scholarly journals Sequential SEM imaging of microbial calcite precipitation consolidation treatment

2021 ◽  
Vol 136 (5) ◽  
Author(s):  
Nadim C. Scherrer ◽  
Matthias Kocsis ◽  
Petra Dariz ◽  
Claire Gervais

AbstractCultural heritage built from limestone is prone to deterioration by chemical weathering, a natural process, that is enhanced by pollution. There are many historic monuments built from calcareous rocks that suffer from deterioration, and thus there have been a number of approaches over the last few decades to consolidate these types of rocks and surfaces. Using natural biological processes by fostering the activity of calcite-producing bacteria, also referred to as biomineralization, is one strategy that has also been commercialized. The base of proving the effectiveness of any surface treatment is the observation of the surface at sequential stages before and after treatment, as well as after exposure to weathering. Due to the heterogeneity of natural materials and processes, our aim was to observe identical test areas at the micron scale throughout the observation period. In order to achieve this on a tungsten SEM, we employed a beam deceleration accessory that allowed low kV imaging on non-conductive surfaces at a sufficiently high image resolution with a modified sample holder accommodating drill cores of 25 mm diameter and up to 15 mm height. The presented method is capable of producing time-sequenced images on the same test area on natural rock surface samples without manipulation for imaging purposes. This offers interesting perspectives for effective documentation of such processes in various fields.

1979 ◽  
Vol 42 (04) ◽  
pp. 1332-1339 ◽  
Author(s):  
Hiroh Yamazaki ◽  
Takeshi Motomiya ◽  
Minoru Sonoda ◽  
Noboru Miyagawa

SummaryChanges in platelets in 48 patients with uterine myoma before and after hysterectomy with and without ovariectomy were examined. Bilateral ovariectomy in 25 cases (ovariec-tomized group) and unilateral or non-ovariectomy in 23 cases (control group) were performed at the hysterectomy. Platelet count and an appearance rate of secondary aggregation decreased at one day after and increased at one week after the operation, similarly in both the ovariectomized and the control group. The appearance rate of secondary aggregation was reflected in an intensity of aggregation at 5 min after the addition of reagent to PRP. At one month after the operation, the appearance rate of secondary aggregation induced by 3 μM ADP showed a statistically significant decrease in comparison with the preoperation value (P <0.05) and the enhancement of 5-min aggregation was still observed in the control group, while ceased in the ovariectomized group. The difference between the two groups was significant (P < 0.05). There was almost no change in the speed and intensity of primary and secondary aggregation during the observation period. No significant differences in collagen-induced aggregation were noted between the two groups. The results suggest that ovarian hormones, mainly estrogen, facilitate platelet activation which is mediated by the so-called secondary aggregation.


Author(s):  
Tan-Chen Lee ◽  
Jui-Yen Huang ◽  
Li-Chien Chen ◽  
Ruey-Lian Hwang ◽  
David Su

Abstract Device shrinkage has resulted in thinner barriers and smaller vias. Transmission Electron Microscopy (TEM) has become a common technique for barrier profile analysis because of its high image resolution. TEM sample preparation and image interpretation becomes difficult when the size of the small cylindrical via is close to the TEM sample thickness. Effects of different sample thickness and specimen preparation methods, therefore, have been investigated. An automatic FIB program has been shown to be useful in via sample preparation. Techniques for imaging a TEM specimen will be discussed in the paper. Conventional TEM bright field (BF) image is adequate to examine the barrieronly via; however, other techniques are more suitable for a Cu filled via.


2014 ◽  
Vol 716-717 ◽  
pp. 363-369
Author(s):  
Zhen Hua Xie ◽  
Dong Yang ◽  
Sha Sha Liang ◽  
Zhi Yun Jia

The technology of hierarchical multiple high-pressure grouting is an effective approach to manage high and steep slope of broken rock mass. The number of grouting is one of the key parameters of this technology. By the analysis of mechanics and grouting theory, the anchoring effect mainly is affected by anchor slurry vein and the contact area with rock mass. Based on the system analysis of slurry vein development for first time and many times high-pressure grouting, the process flow for hierarchical multiple high-pressure grouting is put forward. Serve the rock permeability changes before and after grouting as an indicator measuring slurry and rock surface area, the method of determining grouting number based on the reliable probability is got. Combined with the engineering example of Shouyun Iron Mine, this paper puts forward the reliability criteria of working state of hierarchical multiple high-pressure grouting. Through the probability calculation, the best number of grouting is 4 times. The tests of permeability of rock mass and drawing force verify the accuracy of this determination method.


