Diatom Extracts Research Articles

A Study Investigating The Presence Of Diatoms On Tooth Samples Using The Acid Digestion Method For The Estimation Of Time Since Death In Drowning Cases

Teeth are a further source of diatoms in establishing the cause of death and time since death by analysis of the stage qualitative and quantitative evaluation of diatoms diversity. Trials also confirmed that diatoms have also been a useful tool in differentiating antemortem and postmortem drowning (Jian Zhao April 2014). Diatoms are a type of algae that belong to the phylum Bacillariophyta. They are unicellular organisms with a unique feature – their cell walls are made of silica, which gives them a glass-like appearance. Diatoms are a diverse group of microorganisms found in various aquatic environments, including oceans, lakes, rivers, and even damp soil. This study mainly focuses on a tooth immersed in a water sample from a known water body for a day and the 7th day to observe the variation and the stages of the life cycle. The method of extraction used is the acid digestion method using concentrated Sulphuric Acid. We could find the centric and pennate types of diatoms. Diatoms are also important as they indicate natural water quality (European Committee of Standardization 2004). According to the results, we cannot deny that teeth are a source for the extraction of diatoms and also an indicator of time since death when other methods fail.

Application of Protease-Hydrogen Peroxide Digestion Method in Forensic Diatom Examination.

To propose a novel forensic diatom examination method, namely the protease-hydrogen peroxide (PHP) digestion method, and to explore its potential application in forensic practice. The PHP digestion method was applied to process lung tissues and compared with the traditional nitric acid digestion method in terms of diatom quantity, recovery rate, proportion of diatom fragments, and recovery efficiency of different diatom genera. The PHP digestion method showed higher diatom quantity, recovery rate, and proportion of diatom fragments compared to the traditional nitric acid digestion method with statistical significance. The average diatom recovery rate was as high as 93.95%. In the lung tissues digested with nitric acid, there were 65 Achnanthes, 36 Nitzschia Ⅰ, 22 Nitzschia Ⅱ, 20 Diploneis and 8 Cymbella, showing significantly lower recovery rates compared to water samples which had 154 Achnanthes, 44 Nitzschia Ⅰ, 45 Nitzschia Ⅱ, 33 Diploneis and 23 Cymbella. However, with the PHP digestion method, only Nitzschia Ⅱ showed a lower recovery rate compared to water samples (P<0.05). At the same time, the diatom recovery stability of the PHP digestion method was higher than that of the nitric acid digestion method. The PHP digestion method is superior to the traditional nitric acid digestion method in the lung tissue diatom extraction efficiency. Additionally, it holds significant advantages in safety, environmental protection, and other aspects. It is expected to be applied in forensic drowning identification.

Evaluation of the Effectiveness of an Alternate Diatom Extraction Procedure in Diatomological Study

Background: The “Diatom Test” is based on the recovery of diatoms in high concentration in the organs of drowned persons because diatoms pass through the alveoli into the great circulation. Acid digested extracts of various internal organs and water collected from waterbodies demonstrate the presence of diatoms. If quantitatively and qualitatively these diatoms match to each other, that is the confirmatory diagnosis of death due to drowning in that drowning medium. This study was conducted to analyze the effectiveness of alternate method of diatom extraction using diluted Sulphuric acid solution and to compare its effectiveness with the traditional method of extraction of diatoms using concentrated nitric acid.Methods: It was a prospective study. Samples were collected from ten different water bodies which included lakes,rivers, canals and reservoirs, for a period of one year in all the seasons. The pH and temperature of water were recorded during sampling. From each of water samples, diatoms were extracted using both classical and alternate method. And then compared by observing the diatoms at 100X magnification under compound microscope. Total 22 genera of diatoms were identified. Most of them were pennales and few were centrales. The time demanded for complete digestion of samples with strong acids like concentrated nitric acid was much lesser time than with diluted acids as it hasstronger digestive capability in comparison to diluted sulphuric acid. The structures of different diatoms specifically Cyclotella, Cybella, Navicula were better found in almost intact state with clear background after digestion by diluted sulphuric acid.Conclusion: Depending on different criterion, digestion by diluted sulphuric acid has procured better result than concentrated nitric acid digestion method. Therefore, for qualitative and quantitative diatom analysis alternate diatom extraction method is a better choice than traditional method.

