scholarly journals Disintegration half-life of biodegradable plastic films on different marine beach sediments

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11981
Author(s):  
Andreas Eich ◽  
Miriam Weber ◽  
Christian Lott

The seafloor is considered the major sink for plastic debris in the world’s oceans. Biodegradable polymers are available on the market as a substitute for conventional plastic and could potentially end up in the same environment. To gain more insight into the effects of different sediments on the degradation rate of biodegradable plastic we performed two iterative seawater tank experiments. First, to test the effect of sediment grain size, film of Mater-Bi HF03V, a blend of thermoplastic starch and biodegradable polyesters, was placed on the surface of mud as well as on four different grain size fractions of beach sand. Disintegration half-life was shortest on mud (139 days) and increased with the grain size of the beach sediment fractions (63–250 µm: 296 days; 250–500 µm: 310 days; 500–1,000 µm: 438 days; >1,000 µm: 428 days). We assume that the higher surface-to-volume ratio in fine sediment compared to coarse sediment led to a higher bacterial abundance and thus to faster disintegration rates. In a follow-up experiment, the <500 µm fraction of sediment from four different beaches around Isola d’Elba, Italy, was used to test plastic disintegration as above. Additionally, polyhydroxybutyrate (PHB, MIREL P5001) was used as a positive control and high-density polyethylene (HD-PE) as a negative control. No disintegration was observed for HD-PE. Mater-Bi HF03V and PHB disintegrated significantly differently on sediment from different sites, with half-lives of Mater-Bi HF03V ranging from 72 to 368 days and of PHB from 112 to 215 days. Here, the half-life was shortest on slightly coarser sediment and at potentially anthropogenically impacted sites. We assume that the effect of the grain size on the disintegration rate was masked by other parameters influencing the microbial community and activity. Understanding the parameters driving biodegradation is key to reliably report the range of disintegration rates occurring under the various conditions in different ecosystems.

2017 ◽  
Vol 9 (2) ◽  
pp. 71
Author(s):  
Nurhasanah Nurhasanah ◽  
Fauzia Andrini ◽  
Yulis Hamidy

Shallot (Allium ascalonicum L.) has been known as traditional medicine. Shallot which has same genus with garlic(Allium sativum L.) contains allicin that is also found in garlic and has been suspected has fungicidal activity toCandida albicans. It is supported by several researches. Therefore, shallot is suspected has antifungal activity too.The aim of this research was to know antifungal activity of shallot’s water extortion againsts Candida albicans invitro. This was a laboratory experimental research which used completely randomized design, with diffusion method.Shallot’s water extortion was devided into three concentrations, there were 50%, 100% and 200%. Ketoconazole 2%was positive control and aquadest was negative control. The result of this research based on analysis of varians(Anova), there was significant difference between several treatments and was confirmed with Duncan New MultipleRange Test (DNMRT) p<0,05, there was significant difference between 100% shallot’s water extortion with othertreatments, but there was no significant difference between 50% shallot’s water extortion with 200% shallot’s. Theconclusion was shallot’s water extortion had antifungal activity againsts Candida albicans with the best concentration100%, but it was lower than ketoconazole 2%.


DENTA ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 34
Author(s):  
Arya Barahmanta ◽  
Muhammad Faizal Winaris ◽  
Pambudi Raharjo

