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A novel infrared and microwave alternate thawing method for frozen pork: Effect on thawing rate and products quality

Hu R, Zhang M, Jiang Q, Law CL

Meat Sci, 2023 Apr;198:109084.
PMID: 36599205 DOI: 10.1016/j.meatsci.2022.109084

The effect of infrared and microwave alternate thawing (IR + MWT) on frozen pork were compared to fresh, air thawing (AT), infrared thawing (IRT), microwave thawing (MWT). The IR + MWT took only about 11.81 min of the thawing time compared to AT 66.5 min, and the Raman spectroscopy and Low-field nuclear magnetic resonance (LF-NMR) results showed that the IR + MWT maintained better protein secondary structure composition and moisture state compared to MWT and IRT. In terms of thawing losses, IR + MWT had the lowest loss 1.92%. In terms of texture, IR + MWT had the least effect on the post-thawing textural properties and increased the springiness of the meat. Scanning electron microscopy results also showed that there was reduced damage to the muscle structure with IR + MWT. Regarding the odor of the meat after thawing, IR + MWT retained the odor better and was closer to the fresh sample. Therefore, IR + MWT can be used to enhance the thawing rate to protect the quality of the thawed pork.

Matched MeSH terms: Freezing
An analytical method with a single extraction procedure and two separate high performance liquid chromatographic systems for the determination of artesunate, dihydroartemisinin and mefloquine in human plasma for application in clinical pharmacological studies of the drug combination

Lai CS, Nair NK, Mansor SM, Olliaro PL, Navaratnam V

J Chromatogr B Analyt Technol Biomed Life Sci, 2007 Oct 01;857(2):308-14.
PMID: 17719858

The combination of two sensitive, selective and reproducible reversed phase liquid chromatographic (RP-HPLC) methods was developed for the determination of artesunate (AS), its active metabolite dihydroartemisinin (DHA) and mefloquine (MQ) in human plasma. Solid phase extraction (SPE) of the plasma samples was carried out on Supelclean LC-18 extraction cartridges. Chromatographic separation of AS, DHA and the internal standard, artemisinin (QHS) was obtained on a Hypersil C4 column with mobile phase consisting of acetonitrile-0.05 M acetic acid adjusted to pH 5.2 with 1.0M NaOH (42:58, v/v) at the flow rate of 1.50 ml/min. The analytes were detected using an electrochemical detector operating in the reductive mode. Chromatography of MQ and the internal standard, chlorpromazine hydrochloride (CPM) was carried out on an Inertsil C8-3 column using methanol-acetonitrile-0.05 M potassium dihydrogen phosphate adjusted to pH 3.9 with 0.5% orthophosphoric acid (50:8:42, v/v/v) at a flow rate of 1.00 ml/min with ultraviolet detection at 284 nm. The mean recoveries of AS and DHA over a concentration range of 30-750 ng/0.5 ml plasma and MQ over a concentration of 75-1500 ng/0.5 ml plasma were above 80% and the accuracy ranged from 91.1 to 103.5%. The within-day coefficients of variation were 1.0-1.4% for AS, 0.4-3.4% for DHA and 0.7-1.5% for MQ. The day-to-day coefficients of variation were 1.3-7.6%, 1.8-7.8% and 2.0-3.4%, respectively. Both the lower limit of quantifications for AS and DHA were at 10 ng/0.5 ml and the lower limit of quantification for MQ was at 25 ng/0.5 ml. The limit of detections were 4 ng/0.5 ml for AS and DHA and 15 ng/0.5 ml for MQ. The method was found to be suitable for use in clinical pharmacological studies.

Matched MeSH terms: Freezing
Fulltext Anti-icing performance on aluminum surfaces and proposed model for freezing time calculation

Nguyen VH, Nguyen BD, Pham HT, Lam SS, Vo DN, Shokouhimehr M, et al.