Accelerated sonosynthesis of chromeno[4,3‐b]quinoline derivatives via marine‐bioinspired tin oxide nanocatalyst

Green nanocatalysts play a crucial role in organic synthesis. In this study, a novel approach utilizing marine diatom extract is presented for the production of tin oxide nanoparticles (SnO2 NPs). These NPs possess distinctive characteristics, including crystalline properties, a spherical shape, and an average size of 20 ± 2 nm. The reduction and surface coating of the NPs involve organic components derived from marine sources. The resulting SnO2 NPs serve as highly effective catalysts for the synthesis of chromeno[4,3‐b]quinoline derivatives, facilitated by ultrasound‐assisted reactions. This process demonstrates remarkable efficiency, yielding a variety of organic products with impressive results, reaching yields of 82–97% and requiring short reaction times. Moreover, the SnO2 nanocatalyst employed exhibits advantageous properties, such as low loading, durability, and the ability to be reused up to six cycles.

Nutritional profile, bioactive compounds, and antioxidant activity of microalgal strain, Amphora sp., isolated from the Cape coastal waters, South Africa

Microalgae represent a potential source of renewable nutrition, and there is growing global interest in algae-based dietary supplements. However, the selection of suitable and indigenous microalgae species is a fundamental requirement in developing value-added bioactive compounds in the food industry. The proximate composition, fatty acids, amino acids, and mineral profile, as well as bioactive compounds and antioxidant activity of an unexplored diatom strain, Amphora sp. WCA23.2, isolated from the Cape coastal waters, South Africa, were evaluated as a potential nutraceutical. The Amphora sp. WCA23.2 biomass had 44.2% ash, 28% carbohydrates, 15% protein, and 4% lipids. The fatty acid profile revealed that the diatom accumulates a significant amount of omega-7-monounsaturated fatty acid palmitoleic acid (24.50 mg/g), while the amino acid profile demonstrated that it contained all the nine essential amino acids. The antioxidant activities of the diatom extracts showed that the methanolic extract displayed the highest DPPH radical scavenging activity (1.90±0.11 mg GAE/g dry weight (DW)) and the lowest IC50 in all the antioxidant indices evaluated. These results suggest that Amphora sp. WCA23.2 biomass and its extracts can be utilized as a potential source of ingredients and nutraceuticals in food systems for humans.

Hyperhalophilic Diatom Extract Protects against Lead-Induced Oxidative Stress in Rats and Human HepG2 and HEK293 Cells.

This work investigated the protective effects of microalga Halamphora sp. extract (HExt), a nutraceutical and pharmacological natural product, on human lead-intoxicated liver and kidney cells in vitro and in vivo in Wistar rats. The human hepatocellular carcinoma cell line HepG2 and the human embryonic kidney cell line HEK293 were used for the in vitro study. The analysis of the fatty acid methyl esters in the extract was performed via GC/MS. The cells were pretreated with HExt at 100 µg mL-1, followed by treatment with different concentrations of lead acetate, ranging from 25 to 200 µM for 24 h. The cultures were incubated (5% CO, 37 °C) for 24 h. Four groups, each containing six rats, were used for the in vivo experiment. The rats were exposed to subchronic treatment with a low dose of lead acetate (5 mg kg-1 b.w. per day). Pretreating HepG2 and HEK293 cells with the extract (100 µg mL-1) significantly (p < 0.05) protected against the cytotoxicity induced by lead exposure. For the in vivo experiment, the biochemical parameters in serum-namely, the level of malondialdehyde (MDA), and the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)-were measured in the organ homogenate supernatants. HExt was found to be rich in fatty acids, mainly palmitic and palmitoleic acids (29.464% and 42.066%, respectively). In both the in vitro and in vivo experiments, cotreatment with HExt protected the liver and kidney cell structures and significantly preserved the normal antioxidant and biochemical parameters in rats. This study discovered the possible protective effect of HExt, which could be beneficial for Pb-intoxicated cells.

A method for bone marrow extraction of diatoms for forensic science applications.