2017 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Juli Juli Juli

This study examined differences in the local government's financial performance before and after the transition from central tax BPHTB be local taxes? In general, this study aims to determine the contribution BPHTB to the PAD as a source of funding for the survival of each region in order to achieve local autonomy system. The samples used in this study is the district/city that has existed since autonomy BPHTB not be treated as 114 cities/districts. The realization of the study observation period is the period before the transition budget BPHTB (Year 2010) and after the transition BPHTB (Year 2011). The research data were statistically tested with a different test of two paired samples. The results show that the performance of local government in Java have differences before and after the transition BPHTB from the central government to local governments. This research can provide empirical evidence of the differences in the financial performance of the post-transition region from the center to the regions BPHTB especially Java. The results of this study can also be used as a reference in future studies with similar themes to consider several things. First, the use of samples that are not confined to the local government but the entire Indonesian island of Java. Second, adding the growth rate ie performance measurement. Third, review the compatibility ratio because in addition to operational expenditure and capital expenditure is no longer heading in the budget expenditure is financing and transfer.     Keywords: Bea Perolehan Hak atas Tanah dan Bangunan, Financial Performance, Autonomous Region.


2018 ◽  
Vol 1 (2) ◽  
pp. 14-22
Author(s):  
Sonny Haryanto ◽  
Umi Mardiyati ◽  
Agung Dharmawan Buchdadi

This study aims to analyze the abnormal returns before and after the announcement of mergers and acquisitions in the companies listed on the IDX 2018. In this study the observation period taken was three days before and after the announcement of mergers and acquisitions with the number of samples observed were 9 companies. The method for calculating abnormal returns used is the market adjusted return by using an intraday stock price of 15 minutes. Based on testing hypotheses conducted by paired sample t-test, it was found that there were no significant differences in abnormal returns before and after the announcement of mergers and acquisitions in each 15 minute period.


2019 ◽  
Vol 7 (2) ◽  
pp. 177
Author(s):  
Happy Sista Devy ◽  
Bahrain Pasha Irawan

<p>Goals of the research to analyze whether occurred abnormal return of ASIAN Games phenomena and see how investors react to the big ASIAN Games 2018 event in Indonesia. . This reseach uses a sample of companies included in the hotel, restaurant and tourism sub-sector on the Indonesia Stock Exchange (IDX) during the observation period, based on the purposive sampling method which obtained 22 companies and used the event study method. There is a significant abnormal return but not on the phenomenon of the Asian Games 2018. This shows that investors still wait and see to the organization of the Asian Games in 2018. No difference of abnormal return before and after the Asian Games 2018. This is because, as investors look to the many tourists who have started to flock to Indonesia before the Asian Games in 2018 took place.<em></em></p><p><strong><em></em></strong><em><br /></em></p>


2019 ◽  
Vol 89 (4) ◽  
pp. 535-543 ◽  
Author(s):  
Niko C. Bock ◽  
Julia Ruehl ◽  
Sabine Ruf

ABSTRACT Objective: To assess the prevalence and magnitude of labial gingival recession (LGR) before and after as well as the incidence during Class II:1 Herbst-Multibracket appliance (Herbst-MBA) treatment (Tx) plus retention in a retrospective cohort study. Materials and Methods: Records of Class II:1 patients who completed Herbst-MBA Tx (mean pre-Tx age 14.4 years) at Department of Orthodontics, University of Giessen, Giessen, Germany were analyzed. Tx consisted of a Herbst phase (mean 8.1 months) and a subsequent MBA phase (mean 16.1 months). Study casts from before and after Herbst-MBA Tx plus ≥24 months of retention were evaluated. Results: A total of 460 pre-Tx and 222 postretention study casts were available (total observation period: 59.2 ± 14.8 months). The overall prevalence for teeth with LGR ≥0.5 mm was 1.1% pre-Tx and 5.3% postretention. The highest prevalence of up to 5.3% (pre-Tx) and 16.4% (postretention) were seen for the lower incisors. Overall, the median magnitude of LGR was 0.0 mm pre-Tx/postretention (mean: 0.05 mm/0.08 mm). Incidence values of 4.0% (all teeth) and 10.0% to 11.4% (lower central incisors) were calculated for LGR ≥0.5 mm. Conclusions: The prevalence of LGR ≥0.5 mm increased from, on average, 1.1% to 5.3% during ≈6 years of Herbst-MBA Tx plus retention. The highest incidence was seen in lower incisors (10.0%–11.4%). However, because of the overall mean magnitude of 0.08 mm postretention, the clinical relevance can be considered as insignificant.


Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1483 ◽  
Author(s):  
Valentina Candotto ◽  
Dorina Lauritano ◽  
Francesco Carinci ◽  
Carlo Bignozzi ◽  
Daniele Pazzi ◽  
...  