Sci Rep, 2021 Feb 11;11(1):3641.
PMID: 33574397 DOI: 10.1038/s41598-020-80886-x

In this work, we proposed a facile approach to fabricate a superhydrophobic surface for anti-icing performance in terms of adhesive strength and freezing time. A hierarchical structure was generated on as-received Al plates using a wet etching method and followed with a low energy chemical compound coating. Surfaces after treatment exhibited the great water repellent properties with a high contact angle and extremely low sliding angle. An anti-icing investigation was carried out by using a custom-built apparatus and demonstrated the expected low adhesion and freezing time for icephobic applications. In addition, we proposed a model for calculating the freezing time. The experimented results were compared with theoretical calculation and demonstrated the good agreement, illustrating the importance of theoretical contribution in design icephobic surfaces. Therefore, this study provides a guideline for the understanding of icing phenomena and designing of icephobic surfaces.

Matched MeSH terms: Freezing
Fulltext Antifreeze Proteins and Their Practical Utilization in Industry, Medicine, and Agriculture

Eskandari A, Leow TC, Rahman MBA, Oslan SN

Biomolecules, 2020 12 09;10(12).
PMID: 33317024 DOI: 10.3390/biom10121649

Antifreeze proteins (AFPs) are specific proteins, glycopeptides, and peptides made by different organisms to allow cells to survive in sub-zero conditions. AFPs function by reducing the water's freezing point and avoiding ice crystals' growth in the frozen stage. Their capability in modifying ice growth leads to the stabilization of ice crystals within a given temperature range and the inhibition of ice recrystallization that decreases the drip loss during thawing. This review presents the potential applications of AFPs from different sources and types. AFPs can be found in diverse sources such as fish, yeast, plants, bacteria, and insects. Various sources reveal different α-helices and β-sheets structures. Recently, analysis of AFPs has been conducted through bioinformatics tools to analyze their functions within proper time. AFPs can be used widely in various aspects of application and have significant industrial functions, encompassing the enhancement of foods' freezing and liquefying properties, protection of frost plants, enhancement of ice cream's texture, cryosurgery, and cryopreservation of cells and tissues. In conclusion, these applications and physical properties of AFPs can be further explored to meet other industrial players. Designing the peptide-based AFP can also be done to subsequently improve its function.

Matched MeSH terms: Freezing
Application of freeze-drying technology in manufacturing orally disintegrating films

Liew KB, Odeniyi MA, Peh KK

Pharm Dev Technol, 2016;21(3):346-53.
PMID: 25597618 DOI: 10.3109/10837450.2014.1003657

Freeze drying technology has not been maximized and reported in manufacturing orally disintegrating films. The aim of this study was to explore the freeze drying technology in the formulation of sildenafil orally disintegrating films and compare the physical properties with heat-dried orally disintegrating film. Central composite design was used to investigate the effects of three factors, namely concentration of carbopol, wheat starch and polyethylene glycol 400 on the tensile strength and disintegration time of the film. Heat-dried films had higher tensile strength than films prepared using freeze-dried method. For folding endurance, freeze-dried films showed improved endurance than heat-dried films. Moreover, films prepared using freeze-dried methods were thicker and had faster disintegration time. Formulations with higher amount of carbopol and starch showed higher tensile strength and thickness whereas formulations with higher PEG 400 content showed better flexibility. Scanning electron microscopy showed that the freeze-dried films had more porous structure compared to the heat-dried film as a result of the release of water molecule from the frozen structure when it was subjected to freeze drying process. The sildenafil film was palatable. The dissolution profiles of freeze-dried and heat-dried films were similar to Viagra® with f2 of 51.04 and 65.98, respectively.

Matched MeSH terms: Freezing
Association rules between the microstructure and physical mechanical properties of rock-mass under coupled effect of freeze-thaw cycles and large temperature difference

Haibo Jiang, Zuguo Mo, Xiongbin Hou, Haijuan Wang

Sains Malaysiana, 2017;46:2205-2213.

The mechanical properties of fractured rock mass are largely dependent on the fracture structure under the coupling of freeze-thaw cycles and large temperature difference. Based on the traditional macroscopic continuum theory, the thermal and mechanical model and the corresponding theories ignore the material internal structure characteristics, which add difficulty in describing the mesoscopic thermal and mechanical behavior of the fractured rock mass among different phases. In order to uncover the inherent relationship and laws among the internal crack development, structural change and the physical and mechanical properties of rock under strong cold and frost weathering in cold area, typical granite and sandstone in cold region were analyzed in laboratory tests. The SEM scanning technology was introduced to record the microstructural change of rock samples subject to freeze-thaw cycles and large temperature difference. Association rules between the microstructure and the physical mechanical properties of rock mass were analyzed. The results indicated that, with the increase of the cyclic number, the macroscopic physical and mechanical indexes and the microscopic fracture index of granite and sandstone continuously and gradually deteriorate. The width of original micro crack continues to expand and extend and new local micro cracks are generated and continue to expand. The fracture area and width of the rock increase and the strength of the rock is continuously damaged. In particular, the strength and elastic modulus of granite decrease by 20.2% and 33.36%, respectively; the strength and elastic modulus of sandstone decrease by 33.4% and 36.43%, respectively.