Diatoms show potential as trace evidence indicators, particularly as evidence of drowning. Often, the diatom test to diagnose drowning is done on soft tissue or bone marrow from a recently deceased individual. This method presented here combines elements from previous forensic literature and methods of diatom isolation in phycology to extract diatoms from bone marrow of skeletal remains for forensic use. This diatom extraction method is time-efficient, minimizes contamination risk, and produces samples of intact diatoms. This method is designed to complete sample preparation within 24 h, sampling the bone for diatoms internally and externally. This method was developed using porcine long bones submerged in water with live diatoms for up to 3 months. Three marrow samples were extracted from each bone so the method was developed using 102 marrow samples. Additionally, 132 surficial bone and environmental samples were collected and prepared during method development. To briefly summarize the method, the bone joints were cut off with an angle grinder in a biosafety hood to expose the marrow, which was removed from the hip, knee, and shaft as separate samples. The marrow was digested with nitric acid at 400°C in glass beakers before being centrifuged with DI water, plated onto microscope slides, and observed with a compound microscope. Observation found good preservation of unbroken diatom cell walls throughout the process. This method can be used to prepare diatoms as forensic trace evidence.

Isotope sample preparation of diatoms for paleoenvironmental research.

Isotopes in diatoms are increasingly used in palaeoenvironmental studies in both lacustrine and marine settings, enabling the reconstruction of a range of variables including temperature, precipitation, salinity, glacial discharge, carbon dynamics and biogeochemical cycling. This protocol details an optimised methodology for extracting diatoms for isotope analysis from sediment samples, using a range of chemical and density separation techniques that minimise sample loss and avoids the need for expensive equipment. Whilst designed for the extraction of diatoms for oxygen, silicon and carbon isotope analysis, additional stages are outlined for the analysis of other isotopes that are of increasing interest to the palaeo community (e.g., boron and zinc). The protocol also includes procedures for assessing sample purity, to ensure that analysed samples produce robust palaeoenvironmental reconstruction. Overall, the method aims to improve the quality of palaeoenvironmental research derived from isotopes in diatoms by maximising sample purity and the efficiency of the extraction process.

Diatom Examination From Ganga River at Vindhyachal - A Forensic Approach

Diatoms are unicellular, photosynthetic (autotrophic), eukaryotic organisms often classified as among the algae.They are scientifically known as Bacillariophyceae. Diatoms study can be used in medico-legal purpose to solvethe cases of unclaimed drowned or dumped bodies. The detection of diatoms in the organscan contribute toa diagnosis of death by drowning, a process referred to as the ‘diatom test’.This study was conducted in thedepartment of Forensic Science, SHUATS, Prayagrajwhich included the extraction and identification of diatomsfrom the collected water samples from three different sites of Ganga River in Vindhyachal. The acid-digestionmethod was used for diatom extraction. 27 samples were collected (3 from each site) in the month of January,February, March 2022 from 3 different ghats of Vindhyachali.e Babu Ghat, Pakka Ghat, Diwan Ghat. Samples weretaken from surface, 1 feet and 2 feet deep inside river. After examination and analysis total 18 genera of diatomswere found. The identified diatoms were of greatecological importanceand plays an important role in criminalinvestigations related to pre-mortem or ante-mortem drowning deaths in Ganga river at Vindhyachal,district ofU.P,India

3D Printing Characteristics and Mechanical Properties of a Bio Scaffold Obtained from a Micro-CT Scan, Using the Fused Deposition Modeling Technique

The objective is to determine which biopolymer has the best 3D printing characteristics and mechanical properties for the manufacture of a bioscaffold, using the fused deposition printing technique, with models generated from a Micro-CT Scan. Through an experimental exploratory study, the 3D printing of a bioscaffold was carried out using the fused deposition modeling (FDM) technique, from an STL file obtained from a Micro-CT scan taken from a bovine iliac crest bone structure Three study groups of the analyzed biopolymers were carried out with thirteen printed structures of each one. The first is made of 100% PLA. The second, 90B, is composed of 20g of polylactic acid per 1g of diatom extract, and the third, 88C, differs from the previous one in that it also contains 1g of calcium phosphate. The 39 printed structures underwent a visual inspection test, which required the fabrication of a gold standard scaffold in resin, with greater detail and similarity to the scanned bone structure. Finally, the structures were subjected to a compressive force (N) to obtain the modulus of elasticity (MPa) and compressive strength (MPa) of each one of them. A statistically significant difference (p=0.001) was obtained in the printing properties of the biomaterial 88C, compared to 90B and pure PLA. The 88C biopolymer presented the best 3D printing characteristics using the fused deposition printing technique, from stereolithographic models obtained with Micro-CT Scan. In addition, the 88C biopolymer presented the best mechanical properties compared to the other groups of materials. Although the difference between these was not statistically significant (p=0.388), in the structures of the 88C biomaterial, values of compressive strength (8,84692 MPa) and modulus of elasticity (43,23615 MPa) were similar to those of cancellous bone in the jaws could be observed. In conclusion, the biomaterial that exhibited the best printing and mechanical characteristics to produce a 3D printed bio scaffold using the fused deposition technique from stereolithographic models obtained from a Micro-CT Scan was the 88C biopolymer. Because of this result, the 88C biomaterial has the potential to be used in the manufacture of bioscaffolds in tissue engineering.

