2019 to 30 June 2021 in the English language using the following keywords alone or in combination: COVID-19 OR SARS-CoV-2 AND diabetic ketoacidosis OR DKA OR ketosis OR ketonemia OR hyperglycaemic emergency OR hyperglycaemic crisis. We included studies in adults and children of all ages in all healthcare settings. Binary logistic regression model was used to explore the effect of various demographic and biochemical parameters variables on patient's final treatment outcome (survival or death). RESULTS: Of the 484 papers that were identified, 68 articles were included in the systematic review and meta-analysis (54 case report, 10 case series, and 4 cohort studies). Studies involving 639 DKA patients with confirmed SARS-CoV-2 [46 (7.2%) were children and 334 (52.3%) were adults] were analyzed. The median or mean patient age ranged from < 1 years to 66 years across studies. Most of the patients (n = 309, 48.3%) had pre-existing type 2 diabetes mellitus. The majority of the patients were male (n = 373, 58.4%) and belonged to Hispanic (n = 156, 24.4%) and black (n = 98, 15.3%) ethnicity. The median random blood glucose level, HbA1c, pH, bicarbonate, and anion gap in all included patients at presentation were 507 mg/dl [IQR 399-638 mg/dl], 11.4% [IQR 9.9-13.5%], 7.16 [IQR 7.00-7.22], 10 mmol/l [IQR 6.9-13 mmol/l], and 24.5 mEq/l [18-29.2 mEq/l]; respectively. Mortality rate was [63/243, 25.9%], with a majority of death in patients of Hispanic ethnicity (n = 17, 27%; p = 0.001). The odd ratios of death were significantly high in patients with pre-existing diabetes mellitus type 2 [OR 5.24, 95% CI 2.07-15.19; p = 0.001], old age (≥ 60 years) [OR 3.29, 95% CI 1.38-7.91; p = 0.007], and male gender [OR 2.61, 95% CI 1.37-5.17; p = 0.004] compared to those who survived. CONCLUSION: DKA is not uncommon in SARS-CoV-2 patients with diabetes mellitus and results in a mortality rate of 25.9%. Mortality key determinants in DKA patients with SARS-CoV-2 infection are individuals with pre-existing diabetes mellitus type 2, older age [≥ 60 years old], male gender, BMI ≥ 30, blood glucose level > 1000 mg/dl, and anion gap ≥ 30 mEq/l.

7.
Cureus ; 13(2): e13623, 2021 Feb 28.
Article in English | MEDLINE | ID: mdl-33816022

ABSTRACT

Objectives Obstructive sleep apnea (OSA) and nonalcoholic fatty liver disease (NAFLD) are prevalent and commonly associated conditions. We aimed to estimate the prevalence of NAFLD and identify liver fibrosis risk using noninvasive scoring methods in a cohort of patients with OSA. Methodology In this retrospective study of patients with confirmed OSA, patients who underwent abdominal ultrasonography were recruited. The primary outcome was the prevalence of suspected NAFLD (steatosis on ultrasound and/or elevated alanine transaminase [ALT]). The secondary outcomes included the prevalence and predictors of liver fibrosis risk as assessed by the NAFLD fibrosis score (NFS) and fibrosis-4 (FIB-4) score. Results A total of 133 patients fulfilled the study inclusion criteria. The average age was 49.8±15.1 years, and 57.1% were females. The average BMI was 37.3±14.5. According to the apnea-hypopnea index (AHI) scores, 37.9%, 29.6%, and 32.6% of participants had mild (5-14), moderate (15-29), and severe (>=30) OSA, respectively. Radiologically defined NAFLD was detected in 44.4% of the participants, and elevated liver enzymes were detected in 63.9% of the patients. High NFS and FIB-4 scores were recorded in 9% and 3.8% of the patients, respectively. According to logistic regression analysis, age and BMI significantly predicted high NFS scores. Conclusion NAFLD appears to be common among OSA patients. Age and obesity, but not OSA severity, predicted high liver fibrosis risk as assessed by noninvasive scoring systems.