Matched MeSH terms: Freezing
Biobanking of Human Mesenchymal Stem Cells: Future Strategy to Facilitate Clinical Applications

Yong KW, Choi JR, Wan Safwani WK

Adv Exp Med Biol, 2016;951:99-110.
PMID: 27837557

Human mesenchymal stem cells (hMSCs), a type of adult stem cells that hold great potential in clinical applications (e.g., regenerative medicine and cell-based therapy) due to their ability to differentiate into multiple types of specialized cells and secrete soluble factors which can initiate tissue repair and regulate immune response. hMSCs need to be expanded in vitro or cryopreserved to obtain sufficient cell numbers required for clinical applications. However, long-term in vitro culture-expanded hMSCs may raise some biosafety concerns (e.g., chromosomal abnormality and malignant transformation) and compromised functional properties, limiting their use in clinical applications. To avoid those adverse effects, it is essential to cryopreserve hMSCs at early passage and pool them for off-the-shelf use in clinical applications. However, the existing cryopreservation methods for hMSCs have some notable limitations. To address these limitations, several approaches have to be taken in order to produce healthy and efficacious cryopreserved hMSCs for clinical trials, which remains challenging to date. Therefore, a noteworthy amount of resources has been utilized in research in optimization of the cryopreservation methods, development of freezing devices, and formulation of cryopreservation media to ensure that hMSCs maintain their therapeutic characteristics without raising biosafety concerns following cryopreservation. Biobanking of hMSCs would be a crucial strategy to facilitate clinical applications in the future.

Matched MeSH terms: Freezing
Biochemical analyses of Dendrobium Sabin Blue PLBs during cryopreservation by vitrification

James Antony JJ, Zakaria S, Zakaria R, Anak Ujang J, Othman N, Subramaniam S

Physiol Mol Biol Plants, 2019 Nov;25(6):1457-1467.
PMID: 31736548 DOI: 10.1007/s12298-019-00703-2

Dendrobium Sabin Blue is an important orchid hybrid that has been grown extensively as cut flower, potted plant and is also popular for its deep purplish blue flowers. The most efficient long term conservation method of this hybrid is through cryopreservation. Cryopreservation involving the vitrification method consists of explants exposure to highly concentrated cryoprotective solution followed by freezing rapidly in liquid nitrogen. However, these treatments involved highly concentrated cryoprotectant that could incur toxicity to the explants. Hence, cryopreservation protocol requires biochemical analyses in understanding the damages or injuries occurred during cryopreservation treatments. In this study, biochemical analyses revealed a general reduction in chlorophyll, carotenoid and porphyrin content to 0.40 µg/g F W (thawing stage), 31.50 µg/g F W unloading stage and 2230.41 µg/g F W (thawing stage), respectively in comparison to the control treatments. In addition, increased level in proline content were obtained at different cryopreservation stages with highest level (5.42 µmole/g F W) recorded at the PVS2 dehydration stage. Fluctuated outcomes were obtained in catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POX) enzyme activities in PLBs exposed to different cryopreservation stages. Lowest values recorded for CAT enzyme activity were obtained at the dehydration stage (3.94 U/g). Lowest POX enzyme activities were obtained at the dehydration (122.36 U/g) and growth recovery (106.40 U/g) stages. Additionally, lowest APX enzyme activities values were recorded at the thawing (7.47 U/g) and unloading (7.28 U/g) stages. These have contributed to low regeneration of Dendrobium Sabin Blue protocorm like bodies (PLBs) following cryopreservation. Hence, in the future experimental design, exogenous antioxidant could be included in the cryopreservation procedures to improve the existing protocol.