Study of Diatom Flora of Kaalesar Ghat of Rapti River at Gorakhpur for Forensic Consideration

Abstract: Diatoms are unique algae. They are scientifically known as Bacillariophyceae. Diatoms have been used in forensic science in a variety of ways, the most frequent being the diagnosis of death by drowning. When a person drowns, water will enter the lungs and then enter the bloodstream through ruptures in the peripheral alveoli before being carried to the other organs such as the liver and heart. Naturally, the microscopic contents of the water, which will include diatoms, will pass into the blood as well. The detection of diatoms in the organs can contribute to a diagnosis of death by drowning, a process referred to as the ‘diatom test’. A study was conducted in the department of Forensic Science, SHUATS, Prayagraj which included the extraction and identification of diatoms from the collected water samples from three different sites of Kaalesar Ghat of Rapti River in Gorakhpur. The acid digestion method was used for diatom extraction. And, after analysis total 13 diatom species were found. The identified diatoms were of great ecological assessment that plays an important role in criminal investigations related to premortem or ante-mortem drowning. Keywords: Diatom, Drowning, D-mapping, Rapti-River

Translating the diatom-grazer defense mechanism to antiparasitic treatment for monogenean infection in guppies

Monogenean parasites impose a major constraint on sustainable aquacultural production and trade due to fish morbidity and mortality. Traditional chemical treatments carry environmental and human health risks and are frequently banned in aquaculture; associated development of pathogen resistance is also common. These highlight the need for alternative. The pennate diatom Phaeodactylum tricornutum is a potent source for food additives and pharmaceuticals due to its robustness and content of high-value compounds. Its extracts also have antibacterial properties. The use of P. tricornutum to develop a treatment against the monogenean parasite Gyrodactylus turnbulli affecting Poecilia reticulate (guppies) was investigated. Ethanolic extracts of freshly broken P. tricornutum biomass were effective against the parasite in vitro and in vivo. Sonication and Kolliphor EL (food-grade nonionic solubilizer and emulsifier) increased the efficacy of the ethanolic extract in vitro; complete detachment and 97% mortality of the parasite were achieved within 240 min at a concentration of 5 μL mL−1. Complete infection clearance from fish was achieved following a bath treatment with 2.5 μL mL−1 ethanolic extract for 24 h. The diatom extract's antibacterial properties, tested against the Gram-positive Streptococcus iniae and Gram-negative Vibrio harveyi, were used to calibrate P. tricornutum culture conditions and extract preparation. Maximal antibacterial effect was obtained with a two-week-old culture, following cell breakage of the wet biomass and extraction in 100% ethanol. Fatty acid composition analysis of thin-layer chromatography fractions of the ethanolic extracts revealed that the free fatty acids liberated during cell breakage, enriched in 16:0, 16:1n7, and eicosapentaenoic acid (20:5n3), are the major active compounds. In-vitro antiparasitic assays and gas chromatography–mass spectrometry analysis confirmed that free 16:1n7 and 20:5n3 are responsible for most of the antiparasitic activity. Results support the use of broken P. tricornutum ethanolic extracts as a potential treatment against monogenean infection in cultured fish.