<p><strong><em>Background:</em></strong><em> Orthodontic tooth movement is a </em><em>interaction prosess</em><em> of resorption and deposition of bone remodeling. Orthodontic tooth movement by mechanical strength causes changes in alveolar bone. Osteocyte is an essential cell to respond bone remodelling. Hyperbaric Oxygen Therapy affects production of osteocyte because it can release Reactive Oxygen Species (ROS) and Nitrid Oxide (NO).  <strong>Purpose: </strong>To determine the difference number  of osteocyte in pressure and tension area during tooth movement by adjuvant of Hyperbaric Oxygen 2,4 ATA during 7 days starting on day 8 to day 14. <strong>Materials and Methods</strong>: This research used Completery Randomized Control Group Post Test Only Design. 36 cavia cobaya (male)  were divided into 3 groups randomly : the negative control groups, positive control group, and treatment group. Preparat staining used Hematoxylin Eosin (HE) and calculated on microscop 1000x with 20 field of view. Data analyses used one way ANOVA and LSD test then compared each area by using paired T test. <strong>Result:</strong> The data showed that the treatment group (P=10,67) tension area has the highest number of osteocyte than  negative control group (K-=3,67), positive control (K+=7,42). In the pressure area showed that negative control group (K-=5,00) has the highest  than positive control group (K+=3,83) and treatment (P=3,25). <strong>Conclusion: </strong>Therapy HBO 2,4 ATA 7 days starting on day 8 to day 14 is could increase osteocyte in the tissue to stimulate process of bone remodelling.</em></p><pre><strong> </strong></pre><p><strong><em>Keywords:</em></strong><em> Hyperbaric Oxygen, Tooth movement, Bone remodeling, </em><em>Osteocyte</em><em></em></p><p><em> </em></p><p><strong><em>Correspondence:</em></strong><em> </em><em>Arya Brahmanta</em><em>, Department of Orthodonty, Faculty of Dentistry, Hang Tuah University, Arif Rahman Hakim 150, Surabaya, Phone 031-5945864, Email:</em><em> </em><a href="mailto:[email protected]"><em>arya.brahmanta</em><em>@</em><em>hangtuah.ac.id</em></a></p>


2020 ◽  
pp. 68-73
Author(s):  
Yuni Asri Mulatsih Agami ◽  
Eka Wisnu Kusuma

Kasus penyakit hati semakin meningkat seiring penggunaan senyawa hepatotoksin salah satunya karena penggunaan parasetamol dengan dosis berlebih. Hal tersebut dapat meningkatkan produksi radikal bebas sehingga memicu terjadinya stress oksidatif yang dapat menimbulkan kerusakan jaringan yang ditandai dengan peningkatan kadar Malondialdehyde (MDA). Stress oksidatif dapat diatasi dengan antioksidan dari berbagai tanaman. Kulit kayu manis memiliki aktivitas antioksidan dengan nilai IC50 53ppm dan daun pandan wangi 39,7%  Penelitian ini bertujuan untuk mengetahui aktivitas kombinasi ekstrak etanol daun pandan wangi dan kayu manis dalam menurunkan kadar MDA. tikus yang diinduksi parasetamol. Penelitian menggunakan metode eksperimental, dilakukan selama 9 hari dengan 30 ekor tikus jantan dibagi menjadi 6 Kelompok, yaitu: Normal diberi aquadest, Kontrol Positif diberi silimarin 100 mg/kgBB, Kontrol Negatif diberi CMC-Na 0,05%, serta 3 kelompok lainnya diberi kombinasi ekstrak daun pandan wangi:kayu manis berturut-turut dosis I (25:75), dosis II (50:50), dosis III (75:25). Semua kelompok diinduksi parasetamol 2,5 g/kgBB pada hari ke-7  setelah 30 menit perlakuan, kecuali kelompok normal. Pada hari ke 9 dilakukan pengukuran kadar MDA dengan metode TBARs menggunakan spektrofotometri. Pemberian kombinasi ekstrak etanol daun pandan wangi dan kayu manis dapat menurunkan kadar MDA dengan kombinasi dosis yang paling optimal adalah 75:25 berdasarkan statistik dengan nilai signifikan 0,000<0,05 dibandingkan dengan kelompok negatif.    Cases of liver disease have increased with the use of hepatotoxin compounds, one of which is due to the use of paracetamol with excessive doses. This can increase the production of free radicals so that it triggers oxidative stress which can cause tissue damage which is characterized by increased levels of Malondialdehyde (MDA). Oxidative stress can be overcome with antioxidants from various plants. Cinnamomum burmanii has antioxidant activity with IC50 value of 53ppm and Pandanus amarrylifolius 39.7%. This study aims to determine the combined activity of ethanol extract of Pandanus amarrylifolius and Cinnamomum burmanii  in reducing MDA levels. Paracetamol-induced rats. Research using experimental methods, conducted for 9 days with 30 male rats divided into 6 groups, namely: Normal given aquadest, Positive Control were given silimarin 100 mg / kgBB, Negative Control was given CMC-Na 0.05%, and 3 other groups were given a combination of Pandanus amarrylifolius extract: Cinnamomum burmanii dose I (25:75), dose II (50:50), dose III (75:25). All groups induced paracetamol 2.5 g / kgBB on the 7th day after 30 minutes of treatment, except the normal group. On the 9th day MDA levels were measured using the TBARs method using spectrophotometry. Giving a combination of Pandanus amarrylifolius and Cinnamomum burmanii ethanol extract can reduce MDA levels with the most optimal dose combination is 75:25 based on statistics with a significant value of 0,000<0.05 compared with the negative group.