Matched MeSH terms: Freezing
Bovine serum albumin: survival and osmolarity effect in bovine spermatozoa stored above freezing point

Nang CF, Osman K, Budin SB, Ismail MI, Jaffar FH, Mohamad SF, et al.

Andrologia, 2012 May;44 Suppl 1:447-53.
PMID: 21806660 DOI: 10.1111/j.1439-0272.2011.01203.x

Liquid nitrogen preservation in remote farms is a limitation. The goal of this study was to determine optimum temperature above freezing point for bovine spermatozoa preservation using bovine serum albumin (BSA) as a supplementation. Pooled semen sample from three ejaculates was subjected to various BSA concentration (1, 4, 8 and 12 mg ml(-1)), before incubation in different above freezing point temperatures (4, 25 and 37 °C). Viability assessment was carried out against time from day 0 (fresh sample) until all spermatozoa become nonviable. Optimal condition for bovine spermatozoa storage was at 4 °C with 1 mg ml(-1) BSA for almost 7 days. BSA improved bovine spermatozoa viability declining rate to 44.28% at day 4 and 57.59% at day 7 compared to control, with 80.54% and 98.57% at day 4 and 7 respectively. Increase in BSA concentration did not improve sperm viability. Our results also confirmed that there was a strong negative correlation between media osmolarity and bovine spermatozoa survival rate with r = 0.885, P < 0.0001. Bovine serum albumin helps to improve survival rate of bovine spermatozoa stored above freezing point.

Matched MeSH terms: Freezing*
Fulltext Butylated hydroxytoluene protects bull sperm surface protein-P25b in different extenders following cryopreservation

Khumran AM, Yimer N, Rosnina Y, Wahid H, Ariff MO, Homayoun H, et al.

Vet World, 2019 Apr;13(4):649-654.
PMID: 32546907 DOI: 10.14202/vetworld.2020.649-654

Aim: The aim of this study was to investigate the effects of different concentration of butylated hydroxytoluene (BHT) on sperm membrane surface protein "P25b" from cryopreserved bull semen in either lecithin based Bioxcell® (BX) or two egg-yolk based extenders, tris-egg yolk (TEY), and citrate-egg yolk (CEY).
Materials and Methods: Forty-five semen samples, 15 each were extended with either BX, TEY, or CEY extender which contained different concentrations (0.0 - control, 0.5, 1.0, 1.5, 2.0, and 3.0 mM/mL) of BHT. The extended semen samples were frozen at a concentration of 20×106/mL in 0.25 mL straws and stored in liquid nitrogen for 2weeks. The frozen samples were thereafter thawed, proteins extracted and analyzed for quantities of protein P25b through direct sodium dodecyl sulfate-polyacrylamide gel electrophoresis gel densitometry. Peptides were confirmed by Western blotting (WB).
Results: Results showed that supplementation of BHT improved (p<0.05) quantity of protein P25b at concentrations of 0.5mM/mL for BX and at 1.0 mM/mL for TEY and CE when compared with the controls and other treatments.
Conclusion: BHT supplementation at 0.5 in BX and 1.0 mM/mL in TEY and CEY has protected bull sperm fertility marker protein P25b in frozen-thawed bull sperm.

Matched MeSH terms: Freezing
Fulltext Chemical composition changes of two water apple (Syzygium samaragense)

Rosnah, S., Wong, W.K., Noraziah, M., Osman, H.

International Food Research Journal, 2012;19(1):167-174.
MyJurnal

Changes in physical properties (weight, size, colour and weight loss) and chemical properties (proximate analysis, TSS, pH, freezing point, total acidity and sugar content) of two water apple (Syzgium samaragense) cultivars, Semarang Rose and Kristal Taiwan were evaluated during ripening at 10°C and 50% RH. The results showed that the Kristal Taiwan cultivar was larger in size and weight but smaller in length compared to Semarang Rose. The Semarang Rose cultivar was sweeter than Kristal Taiwan. In this study, data obtained suggests that the water apple fruit can be stored at cold storage until 19 days.