Acid Digestion Method for Extraction of Diatoms in Drowning Cases: A Review

Diatoms are single celled algae and is the most found phytoplankton in water sources like rivers, lakes, pools, ponds, etc. In cases of drowning, it becomes essential to prove that the person died due to drowning. In this aspect there are basically two conditions that need to be investigated, to prove it. The point of proving that it was an ante mortem drowning helps in determining the crime committed and plays a vital role in the conviction of the accused with the appropriate punishment. In ante mortem drowning the water is swallowed by the individual and since the person is still alive this water gets absorbed and enters the blood stream. Therefore, if a person was actually drowned which resulted in his or her death there is a possibility of finding some content of the water in which the drowning took place inside the individual and the region to look for this is the bone marrow. Further diatoms are the phytoplanktons that reach the bone marrow in cases of ante mortem drowning. Diatoms are present in all water bodies, but the species of diatoms present in each water body varies. Therefore, diatoms have been used in drowning cases to prove the person had drowned and the location where the drowning took place. The analysis of diatoms is still in the process of development. Since they have silica-based cell wall they are strong, and their analysis needs to be done in such a way that procedures employed should be accepted by the court as a valid protocol and subsequently admit the evidence in that particular case. Extraction of diatoms from bone samples is an important step to isolate diatoms from the human tissue. There are many ways to conduct this extraction, but the most efficient technique is not known. This study reviews the studies conducted on the acid digestion procedures for extracting diatoms and it is found that acid digestion method can be used for numerous types of samples. Some protocols were tweaked to get the best results but the basic utilization of acids like nitric acid, hydrochloric acid and sulphuric acid showed good results in the extraction of diatoms from samples of forensic significance.

Diatom extraction: A new technique with heated H2O2. A technical note

The best method of diatom identification in animal and human tissues is still an important discussion topic, in terms of effectiveness and reliability. In this technical note, authors propose a new method of extraction of diatoms using heated hydrogen peroxide from animal and human tissue samples. This method has been compared with the traditional method of digestion with acids. The results of the comparison show that heated hydrogen peroxide extraction is more efficient in terms of reduction of sediment, extraction of the material and preservation of diatoms proving to be a viable alternative to conventional approaches with acids in terms of costs and operator safety.

The Comparison of Different Diatom Digestive Method using HCl-H2O2 and HCl -KMnO4 in Telaga Pengilon Dieng

Identification diatom has been applied as an important key to tracing paleoenvironmental conditions. The knowledge for diatom extraction from sediment is continuing, but the diatom digestive methods in the tropical area is still limited. Telaga Pengilon, located in Dieng Indonesia, is rich in organic material in the sediment, the sample also associates with epiphytic and benthic diatom. Therefore, extracting pure diatom frustules free of organic matter from the sediments is essential for this application. To find the appropriate method for extracting diatoms in Telaga Pengilon, this research compares HCl with H2O2 and HCl with KMNO4 as the digestive reagent. Based on the statistical result (HCl, KMnO4) less time consumed than (HCl, H2O2) during the digestive process (p&lt;0.05) and produced the same amount of residue (p&gt; 0.05). For Pinnularia and Frustulia, the majority of diatoms could be extracted using both methods. Under microscopy, the structure of diatoms remained almost perfect after digestion with H202, the striae clearly visible and the residue digested correctly. Another method using HCl, KMnO4 fragmentation was found for some Pinnularia, and for Frustulia, the striae are clearly visible. This study demonstrated that different diatoms have different resistance for reagents and some of the locations need different reagents because different materials are contained in the sediment and need help to remove material organically. As far as the HCl and H2O2 are appropriate digestion methods in a tropical area such as Telaga Pengilon, HCl, KMnO4 can be a substitute for the less time-consuming process.

Cultivation of energy crops by ecological methods under the conditions of global climate and environmental changes with the use of diatom extract as a natural source of chemical compounds

