Effectiveness of platelet rich fibrin versus demineralized bone xenograft in periodontally accelerated osteogenic orthodontics: A pilot comparative clinical study

ABSTRACT Objectives To compare the rate of extraction space closure between periodontally accelerated osteogenic orthodontics (PAOO) using platelet-rich fibrin (PRF) (Group 1) and PAOO using demineralized bone xenograft (DMBM) (Group 2) and to compare the level of wound healing between the PRF group vs the DMBM group after PAOO. Materials and Methods A two-arm prospective single blind pilot study with a split-mouth design was used in which 14 patients requiring premolar extraction were divided into two groups: PRF and DMBM. En-masse space closure was carried out with using mini implants after the PAOO procedure. The amount of space closure was measured at five time points with 2-week intervals within 2 months. The gingival healing levels were assessed using early wound healing scores on the first postoperative day. Results The rate of extraction space closure was faster in the experimental quadrant at all time points (T1-T4) in the PRF group and at time points (T3, T4) in the DMBM group. Comparison between experimental quadrants showed a significant increase in the rate of space closure in the PRF group T1 to T3 (P < .05). The PRF group showed higher total early healing scores than the DMBM group. Conclusions PRF, when used in the PAOO procedure, produces a faster rate of space closure with better early wound healing than DMBM.

Multiple steady statehood: the roles of productive and extractive capacities

This paper proposes a model of statehood, defined as elite extraction of resources from a subject population. Different from most of the existing literature, the size of the subject population evolves endogenously in a Malthusian fashion, and the elite take into account the effects on future population levels when taxing the current population. The elite can spend extracted resources by investing in productive and extractive capacities. Productive capacity increases the size of the pie, while extractive capacity makes it easier for the elite to tax it. Together—but not each on its own—these two types of investment can give rise to multiple steady-state equilibria, such that one steady state has both a higher rate of extraction, and higher population density and output, than the other steady state. The model can also account for a positive empirical relationship between land productivity and state antiquity among countries with relatively late state development.

Effects of exogenous addition of cadmium on cadmium speciation in hyperaccumulator of Sedum alfredii Hance

Continuous chemical extraction is considered to be one of the most common methods for the extraction of heavy metals speciations in plants. However, the basis for the extraction order of this method is not explained and has been rarely studied. In this paper, we analyzed the speciations of cadmium in plants by a four-step continuous extraction method. The extraction sequence of ethanol and water was studied to study the effect of extraction sequence on the extraction rate of extraction agent. The results showed that cadmium exists mostly in NaCl extraction state and the extraction rate of the two kinds of extraction agents decreased when the order of ethanol and water was changed.

The effect of «pumping wells» procedure on the flow rate of extraction wells

Study of application of «pumping wells» when mining of uranium deposits by in-situ leaching (ISL) to the mine "Karatau" under conditions of high pressure of groundwater character was performed. The operating «Karatau» mine is located in a deserted, inaccessible, sparsely populated area in the southwestern part of the Shu-Sarysuy depression in the territory of the Suzaksky district, Turkestan oblast. The «Karatau» deposit differs from other deposits in that self-pouring of geotechnological wells with a statistical level of +20 m is observed at all sites. The use of traditional technology for such deposit leads to excessive material and labor costs. Therefore, the technology of "pumping wells" is proposed. It is shown that the use of "pumping wells" procedure leads to achieving a uniform flow rate of extraction wells, reduction in the purchase of the cable production costs for the purchase of submersible pumps and wells in the end cap.

Ultrasonic Assisted Extraction and Gas Chromatography-Tandem Mass Spectroscopy (GC-MS/MS) Analysis of Extracts from Four Cassia Species

Ultrasonic assisted extraction (UAE) process increases the rate of extraction, the yield of extracted components and reduces extraction time. The high sensitivity of GC-MS/MS provides reliable identification of phytoconstituents present in a plant extract. This research is to develop an easy and effective method for the extraction and analysis of phytochemicals in C. singueana, C. sieberiana, C. tora and C. occidentalis using UAE and GC-MS/MS techniques. The crude extracts obtained from the four Cassia species under UAE conditions of 50 mins extraction time, 50 oC extraction temperature and 20 mL/g solvent to sample ratio were analyzed using GC-MS/MS. Thirty-four compounds were identified by comparison of their mass spectra with those in the National Institute of Standards and Technology library, requiring at least 80% similarity. These compounds comprise fatty acids, fatty alcohol, carboxylic acid, long-chain alkanes, diterpenes, triterpenes, sterols and anthraquinones. n-Hexadecanoic acid and phytol were identified in all the Cassia species while anthraquinone was detected only from the methanol extracts of C. tora and C. occidentalis. The bioactivities reported in the literature for these compounds corroborate with the phytoconstituents identified in these plants and support the ethnomedicinal uses of these Cassia species.

Spodumene: The Lithium Market, Resources and Processes

This literature review gives an overview of the lithium industry, including the lithium market, global resources, and processes of lithium compounds production. It focuses on the production of lithium compounds from spodumene minerals. Spodumene is one of the most critical minerals nowadays, due to its high lithium content and high rate of extraction. Lithium is one of the most sought-after metals, due to the ever-growing demand for lithium-ion batteries (LiBs). The data on lithium extraction from minerals is scattered through years of patents, journal articles, and proceedings; hence, requiring an in-depth review, including the comprehension of the spodumene phase system, the phase conversion processes, and the lithium extraction processes.

The study of compositions based on parkent kaolin clay

The results of studies of the structure and composition of compositions based on red-burning kaolinite clay and calcium carbonate, heat-treated at 500oC, in the process of acid activation are presented. It is shown that when a 12 % solution of H2SO4is applied, leaching of iron and aluminum ions and the formation of calcium sulfate occur while maintaining the structure of kaolinite. The introduction of liquid glass into the composition of the material leads to the destruction of the structure of kaolinite, which contributes to an increase in the rate of extraction of aluminum ions during the subsequent acid activation. The components of the compositions with Ca2+and Fe3+in the presence of liquid glass are passivated by active amorphous silica formed during the reaction of liquid glass with CO2air.Ill. 2. Ref. 17. Tab. 1.

Evaluation of activated composite membranes for the facilitated transport of phenol

In this work the results on the first use of an activated composite membrane (ACM) containing Cyanex 923 for the extraction and transport of phenol are presented. A new dense layer-ACM configuration constituted by piperazine showed better stability than that prepared with 1,3-phenylenediamine. The effects of several parameters on the transport of phenol such as feed phase pH, carrier concentration and stripping phase composition were evaluated. The performance of the membrane was also evaluated during continuous additions of phenol and for a long period of time, observing the same rate of extraction and reextraction. Moreover, phenol transport was evaluated starting from synthetic wastewater of resin production plants type. The results exhibit the potential use of ACMs in the elimination and transport of organic species, even when analyte is initially found in complex solutions.