Matched MeSH terms: Freezing
Chitosan coated alginate-xanthan gum bead enhanced pH and thermotolerance of Lactobacillus plantarum LAB12

Fareez IM, Lim SM, Mishra RK, Ramasamy K

Int J Biol Macromol, 2015 Jan;72:1419-28.
PMID: 25450046 DOI: 10.1016/j.ijbiomac.2014.10.054

The vulnerability of probiotics at low pH and high temperature has limited their optimal use as nutraceuticals. This study addressed these issues by adopting a physicochemical driven approach of incorporating Lactobacillus plantarum LAB12 into chitosan (Ch) coated alginate-xanthan gum (Alg-XG) beads. Characterisation of Alg-XG-Ch, which elicited little effect on bead size and polydispersity, demonstrated good miscibility with improved bead surface smoothness and L. plantarum LAB12 entrapment when compared to Alg, Alg-Ch and Alg-XG. Sequential incubation of Alg-XG-Ch in simulated gastric juice and intestinal fluid yielded high survival rate of L. plantarum LAB12 (95%) at pH 1.8 which in turn facilitated sufficient release of probiotics (>7 log CFU/g) at pH 6.8 in both time- and pH-dependent manner. Whilst minimising viability loss at 75 and 90 °C, Alg-XG-Ch improved storage durability of L. plantarum LAB12 at 4 °C. The present results implied the possible use of L. plantarum LAB12 incorporated in Alg-XG-Ch as new functional food ingredient with health claims.

Matched MeSH terms: Freezing
Fulltext Collection, analysis and cryopreservation of semen from Malayan gaur (Bos gaurus hubbacki): A preliminary study

Iswadi MI, Ann ZF, Hafiz MM, Hafiz MD, Fahrul FJ, Hajarian H, et al.

Open Vet J, 2012;2(1):109-14.
PMID: 26623302

The Malayan gaur (Bos gaurus hubbacki) or Seladang is classified as vulnerable by the International Union for Conservation of Nature and Natural Resources (IUCN). The Malayan gaur is mainly distributed in the tropical woodlands of Peninsular Malaysia and Southern Thailand. The aim of this study was to collect, analyze and cryopreserve the semen of wild Malayan gaur. Transrectal massage (TM) and electroejaculation (EEJ) technique was applied in semen collection of the Malayan gaur. The semen was then cryopreserved in liquid nitrogen using slow freezing technique. Makler counting chamber was used to evaluate sperm concentration and motility, while the sperm viability and morphology of fresh and post-thaw sperm was determined using eosin-nigrosin staining protocol. As a result, we have successfully collected the Malayan gaur semen using EEJ technique. Sperm motility, viability and morphological changes of the post-thaw semen of Malayan gaur were found undesirable due to the complication of the cryopreservation process. On the basis of current study it can be concluded that Malayan gaur bulls semen can be obtain by EEJ with no evidence of rectal trauma. Optimization of the process of cryopreservation for Malayan gaur sperm is needed to maintain the cryoviability of the good sperm quality. The data generated in this study would be useful in conservation of genetic diversity program for Malayan gaur.

Matched MeSH terms: Freezing
Fulltext Comparison between mechanical freezer and conventional freezing using liquid nitrogen in normozoospermia

Rahana AR, Ng SP, Leong CF, Rahimah MD

Singapore Med J, 2011 Oct;52(10):734-7.
PMID: 22009393

INTRODUCTION: This study evaluated the effect of human semen cryopreservation using an ultra-low temperature technique with a mechanical freezer at -85°C as an alternative method to the conventional liquid nitrogen technique at -196°C.
METHODS: This was a prospective experimental study conducted in the Medically Assisted Conception unit, Department of Obstetrics and Gynaecology, National University Hospital, Malaysia from January 1, 2006 to April 30, 2007. All normozoospermic semen samples were included in the study. The concentration, motility and percentage of intact DNA of each semen sample were assessed before and after freezing and thawing on Days 7 and 30 post freezing.
RESULTS: Sperm cryopreservation at -85°C was comparable to the conventional liquid nitrogen technique for a period of up to 30 days in a normozoospermic sample. There was no statistical difference in concentration (Day 7 p-value is 0.1, Day 30 p-value is 0.2), motility (Day 7 p-value is 0.9, Day 30 p-value is 0.5) and proportion of intact DNA (Day 7 p-value is 0.1, Day 30 p-value is 0.2) between the ultra-low temperature technique and conventional liquid nitrogen cryopreservation at Days 7 and 30 post thawing.
CONCLUSION: This study clearly demonstrates that short-term storage of sperm at -85°C could be a viable alternative to conventional liquid nitrogen cryopreservation at -196°C due to their comparable post-thaw results.