Modern agriculture must be subject to some adaptation processes due to unpredictable climate changes. One of the activities that enables the production of plant biomass in adverse climatic conditions is the development of ecological and innovative crop technologies using natural plant extracts. The elimination of synthetic fertilizers and their replacement with products based on organic matter will increase the plant’s resistance to negative conditions of environmental stress, will have a positive effect on the development and yielding of plants and will reduce cultivation costs. The plant material: willow (Salix viminalis), Jerusalem artichoke (Helianthus tuberosus) and Virginia mallow (Sida hermaphrodita). The natural extract was obtained from Navicula sp. (Bacillariophyceae) monocultures, which was applied to plants in three variants: watering, spraying (foliar application) and watering and spraying. Every 2 weeks: plant height and chlorophyll content index were determined and at the end of the growing season, an analysis was made of: fresh and dry biomass, gas exchange activity in plants (net photosynthesis, transpiration, stomatal conductivity and intercellular CO2 concentration). The enzymatic activity of acid (pH = 6.0) and alkaline (pH = 7.5) phosphatase, RNase, dehydrogenases, as well as the integrity of cytoplasmic membranes was determined. The obtained results confirmed the positive effect of diatom monoculture extract on the growth and development of the plants. The analyzed physicochemical parameters were characterized by 15–20% higher values in comparison with the control. The use of natural extracts from Navicula sp. can be an alternative to chemical fertilizers and is considered one of the promising strategies in organic agriculture.

Progress in Method and Reliability of Diatom Test in Drowning

The forensic significance of the diatom test in diagnosing death due to drowning has been controversial for a long time as diatoms are detected in the non-drowning cases as well. This false positivity may originate from the ante-mortem as well as postmortem penetration of the diatoms into the bodies. Another problem with the diatom test is the lack of standardization among the different kinds of diatom extraction and identification methods. The author first reviewed the progress in the methods used in the diatom test and then studied the historical arguments in the diagnosis of drowning. Lastly, the research trend in the diatom test since 2000 was evaluated by classifying the manuscripts searched using the keyword “drowning and diatom” on PubMed. Recent studies tend to support the reliability of the diatom test in the diagnosis of drowning when quantitative and qualitative analyses are performed properly with maximum possible reduction in contamination during the preparation of the test samples. Key Words: Diatoms · Drowning · Diagnosis · Research · Review

Abstract 25: Skeletonema marinoi (diatom) extracts are endowed with promising cancer preventive properties in prostate cancer cells

Abstract The exploration of natural antioxidants for nutraceuticals and pharmaceuticals industries has recently increased. In this scenario, marine microorganisms, represent underestimated sources of bioactive products endowed with beneficial effects on health, that include anti-oxidant, anti-tumor and anti-angiogenic activities. Here, we tested the potential cancer preventive activities of extracts from the marine coastal diatom Skeletonema marinoi Sarno and Zingone (CCMP 2092) on prostate cancer cells, in vitro. Skeletonema marinoi was grown under a sinusoidal light distribution with a midday peak of 150 μmol photons m−2 s−1, and then, once cells reached the exponential phase, shifted to a sinusoidal light distribution with a higher midday peak light intensity of 600 μmol photons m−2 s−1. This high light condition induces in cells the synthesis of antioxidant and protective molecules. Total wet biomass was collected and chemically extracted by methanol solvent. The dried extract was tested as a food supplement on prostate (PC-3), as compared to normal prostate epithelium. Gene expression analysis was performed by qPCR, measuring the variation of 365 different genes involved in the apoptosis and immunogenic cell death pathways. Treatments with Skeletonema marinoi extracts (1-10-100 µg ml-1) resulted in a statistically significant, dose dependent, antiproliferative (inhibition at 70% of cell viability at 100 µg ml-1) and pro-apoptotic effects in PC-3 cells, while sparing normal epithelial prostatic cells. Among the gene panel analysed as key indicators of the PC3 cell fate in terms of signalling pathway prediction, we observed up/down regulation of APAF1, BAD, BAG1, BAG3, BAK1, BAX, BCL2, BCL2L1, BCL2L13, BCL2L2, BCL3, BDNF, BECN1, BFAR, BID, BIK, BIRC2, BIRC3, BIRC6, BNIP1, BOK, BRAF, BRCA1, BRE, CARD17, CARD9, CASP1-2-3-4-5-6-7-10-14, CBX4, CRADD, DEDD, DHCR24, FADD, FAS, FASLG, FASTK. The integrated gene expression analysis revealed necroptosis activation in cells with the up-regulation of the inflammatory mediators such as F2R, F2, IL18-19-A-31RA, SOCS2, SOCS3 genes and the downregulation of the angiogenic factors such as ALOX12, ALOX15B, PIK3CA, PIK3R2, and VEGF genes. One of the main candidates as compounds responsible for such cancer preventive activities is the diatom-xanthophyll photoprotective diatoxanthin, probably in synergy with other molecules. Further metabolomics analysis on the extracts will help in understanding and interpretation of the results. These results demonstrate promising cancer preventive activities of Skeletonema marinoi extracts in PC3 cell lines. This confirms microalgal-derived drugs as potential relevant source of nutraceutical novel food and candidate as potential dietary intervention in cancer prevention approaches. Citation Format: Clementina Sansone, Piscitelli Concetta, Galasso Christian, Smerilli Arianna, Bruno Antonino, Noonan Douglas, Albini Adriana, Brunet Christophe. Skeletonema marinoi (diatom) extracts are endowed with promising cancer preventive properties in prostate cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 25.