8.
Environ Sci Pollut Res Int ; 28(11): 13991-13999, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33205277

ABSTRACT

During its aquatic life cycle, nanosized titanium dioxide (nTiO2) may interact with natural organic matter (NOM) ultimately altering the ecotoxicity of co-occurring chemical stressors such as heavy metals (e.g. copper (Cu)). In this context, the following hypotheses were tested: (1) aging of nTiO2 along with Cu reduces Cu toxicity, (2) nTiO2 agglomerates have a lower potential to reduce Cu toxicity and (3) aging of nTiO2 in presence of NOM reduces Cu toxicity further. A multifactorial test design crossing three nTiO2 levels (0.0, 0.6 and 3.0 mg/L) with two levels of NOM (0 versus 8 mg total organic carbon (TOC)/L) and seven nominal Cu concentrations (ranging from 0 to 1536 µg/L) aged in ASTM medium for 0, 1, 3 and 6 days was realised, while two aging scenarios were applied (type 1: nTiO2 jointly aged with Cu; type 2: Cu added after nTiO2 aging). Subsequently, Cu toxicity was assessed using the immobility of Daphnia magna after 48 h of exposure as response variable. The experiments revealed that neither aging duration nor the extent of agglomeration (type 1 vs. type 2 aging) has a substantial impact on Cu induced toxicity. Moreover, it was confirmed that the presence of NOM substantially reduced Cu induced toxicity, independent of the aging scenario and duration. More importantly, the data suggest the ingestion of Cu loaded nTiO2 as additional exposure pathway contributing to Cu toxicity. In conclusion, it seems unlikely that nTiO2 concentrations currently detected in or predicted for aquatic ecosystems, which are at least one order of magnitude below the concentration tested here, influence Cu toxicity meaningfully.


Subject(s)
Nanoparticles , Water Pollutants, Chemical , Aging , Animals , Copper , Daphnia , Ecosystem , Titanium , Water Pollutants, Chemical/toxicity
9.
Int J Food Sci ; 2020: 8380461, 2020.
Article in English | MEDLINE | ID: mdl-32190643

ABSTRACT

Dates' color is known to play a crucial role in determining the value and quality of the fruit. The color changes from the natural accepted golden color to unfavorable dark brown color during storage. In this study, the effect of different color preservation methods (modified atmosphere packaging, cold storage (4°C), sulfur dioxide gas (SO2), and blanching) and its relation to darkening due to action of the browning enzymes and melanin production were investigated. Polyphenol oxidase was shown to be active in all treatments except the samples treated with SO2 gas and steam blanching for ten minutes. Likewise, peroxidase activity showed a similar trend in all samples, but a decrease in activity was observed in sulfated samples and total inactivation in steam blanching for ten minutes. Moreover, sulfated samples have shown improvement in color compared to all other treatments, whereas the steamed samples showed the highest color deterioration. Concurrently, melanin content increased in all samples over the period of storage except in the sulfated samples. FTIR analyses of dates' melanin have revealed similar structural feature to the reference melanin; however, some differences were noticed in the regions 2850-2950 cm-1 and 1690-1705 cm-1 which indicated major structural difference between the two melanin samples. More work is suggested to reveal structural and functional properties of dates' melanin.

10.
Int J Surg Case Rep ; 55: 152-155, 2019.
Article in English | MEDLINE | ID: mdl-30738370

ABSTRACT

INTRODUCTION: Biliary atresia (BA) is a rare condition where the hepatic or common bile ducts get obliterated by fibrous tissue for unknown causes. It is diagnosed in 5-10 per 100,000 live births worldwide in whom liver injury and death are definite if untreated. PRESENTATION: We report a case of BA with associated malrotation and situs ambiguous discovered incidentally during Kasai procedure. The small intestine was found to be malrotated with the duodenojejunal junction to the right of the vertebral column. The liver, stomach, and spleen were in the center, right side, and left side of the abdomen respectively. The malrotation was corrected by performing a Ladd's procedure in addition to the Kasai. She had an uneventful postoperative course. At follow-up on the second, sixth and 12th weeks postoperatively, she had normal stool color and liver function. DISCUSSION: BA patients with associated structural anomalies might have a worse outcome after the Kasai procedure. Several studies demonstrated that the coexistence of malrotation with BA to be in the range of 0.3%-9.4% among BA patients. Also, the presence of situs abnormalities with BA has been reported in some studies to be present in 0.01-0.045% of BA cases. However, the presentation of BA with both situs inversus and intestinal malrotation has seldom been reported. CONCLUSION: The diagnosis of BA should prompt further investigation for other anatomical abnormalities as the presence of which might affect the management plan.