Matched MeSH terms: Freezing*
Composition and thermal characteristics of Madhuca longifolia seed fat and its solid and liquid fractions

Marikkar JM, Ghazali HM, Long K

J Oleo Sci, 2010;59(1):7-14.
PMID: 20032594

This study was to characterize the seed fat from Madhuca longifolia known as Mee fat and its solid and liquid fractions with the objective of distinguishing them. A sample of Mee fat was partitioned into solid and liquid fractions using acetone as the solvent medium. The isolated fractions were compared to the native Mee fat sample with respect to various physico-chemical parameters using standard chemical methods as well as instrumental techniques such as, gas liquid chromatography (GLC), reversed-phase high performance liquid chromatography (RP-HPLC), and differential scanning calorimetry (DSC). Basic analyses indicated that there were wide variations between the native sample and its fractions with respect to iodine value (IV), and slip melting point (SMP). The cloud point (CP) of the liquid fraction was found to be 10.5 degrees C. Fatty acid compositional analyses showed that the proportion of saturated fatty acids (SFA) such as palmitic and stearic went up in the high-melting fraction (HMF) while in low-melting fraction (LMF) the proportion of unsaturated fatty acid (USFA) such as oleic and lenoleic increased. According to the HPLC analyses, Mee fat had a tiacyl glycerol (TAG) sequence similar to that of palm oil. After fractionation, the solid and liquid fractions obtained were found to have TAG profiles very much different from the native sample. Thermal analyses by DSC showed that Mee fat had two-widely separated high and low melting thermal transitions, a feature which was beneficial for the effective separation of solid and liquid fractions. The thermal profiles displayed by the fractions were clearly distinguishable from that of the native sample.

Matched MeSH terms: Freezing
Cryopreservation of Human Mesenchymal Stem Cells for Clinical Applications: Current Methods and Challenges

Yong KW, Wan Safwani WK, Xu F, Wan Abas WA, Choi JR, Pingguan-Murphy B

Biopreserv Biobank, 2015 Aug;13(4):231-9.
PMID: 26280501 DOI: 10.1089/bio.2014.0104

Mesenchymal stem cells (MSCs) hold many advantages over embryonic stem cells (ESCs) and other somatic cells in clinical applications. MSCs are multipotent cells with strong immunosuppressive properties. They can be harvested from various locations in the human body (e.g., bone marrow and adipose tissues). Cryopreservation represents an efficient method for the preservation and pooling of MSCs, to obtain the cell counts required for clinical applications, such as cell-based therapies and regenerative medicine. Upon cryopreservation, it is important to preserve MSCs functional properties including immunomodulatory properties and multilineage differentiation ability. Further, a biosafety evaluation of cryopreserved MSCs is essential prior to their clinical applications. However, the existing cryopreservation methods for MSCs are associated with notable limitations, leading to a need for new or improved methods to be established for a more efficient application of cryopreserved MSCs in stem cell-based therapies. We review the important parameters for cryopreservation of MSCs and the existing cryopreservation methods for MSCs. Further, we also discuss the challenges to be addressed in order to preserve MSCs effectively for clinical applications.

Matched MeSH terms: Freezing
Fulltext Cryopreservation of oil palm (Elaeis guineensis Jacq.) polyembryoids via encapsulation-desiccation