2019 ◽  
Vol 1 (2) ◽  
pp. 11-16
Author(s):  
Yanna Rotua Sihombing ◽  
Debi Dinha Sitepu

Immunomodulator is a compound that can increaase the imuno system. One of the plants that have immunomodulator’s activity is Waru Leaf (Hibiscus tiliaceus). the purpose of this research was to test the effect of immunomodulator by extract of Waru Leaf ethanol on rat male. The activity of immunomodulator was determined by using digital pletysmometer by measuring the differences between the last leg swelling’s volume and the first leg swelling’s volume. The treatment group were divided into 5 groups. Each group consistof 5 rats CMC-Na 0,5% (negative control), Stimuno®  32,5 mg/kgBW (positive control), dose of EEDW 50, 100 and 200 mg/kgBW, and bacteria E.coli as antigen. The results slowed that distribution of EEDW dose 200 mg/kgBW can give the effect of immunostimulant by swelling enthancement compared by CMC-Na 0,5 %. EEDW 200 mg/kgBW that have activity comparable with Stimuno®  32,5 mg/kgBW. Thus, it is concluded that of Waru Leaf extract has immunomodulator effects on delayed-type hypersensitivity response of rat male.


2019 ◽  
Vol 16 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Mohammad Aminianfar ◽  
Siavash Parvardeh ◽  
Mohsen Soleimani

Background: Clostridium botulinum causes botulism, a serious paralytic illness that results from the ingestion of a botulinum toxin. Because silver nanoparticle products exhibit strong antimicrobial activity, applications for silver nanoparticles in healthcare have expanded. Therefore, the objective of the current study was to assess a therapeutic strategy for the treatment of botulism toxicity using silver nanoparticles. Methods: A preliminary test was conducted using doses that produce illness in laboratory animals to determine the absolute lethal dose (LD100) of botulinum toxin type A (BoNT/A) in mice. Next, the test animals were divided into six groups containing six mice each. Groups I, II and III were the negative control (botulinum toxin only), positive control-1 (nano-silver only) and positive control-2 (no treatment), respectively. The remaining groups were allocated to the toxin that was supplemented with three nano-silver treatments. Results: The mortality rates of mice caused by BoNT/A significantly reduced in the treatment groups with different doses and injection intervals of nano-silver when compared to the negative control group. BoNT/A toxicity induced by intraperitoneal injection of the toxin of Clostridium botulinum causes rapid death while when coupled with nano-osilver results in delayed death in mice. Conclusion: These results, while open to future improvement, represent a preliminary step towards the satisfactory control of BoNT/A with the use of silver nanoparticles for human protection against this bioterrorism threat. Further study in this area can elucidate the underlying mechanism for detoxifying BoNT/A by silver nanoparticles.


2018 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
Verawaty Verawaty ◽  
Dhea Claudia Novel