Transferability of Australian diatoms to clothing: Assessment of several extraction methods on different fabric types under laboratory conditions

Crime scene investigation protocols and procedures are well established when concerning terrestrial environments, but are limited when associated with aquatic environments.In aquatic contexts, the soil, sediments and microscopic algae (e.g. diatoms) may all be used as sources of trace evidence for criminal investigations. Diatoms are one such source that can be used to support the diagnosis of death by drowning and can be used to verify contact between a suspect and a specific water body. For the latter, diatoms can be collected from clothing and shoes for forensic comparisons. Over the years, there have been several methods proposed for the extraction of diatoms from clothing, however, a best practice method is yet to be established and is still open to debate.The present research represents the first investigation that evaluates four different methods for the extraction of native and common Australian diatom species from four different types of fabrics. Diatoms of two different species and shape (pennate and centric) were cultivated in stimulated experimental waters – prepared using either monocultures or mixed cultures of the selected diatoms. Diatom concentrations were set to mimic the natural population (low to bloom events) as commonly found in the Swan River Estuary of Western Australia. Cotton, denim, blend, and acrylic fabric types were placed in experimental waters. Diatom extraction was attempted using methods already proposed in the literature, these include: rinsing with ethanol (RE); rinsing with ethanol together with the application of centrifugal force (RECF); digestion with hydrogen peroxide (H); and a new method of ashing that has never been tested before (dry ash, DA).Results of this research showed that a) the type and the concentration of the mono and mix diatom mixtures significantly affects the transfer and extraction from different types of fabric; b) a noticeable extraction difference is observed between the fabrics, establishing denim, acrylic and blend fabrics as possessing the better extraction rates; c) H treatment had the highest extraction rate of diatoms; d) the application of centrifugal force on the RE method significantly improved the extraction of diatoms; e) DA is a potential method for the extraction of pennate-shaped diatoms from all of the tested fabrics, however, does have a tendency to induce modifications of the morphological structure of the diatoms. Overall, the application of different extraction methods is suggested to maximise the extraction of diatoms that would closely reflect their natural assemblage in the water body under investigation.

Comparison of Diatoms Which Were Obtained from The External Surface of The Body and Internal Organs in the Corpses Pulled Out of Water Using Colloidal Silica Gradient Centrifuge Method

Objective: Diatom analysis is a valuable tool in forensic science and it is useful in diagnosis of drowning and determination of the drowning site. The basic principal of the “diatom test” in investigation of drowning is based on correlation between diatoms are present in the medium where the possible drowning took place and inhalation of water causes penetration of diatoms into the alveolar system and blood stream and consequently their deposition into brain, kidneys and other organs, like the bone marrow of large bones. There are various extraction methods that are used to isolate diatoms from water and tissues. Nitric acid digestion is a worlwide known method for the extraction of diatoms. In this study, instead of acid digestion method, colloidal silica gradient centrifuge method was used to extraction diatom and the advantages of this technique has been aimed to be discussed.&#x0D; Materials and Methods: Therefore, 30 visceral and body fluid samples that have been obtained from corpses which were removed from the water and brought to the Council of Forencic Medicine to perform autopsy, were examined and diatom were obtained from samples of 19 cases. Moreover, the diatoms that were obtained from the swab samples taken from the outer body surfaces and the diatoms obtained from the visceral organs were compared.&#x0D; Results: When the diatoms which were obtained from internal organs tissues and body fluids were evaluated numerically, it was seen that the diatoms that were obtained lungs were in high numbers and it was followed by pleural liquid...