The use of chemical devices for periodontitis treatment has led to new strategies aiming primarily to control infections. Over the last few years, new chemical devices have been subjected to many scientific and medical studies. The purpose of the present study was to assess the effect of a new silver based chemical devices gel named “Hydrosilver Plus Gel”, abbreviated here as Hydrosilver, on the pathogenic microorganisms, using Polymerase Chain Reaction (PCR) for microbiological analysis. Materials and methods: Ten patients with a diagnosis of chronic periodontitis in the age group >25 years were selected. None of these patients had received any surgical or non-surgical periodontal therapy, and demonstrated radiographic evidence of moderate bone loss. After scaling and root planning, patients received Hydrosilver to be used at home. Four non-adjacent sites in separate quadrants were selected in each patient for monitoring, based on criteria that the sites localise chronic periodontitis. Microbial analysis was analysed at baseline and at Day 15. SPSS program was used for statistical purposes and a paired samples correlation was performed at the end of the observation period. Results: Mean amounts of bacterial loading before and after Hydrosilver treatment reduced statistically significantly (p = 0.002). Conclusions: The present study demonstrated that Hydrosilver has a good impact on oral biofilm. Additional studies are needed to detect the efficacy of this chemical device.


2019 ◽  
Vol 57 (3) ◽  
pp. 302-309
Author(s):  
Jamie L. Perry ◽  
Katelyn J. Kotlarek ◽  
Kelly Spoloric ◽  
Adriane Baylis ◽  
Lakshmi Kollara ◽  
...  

Purpose: To investigate the dimensions of the tensor veli palatini (TVP) muscle using high image resolution 3-dimensional magnetic resonance imaging (MRI) of the soft palate among children with normal velopharyngeal and craniofacial anatomy and to compare values to individuals with a diagnosis of 22q11.2 deletion syndrome (22q11DS). We also sought to determine whether there is a relationship between hypoplasia of the TVP and severity of middle ear dysfunction and hearing loss. Methods: Three-dimensional MRI were used to collect and analyze data obtained across 53 children between 4 and 12 years of age, including 40 children with normal velopharyngeal and craniofacial anatomy and 13 children with a diagnosis of 22q11.2 DS. Tensor veli palatini muscle length, thickness, and volume as well as bihamular distance were compared among participant groups. Results: A Welch’s t-test revealed that the TVP in participants with 22q11DS is significantly shorter ( P = .005, 17.3 vs 19.0 mm), thinner ( P < .001, 1.1 vs 1.8 mm), and less voluminous ( P < .001, 457.5 vs 667.3 mm3) than participants without 22q11DS. Participants with 22q11DS also had a greater ( P = .006, 27.7 vs 24.7 mm) bihamular distance than participants without 22q11DS. There was an inverse relationship between TVP abnormalities noted above and the severity of audiologic and otologic histories. Conclusion: The TVP muscle is substantially reduced in volume, length, and thickness in children with 22q11DS. These findings serve as preliminary support for the association of patient hearing and otologic severity and TVP dysmorphology.


2018 ◽  
Vol 36 (4_suppl) ◽  
pp. 666-666
Author(s):  
Anuj K. Patel ◽  
Mei Sheng Duh ◽  
Victoria Barghout ◽  
Mihran Ara Yenikomshian ◽  
Yongling Xiao ◽  
...  

666 Background: FTD/TPI and REG both prolong survival in refractory mCRC and have similar indications with different side effect profiles. This study compares real-world treatment patterns with FTD/TPI and REG for mCRC in a large, representative US claims database. Methods: Retrospective data from 10/2014 to 7/2016 from the US Symphony Health Solutions’ Integrated Dataverse (IDV®) database were analyzed for patients receiving FTD/TPI or REG. The index date was the date of first FTD/TPI or REG prescription. Patients were included if: 1) age ≥18 years old, 2) ≥1 CRC diagnosis, 3) no diagnosis of gastric cancer or gastrointestinal stromal tumor, and 4) continuous clinical activity for ≥3 months before and after index date. The observation period spanned from index date to end of data, end of continuous clinical activity, or switch to another mCRC treatment. Adherence was assessed using medication possession ratio (MPR) ≥0.80 and proportion of days covered (PDC) ≥0.80 at 3 months. Compliance was assessed using time to discontinuation over the observation period using allowable gaps of 45, 60, or 90 days. Patients who never discontinued therapy were censored at the end of the observation period. Outcomes were compared between FTD/TPI and REG using multivariate logistic regression and Cox proportional hazards models, adjusting for demographic and clinical baseline characteristics. Results: A total of 1,630 FTD/TPI patients and 1,425 REG patients were identified. Mean ± standard deviation (SD) age of FTD/TPI patients was 61.0 ± 11.0 compared to 62.8 ± 10.9 for REG patients (p < 0.001). FTD/TPI patients were 80% more likely to have a MPR ≥0.80 compared to those on REG (Odds Ratio [OR] = 1.80, p < 0.001) and more than twice as likely to have a PDC ≥0.80 (OR = 2.66, p < 0.001) at 3 months. FTD/TPI patients were 37% less likely to discontinue their treatment compared to those on REG when using gaps of 60 days (Hazard Ratio = 0.63, p < 0.001). Similar results were found with 45 and 90 days. Conclusions: In this retrospective study of mCRC patients, patients on FTD/TPI were significantly more likely to adhere and comply with therapy compared to those on REG.


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