A New Cleaning Method for Accurate Examination of Freshwater Gastropod Shell Specimens Covered with Iron-rich Deposits

AbstractMicroRNAs (miRNAs) are a deeply conserved class of small, single stranded RNA molecules that post-transcriptionally regulate mRNA levels via several targeted degradation pathways. They are involved in a wide variety of biological processes and have been used to infer the deep evolutionary relationships of major groups such as the Metazoa. Here we have surveyed several adult tissues of the freshwater pulmonate Lymnaea stagnalis (the Great Pond Snail) for miRNAs. In addition we perform a shell regeneration assay to identify miRNAs that may be involved in regulating mRNAs directly involved in the shell-forming process. From seven mature tissues we identify a total of 370 unique precursor miRNAs that give rise to 336 unique mature miRNAs. While the majority of these appear to be evolutionarily novel, most of the 70 most highly expressed (which account for 99.8% of all reads) share sequence similarity with a miRBase or mirGeneDB2.0 entry. We also identify 10 miRNAs that are differentially regulated in mantle tissue that is actively regenerating shell material, 5 of which appear to be evolutionarily novel and none of which share similarity with any miRNA previously reported to regulate biomineralization in molluscs. One significantly down-regulated miRNA is predicted to target Lst-Dermatopontin, a previously characterized shell matrix protein from another freshwater gastropod. This survey provides a foundation for future studies that would seek to characterize the functional role of these molecules in biomineralization or other processes of interest.

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A developmentally descriptive method for quantifying shape in gastropod shells

Journal of The Royal Society Interface ◽

10.1098/rsif.2019.0721 ◽

2020 ◽

Vol 17 (163) ◽

pp. 20190721

Author(s):

J. Larsson ◽

A. M. Westram ◽

S. Bengmark ◽

T. Lundh ◽

R. K. Butlin

Keyword(s):

Empirical Studies ◽

Three Dimensional ◽

Shell Shape ◽

Large Set ◽

Littorina Saxatilis ◽

Shape Variation ◽

Gastropod Shell ◽

Geometric Morphometric ◽

Wide Range ◽

Descriptive Method

The growth of snail shells can be described by simple mathematical rules. Variation in a few parameters can explain much of the diversity of shell shapes seen in nature. However, empirical studies of gastropod shell shape variation typically use geometric morphometric approaches, which do not capture this growth pattern. We have developed a way to infer a set of developmentally descriptive shape parameters based on three-dimensional logarithmic helicospiral growth and using landmarks from two-dimensional shell images as input. We demonstrate the utility of this approach, and compare it to the geometric morphometric approach, using a large set of Littorina saxatilis shells in which locally adapted populations differ in shape. Our method can be modified easily to make it applicable to a wide range of shell forms, which would allow for investigations of the similarities and differences between and within many different species of gastropods.

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Studies on the fouling behavior and cleaning method of pervaporation desalination membranes for reclamation of reverse osmosis concentrated water

Separation and Purification Technology ◽

10.1016/j.seppur.2021.119034 ◽

2021 ◽

pp. 119034

Author(s):

Pengbo Zhao ◽

Bowen Yao ◽

Junquan Meng ◽

Rui Zhang ◽

Bing Cao ◽

...

Keyword(s):

Reverse Osmosis ◽

Cleaning Method

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Characterization of Carbonaceous Deposits on an End-of-Life Engines for Effective Cleaning for Remanufacturing

Sustainability ◽

10.3390/su13020950 ◽

2021 ◽

Vol 13 (2) ◽

pp. 950

Author(s):

Xing Wang ◽

Jianfeng Li ◽

Xiujie Jia ◽

Mingliang Ma ◽

Yuan Ren

Keyword(s):

End Of Life ◽

Sustainable Manufacturing ◽

Hybrid Structure ◽

Nuclear Magnetic Resonance Study ◽

Carbonaceous Deposit ◽

X Ray ◽

Cleaning Method ◽

Carbonaceous Deposits ◽

Strong Adhesion

Remanufacturing is one of the most effective strategies to achieve sustainable manufacturing and restore the performance of end-of-life products. However, the lack of an effective cleaning method to clean carbonaceous deposits severely hampers the remanufacturing of end-of-life engines. To explore an appropriate cleaning method, it is necessary to first study the characterization of the carbonaceous deposits. A broad range of analyses including X-ray fluorescence spectrometry, thermogravimetric analysis, 1H-nuclear magnetic resonance study, X-ray diffraction analysis, and scanning electron microscopy were performed to conduct an in-depth characterization of the carbonaceous deposits. The results showed that a hybrid structure composed of organics and inorganics is the most distinguishing feature of the carbonaceous deposit in end-of-life engines. The inorganics form the skeleton on which organics get attached, thereby resulting in a strong adhesion of the deposit and increasing the difficulty of cleaning. Therefore, a method in which several cleaning forces can be simultaneously applied is more suitable for the present purpose. Molten salt cleaning was chosen to verify the feasibility of this proposal. This method was shown to have the potential to effectively clean the carbonaceous deposit. This finding could contribute towards promoting the effective remanufacturing of end-of-life engines.

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Characterization of a New Cleaning Method Using Electrolytic Ionized Water for Polysilicon Chemical Mechanical Polishing Process

Japanese Journal of Applied Physics ◽

10.1143/jjap.41.5098 ◽

2002 ◽

Vol 41 (Part 1, No. 8) ◽

pp. 5098-5103 ◽

Cited By ~ 6

Author(s):

Naoto Miyashita ◽

Shin-ichiro Uekusa ◽

Hiroshi Katumata

Keyword(s):

Chemical Mechanical Polishing ◽

Mechanical Polishing ◽

Polishing Process ◽

Cleaning Method ◽

Chemical Mechanical Polishing Process

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Histochemical studies of dopa oxidase and peroxidase in the mantle-edge of the freshwater gastropod, Helisoma duryi eudiscus (Pilsbry)

Canadian Journal of Zoology ◽

10.1139/z68-026 ◽

1968 ◽

Vol 46 (2) ◽

pp. 165-167 ◽

Cited By ~ 5

Author(s):

S. P. Kapur ◽

M. A. Gibson

Keyword(s):

Positive Reaction ◽

Protein Component ◽

Negative Reaction ◽

Structural Proteins ◽

Freshwater Gastropod ◽

Helisoma Duryi ◽

Mantle Edge ◽

Dopa Oxidase ◽

Oxidase Reaction

The mantle-edge gland produces the highly tanned, densely fibrous periostracum, and the cubocolumnar cells contribute to the deposition of the less highly tanned matrix of the inner shell layers. The mantle-edge gland gives positive reactions for dopa oxidase and peroxidase, but does not contain melanin. The cubocolumnar cells reveal a positive reaction for dopa oxidase, possess numerous melanin granules, and exhibit a negative reaction for peroxidase. It is suggested that quinones may contribute to the process of tanning and hardening of the structural proteins of the shell. The dopa oxidase reaction within the cubocolumnar cells indicates the presence of tyrosine and suggests that these cells are capable of producing quinones to color and harden the protein component of the inner shell layers. It also explains the abundance of melanin granules within these cells. Within the mantle-edge gland, it is suggested that the peroxidase inhibits the formation of melanin from dopa quinone, and peroxidase, by accentuating quinone production, may cause further hardening of the periostracum.

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