<p>Penelitian ini bertujuan untuk melihat pengaruh pemberian ekstrak etanol kulit petai (Parkia speciosa Hassk) terhadap penurunan kadar glukosa darah mencit jantan yang diinduksi aloksan. Hewan percobaan dibagi atas 5 kelompok diantaranya kelompok kontrol negatif, kelompok kontrol positif,dosis I (280 mg/kgBB mencit), dosis II (560 mg/kg BB mencit), dosis III (840 mg/kg BB mencit). Penelitian dilakukan selama 21 hari. Persentase penurunan kadar glukosa darah mencit jantan setelah diberikan ekstrak etanol kulit petai pada hari ke-21 adalah dosis I (77,52 %) lebih besar dibandingkan dengan dosis II (69,5 %) dan dosis III (73,37 %). Data yang diperoleh dianalisis dengan uji Two Way Anova dengan program SPSS 17. Hasil penelitian ini menunjukkan bahwa pemberian ekstrak etanol kulit petai untuk tiga variasi dosis menyatakan perbedaan yang bermakna secara statistik terhadap penurunan kadar glukosa darah mencit jantan.</p><p><em>Petai (Parkia speciosa Hassk) has a compound β-sitosterol and stigmasterol that have efficacy to decreased blood glucose levels. This study aimed to determine the effect of ethanol extract of petai peel for decrease blood glucose levels of male mice induced by alloxan. Experimental animals were divided into 5 groups including negative control group, positive control group, the first dose (280 mg/kg in mice), the second dose (560 mg/kg in mice), the third dose (840 mg/kg in mice). The study was conducted for 21 days. After 21 days, the result found that the percentage of blood glucose levels after the male mice given the ethanol extract of petai peel was, the first dose (77.52%) biger than the second dose (69.5%) and the third dose (73.37%). The data obtained were analyzed by Two Way ANOVA using SPSS 17. The results showed that have signicantly difference between three dose variation of ethanol extract of petai peel in blood glucose levels.</em></p>


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Berkan Celikten ◽  
Ceren Feriha Uzuntas ◽  
Kamran Gulsahi

The aim of this study was to compare the vertical fracture resistance of roots obturated with different root canal filling materials and sealers. Crowns of 55 extracted mandibular premolar teeth were removed to provide root lengths of 13 mm. Five roots were saved as negative control group (canals unprepared and unfilled). Fifty root canals were instrumented and then five roots were saved as positive control group (canals prepared but unfilled). The remaining 45 roots were randomly divided into three experimental groups (n=15root/group) and obturated with the following procedures: in group 1, glass ionomer-based sealer and cone (ActiV GP obturation system); in group 2, bioceramic sealer and cone (EndoSequence BC obturation system); and in group 3, roots were filled with bioceramic sealer and cone (Smartpaste bio obturation system). All specimens were tested in a universal testing machine for measuring fracture resistance. For each root, the force at the time of fracture was recorded in Newtons. The statistical analysis was performed by using Kruskal-Wallis and post hoc test. There were no significant differences between the three experimental groups. The fracture values of three experimental and negative control groups were significantly higher than the positive control group. Within the limitations of this study, all materials increased the fracture resistance of instrumented roots.


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 678
Author(s):  
Julie C. Lynegaard ◽  
Niels J. Kjeldsen ◽  
Julie K. Bache ◽  
Nicolai R. Weber ◽  
Christian F. Hansen ◽  
...  

Soy protein concentrate improves nutrient utilization and growth performance compared to soybean meal, and diets with a low crude protein (CP) level decreases diarrhoea. The objectives were to (1) test a low CP diet based on different soy products, and (2) to test a very-low CP diet (15.1%) with amino acids (AA) on diarrhoea and productivity. A total of 5,635 weaned pigs (~28 days), were assigned to five dietary treatments; PC (positive control): Standard CP levels (192, 189, 191 g/kg CP) with 2500 ppm ZnO; NC (negative control): Same as PC without ZnO; SP (Soy protein concentrate): Low CP levels (176, 174, 191 g/kg CP); SB (Soybean meal): Low CP levels (177, 176, 191 g/kg CP); and XLA (X-low CP + AA): Very low CP levels (154, 151, 191 g/kg CP) with AA. The PC and XLA diets reduced diarrhoea by 41 and 61%, respectively, compared to the NC group, while no difference between SB and SP were observed. The XLA diet reduced feed intake and daily gain compared with PC and NC, where SP, SB, and XLA had a poorer feed conversion compared with PC. Conclusively, the SP and SB low-protein diets did not reduce diarrhoea or growth performance, whereas the XLA diet decreased both diarrhoea and performance.


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