11.
Asian Pac J Cancer Prev ; 17(12): 5071-5074, 2016 12 01.
Article in English | MEDLINE | ID: mdl-28122436

ABSTRACT

Background: Azoxymethane (AOM) is a well-known colon cancer-inducing agent in experimental animals via mechanisms that include oxidative stress in rat colon and liver tissue. Few studies have investigated AOM-induced oxidative stress in rat liver tissue. Red seaweeds of the genera Hypnea Bryodies and Melanothamnus Somalensis are rich in polyphenolic compounds that may suppress cancer through antioxidant properties, yet limited research has been carried out to investigate their anti-carcinogenic and antioxidant influence against AOM-induced oxidative stress in rat liver. Objective: This study aims to determine protective effects of red seaweed (Hypnea Bryodies and Melanothamnus Somalensis) extracts against AOM-induced hepatotoxicity and oxidative stress. Materials and Methods: Sprague­Dawley rats received intraperitoneal injections of AOM, 15 mg/kg body weight, once a week for two consecutive weeks and then orally administered red seaweed (100 mg/kg body-weight) extracts for sixteen weeks. At the end of the experiment all animals were overnight fasted then sacrificed and blood and liver tissues were collected. Results: AOM treatment significantly decreased serum liver markers and induced hepatic oxidative stress as evidenced by increased liver tissue homogenate levels of nitric oxide and malondialdehyde, decreased total antioxidant capacity and glutathione, and inhibition of antioxidant enzymes (catalase, glutathione peroxidase, glutathione S-transferase, glutathione reductase and superoxide dismutase). Both red seaweed extracts abolished the AOM-associated oxidative stress and protected against liver injury as evidenced by increased serum levels of liver function markers. In addition, histological findings confirmed protective effects of the two red seaweed extracts against AOM-induced liver injury. Conclusion: Our findings indicate that red seaweed (Hypnea Bryodies and Melanothamnus Somalensis) extracts counteracted oxidative stress-induced hepatotoxicity in a rat model of colon cancer.

12.
BMC Complement Altern Med ; 14: 60, 2014 Feb 18.
Article in English | MEDLINE | ID: mdl-24533833

ABSTRACT

BACKGROUND: Azoxymethane (AOM) is a potent carcinogenic agent commonly used to induce colon cancer in rats; the cytotoxicity of AOM is considered to mediate oxidative stress. This study investigated the chemopreventive effect of three natural extracts [pomegranate peel extract (PomPE), papaya peel extract (PapPE) and seaweed extract (SE)] against AOM-induced oxidative stress and carcinogenesis in rat colon. METHODS: Eighty Sprague-Dawley rats (aged 4 weeks) were randomly divided into 8 groups (10 rats/group). Control group was fed a basal diet; AOM-treated group was fed a basal diet and received AOM intraperitonial injections for two weeks at a dose of 15 mg/kg bodyweight, whereas the other six groups were received oral supplementation of PomPE, PapPE or SE, in the presence or absence of AOM injection. All animals were continuously fed ad-libitum until aged 16 weeks, then all rats were sacrificed and the colon tissues were examined microscopically for pathological changes and aberrant crypt foci (ACF) development, genotoxicity (induced micronuclei (MN) cells enumeration), and glutathione and lipid peroxidation. RESULTS: Our results showed that AOM-induced ACF development and pathological changes in the colonic mucosal tissues, increased bone marrow MN cells and oxidative stress (glutathione depletion, lipid peroxidation) in rat colonic cells. The concomitant treatment of AOM with PomPE, PapPE or SE significantly ameliorated the cytotoxic effects of AOM. CONCLUSIONS: The results of this study provide in-vivo evidence that PomPE, PapPE and SE reduced the AOM-induced colon cancer in rats, through their potent anti-oxidant activities.