Palanyandy SR, Gantait S, Subramaniam S, Sinniah UR

3 Biotech, 2020 Jan;10(1):9.
PMID: 31850156 DOI: 10.1007/s13205-019-1997-9

The current report assesses the efficiency of encapsulation-desiccation protocol to cryopreserve oil palm (Elaeis guineensis Jacq.) polyembryoids. Specifically identified polyembryoids, comprising of haustorium and torpedo-shaped structures, were encapsulated [comprising 3% (w/v) sodium alginate and 100 mM CaCl2]. Calcium alginate-encapsulated and sucrose-precultured polyembryoids were subjected to different spans of desiccation in a laminar air-flow cabinet, followed by freezing in liquid nitrogen. The effect of sucrose preculture (with gradual exposure to 0.3, 0.5, 0.75 and 1 M for 7 days) and dehydration periods (0-10 h) under sterile air-flow on post-freezing survival and regrowth of encapsulated polyembryoids were studied. Cryopreserved and thawed polyembryoids (initially precultured in sucrose, followed by 9 h air-desiccated to 23.3% moisture content) displayed the highest survival percentage (73.3%) and regeneration (of shoot, root and secondary somatic embryo) on Murashige and Skoog regrowth medium containing sucrose (0.3-1 M) and 0.2 mg/l 2,4-dichlorophenoxy acetic acid. In addition, ultrastructural study using scanning electron microscopy exhibited successful revival of cryopreserved polyembryoids, owing to retention of cellular membrane stability through optimized and protected (encapsulated) desiccation. The present study thus substantiates the potential of this encapsulation-desiccation procedure in cryopreservation of oil palm polyembryoids for long-term conservation programs.

Matched MeSH terms: Freezing
Cryopreservation of shoot tips of recalcitrant and tropical species: Advances and strategies

Normah MN, Sulong N, Reed BM

Cryobiology, 2019 04;87:1-14.
PMID: 30677412 DOI: 10.1016/j.cryobiol.2019.01.008

There is a pressing need for practical and successful conservation efforts to establish long-term germplasm collections of recalcitrant and tropical species, given the challenge and threat that these plants are facing. Cryopreservation is the only way of conserving some of these species, especially those with temperature or desiccation sensitive (recalcitrant) seeds. This review covers reports on cryopreservation studies of shoot tips (apical and axillary) of tropical and subtropical plants. Since many of these species have recalcitrant seeds, the cryopreservation successes, failures and problems involved with these seeds are also discussed. The methodologies, important factors and steps involved in successful cryopreservation protocols are analyzed. Finally strategies are suggested to develop a successful cryopreservation protocol for new plant species, in particular those with tropical recalcitrant seeds.

Matched MeSH terms: Freezing
Cryotherapy: A Successful Monotherapy for Earlobe Keloids

Muthanna AM, Al-Qubati YA

Malays Fam Physician, 2020;15(3):83-85.
PMID: 33329867

A keloid represents an excessive overgrowth of skin beyond the boundaries of an injury. Earlobe keloids usually follow ear piercing and can become large, sometimes producing remarkable disfigurement. Surgical excision, pressure dressing, intralesional corticosteroid injection, cryosurgery, radiation, and lasers have all been used to treat earlobe keloids. However, none has produced uniformly satisfactory results. Combinations of more than one modality have also been employed to yield successful outcomes. We describe cryotherapy as a single modality to treat seven-year-old, multiple earlobe keloids. Three cryotherapy sessions with two freezing-thawing cycles of 30-40 seconds' freezing time and two minutes' thawing time, undertaken one month apart, resulted in complete flatness of the keloids and no recurrence after 5 years. We also evaluate keloid-related and operational factors that determine the success of cryotherapy as a monotherapy for earlobe keloids.

Matched MeSH terms: Freezing
Fulltext Crystal habit during crystallization of RBDPO with the addition of Diacylglycerol (DAG): effect of time and percentage of DAG added

Normah, I., Cheow, C.S., Chong, C.L.

International Food Research Journal, 2014;21(5):2045-2049.
MyJurnal

Diacylglycerol at 1 or 6% was added into refined bleached and deodorized palm oil (RBDPO) and crystallized from the melt in a thermally controlled water bath at 22°C for 90 min. Slurries were withdrawn after 5, 15, 30, 60 and 90 min of crystallization for solid fat content (SFC) and crystal morphology studies. Crystallization was also performed in a similar manner using a Labmax reactor connected to a FBRM detector to obtain the information on crystal count and size distribution during crystallization. SFC of the slurries increased with increase in crystallization time up to a certain level followed by a plateau. SFC of RBDPO added with DAG was also higher with the increase in percentage of DAG added and no induction time was observed to initiate crystallization in RBDPO added with DAG. The addition of DAG caused rapid crystallization of RBDPO as observed by enhance nucleation and larger crystal size with increase in the percentages of DAG added.

Matched MeSH terms: Freezing

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