Subject(s)
Carcinogenesis/drug effects , Colon/drug effects , Colonic Neoplasms/drug therapy , Fruit , Oxidative Stress/drug effects , Plant Extracts/therapeutic use , Seaweed , Animals , Anticarcinogenic Agents/pharmacology , Anticarcinogenic Agents/therapeutic use , Antioxidants/pharmacology , Antioxidants/therapeutic use , Azoxymethane/adverse effects , Carica , Colon/metabolism , Colon/pathology , Colonic Neoplasms/chemically induced , Colonic Neoplasms/metabolism , Colonic Neoplasms/pathology , Dietary Supplements , Glutathione/metabolism , Humans , Intestinal Mucosa/drug effects , Intestinal Mucosa/pathology , Lipid Peroxidation/drug effects , Lythraceae , Male , Micronuclei, Chromosome-Defective , Phytotherapy , Plant Extracts/pharmacology , Rats , Rats, Inbred F344 , Rats, Sprague-Dawley
13.
Mar Biotechnol (NY) ; 13(5): 893-9, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21240534

ABSTRACT

Carrageenophyte red seaweed from Oman, Hypnea bryoides, extracted using three different processes: an aqueous, a mild alkaline, and a more vigorous alkaline extraction was investigated. The resulting extract precipitated by alcohol was subject to chemical and rheological measurements. The total carbohydrate [ranged from 36.78 to 41.65 g/100 g], and ash [39.04 to 43.11 g/100 g] were the most abundant components in H. bryoides and contrary to the two, lipid content was found at a minimum [ranging from 2.95 to 3.38 g/100 g]. Alkali treatment with NaOH allowed complete conversion of kappa (κ) carrageenan form as detected by FTIR analysis. Total yield by alkali treatments gave higher yields (33%) compared with aqueous treatments (12%). However, subsequent aqueous treatment produced mixed carrageenan (µ and κ) with higher molecular weight compared with the alkali treatments which produced single carrageenan form (κ) with molecular weight of 4.1 × 10(5) Da. The effects of thermal history on gel-sol and sol-gel transition were investigated by differential scanning calorimeter (DSC) and rheology on a pure sample and 1.5% κ-carrageenan mixture added with 30 mM KCl. Transition temperatures from DSC and rheology showed comparable results and were in good agreement with those previously reported.


Subject(s)
Carrageenan/chemistry , Carrageenan/metabolism , Rhodophyta/metabolism , Chromatography, Gel , Oceans and Seas , Oman , Rheology
14.
Appl Spectrosc ; 59(10): 1295-9, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16274543

ABSTRACT

A rapid, practical, and accurate Fourier transform infrared (FT-IR) method for the determination of moisture content in edible oils has been developed based on the extraction of water from oil samples into dry acetonitrile. A calibration curve covering a moisture content range of 0-2000 ppm was developed by recording the mid-infrared (MIR) spectra of moisture standards, prepared by gravimetric addition of water to acetonitrile that had been dried over molecular sieves, in a 500 microm ZnSe transmission flow cell and ratioing these spectra against that of the dry acetonitrile. Water was measured in the resulting differential spectra using either the OH stretching (3629 cm(-1) or bending (1631 cm(-1)) bands to produce linear standard curves having standard deviations (SDs) of approximately +/-20 ppm. For moisture analysis in oils, the oil sample was mixed with dry acetonitrile in a 1:1 w/v ratio, and after centrifugation to separate the phases, the spectrum of the upper acetonitrile layer was collected and ratioed against the spectrum of the dry acetonitrile used for extraction. The method was validated by standard addition experiments with samples of various oil types, as well as with oil samples deliberately contaminated with alcohols, hydroperoxides, and free fatty acids to investigate possible interferences from minor constituents that may be present in oils and are potentially extractable into acetonitrile. The results of these experiments confirmed that the moisture content of edible oils can be assessed with high accuracy (on the order of +/-10 ppm) by this method, thus providing an alternative to the conventional, but problematic, Karl Fischer method and facilitating the routine analysis of edible oils for moisture content.


Subject(s)
Dietary Fats, Unsaturated/analysis , Food Analysis/methods , Plant Oils/chemistry , Spectroscopy, Fourier Transform Infrared/methods , Water/analysis
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